,transcriber's ,notes3 ,underscores 80 before and after a word or phrase indicate italics in the original text4 ,equal signs 80 before and after a word or phrase indicate bold in the original text4 ,small capitals have been converted to ,,solid capitals4 ,illustrations have been moved so they do not break up paragraphs4 ,old or antiquated spellings have been preserved4 ,typographical and punctuation errors have been silently corrected4 ,the text has numerous references to 8figure #ah01 the schematic diagram for the 8,operating ,board01 however this figure appears to be not available4 ,,manual ,,for ,,submarine ,,mining ,illustration ,,edition ,,of #aiab ,illustration ,,washington ,,government ,,printing ,,office #aiab ,,war ,,department1 ,document ,no4 #cii4 ,office of the ,chief of ,staff4 ,this ,manual for ,submarine ,mining1 revised to #aiab1 is approved and published for the confidential information and guidance of the ,army of the ,united ,states4 ,under no circumstances shall its contents be divulged to persons not in the military or naval service of the ,united ,states4 ,by order of the ,secretary of ,war3 ,,wm4 ,h4 ,,carter1 ,major ,general1 ,acting ,chief of ,staff4 ,,contents4 ,page4 ,,chapter ,i4 ,definitions and general principles #g ,,ii4 ,matriel of the system #aa ,,iii4 ,loading room duties #cd ,,iv4 ,locating distribution box1 laying multiple cable1 marking out mine field #db ,v4 ,assembling and planting mines #dh ,,vi4 ,test of mines and apparatus #ef ,,vii4 ,taking up mines #fb ,,viii4 ,the mine command #fe ,,appendixes4 #a4 ,explosives #fi #b4 ,oil engine and generator #gg #c4 ,storage battery #hd #d4 ,submarine mine cable #ib #e4 ,care and preservation of matriel #ajg #f4 ,instructions for masters of mine planters #aaa #g4 ,manual for small boats #aae #h4 ,supply list #aba ,,chapter ,i4 ,,definitions ,,and ,,general ,,principles4 ,a submarine mine consists of an explosive charge inclosed in a water-tight case1 and a firing device1 the whole intended to be submerged in a waterway which it is desired to close against the passage of an enemy's vessels4 ,with respect to the position of the case containing the explosive1 submarine mines are of two classes1 buoyant and ground4 ,in the buoyant mine1 the case contains the explosive and the firing device1 and has such excess of buoyancy that it would float were it not held below the surface by a mooring rope and an anchor4 ,the submergence is such that1 while the mine would be struck by the hull of a passing vessel1 it is not so near the surface as to be seen4 ,buoyant mines may be planted and operated successfully in water #aej feet deep4 ,they should not1 in general1 be used where the depth of water is less than #bj feet4 ,in the ground mine1 the case contains the explosive and the firing device1 and is heavier than the displaced water2 it therefore rests upon the bottom and requires no anchor4 ,ground mines are not used where the depth of water exceeds #ce feet4 ,with respect to the means used to fire them1 mines may be classed as mechanical and electrical4 ,electrical mines are1 in turn1 of two general classes1 controllable--in which the firing device is under control after the mine has been fixed in position2 and noncontrollable--in which no such control is had4 ,mechanical and noncontrollable electrical mines are intended to be fired only by the blow of a passing vessel4 ,when once in position they are dangerous alike to friend and foe1 while controllable mines may instantly be made safe for friendly vessels or as quickly made dangerous to vessels of the enemy4 ,controllable electrical mines are arranged so as to give a signal to the operator when they are struck4 ,they may be set to fire automatically when struck or tampered with1 or may be fired at the will of the operator4 ,in the latter case the firing may be delayed1 in which case the operator fires the mine some short interval after the signal indicates that it has been struck2 or by observation1 in which case he fires it after the position-finding system shows that the vessel has come within the mine's destructive radius4 ,,location ,,of ,,mines4 ,the considerations involved in the location of mines are of two general classes1 tactical and local4 ,tactical considerations deal with the position of mines with reference to the other defenses4 ,local considerations deal with the width and depth of the channel1 the swiftness of the current1 the variation of the tide1 and the relative importance of the harbor4 ,where ordinary ship channels are unobstructed it is possible for modern battleships1 with their high speed and heavy armor1 to run by shore batteries1 at least in the night or during a fog2 hence the defense of such channels should not be left to guns alone4 ,on the other hand1 where mines are unprotected by the fire of shore batteries it is possible for an enemy to remove or disable them4 ,therefore guns and mines1 the two elements of the fixed defenses of a harbor1 are mutually dependent1 and when the location of one has been decided upon that of the other must conform thereto4 ,within the zone between #d1jjj and #h1jjj yards of the main defense the fire of heavy guns is destructive for warships1 yet the latter are at such a distance that their rapid-fire guns will be of little effect against the batteries4 ,moreover1 at #d1jjj yards vessels are just beyond the inner limit of mortar fire4 ,if possible1 therefore1 hostile vessels should be held in this zone by some obstacle4 ,such obstacle is afforded by a mine field4 ,on the other hand1 attacks upon a mine field are most liable to be made by small boats at night4 ,if the mine field be at too great a distance from the defenses1 these boats will not be revealed by the mine searchlights4 ,furthermore1 for protection against such attacks1 the defense relies upon rapid-fire guns of relatively limited range4 ,due to the above considerations the outermost mines are usually placed between #c1jjj and #d1ejj yards from the main defense4 ,in general1 there should be in each main channel at least three lines of mines4 ,,elements ,,of ,a ,,mine ,,system4 ,the elements of a mine system are3 #a4 ,the mining casemate1 consisting typically of four rooms3 7#a7 ,the operating room1 containing the power panel and the operating boards2 7#b7 the engine room1 containing the engine and the generator2 7#c7 the battery room1 containing the storage battery2 and 7#d7 the sleeping room for the personnel4 #b4 ,the multiple cables1 #g and #ai conductor1 leading from the casemate out to the distribution boxes1 one of which is in the center and rear of each group of mines4 #c4 ,the single-conductor cables1 radiating to the front from the distribution boxes1 one leading to each mine4 #d4 ,the mines1 in groups of #ai or less1 extending across the waterway to be defended1 planted approximately #ajj feet apart and anchored so as to have a submergence of about #aj feet at low water4 ,the groups are numbered #a1 #b1 #c1 etc41 from left to right of the observer stationed in rear of the line1 and the mines in each group are numbered similarly1 ,no4 #a being on the left1 ,no4 #aj in the center1 and ,no4 #ai on the right4 ,the groups composing a line of buoyant mines are not usually planted in prolongation of each other1 but with a space for the passage of friendly vessels1 and also for the movement of the planter when at work upon adjacent groups4 ,groups of ground mines may be placed in prolongation of each other or between the groups of buoyant mines1 as they will always be below the hulls of passing vessels4 #e4 ,the mine planters and other boats with the necessary equipment for planting and maintaining the planted mines4 #f4 ,the range-finding system1 the same as or similar to that used for the guns1 enabling accurate plotting of the positions of the individual mines1 and consequently permitting vessel tracking and observation firing4 #g4 ,the searchlights1 for illuminating the mine fields at night4 #h4 ,the rapid-fire guns1 for the protection of the mine fields4 ,,chapter ,,ii4 ,,mat,,riel ,,of ,,the ,,system4 ,the generating set4--,this consists of a ,d4 ,c41 shunt-wound generator driven by a kerosene oil engine1 or of a direct-connected gasoline set4 7,for method of operation of a ,hornsby-,akroyd oil engine1 see ,appendix #b47 ,the storage battery4--,this is a #dj-;cell chloride accumulator1 with a normal charge and discharge rate of #e amperes4 ,the voltage may be taken at #b volts per cell2 the internal resistance is negligible4 ,directions for setting up1 care1 and usage of the storage battery are given in ,appendix #c4 ,the #e-;ampere battery is the standard equipment at the present time1 but the new installations will have batteries with a normal charge and discharge rate of #ae amperes4 ,the motor-generator1 ,d4 ,c4-,a4 ,c4--,this is a ,d4 ,c4-,a4 ,c4 7#fj-;cycle1 single phase7 machine1 running on ,d4 ,c4 voltage 7#hj-aaj7 and designed to give one-half kilowatt at #hj volts4 ,to insure against breakdown two of these motor-generators are supplied to each casemate4 ,starting switch4--,this is a #d-point lever switch and is used to start the motor-generator and to accelerate it to full speed4 ,to insure against breakdown two of these motor-generators circuit to the fourth point4 ,resistances are connected between the points1 as shown in figure #a4 ,the contact made at point #a is not broken as the lever is moved to its successive positions4 ,it is seen that the total resistance is #h ohms2 it is all in the armature circuit when the switch blade is in the first point2 #d ohms when in the second point2 #b ohms when in the third point2 none when in the fourth point4 ,the operation of closing the lever short circuits in turn the resistances #d1 #b1 and #b4 ,the casemate transformer4--,this is a step-up transformer1 of the oil-insulated core type1 and is rated at #fj cycles1 #ejj watts1 #hj volts primary and #ejj volts secondary1 when carrying full load4 ,illustration3 ,,fig4 #a4--,starting switch4 ,the power panel4--,this panel is shown in figure #b1 its wiring diagram in figure #ah at the end of the book4 ,it consists of an enameled slate panel upon which the apparatus is mounted4 ,it is #cb inches wide1 #fi inches high1 and is set up with its face #cd inches from the wall in rear4 ,illustration3 ,,fig4 #b4--,,power ,,panel4 ,across the top are two lamps1 a double circuit breaker1 a ,d4 ,p4 ,d4 ,t4 switch1 and a single circuit breaker4 ,below these there are an ammeter1 an ,a4 ,c4 voltmeter1 and a ,d4 ,c4 voltmeter4 ,below the ammeter is a battery rheostat and below the ,d4 ,c4 voltmeter a field rheostat4 ,on a bracket at the side there is a mil-ammeter1 with a #af c4 p41 #aaj-volt lamp in series with it4 ,the remaining switches1 receptacles1 and attachments are sufficiently well indicated in the figures4 ,switch ,no4 #a controls the lamps at the top of the board4 ,when it is up1 they are supplied from an external source of power4 ,when it is down1 they are supplied from the storage battery4 ,the ,d4 ,c4 terminals are all carried to one terminal bar1 the ,a4 ,c4 terminals to another4 ,all terminals and all switches are labeled4 ,provision is made for energizing the ,d4 ,c4 busses3 7a7 ,from an external source of power3 ,close single circuit breaker and close switch ,no4 #b to the right--facing the board4 7b7 ,from the casemate generator3 ,close single circuit breaker and close switch ,no4 #b to the left--facing the board4 7c7 ,from the storage battery3 ,with switch ,no4 #b open1 close double circuit breaker4 ,feeder switches are plainly marked4 ,the ,d4 ,c4 switches supply power as follows3 ,no4 #c4 ,when up1 supplies the operating boards 7negative pole to boards1 positive to earth72 when down1 it is spare4 ,no4 #d4 ,when up1 supplies motor-generator ,no4 #a2 when down1 motor-generator ,no4 #b4 ,no4 #e4 ,when up1 supplies the mine commander's station4 ,no4 #f4 ,when up1 supplies casemate lamps2 when down1 it does the same1 but the power is now drawn from an external source and not from the ,d4 ,c4 busses4 ,no4 #g4 ,when up1 grounds the positive bus and connects the negative bus through the protective lamp and mil-ammeter to the mil-ammeter lead4 ,the ,a4 ,c4 switches supply power as follows3 ,no4 #h4 ,when up1 supplies the operating boards1 one pole to boards1 the other to earth through an independent lead2 when down1 it does the same1 but the side grounded is grounded through a choke coil4 ,no4 #i4 ,when up1 energizes the ,a4 ,c4 busses from motor-generator ,no4 #a2 when down1 the ,a4 ,c4 busses from motor-generator ,no4 #b4 ,no4 #aj is spare4 ,no4 #aa4 ,when up1 supplies power to the primary of the testing transformer2 when down1 it is spare4 ,no4 #ab4 ,when up1 supplies power from the secondary of the testing transformer to the test fuses4 ,voltmeter receptacles and plugs1 all of which are properly marked1 are provided for obtaining the reading of the ,a4 ,c4 and ,d4 ,c4 voltages4 ,the ,d4 ,c4 receptacles are on the right and the ,a4 ,c4 on the left4 ,the first receptacle of each set is spare to hold the plugs when the latter are not in use4 ,with the ,d4 ,c4 plug3 ,in the second receptacle1 the voltage of the casemate generator is indicated4 ,in the third receptacle1 voltage of external ,d4 ,c4 power4 ,in the fourth receptacle1 voltage of storage battery4 ,with the ,a4 ,c4 plug3 ,in the second receptacle1 voltage of ,a4 ,c4 power on the busses is indicated4 ,in the third receptacle1 voltage of external ,a4 ,c4 power1 if the latter is supplied4 ,in general1 no external ,a4 ,c4 power should be led into the casemate1 as the system would be unsafe1 owing to the liability of a 8cross40 ,the standard system is perfectly safe1 as it is impossible for a mine to be fired when the motor-generators are idle4 ,the double circuit breaker is an ordinary single-coil breaker4 ,the single circuit breaker is an overload and reverse-current circuit breaker4 ,the reverse-current coil has two windings1 one of which is bridged across the power supply1 and the other is in series with it4 ,on charge1 the effect of these coils is differential1 and on discharge it is cumulative and will trip the circuit breaker when the current from the storage battery exceeds #b amperes4 ,illustration3 ,,fig4 #c4--,,operating ,,board4 ,to charge the storage battery3 7a7 ,from an external source of power3 ,both the single and the double circuit breakers are closed and switch ,no4 #b is closed to the right 7facing the board74 7b7 ,from the casemate generator3 ,both circuit breakers are closed and switch ,no4 #b is closed to the left 7facing the board74 ,the operating board4--,a front view of this is given in figure #c1 its wiring diagram in figure #ah at the end of the book4 ,one is required for each group of #ai mines4 ,it consists of an iron frame to which are attached a signal block1 a master block1 #ai mine blocks 7#a for each mine71 busses1 and a terminal bar with #ai numbered terminals4 ,the frame is #gh inches high by #bd inches wide4 ,it should be set up so that its face is #cd inches from the wall in rear4 ,the signal block 7see fig4 #ah74--,this is an enameled slate block #bd inches wide and #aa inches high1 upon which are mounted three binding posts1 three lamps 7red1 white1 and green71 a bell and bell switch1 a #ij-ohm non-inductive resistance in parallel with the white lamp1 and a #abe-ohm resistance in series with the bell4 ,the binding posts are marked 8,earth0 or 8,g410 8,a4 ,c410 and 8,d4 ,c410 respectively4 ,the bell1 the #ij-ohm non-inductive resistance1 and the #abe-ohm resistance are so indicated on the figure4 ,the lamps are marked as follows3 ,red1 8,r4 ,l402 white1 8,w4 ,l402 green1 8,g4 ,l40 ,the circuit1 under normal conditions1 is3 ,from negative ,d4 ,c4 bus on power panel1 to switch #c closed up1 to 8operating board0 terminal1 to ,d4 ,c4 lead1 to ,d4 ,c4 post on signal block1 through green lamp1 to ,d4 ,c4 jaw on master block1 to ,d4 ,c4 bus on operating board1 through power switch ,p on mine block1 through solenoid ,s1 to middle of testing switch ,t1 to upper contact of same1 to upper contact of automatic switch ,a1 to middle of same1 to mine switch ,m1 through same to terminal bar1 through #ai-;conductor and single-conductor cables1 through mine transformer primary1 to mine case1 to ground1 to ,d4 ,c4 8earth0 terminal on power panel1 to switch #c1 and to positive ,d4 ,c4 bus on power panel4 ,green lamps of #h1 #af1 and #cb candlepower are supplied4 ,the #af-;candlepower green lamp glows dimly when #ai mines are connected to the operating board and all are free from short circuits1 grounds1 or abnormal resistances4 ,if it should glow abnormally bright1 due to grounds1 a #cb-;candlepower lamp should be substituted4 ,if it should glow very dimly1 due to a less number of mines connected1 an #h-;candlepower lamp should be used4 ,a short circuit in a mine circuit causes the green lamp to glow more brightly4 ,breaks in conductors not causing short circuits will not be revealed ordinarily by this lamp4 ,to detect breaks1 tests of individual mines must be made4 ,the red lamp glows and the bell rings when any automatic switch is down4 ,the circuit under this condition is3 ,from negative ,d4 ,c4 bus on power panel to switch #c closed up1 to 8operating board0 terminal1 to ,d4 ,c4 lead1 to ,d4 ,c4 post on signal block1 through green lamp to ,d4 ,c4 jaw1 to ,d4 ,c4 operating board bus1 through power switch on mine block whose automatic switch is down1 through insulated pin of lower arm of automatic switch1 to lower point of testing switch ,t1 to operating board lamp bus1 through bell1 #abe-ohm resistance and bell switch1 and red lamp in parallel1 to 8earth0 post1 to earth lead1 to ,d4 ,c4 8earth0 terminal on power panel1 to switch #c1 and to positive ,d4 ,c4 bus on power panel4 ,the resistance of the bell is such that a resistance of #abe ohms must be placed in series with it to make the joint resistance of the red lamp-bell circuit so large that if one automatic switch is down it will not interfere with the tripping of another4 ,the white lamp1 ,w4 ,l41 is in the firing and ,a4 ,c4 testing circuits4 ,the #ij-ohm resistance is in parallel with this lamp1 and in addition to protecting it from excessive current1 serves to keep the firing circuit complete should the lamp burn out4 ,the master block 7see fig4 #ah74--,this is an enameled slate block #f inches wide by #i inches high1 upon which are mounted two jaws for the terminals of a jumper1 a testing switch1 ,t4 ,s41 and a firing switch1 ,f4 ,s4 ,illustration3 ,,fig4 #d4--,,mine ,,block4 ,the testing switch1 ,t4 ,s41 is used to determine if the ,a4 ,c4 power be on the signal block4 ,if so1 when it is closed the white lamp on signal block glows4 ,this switch is marked to indicate its 8off0 and 8on0 positions4 ,when 8on0 the circuit is as given in 8test of the delivery of the ,a4 ,c4 power to the operating board10 ,chapter ,,vi4 ,the firing switch1 ,f4 ,s41 is used to throw the ,a4 ,c4 power on the operating board ,a4 ,c4 busses4 ,this is marked to show its 8on0 and 8off0 positions4 ,no mine can be fired unless this switch is in its 8on0 position4 ,when 8on0 the firing circuit is as follows3 ,from ,a4 ,c4 bus on power panel to switch #h closed up1 to 8operating board0 terminal1 to ,a4 ,c4 lead1 to ,a4 ,c4 post on signal block1 to white lamp and resistance in parallel1 to ,a4 ,c4 jaw1 through firing switch1 ,f4 ,s41 to ,a4 ,c4 bus on operating board1 to lower point of automatic switch when it is closed down1 to middle point of automatic switch1 through mine switch to terminal bar1 through #ai-;conductor and single-conductor cables1 through mine transformer primary1 to mine case1 to ground1 to ,a4 ,c4 8earth0 terminal on power panel1 to switch #h1 and to other ,a4 ,c4 bus on power panel4 ,the white lamp glows after the mine has been fired4 ,the mine block 7see figs4 #d and #ah74--,this consists of an enameled slate block1 #f inches wide and #i inches high1 on which are mounted four switches4 #a4 ,the upper switch is the 8mine switch40 ,when it is open the corresponding mine is cut out and can not be fired4 ,it is placed horizontally on the blocks of the old model and vertically on those of the new model4 #b4 ,the right-hand switch1 a ,s4 ,p4 ,s4 ,t4 knife switch1 is the 8power switch40 ,when it is closed the ,d4 ,c4 power is on the block and the automatic switch will function when the corresponding mine is struck4 ,when it is open the mine can be fired by raising the automatic switch release1 thus tripping the automatic switch4 #c4 ,the central switch is the 8automatic switch10 a single-pole double-throw switch1 operated by the plunger of a solenoid4 ,through its lower arm there passes an insulated pin which1 when the switch is down1 makes connection between two contacts to the right and left of this arm4 ,if for any cause the current through the solenoid rises above that for which it is set 7normally #j4jge ampere71 its plunger is drawn up and the switch is tripped4 ,such rise in current is produced when a mine is struck1 the resistance through the circuit-closer circuit being far less than that through the primary coil of the transformer4 ,such would also be the case when a mine cable is grounded4 ,when the automatic switch is tripped1 the ,d4 ,c4 circuit to the mine is broken at its upper contact 7see fig4 #ah7 and ,d4 ,c4 circuit through red lamp and bell is made through the insulated through pin in the lower arm1 thus giving warning4 ,if at the same time ,a4 ,c4 power be on the busses and the firing switch on the master block be closed1 ,a4 ,c4 will be thrown on the mine through the lower contact of the automatic switch1 and the mine will be fired4 ,just above the plunger of the solenoid there is a red knob attached to the tripping bar of the automatic switch release4 ,this enables the automatic switch to be released by hand in observation firing and in testing4 #d4 ,the left-hand switch1 a ,s4 ,p4 ,d4 ,t4 switch1 is the 8testing switch40 ,it is used to test the automatic switch1 which should open when the testing switch is thrown down4 ,the bell switch should be opened before throwing down testing switch4 ,when the testing switch is in this position1 the circuit being broken at its upper contact1 the mine is cut out1 and in place of the mine there is thrown in the red lamp of the signal block4 ,the resistance of this red lamp is greater than that of the mine circuit when the mine is struck1 so that if the automatic switch works for the current through the red lamp it will certainly work for that through the circuit closer when the mine is struck4 ,the circuit when the testing switch1 ,t1 is down and before the automatic switch drops is3 ,from negative ,d4 ,c4 bus on power panel1 to switch #c closed up1 to 8operating board0 terminal1 to ,d4 ,c4 lead1 to ,d4 ,c4 post on signal block1 through green lamp1 to ,d4 ,c4 jaw1 to ,d4 ,c4 bus on operating board1 through power switch1 through solenoid to middle of testing switch ,t1 to lower point of same1 to operating board lamp bus ,l1 through red lamp to 8earth0 post1 to earth lead1 to ,d4 ,c4 8earth0 terminal on power panel1 to switch #c1 and to positive ,d4 ,c4 bus on power panel4 ,the circuit1 when testing switch1 ,t1 is down1 and after the automatic switch has dropped1 is the same as the above up to the power switch1 then from the power switch through the insulated pin in the lower part of the automatic switch1 to the lower jaw of the testing switch1 and then the same as the circuit above4 ,a diagram similar to the wiring diagram1 figure #ah1 at the end of the book should be made of the power panel and of one of the operating boards of each casemate and posted in a conspicuous place in the casemate4 ,any changes made in the wiring of either of these boards should be made immediately on this diagram4 ,submarine mine cable1 #ai-;conductor4--,this is an armored cable about #a inch in diameter and contains #ai insulated single conductors of ,no4 #af ,american wire gauge wire 7#ea mils in dia474 ,the conductors are arranged in two concentric layers around a single central conductor1 the inner layer containing #f1 the outer #ab4 ,one conductor in each layer is distinguished from the rest by some characteristic mark1 as a spiral white thread1 a wrapping of tape1 or other easily detected mark4 ,the marked conductor in the outer layer is ,no4 #a1 that in the inner layer ,no4 #ac1 and the central conductor is ,no4 #ai4 ,the other conductors are numbered at the shore end of the cable in a clockwise direction2 at the distant end in a contraclockwise direction4 ,submarine mine cable1 #g-;conductor4--,in many cases the #g-;conductor cable now on hand can be used to advantage for mine work1 particularly in planting groups which do not require great lengths of multiple cable4 ,in all such cases the old grand junction boxes are to be used as distribution boxes1 thus providing for separate groups of #g mines4 ,submarine mine cable1 single conductor4--,this is an armored cable1 about three-fourths inch in diameter1 and contains an insulated conductor made of #g strands of soft annealed ,no4 #bb ,american wire gauge copper wire 7#be4ce mils in dia474 ,the buoyant mine case4--,the service #cb-;inch pattern is made of #aj-pound1 -inch1 open-hearth steel1 of great toughness and elasticity1 and is thoroughly galvanized4 ,the shell consists of two hemispheres1 ribbed and welded together at the equator1 thus avoiding all rivets4 ,every case before it is accepted is tested with an internal hydraulic pressure of #ajj pounds per square inch4 ,the top hemisphere is provided with an external maneuvering ring2 the bottom hemisphere has a hole #e inches in diameter at the pole4 ,the edge of the hole is reenforced by a welded ring #a inches thick2 and near it are four bosses1 also welded1 carrying screw bolts which project #b inches outside to secure the cap4 ,the cap consists of a hemisphere of #ae-pound1 -inch wrought iron1 flanged and dished at the base to fit the case1 to which it is attached by the four bolts already mentioned4 ,they pass through slots in the flange1 which is then held in place by shoes and nuts which are keyed on4 ,the water has free access to the chamber inside the cap4 ,the uses of the cap are3 ,to clamp the ,turk's-head of the mine cable1 to cover and protect the portion of the core exposed outside the case1 and to serve as an attachment for the wire mooring rope4 ,a hole #a inches in diameter at the pole of the cap is connected by means of a slot with a #c-;inch hole punched through the cap between two of the bails4 ,this arrangement permits the entrance or removal of the ,turk's-head without removing the cap from the mine case4 ,the mooring attachment consists of a ring of #a-;inch wrought iron1 having a hole #b inches in diameter1 attached to the cap by three bails of #a-;inch wrought iron permanently double riveted to the sides4 ,the cap is thoroughly galvanized4 ,illustration3 ,,fig4 #e4--;,,compound ,,plug1 ,,old ,,model ,,fuse ,,can4 ,illustration3 ,,fig4 #f4--;,,compound ,,plug1 ,,rubber ,,fuse ,,can4 ,illustration3 ,,fig4 #g4--;,,compound ,,plug1 ,,trotol ,,fuse ,,can4 ,the large hole in the mine case covered by the cap is closed by a plug4 ,the joint is made water-tight by a lead washer jammed between the plug proper and the case and by a coating of red lead or similar waterproofing material upon the screw threads4 ,in the strong currents and deep water of some harbors more buoyancy than is possessed by the #cb-;inch case is required4 ,this is obtained by inserting between the hemispheres a cylinder of #bj-pound wrought iron which is stiffened by extra welded ribs for the larger sizes4 ,such cases are designated by the diameter in inches of a sphere having the same buoyancy4 ,thus1 a ,no4 #dj case is made by inserting a cylinder #cb inches in diameter and #bj4d inches in length between the two hemispheres of a ,no4 #cb case2 this is sufficient to make the displacement equal to that of a spherical case #dj inches in diameter4 ,in the latest types the cylinders are made of corrugated mild steel of less thickness1 which diminishes very materially the weights of the cases4 ,the following table exhibits the dimensions and weights of buoyant mines1 with trotol fuse cans1 complete except the charges and moorings4 ,the actual free buoyancy when planted will be the difference between the displacement and weight as given in the table1 reduced by the weight of the charge and of the moorings and cables3 ,,plain ,,cases4 ---------------------------------------- ---------------------- ,computed,measured ,length ,no4 ,displace- weight1 weight1 of ,remarks4 ment4 empty4 empty4 cylinder4 ---------------------------------------- ---------------------- ,pounds ,pounds,pounds ,feet #cb #fce #cjh #caa #j4jj ,all are about #cc inches in outside diameter2 the extreme length in each case is #d4c feet plus the length #cc #fie #cfd 4#ag #cd #gfb #cie 4#ce #ce #hbi #dbg 4#ed #cf #ijd #dfb 4#ge #cg #ihb #dih 4#if #ch #a1jfd #ech #a4bj #ci #a1adi #egh #a4dc #dj #a1bdb #fba #fbe #a4gj #da #a1cda #ffe #a4if #db #a1dcf #gab #b4bd #dc #a1edj #ghh #gei #b4ec #dd #a1feb #hdb #b4gg ,one extra welded rib4 #de #a1gfg #hgf #c4ag ,do4 ,lot of #ahgi2 one #hii extra welded rib4 #df #a1hhg #ieb #c4ej #icf ,lot of #ahhd2 one extra welded rib4 #dg #b1jac #a1jaa #c4he ,one extra welded rib4 #dh #b1add #a1jgc #a1jcg #d4bj ,do4 ---------------------------------------- ---------------------- ,,corrugated ,,cases4 ---------------------------------------- ---------------------- #dg #a1ecf #egb #b4bd #ej #b1cbc4b #ggg #d4bb ---------------------------------------- ---------------------- ,the compound plug1 with old model brass fuse can4--,a section of this plug1 with the names of all the parts1 is shown in figure #e4 ,the brass fuse can is not used when guncotton is used as a priming charge4 ,the compound plug1 with rubber fuse can4--,a section of this plug1 with the names of all the parts1 is shown in figure #f4 ,the compound plug1 with trotol fuse can4--,a section of this plug1 with the names of all the parts1 is shown in figure #g4 ,in each plug the main parts are screwed together and held in place by set-screws4 ,the connection of the compound plug with the mine case makes an earth plate1 of which the electrical resistance in salt water is about #a ohm4 ,the mine transformer 7see fig4 #h74--,this consists of a cylindrical brass case1 which contains the primary and secondary coils of the transformer and the reactance coil4 ,the transformer is screwed into the brass collar or the reenforce and in turn has the circuit closer screwed upon its top4 ,the fuses are attached to the secondary and are fired when proper voltage is applied to the primary4 ,the primary leads are black2 those of the secondary are red4 ,the terminal1 ,p1 of the primary coil is left free for the purpose of testing1 but when preparing the transformer for use it is attached securely to the binding post1 ,t4 ,the upper terminal1 ,r1 of the reactance is prepared for attachment to the ball seat of the circuit closer4 ,the normal circuit is from ,p1 through the primary coil 7the resistance of which is about #b1djj ohms71 to the transformer case1 and thence to earth4 ,however1 when the mine is struck1 so as to close the circuit closer1 a parallel circuit is closed through the reactance 7the resistance of which is about #acj ohms71 thence to the ball seat of the circuit closer1 through the ball and springs to the transformer case1 and thence to earth4 ,in this latter case1 therefore1 the resistance is lessened by about #b1cjj ohms4 ,the reactance coil will permit only a small amount of alternating current to pass through it when the ball is displaced1 hence mines may be fired whether the ball is displaced or not4 ,illustration3 ,,fig4 #h4--,,mine ,,transformer4 ,two fuses are connected in multiple across the ends of the secondary terminals4 ,these terminals are #aj inches in length1 to allow ample margin for inserting fuses in the primer4 ,the transformer is of the step-down type and is rated at #bb4e watts1 #fj cycles1 #ejj volts primary1 and #ad volts secondary4 ,the mine circuit when normal is such that #hj volts should give only #cj mil-amperes1 but a mine may be fired even when the circuit is so defective that #hj volts give #abj mil-amperes4 ,furthermore1 #aej volts ,d4 ,c4 may be applied to the primary without danger of explosion4 ,an explosion can not be produced unless the ,a4 ,c4 busses on the operating board are energized1 and as long as the firing switch on the master block is open1 there is no danger from accidental closing of switches in making mine tests or from short circuits in the mine4 ,,note4--,in designing this transformer the following variations were considered3 7a7 ,omitting reactance and tapping to ball seat beyond primary of transformer2 7b7 using a condenser2 7c7 using two sets of fuses1 so as to be able to fire with either ,d4 ,c4 or ,a4 ,c4 ,all were eliminated1 as they impaired either the safety1 the simplicity1 or the efficiency of the system4 ,the circuit closer4--,this1 when used with the buoyant mine1 consists of the following parts3 ,the cap1 the spring plate1 the distance ring1 the steel ball1 and the ball seat1 which1 when assembled1 are mounted on the top of the mine transformer4 ,the ground mine case4--,the form and details of construction adopted for the service pattern are the following 7see fig4 #i73 ,the case is cast-iron1 in form a segment of a sphere1 of which the height is two-thirds of the radius4 ,the bottom is nearly flat1 with a central sand-hole plug to empty the casting4 ,six internal radial ribs are added to give additional supports to the top2 the loading hole1 #e inches in diameter 7#c inches in old pattern71 is at the pole and is closed by a compound plug4 ,before acceptance a hydraulic pressure of #ajj pounds per square inch must be borne without developing leakage4 ,only one size of ground mine has been introduced into our service4 ,this pattern is designed to contain from #bjj to #cjj pounds of explosive and to rest on the bottom in water not exceeding #ce feet in depth at high tide4 ,the dimensions are as follows3 ,radius of the sphere1 #ba_/ inches2 diameter of the base1 #dj inches2 extreme height1 #be inches2 thickness of iron1 seven-tenths of an inch2 weight1 empty in the air1 #a1cee pounds2 when submerged it loses #eae pounds4 ,the capacity of this case is about #e cubic feet4 ,illustration3 ,,fig4 #i4--;,ground mine case4 ,a mine cap is provided to clamp the ,turk's-head of the mine cable1 to cover and protect the portion of the core exposed outside the case1 and to serve as an attachment for the mooring and the raising ropes4 ,this cap is held to the mine case by six bolts1 and is fitted with two rings1 one for attachment of the mooring rope of the circuit-closer buoy and the other for attachment of the raising rope4 ,the compound plug1 ground mine4--,this is similar to the compound plug for buoyant mines4 ,the circuit closer is placed in a buoy above the mine4 ,illustration3 ,,fig4 #aj;a4--,,automatic ,,anchor4 ,the mushroom anchor4--,the #a1jjj-pound anchor is in shape a right cylinder about #aj inches in height and #bf inches in diameter1 slightly dished on the bottom to increase the holding power in mud4 ,for a rock bottom six projecting toes increase the holding power2 corresponding depressions on the top permit piling when in store4 ,the heavy anchors1 #b1jjj and #c1jjj pounds1 are of the same form4 ,the cylindrical form is adopted to facilitate handling1 since in that shape the anchor may be rolled readily on its edge4 ,the absolute stress of the mine and its moorings upon a mushroom anchor of this kind is easily computed1 being the square root of the sum of the squares of the buoyant effort and of the horizontal pressure exerted by the current4 ,the latter1 in pounds per square foot of exposed cross section1 may be estimated at one-half the square of the velocity of the current in feet per second4 ,a coefficient of safety should cover the jerking effect of the waves and the shocks of friendly vessels4 ,it will1 of course1 vary with the locality and with the absolute weight of the anchor1 but in general a value from #c to #e is considered sufficient4 ,the holding power of such an anchor varies greatly with the nature of the bottom4 ,if this be hard1 the dead weight alone must be depended upon2 if soft1 at least double power may be anticipated4 ,in swift water the buoyant mine can be better held in position by two anchors chained together4 ,the shackles4--,the wire mooring rope is attached to the anchor and to the case by shackles1 of which there are two sizes4 ,the anchor shackle consists of a wrought iron strap with two eyes bent into the usual curved form and offering a thickness of #a inches at the bottom1 where the wear and sand cutting is greatest1 and of a #a-;inch wrought iron bolt fitted flush with the outside of the straps4 ,the bolt is held in position by a split key1 which1 after insertion through a small hole in the bolt and one of the eyes 7in the old model71 is opened so that it can not work loose4 ,the mine shackle is lighter1 being #a inch thick at the bottom1 with a #a-;inch bolt2 otherwise it is identical in pattern with the anchor shackle4 ,sister hooks4--,they are used to connect the bail of the mushroom anchor to the anchor shackle4 ,they are of drop-forged steel of high tensile strength and weigh about #g pounds per pair4 ,the automatic anchor1 ,artillery type1 #aiaj 7see figs4 #aj a and b74--,this is a device intended for use with buoyant mines1 and by means of which such mines may be anchored in any depth of water1 with any desired depth of submergence given automatically4 ,the anchor is bell-shaped1 #bh inches in diameter at the bottom1 #bh inches high over all1 and composed of the following parts3 ,body1 cover1 reel1 journal-box caps1 ratchet1 pawl1 pawl spring1 distance rope1 distance weight1 brakes1 bails1 necessary bolts1 wrenches1 and crank handles4 ,the pawl is drawn away from the ratchet by a weight suspended a certain distance below the anchor4 ,this is called the distance weight1 and the submergence is regulated by the distance this weight is from the anchor4 ,in falling through the water the mooring rope will unreel and the mine will remain on the surface1 but when the distance weight reaches the bottom the pawl spring forces the pawl into the teeth of the ratchet1 and as the latter is attached to the reel shaft1 it prevents the reel from turning and hence unreeling4 ,these anchors weigh approximately #a1ejj pounds1 including the #bjj-pound distance weight4 ,in order to control the speed of revolution of the reel1 the friction brakes must be adjusted properly4 ,to do this1 a pull is put on the mooring rope with a spring balance rigged to show the amount of pull2 the pull for a particular size of case is determined by experiment4 ,for a ,no4 #dj mine case the adjusting screws of the brake shoes are regulated so that the reel will revolve slowly when a pull of #cjj pounds is registered4 ,the pawl spring is #i inches long and of such strength that a pull of #cf pounds will extend the spring #a inches4 ,the pawl spring bolt is of such length that the pawl spring will be just at the point of tension when the top of the pawl spring bolt is flush with the top of the pawl spring-bolt nut and the pawl fully seated in the ratchet4 ,when the tidal currents are such as to require a heavier anchor to hold the mine than the #a1ejj-pound automatic anchor1 the following combination anchor will be used3 ,attach a mushroom anchor by means of a mooring rope 7about #h feet long7 and clips to the bail in the bottom of the automatic anchor4 ,if necessary1 two mushroom anchors may be fastened together by bolts and these attached to the automatic anchor as stated above4 ,illustration3 ,,fig4 #aj;b4--,,automatic ,,anchor4 ,a #c1jjj-pound automatic anchor1 similar to the #a1ejj-pound automatic anchor1 is supplied for some localities4 ,the mooring sockets4--,to connect the wire mooring rope to the shackles at the mine and the anchor1 a closed socket is attached at each end4 ,the eye of the socket has a clear opening1 #a_/ inches1 designed to receive the bolt of the shackle4 ,the end of the rope is passed into the socket1 spread out1 and secured by pouring in a melted socket alloy4 ,a substitute method for connecting the wire mooring rope to the shackles is to bend the ends of the mooring rope by means of a small vise around a galvanized iron thimble and fasten the end by two bolted clips4 ,wire mooring rope4--,this is the highest grade of -inch galvanized-steel wire rope1 consisting of #f compound strands1 each made of #ai wires1 the whole laid around a steel center4 ,its breaking strength when new is about #ah tons4 ,its weight per running foot1 submerged1 is about eight-tenths of a pound4 ,it is used for mooring mines to mushroom anchors4 ,marline-covered wire mooring rope4--,for mooring mines to the automatic anchors and for raising rope marline-covered wire rope is used4 ,this rope consists of five outer strands wound around a central hemp core4 ,each of the outer strands consists of a small twisted wire rope wound around with four strands of marline4 ,one end of the rope is prepared for attachment to the mine by passing it over a thimble and fastening it to the standing part by means of two clips4 ,a shackle joins the thimble and the bail of the mine4 ,the other end of the rope is made secure to the reel of the anchor4 ,the breaking strength of -inch marline-covered rope is #ag1jjj pounds1 that of -inch marline-covered rope is #bg1jjj pounds4 ,the weight per running foot of the -inch rope is #j4e pound1 that of the -inch rope is #j4h pound4 ,the weight of this rope submerged is about #fj per cent of its weight in air4 ,about #aee feet of the -inch and #he feet of the -inch marline-covered rope can conveniently be wound on the #f-;inch reel of the #a1ejj-pound automatic anchor4 ,marline-covered wire distance weight rope4--,for attaching distance weights to the automatic anchor -inch marline-covered wire rope is used4 ,this rope is identical in pattern with the marline-covered wire mooring rope4 ,the distribution box1 #ai-;conductor4--,this is a circular1 cast-iron1 disk-shaped box which receives the end of the multiple cable1 in which taped joints are made between the separate conductors of this cable and the single-conductor mine cables1 and from which these mine cables radiate4 ,it is about #bg inches in diameter and weighs about #cjj pounds4 ,it consists of two parts1 a bowl-shaped bottom #f inches deep inside and a slightly curved lid4 ,the latter has an iron ring in its center by which the box is raised and lowered4 ,eight pins1 fastened to the bottom1 fit in corresponding holes in the edges of the lid and are slotted for keys by which the two parts are fastened together4 ,the vertical edge of the bottom is cut with #bj slots1 each about #b inches deep4 ,one of these is larger than the others and receives the multiple cable2 the others are for the single conductor cables4 ,when in use these slots are numbered clockwise from the multiple-conductor slot1 looking down into the box4 ,the lid has corresponding projections or lugs which enter these slots1 and which1 in position1 fit snugly against the cable ends4 ,the cables are held from being pulled out by ,turk's-heads worked upon them4 ,to prevent the cable ends from accidentally slipping out of the slots while joints are being made between them before the lid is put on1 the multiple cable is secured by a bolted collar on the inside of the box1 the single-conductor cables by clipping their ,turk's-heads under claw-like radial projections cast upon the inside rim between the slots4 ,the distribution box1 #g-;conductor4--,this box is used with multiple cable1 #g-;conductor4 ,it consists of two circular plates of cast-iron #ba inches in diameter and three-fourths of an inch thick united by four #a-;inch bolts1 which are placed in rounded projections forming the angles of a square4 ,the cables are separately clamped1 the top plate overlapping the clamp straps4 ,the multiple cable enters on one side2 three single-conductor cables enter on the opposite side1 and two on each of the intermediate sides4 ,the top plate is provided with a lowering ring4 ,the junction boxes4--,these boxes1 in different sizes1 are used in splicing multiple and single-conductor cables2 they consist of two rectangular plates of iron or steel united by four -inch bolts at the corners4 ,the plates are hollowed in the middle to form a chamber to receive the ,turk's-heads and the joints connecting the conductors4 ,the ends of the plates are curved to admit the cable ends4 ,the ,turk's-heads are clamped to the lower plate by straps and screw bolts1 the cavity of the upper plate covering them when bolted in position4 ,each cable end is thus made fast before the box is closed4 ,the distribution box buoy4--,this buoy is used to mark the position of the distribution box during the planting of mines and subsequently1 in practice and in service1 until such time as the mine commander desires to remove it4 ,it may be either a can or a keg buoy--a beer keg of one-half barrel capacity is well suited for this purpose4 ,the mine buoy4--,this buoy is used to mark the position of the mine when planted4 ,it may be a small can buoy1 preferably cork filled1 or a piece of wood with a hole bored through it4 ,the size of the buoy is determined by the swiftness of the current4 ,it is attached to the maneuvering ring of the buoyant mine by #fj feet of -inch rope4 ,the measuring reel and frame4--,the frame consists of two longitudinal pieces1 #c by #d by #ff inches1 placed #ag inches apart1 center to center4 ,at #aa inches from each end two cross pieces1 #c by #d by #bj inches in length1 are fastened to the longitudinal pieces with through bolts4 ,at the center point of these cross pieces are placed standards1 #c by #d by #af inches1 which have journals for the axle of the reel1 counter-sunk in their upper ends4 ,two iron braces1 one on each side1 hold each standard firmly in a vertical position4 ,an iron clamp is also attached to the upper ends of the standards1 by means of which the axle is prevented from jumping out of the journals4 ,distance from center to center of standards is #dc inches4 ,the iron axle of the reel is #a-;inch round iron1 #ed inches in length4 ,at each end of the axle a screw thread is cut for the nut which holds the crank in place4 ,inside the screw thread the axle is squared to receive the socket of the crank4 ,two collars prevent the wooden reel from binding on either standard4 ,the cranks are of the usual design4 ,the drum of the reel is #h inches in diameter2 heads are #b inches thick1 made in two layers1 cross-grained1 and are #bd inches in diameter2 length of drum over all is #cf inches4 ,iron plates are fastened in the center of each head1 through which the axle passes4 ,the reel is prevented from turning on the axle by keys4 ,three -inch rods pass through the iron plates and drum and bind these parts firmly together4 ,at #f inches from the ends of the longitudinal pieces a hole is bored to receive a lag screw1 inch by #f inches1 by means of which the whole apparatus can be firmly fastened to the deck4 ,the brake is a piece of #c by #c by #cf inch hardwood1 used as a lever to bring pressure on the drumhead4 ,there is one for each side1 and1 when not in use1 each rests on one of the longitudinals1 being held in place at one end by two staples and at the other end by a bolt and pin4 ,near the drum on one head is a hole through which the inner end of the measuring line can be passed and stapled to the outside of the head4 ,the cable-reel frame4--,the frame is made in two parts which1 when in use1 are held in proper relative positions by means of two iron ties provided with turnbuckles at their centers4 ,the ends of these ties are bent over at right angles and fit in sockets in the two end parts4 ,each end part consists of a standard having an iron head through which works a screw turned by a small lever1 the upper end carrying a journal in which the end of the reel axle rests4 ,the lower end of the standard rests on a horizontal piece and has a diagonal brace on each side1 the outer ends of these braces being dovetailed into the longitudinal piece and the inner ends into the standard near the top4 ,dovetailed into the longitudinal piece at its middle point is a piece extending out at right angles1 bottom flush with bottom of the longitudinal4 ,a diagonal brace similarly fastened prevents any outward movement of the standard4 ,the whole is held firmly together by bolts and lag screws4 ,illustration ,illustration3 ,,fig4 #aa4--;,,boat ,,telephone1 ,,model #aijf4 ,lag screws are also provided1 by means of which the ends of the frames can be fastened to the deck of the vessel if desired4 ,the reel axle is #b by #b inch squared iron1 rounded at the ends for #f inches to fit the journals of the frame4 ,a disk secured by a set-screw at one end of the axle and the friction brake wheel at the other end hold the axle in position with respect to the reel4 ,the brake wheel is #ah inches in diameter4 ,the friction band is #a inches by inch1 and is fastened at one end to one of the standards of the frame4 ,the other end is attached to a lever whose fulcrum is also attached to the same standard4 ,boat telephones4--,the different models in use are as follows3 7a7 ,model #aijd4--,the system consists of two telephone hand sets1 a buzzer1 and a battery of dry cells of about #h volts1 all connected in series by means of cable and earth connections4 ,in operating the telephones a call is made by pressing the button1 and when talking the lever is held down4 7b7 ,model #aijf4--,the system consists of two telephone hand sets1 a reactance coil1 and a source of energy that will furnish about #ae volts1 dry cells preferred1 connected as shown in figure #aa4 ,the terminals do not have to be poled1 as the receiver is not in the primary circuit and can not be demagnetized4 ,to regulate the buzzer1 remove the cap in the base and with a small screw driver loosen the lock nut on the center screw 7a small portion of a turn is all that is necessary74 ,with a smaller screw driver the screw may be adjusted to increase or decrease the rate of vibration1 increasing or decreasing the sound4 ,then tighten the lock nut4 ,in case the contact is dirty the entire buzzer and condenser may be removed by disconnecting the cord and removing the screw on the back of the telephone just below the call button4 ,as the contacts are aluminum1 this will seldom have to be done4 7c7 ,model #aiji4--,the system consists of two telephone hand sets1 an apparatus box1 and a battery of from #g to #aj volts1 all connected as shown in figure #ab4 ,the talking and ringing circuits are normally open at the talking and ringing buttons1 respectively4 ,apparatus box4--,seven dry cells in series should be connected to the posts of the apparatus box marked 80 and 8-10 and the post marked 8,g0 connected to a ground plate4 ,shore hand set4--,the blue cord of the shore hand set should be connected to the ground plate4 ,either of the red cords of the shore hand set should be connected to the post in the apparatus box marked 8,l0 and the other to the conductor in the cable that is to be used for telephoning purposes4 ,boat hand set4--,the blue cord of the boat hand set should be connected to the ground plate and one of the red cords to the conductor in the cable to which the hand set on the shore is connected4 ,the other red cord is free4 ,signaling4--,from figure #ab it will be seen that in either hand set1 when neither the ringing nor the talking switch is closed1 a condenser within the hand set is in series with the transmitter and the receiver1 so that the practical effect is to permit an alternating or variable current to pass through the transmitter and the receiver1 but to prevent a direct or continuous current from so doing4 ,by pressing the ringing key of either hand set the circuit in that hand set is closed through the #a1jjj ohms resistance and the receiver to ground4 ,thus1 when the ringing key of the boat hand set is pressed1 this allows the direct current from the battery to pass 7see fig4 #ab7 through f1 e1 d1 c1 8,b10 b1 a1 line1 the ringing key1 #a1jjj-ohm resistance1 and receiver of the boat hand set1 to ground1 and back through o and p to battery4 ,similarly1 a circuit through the battery1 f1 8,a10 and a1 is made1 thus placing relays 8,a0 and 8,b0 in parallel4 ,the relay 8,b0 operates1 but relay 8,a10 being less sensitive than 8,b10 does not operate4 ,relay 8,b0 closes the circuit at l1 and thus completes the circuit from battery through f1 e1 d1 c1 k1 l1 8,c10 o1 p1 back to battery4 ,this causes relay 8,c0 to operate and to complete a local circuit from battery through f1 e1 d1 k1 m1 s1 primary1 t1 vibrator1 p1 back to battery1 causing the vibrator to vibrate and inducing in the secondary winding of the induction coil an alternating current1 which passes through the #a ,m4 ,f4 and #b ,m4 ,f4 condensers1 through the hand sets in parallel1 and by alternately increasing and decreasing the attraction of the receiver magnets for their diaphragms produces a loud humming sound in each receiver4 ,similarly the shore station may call the boat station4 ,illustration3 ,,fig4 #ab4--;,,boat ,,telephone1 ,,model #aiji4 ,talking4--,when the ringing key is released and the talking key is depressed the #a1jjj-ohm resistance is cut out and the condenser in the hand set is short circuited4 ,the current is then sufficient to operate relay 8,a10 and this relay in operating allows the other relays to resume their normal positions4 ,when the variations in the pressure upon the transmitter diaphragm in either hand set varies the resistance of the corresponding branch circuit a slight variation in the current from the battery is produced4 ,the internal resistance of the battery is sufficient to produce a slight variation in its terminal voltage4 ,the resulting variations in the line voltage1 and hence in the drop across the receivers1 produce the usual vibrations in the receiver diaphragms4 ,these variations also produce slight variations in the current through the primary winding of the induction coil1 resulting in greater variations across the terminals of the secondary winding4 ,since the secondary winding is in series with the battery1 the practical effect is to amplify the variations in the line voltage1 and hence in the talking currents4 ,successful working of the relays is obtained only by a careful adjustment of the screws which regulate the throw of the armatures4 ,the relay 8,a0 is located in front of the 80 battery post1 the relay 8,c0 in front of the 8,g0 post4 ,in addition to the above matriel there are necessary for the mine system certain electrical instruments1 as well as tools1 appliances1 and supplies requiring no special description1 which are enumerated in the supply list4 7,appendix #h47 ,figures #ag;a and #ag;b1 at the end of the book1 show the construction of an improvised mine target4 ,,chapter ,,iii4 ,,loading ,,room ,,duties4 ,making a telegraph joint4--,the insulation is removed from the ends for #a inches and the wires brightened4 ,the ends to be joined are placed across each other about one-third distance from the insulation1 making an angle of about #de with each other4 ,the wires are grasped firmly at the junction and each free end wound tightly around the other wire for four turns2 the winding should be in opposite directions4 ,the ends of the wires are trimmed down so they will be smooth and present no sharp points4 ,when wires are joined with brass jointers three-fourths inch of each wire is bared and the wires are inserted in the jointer2 each end is crimped with pliers in the direction of the longer axis2 the rest of the jointer is crimped and the ends or sharp points rounded off4 ,when brass jointers are used care should be exercised not to crimp them too hard1 as the wires may be partly cut through and finally broken4 ,special care must be used with the fuse leads1 as the secondary circuit of the mine transformer can not be tested after the compound plug is assembled4 ,insulating a joint4--,a piece of rubber tape about #b inches long is used1 with ends cut diagonally4 ,the tape is stretched1 and starting at a point about three-fourths inch back on the insulation1 with the long edge of the tape on the inside1 it is wound around the joint under tension1 each turn covering the previous turn about one-third4 ,the wrapping is continued until the same amount of insulation is covered on each side1 when the wrapping is worked backward over the joint and the end is secured by pressing it firmly a short time or placing a drop of cement under it4 ,making a water-tight joint4--,the two ends of wire are scraped clean for about three-fourths of an inch and joined by a brass jointer1 which is then crimped4 ,the insulation is scraped clean about #b inches on each side of the jointer and covered with rubber cement4 7,cement is not absolutely essential47 ,two strips of rubber tape are cut about #f inches long1 with diagonal ends1 and stretched4 ,beginning about #a inches along the insulation1 the tape1 with the long edge on the inside1 is wrapped firmly and tightly until about one-fourth of an inch of the insulation on the other side is covered2 it is wound back and forth over the joint so as to taper toward the ends4 ,the other piece of tape is used1 beginning at the other end and wrapping as before4 ,the finished insulation should be thick at the middle and taper toward the ends4 ,it should be firm and tight4 ,the insulation is covered with tin foil1 wrapped with protective tape1 and vulcanized for about #cj seconds4 ,the protective tape and tin foil are then removed1 the joint inspected1 and new protective tape wrapped on1 using two pieces1 starting at opposite ends and finally ending each beyond the center4 ,making a ,turk's-head4--,the cable is trimmed square and a wrapping of four or five turns of marline is made about #ae inches from the end4 ,the collar1 flat side first1 is slipped on until it rests on the marline2 the iron wires are bent back regularly over the collar4 ,the jute wrapping is unwound to the collar and trimmed1 and all the iron wires are cut with the pliers1 removing all but #d inches and #f inches from alternate strands2 the iron wires are bent separately to fit the collar closely 7making two right angles with the pliers71 and the ends arranged smoothly along the cable2 the end of a piece of marline is engaged under one of the wires near the collar and wrapped regularly and closely around the cable1 and the free end of marline secured with two half hitches4 ,about #ae feet of marline are required for single conductor cable2 #bd feet for multiple cable4 ,testing fuses4--,the following apparatus is used for testing in the loading room3 ,a double-pole double-throw switch1 a #aej-volt voltmeter1 and sufficient dry cells to give a full throw when using the lower scale of the voltmeter4 ,the apparatus is connected up on the testing table so as to make resistance measurements by the voltmeter method4 ,to test fuses1 leads are carried from the switch to an iron or other suitable receptacle outside of the building and the fuse leads joined thereto4 ,a full deflection should be obtained when the circuit is closed through the fuses4 ,preparing a compound plug for service4--,the transformer to be used is first tested for a good circuit between the red wires1 a poor circuit between the ends of the black wire1 a good circuit between the black or primary lead and the reactance terminal1 no circuit between the red and black wires1 and no circuit between any wire and the case4 ,the resistance of the circuits is determined by the voltmeter method4 ,the upper end of the black wire 7see fig4 #h7 is prepared for use by baring the wire for about one-half inch and securing it to the binding post in the neck of the transformer4 ,the ball seat is screwed home4 ,the spring plate1 distance ring1 and ball are placed in the circuit-closer cap1 which is held inverted and the transformer screwed into it1 the threads being coated with ruberine4 7a7 ,old model1 brass fuse can4--,starting with the compound plug dismantled4 ,a piece of loading wire is cut about #c feet long and the ends bared4 ,one end is joined by a telegraph joint to the primary terminal of the transformer and the joint is taped4 ,this wire and the two secondary wires are drawn through the fuse can1 which is screwed on the transformer1 the threads of the latter having first been coated with ruberine4 ,two mine service fuses1 which have been tested for continuity of circuit1 are connected in multiple across the secondary 7red7 terminals and the joints taped4 ,the can is held vertically and the explosive1 if trotol1 poured in up to the screw threads for the fuse can cap2 if dynamite1 inclosed in a cloth bag and placed in the can4 ,the fuses are embedded in the explosive4 ,the loading wire is drawn through a lead washer and the fuse can cap2 the latter1 its threads having been coated with ruberine1 is screwed into place4 ,a rubber packing is pushed over the loading wire into the stuffing box in the fuse can cap1 a brass gland is threaded down so that it is close against the rubber packing1 and the follower is screwed home with moderate pressure4 ,the lower tube is screwed into place1 compressing a lead washer between it and the fuse can cap4 ,the threads of the follower and lower tube are coated with ruberine4 ,the loading wire is drawn through a lead washer and the hole in the plug proper1 and the latter screwed hard against the lower tube4 ,a rubber packing and a brass gland are placed upon the loading wire and forced into their seat in the plug proper by means of the follower1 the threads of which have been coated with ruberine4 7b7 ,rubber fuse can4--,starting with the compound plug dismantled4 ,two mine service fuses1 which have been tested for continuity of circuit1 are cut with #i-;inch leads1 wires bared for about #a inch and connected in multiple4 ,a piece of loading wire is cut about #c feet long and the ends bared for telegraph joints4 ,it is threaded through a hole in a cake of dry guncotton4 ,the two fuses are inserted by pushing each separately into the same hole and the loading wire drawn up until it is the same length above the cake as the fuse leads4 ,three other primer cakes are threaded on the wire2 two above the fuses1 and one below4 ,this arrangement will leave the fuses in the third cake4 ,the cakes are held in one hand with the fuse leads upright1 and the fuse can slipped over the cakes1 being careful to thread the fuse leads and loading wire through the opening4 ,the screw threads of the fuse can cap are covered with ruberine and it is screwed firmly into place onto the fuse can4 ,the stuffing box of the cap is assembled4 ,the plug proper is held upright in a vise4 ,the fuse can1 the threads of the cap having been coated with ruberine1 is screwed home and secured by its set-screw4 ,the loading wire must be pulled through the opening in the plug proper with extreme care4 ,it must not be injured in placing the fuse can in position and in screwing it home4 ,the transformer leads are cut about #f inches long1 and the ends bared for #a inch4 ,the brass collar is screwed on the transformer2 a little ruberine on the screw threads facilitates the operation4 ,the connecting collar is slipped over the fuse leads and loading wire and allowed to rest on the fuse can4 ,the transformer is supported by allowing two of the connecting bolts to slip into the holes in the collar2 telegraph joints or brass jointers may be used between the secondary leads and the fuses and between the primary lead and the loading wire4 ,the joints are wound with rubber tape1 care being taken that there are no sharp ends to cut through the tape4 ,the transformer is raised vertically above the fuse can until the lead wires are extended4 ,it is lowered and at the same time the leads are coiled in the base of the transformer4 ,as the transformer and collar approach their position on the connecting bolts1 the connecting collar is screwed on the transformer1 the threads of the transformer having been covered with ruberine4 ,the connecting collar will take care of the remainder of the leads and joints4 ,the set-screw in the connecting collar is screwed home2 the brass collar is placed on the connecting bolts and secured in position by the nuts and cotter pins4 ,the lips of the fuse can and connecting collar are covered with a thin covering of rubber cement4 ,a piece of rubber tape is cut about #ah inches long and laid around this opening without stretching4 ,a piece of protective tape is cut about #ah inches long and laid over the rubber tape with considerable stress4 ,this forces the soft tape over the lips on the connecting collar and the fuse can and makes a tight but flexible joint4 ,the stuffing box in the plug proper is prepared as under 7a74 ,great care must be taken not to injure the insulation of the loading wire in tightening up the follower in the stuffing box of the fuse can or of the plug proper4 7c7 ,trotol fuse can4--,starting with the compound plug dismantled4 ,two mine service fuses1 which have been tested for continuity of circuit1 are cut with #ab-;inch leads1 the wires bared for #a inch and connected in multiple4 ,a piece of loading wire is cut about #c feet long and the ends bared for telegraph joints4 ,the loading wire is threaded through the fuse can and cap4 ,the threads of the fuse can are covered with ruberine4 ,the can is screwed into the cap4 ,the threads of the connecting collar are coated with ruberine and the collar is screwed down entirely4 ,the loading wire should project about #d inches above the connecting collar4 ,the stuffing box of the cap is prepared4 ,the plug proper is held upright in a vise4 ,the fuse can cap1 its threads having been coated with ruberine1 is screwed firmly into the plug proper by means of a spanner wrench4 ,the loading wire must be pulled through the opening in the plug proper with extreme care4 ,it must not be injured in placing the fuse can in position and screwing it home4 ,the fuses are inserted in the fuse can1 which is filled with trotol to the top of the connecting collar4 ,the transformer leads are cut #d inches long and the ends bared for #a inch4 ,the threads of the brass collar are covered with ruberine4 ,it is screwed on the transformer4 ,the latter is raised vertically above the fuse can and lowered on the connecting bolts4 ,telegraph joints are made between the secondary leads and the fuses and the primary lead and the loading wire4 ,the joints are wound with rubber tape1 care being taken that no sharp ends cut through the tape4 ,the leads and joints are coiled in the base of the transformer4 ,the connecting collar1 its threads having been covered with ruberine1 is screwed upon the transformer against the brass collar4 ,the bolt-securing nuts and cotter pins are placed in position4 ,the stuffing box in the plug proper is assembled as under 7a74 ,the actual resistance of the assembled plug in the vertical and the horizontal positions is determined by testing with a voltmeter4 ,in service1 after the loaded plug tests out satisfactorily1 all set screws are set up4 ,when compound plugs are prepared for drill or for instruction purposes the use of ruberine or other waterproofing material on the screw threads is omitted2 care must be taken that the transformer leads are not needlessly shortened4 ,loading a mine4--,the mine case is carried from the storeroom to the loading room and placed on a loading skid or other receptacle with the loading hole up4 ,the plug is removed and the screw threads are thoroughly cleaned4 ,the explosive detail brings in a box of explosive from the explosive house and inserts a loading funnel into the loading hole4 ,the charge for a #cb-;inch mine case is #ajj pounds of explosive4 ,for the larger cases1 the charge should be the maximum that the conditions warrant2 it is specified at present as #bjj pounds1 though larger charges are desirable if enough explosive can be obtained and the excess buoyancy of the case will warrant the use of more than #bjj pounds4 ,the cartridges of dynamite1 the trotol1 or the blocks of guncotton are inserted by hand and so placed in the mine case that there will be ample room for inserting the compound plug4 ,only one box of explosive for each mine being loaded is brought into the loading room at one time4 ,after the proper amount of explosive has been placed in the mine case the screw threads are thoroughly cleaned with button brushes and then coated with ruberine or other material to prevent access of water4 ,the compound plug1 with its screw threads similarly coated1 is screwed home with the socket wrench1 a lead washer being used between the plug and mine case4 ,a bar put through holes in the sides of the skids and through the maneuvering ring will prevent the case from falling over and from turning while the compound plug is being screwed home4 ,in order to insure setting the compound plug tight1 it is advisable to tap the end of the lever of the socket wrench a few times with a large mallet or a large wooden bar4 ,the mine cap is bolted on and the mine put in a tank for test4 ,if time admits1 it may remain in the water #bd hours4 ,it should show practically the same resistance as the compound plug4 ,if this test be made1 the loading wire must be long enough for this purpose4 ,upon completion of this test the mine is taken from the tank1 the loading wire pushed inside the cap to avoid injury in handling1 and the loaded mine taken to the planting wharf4 ,the precautions to be observed in handling explosives and loading mines are given in ,appendix #a4 ,,chapter ,,iv4 ,,locating ,,distribution ,,box1 ,,laying ,,multiple ,,cable1 ,,and ,,marking ,,out ,,mine ,,field4 7,,note4--,the operations in ,chapters ,,iv and ,v are described in what is thought to be the logical order1 but circumstances may alter their sequence1 and1 in fact1 several of the steps may be carried on simultaneously47 ,for the work on the water there will be needed five boats1 viz41 a mine planter or suitably fitted-up heavy tug1 a small tug or heavy launch called the distribution box boat1 and three launches or yawls4 ,the capacity of the planter is such that a group of #ai mines can be handled at one time4 ,the instructions to be observed by the master of a mine planter in marking out a mine field and in planting mines are to be found in ,appendix ,no4 #f4 ,determining location for distribution box4--,from an examination of the chart1 or of the approved scheme for mining1 the locations of the lines and groups of mines are determined4 ,a distribution box is to be placed about #cej feet in rear of the center of each group of mines4 ,the locations for the distribution boxes are marked on the plotting board and their azimuths from each of the ends of the horizontal base or their azimuth and range from the vertical base station are determined4 ,marking location of distribution box4--,an anchor with buoy attached is placed upon the deck of a small tug and carried out to one of the selected spots4 ,by a system of signals the boat is directed to the location determined and there the anchor is thrown overboard4 ,the locations for the other distribution boxes are marked in a like manner4 ,laying multiple cable4--,the cable-reel is placed upon the forward deck of the planter and raised on the jacks4 ,the planter then proceeds as near the mining casemate as the depth of water permits1 and one end of the cable is passed ashore1 either by a launch1 by yawls1 or by any other suitable method4 ,in case the planter can not approach nearer the shore than #ajj yards it will be necessary to coil more than enough cable to reach the shore in a figure of eight in a yawl1 which is then towed toward the desired point on shore1 the men aboard the yawl paying out the cable as it proceeds4 ,this end is drawn in through the conduit or gallery to the casemate or terminal hut4 ,it may be secured by taking a telegraph hitch around it with a chain and spiking the chain to some heavy timbers or fastening it to some holdfast4 ,when cable ends have already been laid they will be picked up and joined to the multiple cable for the groups4 ,the shore end having been secured1 the planter moves out to the position of the distribution box1 unreeling the cable as it goes4 ,if the water be very deep1 a friction brake must be extemporized to prevent the reel from overrunning4 7,while the planter is laying the cable1 the casemate party tags and attaches the shore end as explained later47 ,to prevent kinks as far as possible cable should be laid with as much tension as practicable4 ,if the cable is not long enough1 a second one must be joined to it4 ,this is preferably done by passing the ends to a small boat4 ,the junction is made1 either using a junction box with ,turk's-heads and taped joints1 or opening back the armor for about #e feet from the ends1 making taped joints1 protecting them with tape1 and then rewrapping the armor and seizing the ends with wire4 ,care must be taken to join the proper conductors of the two ends4 ,in the meantime the distribution box boat with a detachment of one noncommissioned officer and five men takes the distribution box and moves out to the spot marked by the buoy4 ,it picks up the buoy and makes fast to the anchor line4 ,the planter continues laying the multiple cable until it reaches the distribution box boat4 ,the multiple cable is then cut and the end passed to the distribution box boat1 usually by a heaving line4 ,the cable is lashed to the boat2 a ,turk's-head is worked upon the end and then secured in the distribution box4 ,as a precautionary measure for the recovery of the distribution box1 should it be lost overboard during mine planting1 it is well to have the multiple cable buoyed about #ajj yards in rear of the distribution box4 ,in case it may be desired not to use the distribution box at once1 the separate conductors of the multiple cable should be tagged1 tested1 and insulated4 ,the cable should be buoyed and dropped overboard to be recovered subsequently4 ,identifying1 tagging1 and testing the conductors of the multiple cable4--,tagging4--,in the casemate the conductors are separated1 carefully identified1 tagged1 and attached to the corresponding terminal of the terminal bar on the operating board4 ,the mine switch for ,no4 #ai is opened and the telephone terminal attached to its stud so as to use ,no4 #ai for communicating with the distribution box boat4 ,the ends in the distribution box boat are separated1 one terminal of a boat telephone is attached to ,no4 #ai1 and the other earthed either by attaching to the cable armor or to an earth plate hanging overboard in the water4 ,communication is thus established with the operator in the casemate4 ,nos4 #a1 #ac1 and #ai are picked out easily2 the remaining ones are tagged in contraclockwise direction4 ,verifying the tagging4--,the casemate is then notified that the boat party is ready to check the tagging4 ,this is done as follows3 ,the power switches on the operating board are all closed1 except #ai1 and direct current put on the cable by closing switch ,no4 #c up4 ,the casemate operator then directs the boat party to earth in regular succession the various conductors4 ,this is done most quickly by touching the conductor to the cable armor4 ,the corresponding automatic switch on the operating board should drop4 ,any errors in tagging detected by this test should be corrected at once4 ,this test also checks the continuity of circuit of each conductor4 ,insulation test4--,the operator then directs the boat party to prepare the cable end for insulation test4 ,this is done by separating the conductors1 holding them in the air1 and drying them if necessary4 ,when prepared1 word is sent to the casemate operator1 who tests as follows3 ,he closes switch ,no4 #g up4 ,this throws ,d4 ,c4 power on the mil-ammeter plug of the operating board and introduces in the circuit the mil-ammeter and its protective lamp4 ,the green lamp is then unscrewed and the mil-ammeter plug used on the ,d4 ,c4 jaw4 ,if there be no leak in the multiple cable1 since the ends at the distribution box boat are held in the air1 there will be no appreciable reading of the mil-ammeter4 ,if there be a leak1 this fact will be revealed by a reading on the mil-ammeter4 ,to discover the particular conductor or conductors on which this leak exists1 each power switch is opened in succession and the mil-ammeter plug inserted on the jaw of the power switch4 ,no4 #ai is now tested in the same way by first shifting both telephones to ,no4 #a1 the boat end being held in the air4 ,the operator reports the result of the test4 ,upon completion of these tests the power is turned off4 ,post power should not be used for testing1 because the negative side of the post power may be grounded4 ,marking out the mine field4--,in using automatic anchors it is not necessary to mark the mine field2 but in using mushroom anchors it is generally done4 ,the material required consists of #a measuring line with reel and frame1 #e anchors1 #e keg buoys1 and #e raising ropes4 ,a buoyed anchor is dropped about #cej feet in front of the distribution box buoy4 ,this marks the position of mine ,no4 #aj and of the center of the group4 ,this marking buoy is picked up by a launch which makes fast to the anchor rope4 ,the planter now passes to the launch one end of a measuring line1 which has marks at #bhj1 #cjj1 #cej1 #ehj1 and #fjj feet4 ,these marks may be made by painting #c feet of the measuring line some distinctive color at the designated points4 ,the planter moves out slowly along the line to be occupied by the mines1 unreeling the measuring line as it goes1 and drops buoys at the #cjj and #fjj foot marks4 ,it then returns and does the same for the other side of the line4 ,these five buoys mark the line to be occupied by the mines1 indicate the positions of mines ,nos4 #d1 #g1 #aj1 #ac1 and #af1 and in addition cut up the distance into #cjj-;foot lengths1 which enable the planter to plant mines at a close approximation to #ajj feet apart4 ,taking soundings on line of mines4--,when automatic anchors are used1 such information as may be required about depth of water may usually be obtained from charts4 ,this may not be sufficiently accurate for planting with ordinary anchors4 ,in the latter case soundings must be taken at the spots where the mines are to be planted4 ,these soundings are made from the launches4 ,the launches take a measuring line marked at every #ajj feet1 stretch it between the planted buoys1 and take the soundings at every #ajj-;foot point4 ,the soundings are recorded in a blank book showing the number of the corresponding mine and state of the tide4 ,it may be found more satisfactory to hold one end of the measuring line at the buoy and circle across the line of mines with the launch1 getting the sounding at the point of crossing4 ,preparing mooring ropes4--,the mooring ropes are cut off with square ends1 and the ends passed through the holes in the mooring sockets4 ,the strands and wires are untwisted and spread out for a length equal to the length of the socket hole4 ,the rope is pulled back until the ends are about flush with the top ends of the hole2 a piece of marline is tied about the rope below the socket4 ,if necessary to hold the socket1 a piece of burlap may be wrapped around below the socket1 and a fold allowed to fall over the hand4 ,generally1 means can be found to set the socket upright while pouring full of alloy4 ,the alloy consists of #i parts of lead and #a part of antimony melted together4 ,a melting pot heated by a plumber's furnace1 or preferably a ,khotal lamp1 is used for this purpose4 ,great care must be taken to see that there is no oil or water on the socket or mooring rope before pouring the alloy4 ,the length of the mooring rope for buoyant mines ,no4 #cb equals the depth at low tide1 less #ae feet4 ,this allows #e feet for the length of the mine1 anchor1 and shackles1 and #aj feet for submergence4 ,when thimbles and clips are used the mooring rope is cut #c feet longer and is bent back a foot and a half at each end for the thimbles and clips4 ,for the larger mine cases1 an additional allowance must be made for the length of the cylindrical part of the case4 ,each mooring rope is carefully tagged at each end with the number of the corresponding mine4 ,,chapter ,v4 ,,assembling ,,and ,,planting ,,mines4 ,,note4--,the instructions to be observed by the master of a mine planter in marking out a mine field and in planting mines are to be found in ,appendix ,no4 #f4 ,the planter detail4--,this consists of the chief planter and #c noncommissioned officers and #af privates1 distributed in three details1 as follows3 ,one noncommissioned officer and six privates on each side of the planter and one noncommissioned officer and four privates aft4 ,tools and supplies4--,the tools and supplies to be taken aboard for the work described are3 ,on the planter4 ,alcohol4 ,anchors4 ,axe4 ,boat hooks4 ,buoy1 key4 ,buoys1 mine4 ,cable cutter4 ,cables1 multiple4 ,cables1 single conductor4 ,cable tags4 ,clips1 cable4 ,cotter pins4 ,crank handle for automatic anchor4 ,dry cells4 ,grappling hooks4 ,hammers4 ,heaving lines4 ,kerosene4 ,knives1 submarine mine4 ,lamps1 alcohol 7#b74 ,life buoys 7#c74 ,marline4 ,marlinespikes4 ,matches4 ,megaphone4 ,mines4 ,monkey wrenches4 ,nuts4 ,ropes1 mooring4 ,ropes1 raising4 ,shackles1 anchor4 ,shackles1 mine4 ,shoes1 mine-cap4 ,sister hooks4 ,spring balance4 ,stamping outfit4 ,tools and materials necessary to make ,turk's-heads and joints4 ,voltmeter4 ,washers4 ,waste4 ,wire1 soft-drawn copper4 ,wrench1 socket1 for automatic anchor4 ,on distribution box boat4 ,alcohol4 ,anchors1 boat 7#b74 ,axe4 ,boat hook4 ,boat telephone with connectors and earth plate4 ,breaker of drinking water4 ,buoy4 ,cable tags4 ,compass1 boat4 ,distribution box4 ,flags1 boat 7#b74 ,gasoline 7tankful74 ,green light4 ,hammers4 ,heaving lines4 ,kerosene4 ,knives1 submarine mine4 ,lamps1 alcohol 7#b74 ,lashings4 ,life buoys 7#b74 ,life preservers1 one for each man4 ,marline4 ,marlinespike4 ,matches4 ,megaphone4 ,monkey wrenches4 ,notebook and pencil4 ,red light4 ,rope1 raising4 ,ropes1 buoy 7#b74 ,shackles4 ,tools and materials to make ,turk's-heads and joints4 ,waste4 ,white lights 7#b74 ,in each yawl4 ,anchor1 boat4 ,anchor line4 ,boat hook4 ,heaving line4 ,life buoy4 ,life preservers1 #a for each man4 ,marline4 ,megaphone4 ,oars and locks 7#g74 ,sounding line4 ,preparing mine cables4--,a reel of single-conductor cable is taken from the tank and placed on a cable-reel frame4 ,a piece #bj feet long is cut off the end to eliminate the part which was above water during storage4 ,the cable for the mines is now unreeled1 cut to the following lengths plus twice the approximate depth of the water1 and each end carefully tagged with the number of the corresponding mine4 ,a ,turk's-head is made on each end4 ,feet4 ,feet4 ,no4 #a #a1dbe ,no4 #aa #dbe ,no4 #b #a1bbe ,no4 #ab #dge ,no4 #c #a1jbe ,no4 #ac #ebe ,no4 #d #hbe ,no4 #ad #fbe ,no4 #e #gbe ,no4 #ae #gbe ,no4 #f #fbe ,no4 #af #hbe ,no4 #g #ebe ,no4 #ag #a1jbe ,no4 #h #dge ,no4 #ah #a1bbe ,no4 #i #dbe ,no4 #ai #a1dbe ,no4 #aj #cge ,the mine cables are coiled in figure #h's4 ,in order to secure uniformity in the size of the coils1 they may be coiled on a rack 7improvised at the post74 ,this rack is made of one #ab-;foot length of #d by #f-;inch scantling1 crossed at right angles by two #f-;foot lengths 7#d by #f inch7 placed #e feet apart4 ,four #a-;inch holes are bored through each of the timbers about #b feet from each of the crossings1 and a #b-;foot length of gas pipe is inserted in each hole4 ,these pipes make the form on which the coils are made4 ,a cable must be coiled for planting so that both ends are free1 one to be passed to the distribution box boat1 the other to be carried forward on the planter and attached to the mine4 ,this is accomplished by starting the coil about #ace feet from the mine-cap end1 the approximate length required to run forward when using a mine planter4 ,the cable is coiled on the form1 spreading out the laps at the center to reduce the height at that point1 until the entire length is coiled4 ,the outer loops and the center of the figure #h coil are lashed1 leaving the ends sufficiently long to lash the part of the cable remaining uncoiled4 ,the mine-cap end of the cable is then coiled on top of the coil and lashed with the ends of the rope4 ,single-conductor cables when coiled should be tested for continuity of circuit and grounds before being placed aboard the planter4 ,for continuity of circuit the two ends of the cable are connected to a battery and voltmeter in series4 ,if the cable has no break1 the reading of the voltmeter should show approximately the same deflection as when the battery circuit and voltmeter alone are in circuit4 ,to test for a ground the cable is submerged in a testing tank1 leaving both ends out4 ,it is advisable1 when practicable1 to extend a lead from one of the operating boards of the mining casemate to the cable tank4 ,one end of the cable to be tested is connected to this lead and the test made as prescribed for 8insulation test0 on page #dd4 ,the condition of a multiple-conductor cable can be quickly determined by this arrangement4 ,if the above method is not practicable1 a dry-cell battery with a mil-ammeter and protective lamp may be installed at the cable tank2 or1 in place of the mil-ammeter and lamp1 a voltmeter placed in series with the battery and cable may be used1 the resistance being obtained by the voltmeter method4 ,one side of the battery should be grounded by touching the cable armor or by using an earth plate4 ,in actual service1 cable which tests under #a megohm should not be used2 for practice1 cable under #aj1jjj ohms should not be used4 ,if post power is used as a source of energy for testing1 the system should be free from grounds4 ,care should be taken to have the cable ends and battery leads free from grounds and dry4 ,cables are raised and lowered into the tank by means of a cable yoke1 which consists of an #aa-;foot length of #d by #f inch scantling1 with three hooks on the lower side and a ring on the upper side at the center for hoisting4 ,the lower hooks1 which are secured to the scantling by a bolt and ring1 hook into the lashing on the cable4 ,washers are placed under the bolt heads to prevent their slipping through the holes4 ,swinging or traveling cranes with triplex blocks are used for lowering and raising cable and yoke4 ,the coils of single-conductor cable are carried aboard the planter1 to the aft deck1 by the cable detail1 or they may be lowered onto the deck by means of the cable yoke and a derrick on the wharf4 ,the cable for mine ,no4 #a is placed on the starboard side of the aft deck and its mine-cap end is carried forward on the cable racks close to the mines4 ,the other cables1 ,nos4 #b to #i1 inclusive1 are placed in succession on the starboard side in the same manner4 ,the cables1 ,nos4 #ai to #aj are placed in succession on the port side1 with ,no4 #ai at the bottom4 ,the coils on each side are placed on top of each other4 ,the cable should be removed from the racks when its corresponding mine is being prepared for planting4 ,at the same time the other apparatus and appliances are carried aboard and placed forward1 the proper supply on each side4 ,the anchors are placed as convenient to the forward davits as possible4 ,finally1 the loaded mines are put aboard4 ,if they contain dynamite they should be protected from the direct rays of the sun by being covered with a paulin4 ,preparing mines for planting4--,the detail on each side of the planter prepares a mine on its own side4 ,the loading wire from the mine is cut to the proper length1 a water-tight joint is made with the single conductor of the corresponding cable1 and the ,turk's-head is clamped in place1 care being exercised that no part of the leading-in wire is caught under the clamp4 ,the cable is lashed with soft-drawn copper wire or secured by clips to the bails just above the ring4 ,the proper mooring rope is now shackled at one end to an anchor1 at the other end to the mine1 and is lashed to the mine cable with soft-drawn copper wire at every #e feet4 ,if automatic anchors be used1 the mooring rope is shackled to the mine after the anchor and mine are swung outboard2 the lashing of the cable to the mooring rope is omitted4 ,a rope for raising the mine is cut to the length of #hj feet plus the depth of water4 ,one end is attached to the anchor by an anchor knot or bowline1 the other to the mine cable by two half hitches and a seizing of soft-drawn copper wire4 ,it should not be secured at other points4 ,the mine buoys have attached to them #fj feet of -inch rope1 which is marked at every #e feet4 ,the free end is slipped through the maneuvering ring of the mine and tied to the buoy4 ,when planting mines for practice1 marline may be used to seize the raising rope to the cable and to lash the cable to the bail and mooring rope4 ,a mousing must be put around the upper hook of the differential block to prevent the block from jumping off the hook when the mine or anchor is tripped4 ,the tripping hook of the differential block on the forward davit is attached to the anchor and it is hoisted and swung outboard clear of the rail4 ,the mine is similarly slung from the after davit by its maneuvering ring or by a rope sling through the latter4 ,both mine and anchor are lowered as close to the water as conditions will permit4 ,a heaving line is bent onto the free end of the mine cable1 generally by means of a clove hitch and two half hitches4 ,the aft detail now removes or cuts the rope lashings of the coil of the corresponding mine cable4 ,a detail sees that the cable and raising rope are held on the gunwale ready for planting4 ,these should not be allowed to trail in the water4 ,a man stands near the mine davit ready to throw the mine buoy clear of the planter when the mine is tripped4 7,fig4 #ac shows the mine and anchor slung for planting and fig4 #ad shows the relative position of the various parts in the water4 ,in these figures the cable should be shown as lashed to the mooring rope47 ,the distribution box boat should precede the planter to the mine field4 ,the distribution box buoy1 to which the anchor rope is fastened by a bowline1 to the bight of which the raising rope is secured1 is taken aboard at the bow1 if the tide is coming in toward the box1 and the anchor rope is made fast4 ,the distribution box is then raised by its raising rope and secured in the stern4 ,the boat is thus anchored fore-and-aft1 perpendicular to the line of mines1 with its bow pointed toward the position of the center mine of the group4 ,if the tide is running out from the box1 the buoy should be taken in at the stern1 the boat being held in position by the raising rope of the distribution box and then by the multiple cable4 ,the anchor rope is finally made fast in the bow4 ,during the planting of mines a man should always stand ready to slacken away on the anchor rope if necessary4 ,illustration3 ,,fig4 #ac4--,,mine ,,ready ,,for ,,planting4 ,illustration3 ,,fig4 #ad4--,,mine ,,planted4 ,if the buoy for the distribution box is not in place1 the cable must be underrun1 either from shore or from a buoy planted for this purpose4 ,this is done preferably with a yawl4 ,the cable is raised1 taken aboard1 and placed over a roller or rowlock in the stern4 ,the cable is then pulled in over the stern and lowered over a roller or rowlock in the bow4 ,if the planter is to underrun cable1 a cathead is put in place and a snatch block is lowered by a raising rope secured to a hoisting windlass4 ,the cable is placed in the snatch block and the planter moves forward slowly4 ,when it is desired to transfer the cable to a small boat the snatch block is lowered into the boat and the cable removed4 ,after the distribution box boat has secured the box in position1 the lid is removed and the cable is tested as prescribed on page #dd4 ,a signal is then raised to indicate to the planter that the distribution box boat is ready for the planting of mines4 ,planting the mines4--,if there be a strong tide1 the mines should1 if possible1 be planted at such time that the planter1 in going out toward the line of mines1 moves against the tide4 ,the planter moves out and passes close to the distribution box boat1 with the latter to port4 ,as it passes slowly by1 a heaving line is thrown by a man forward of the beam to the distribution box boat1 whose party immediately hauls in the mine cable1 bends on another heaving line1 and lashes the cable to the boat4 ,it is desirable to have a second heaving line ready in case the first one fails4 ,if the water be rough the cable end is passed to the boat by a launch4 ,the planter moves forward to the position to be occupied by mine ,no4 #aj4 ,if automatic anchors are used1 the distance weight is lowered at the command 8,lower weight10 given after the cable is secured in the distribution box boat4 ,as the planter approaches this position the command 8,get ready0 is given4 ,as the forward davit comes abreast of the position of ,no4 #aj mine1 the officer in charge of the planting commands 8,let go02 the tripping hook of the mine is released first and that of the anchor immediately thereafter4 ,the mine buoy1 cable1 and raising rope are then thrown overboard4 7,caution4--,the men operating the tripping hooks must be very careful that they stand back of all cable and rope1 so that they may not be caught4 ,all others must stand clear47 ,the planter turns so that the stern will be thrown away from the planted mine4 ,when the stern is clear of the mine buoy 8,all clear0 is signaled from the stern4 ,the planter then executes a sweeping circle to starboard1 passes to the rear1 and comes up with the distribution box boat to starboard4 ,as it moves by1 the free end of mine cable ,no4 #i is passed to the boat and secured as before4 ,the planter moves ahead to a point #ajj feet to the left of mine ,no4 #aj1 and as it crosses the line1 plants mine ,no4 #i1 swings off to port1 circles and comes up from the rear with the distribution box to port1 and so on alternately until all the mines are planted4 ,as soon as a mine is dropped the detail for that side of the planter prepares another for planting4 ,there is ample time to do this while the vessel is turning and planting the other mine4 ,two small boats1 one on each side of the line1 work as follows3 ,as soon as a mine is dropped the boat on the corresponding side moves to it1 picks up the buoy1 pulls the rope taut1 notes the submergence of the mine1 transmits the data to the planter1 and holds up an oar or a flag in prolongation of the buoy rope4 ,the observers at the ends of the base line take observations on this marker and are thus able to plot the position of the mine accurately4 ,this process is repeated for each mine4 ,these boats also serve as guides to the planter in dropping mines by holding on to their buoys until the adjacent mines are planted4 ,with automatic anchors the line may not be marked otherwise than in this manner4 ,after the mine is dropped1 the members of the distribution box boat party remove the lashing from the cable1 insert the ,turk's-head in the proper slot1 make a temporary joint between it and the corresponding conductor of the multiple cable1 and telephone to the casemate operator4 ,the latter opens all the power switches on the corresponding operating board1 closes switch ,no4 #g up 7this throws ,d4 ,c4 power on the mil-ammeter lead71 and then plugs in on the upper jaw of the power switch of the mine under test4 ,if the ,d4 ,c4 voltage be #aaj1 the mil-ammeter should read about #dj mil-amperes2 if the voltage be #hj1 the reading should be about #cj4 ,if this test be satisfactory1 the joint is made permanent4 ,for the last mine the telephones are removed from the corresponding conductor1 a temporary joint is made in the boat1 and the test made as above4 ,by arrangement with the casemate operator the mine is left on two minutes for test4 ,at the end of this time the joint is opened and the telephones put back4 ,if the casemate operator reports the test satisfactory1 the telephones are again removed and a permanent joint is made4 ,when the last joint has been made1 the distribution box is closed and the raising rope fastened to its lid4 ,the box is then lowered4 ,this is done by the distribution box boat if it is provided with the necessary davit and power1 otherwise it is done by the planter4 ,generally the anchor rope is made fast to a buoy by a bowline1 and the raising rope of the distribution box is secured to the bight of the bowline4 ,after the distribution box is lowered all buoys are removed except that for the box1 and such others as it may be desired to place for marking the ends of lines4 ,the marking boats may remove the mine buoys as they work1 provided they are notified from the mine commander's station that proper observations for plotting have been obtained4 ,such notification is usually sent by telephone to the distribution box boat4 ,in time of war decoy buoys judiciously placed would be very useful in deceiving the enemy4 ,,chapter ,,vi4 ,,tests ,,of ,,mines ,,and ,,apparatus4 ,after the mines have been planted the following tests are made daily1 or more frequently if need be1 the results being recorded carefully on the form given at the end of the chapter4 7,note3 ,this applies also to such test mines as may be kept planted for purposes of observation and instruction47 ,caution4--,if ,a4 ,c4 power be supplied from the casemate motor-generator1 there is no possibility of accidental firing of mines if the motor-generator is not running2 and when it is running the chance is remote1 since it would require the committing of three blunders4 ,however1 the following precautions must be enforced rigidly3 7a7 ,never start the motor-generator during the planting of mines nor when any friendly vessels are in the neighborhood of the mine field4 7b7 ,before starting the motor-generator for testing it1 see that all automatic switches are up1 all firing switches open1 and the ,a4 ,c4 operating switch 7,no4 #h of the power panel7 open4 #a4 ,test of the ,d4 ,c4 voltage4--,plug in at the proper receptacle and read the voltmeter4 #b4 ,test of the ,a4 ,c4 voltage4--,caution4--,first see that all automatic switches are up1 that the firing switches are open1 and that the ,a4 ,c4 operating switch ,no4 #h is open4 ,close switch ,no4 #d up2 close starting switch of motor-generator1 and when the latter has attained its full speed close switch ,no4 #i up2 plug in at the proper receptacle1 and read the voltmeter4 ,when the source of power is the storage battery1 the battery rheostat should be adjusted until the ,a4 ,c4 voltage is #ejj or above2 when the casemate generator is used1 its field rheostat should be adjusted for the same purpose4 #c4 ,test of the mines4--,leakage in mine circuits will be indicated automatically by an increased brightness of the green lamp on the signal block2 an excessive leakage in any mine circuit may cause the automatic switch to trip4 ,however1 each mine should be tested separately1 as follows3 ,with the ,d4 ,c4 on the ,d4 ,c4 busses of the power panel1 close switch #g up1 open the power switch on the mine block of the mine circuit to be tested1 and put the ,m-,,am 8plug0 on the upper point of the power switch4 ,if the automatic switch falls1 adjust the solenoid or hold the switch up while testing the circuit1 otherwise the reading obtained will be that of the red lamp and bell circuit4 ,these operations put the mil-ammeter and its protective lamp in series with the mine circuit4 ,the circuit is as follows3 ,from the negative ,d4 ,c4 bus on the power panel1 to switch #g closed up1 through the mil-ammeter and its protective lamp1 to the terminal bar1 to the ,m-,,am lead1 to the plug1 to the upper point of the power switch ,p1 through the solenoid1 to the middle of the testing switch ,t1 to the upper point of same1 to the upper point of the automatic switch1 to the middle of same1 to the mine switch1 through same1 to the terminal bar1 through the #ai-;conductor and the single-conductor cables1 to the mine transformer primary1 to the mine case1 to ground1 to the ,d4 ,c4 8earth0 terminal on the power panel1 to switch #g1 and to the positive ,d4 ,c4 bus on the power panel4 ,with from #hj to #aaj volts these readings should normally be between #cj and #dj mil-amperes4 ,a mine may be fired if the reading with #hj volts is between #ad and #abj mil-amperes4 ,these limits increase with the testing voltage4 ,if the mine tests within the firing limits1 the solenoid should be adjusted if the current is above its normal setting 7#j4jge amperes74 ,if the test indicates that the mine can not be fired1 the mine switch should be opened4 #d4 ,test of the automatic switch1 red lamp1 and bell4--,throw the ,d4 ,c4 power on the busses of the operating board by closing switch #c up4 ,open the bell switch4 ,next close the testing switch down on the mine block under test4 ,the red lamp should glow and the corresponding automatic switch trip4 7,for circuit see fig4 #ah47 ,now close the bell switch1 throwing the bell in parallel with the red lamp2 the bell should ring4 ,next open the bell switch and repeat the test for each mine block in turn4 #e4 ,test of the alternating circuit4--,this circuit is tested with ,d4 ,c41 as follows3 ,connect the ,a4 ,c4 and ,d4 ,c4 jaws on the master block with a jumper1 open the power switches1 close switches #c1 #h1 and #i up on the power panel4 ,the green and white lamps of the operating board under test should glow4 ,a break or an excessive resistance in the casemate grounds1 or elsewhere in the circuit1 will be indicated by the lamps not glowing1 or glowing dimly4 ,the circuit is as follows3 ,from the negative ,d4 ,c4 bus on the power panel1 to switch #c1 to the 8operating board0 terminal1 to the ,d4 ,c4 lead1 to the ,d4 ,c4 post on the signal block1 through the green lamp1 to the ,d4 ,c4 jaw on the master block1 through the jumper1 to the ,a4 ,c4 jaw on the master block1 through the white lamp and resistance in parallel1 to the ,a4 ,c4 post on the signal block1 to the ,a4 ,c4 lead1 to the ,a4 ,c4 8operating board0 terminal1 to switch #h1 to the ,a4 ,c4 bus1 to switch #i1 to the casemate transformer secondary1 back to switch #i1 to the other ,a4 ,c4 bus1 back to switch #h1 to the ,a4 ,c4 earth1 through ground1 to the ,d4 ,c4 earth1 to switch #c1 and to the positive ,d4 ,c4 bus on the power panel4 ,with this circuit on1 remove the #ij-ohm resistance in parallel with the white lamp2 the white lamp should glow more brightly1 indicating continuity of circuit through the resistance as well as the white lamp4 ,it will be observed that the above test is for only a part of the ,a4 ,c4 circuit4 ,to test the firing switch and the lower contact of the automatic switch1 open switches #c1 #h1 and #i1 close #g up1 remove the jumper1 put the ,m-,,am 8plug0 on the ,a4 ,c4 jaw on the master block1 close the firing switch1 and trip in turn each automatic switch by raising the corresponding knob on the solenoid and observe the reading of the mil-ammeter4 ,close each automatic switch up before tripping the next one4 ,the mil-ammeter reading should be from #cj to #dj mil-amperes1 indicating a circuit through the firing switch and the automatic switch4 ,the circuit is as follows3 ,from the negative ,d4 ,c4 bus on the power panel1 to switch #g closed up1 through the mil-ammeter and its protective lamp1 to the operating board terminal1 to the ,m-,,am lead1 to the 8plug10 to the ,a4 ,c4 jaw on the master block1 through the firing switch ,f4 ,s41 to the ,a4 ,c4 bus on the operating board1 to the lower point of the automatic switch which was tripped1 to the middle of same1 to the mine switch1 through the same1 to the terminal bar1 through the #ai-;conductor and the single-conductor cables1 to the mine transformer primary1 to the mine case1 to ground1 to the ,d4 ,c4 8earth0 post on the power panel1 to switch #g1 to the positive ,d4 ,c4 bus on the power panel4 #f4 ,test of the delivery of the ,a4 ,c4 power to the operating board4--,see that all the automatic switches of the operating boards are up and all the firing switches of the master blocks open4 ,close switches #d and #i up 7or down7 and #h down2 close the testing switch ,t4 ,s4 on the master block4 ,the white lamp should glow and the ,a4 ,c4 bus-bar voltage should drop appreciably4 ,the circuit is as follows3 ,from the ,a4 ,c4 bus on the power panel1 to the lower right terminal of switch #h1 to the 8operating board0 terminal1 to the ,a4 ,c4 lead1 to the ,a4 ,c4 post on the signal block1 to the white lamp and the resistance in parallel1 to the ,a4 ,c4 jaw on the master block1 to the testing switch ,t4 ,s41 to the 8earth0 post on the signal block1 to the earth lead1 to the ,d4 ,c4 earth1 through earth1 to the ,a4 ,c4 earth terminal on the power panel1 through the choke coil1 to switch #h1 to the other ,a4 ,c4 bus on the power panel4 ,in this test it is imperative to see that all the automatic switches are up and all the firing switches are open4 #g4 ,test of the power4--,insert two fuses in multiple across the fuse leads from the power panel4 ,put the fuses in a place prepared for the purpose outside of the casemate1 so that there will be no danger from flying fragments4 ,with all the switches on the power panel open1 all the automatic switches up1 and the firing switches on the master blocks open1 energize the ,d4 ,c4 busses of the power panel1 close switch ,no4 #d up 7or down71 and close the starting switch2 close switch ,no4 #i up 7or down72 close switch ,no4 #ab up 7which connects the mine transformer secondary to the fuses72 and1 finally1 close switch ,no4 #aa up 7which throws the ,a4 ,c4 power on the mine transformer primary74 ,the fuses should explode4 ,if fuses are not available for this test1 a low-voltage lamp or a short piece of fine wire may be heated to incandescence4 #h4 ,test of grounds4--7a7 8,separate0 grounds shall be made for the ,a4 ,c4 power and the ,d4 ,c4 power on the power panel4 ,the word 8separate0 as here used means actual connection to earth without metallic contact of the earth leads4 ,a convenient method of making a ground is to connect to the armor of a cable running to salt water1 a bond being made in case the armor of the cable in the casemate does not reach water before a joint is made4 ,if a cable armor is used for one ground1 the other ground lead must go to earth without contact with that armor4 ,this may be accomplished by using the conductors of a cable1 the ends of which are grounded to an earth plate in salt water4 7b7 ,neither of the grounds made should have more than #aj ohms resistance4 ,to verify this1 tests should be made as follows3 ,close the double circuit breaker2 close switch #g up and plug the extension cord of the mil-ammeter lead of the power panel on the upper left-hand terminal of switch #h1 the mil-ammeter extension cords for the operating boards being disconnected4 ,ascertain the voltage across the mil-ammeter and lamp1 and across the bus bars4 ,read the mil-ammeter4 ,from these readings the combined resistance of the grounds can be determined4 ,a table or chart may be prepared giving the resistances for various testing voltages and mil-ammeter readings4 ,illustration3 ,form for record of tests1 ,group ,no4 ,,chapter ,,vii4 ,,taking ,,up ,,mines4 ,mines should be raised in the reverse order from that in which they were planted if the conditions of wind and tide are favorable4 ,with a cross tide or a strong cross wind1 the mines should be taken up in regular order from one side so that the planter will not drift onto the mine field4 ,a yawl or launch takes position at the outer mine on each side4 ,the mine-buoy rope is hauled up taut in order to locate the exact position of the mine4 ,the boat holds fast until directed from the planter to let go4 ,while the anchor and mine are being taken aboard the planter1 the boat remains off the bow to render assistance if necessary4 ,the distribution box is raised by underrunning the multiple cable1 or by means of its raising rope if the buoy has not been removed4 ,the box is taken aboard the distribution box boat1 the lid is removed1 and the mine cables1 in turn1 disconnected from the multiple cable4 ,the planter passes close to the distribution box boat4 ,a heaving line which has been made fast to the outer mine cable is thrown to the bow of the planter4 ,if this should fail1 a man throws a heaving line from the bow of the planter4 ,if the conditions be unfavorable for passing a heaving line1 a launch may carry the line to the planter4 ,the heaving line attached to the cable is hauled aboard and the cable placed over the cathead4 ,the planter then proceeds to underrun the cable4 ,if the water be shallow1 the cable is carried through a snatchblock to the aft deck and coiled1 or it may be carried to a cable-reel forward4 ,if the water be deep1 or the cable can not be raised easily by hand1 it is carried through a snatchblock to the drum of a hoisting windlass and coiled as before mentioned4 7,if placed on a cable-reel1 the ends should be insulated and tagged4 ,mine cables ,nos4 #a to #i should be placed on one reel and ,nos4 #aj to #ai on another1 both reels being carefully marked47 ,when the raising rope is reached1 it is carried with the cable over the cathead4 ,the bight of the rope is hauled in quickly1 carried through a snatchblock1 and a few turns taken on the drum of a hoisting windlass4 ,the rope is untied from the cable as soon as possible4 ,if there be danger of losing the rope1 it should be made fast at once4 ,the anchor is raised until within a few feet of the cathead4 ,it is lifted aboard by means of the boom1 or by the differential block on the anchor davit4 ,at the same time a man is sent over the side of the planter near the mine davit 7a rope ladder may be used7 to secure the hook of the differential block in the sling attached to the maneuvering ring of the mine when it comes to the surface4 ,to bring the mine to the proper place to accomplish this1 a man should be ready to secure the mine-buoy rope with a boathook2 other men should be ready to pull the mine forward1 if necessary1 by means of the cable4 ,the mine is raised by the differential block of the mine davit4 ,it may be raised by the boom and fall2 or by means of a tackle secured to the mine davit1 the end of the rope running through a snatchblock to the drum of a windlass4 ,the distance weight of the automatic anchor may be raised by the fall of the boom1 or by an improvised tackle4 ,an eye should be made in the distance rope for this purpose4 ,if the end of the cable is lost1 the work may proceed as follows3 ,the planter moves out to the mine if its buoy is still in place4 ,a sling made of raising rope may be thrown over the mine1 or two raising ropes are tied together and one end is passed to a launch which moves around the mine and brings the end back to the planter4 ,both ends are placed over the cathead1 through a snatchblock1 and around the drum of a hoisting windlass4 ,the mine is hoisted1 bail up1 until near the cathead4 ,it can then be transferred to the anchor davit4 ,the mine cable is pulled in until the raising rope is reached4 ,the work then proceeds as before4 ,if the mine buoy has been removed1 a yawl may drag for the cable with a grappling iron4 ,if the raising rope should break or be lost1 the mine may be raised as mentioned above1 except that the mine must be transferred to the fall of the boom and the anchor raised by means of its mooring rope1 or the mine may be transferred to the anchor davit1 as before1 and a raising rope made fast to the mooring rope of the anchor and carried over the cathead1 through a snatchblock1 to a hoisting windlass4 ,the mine1 as soon as the strain is taken up by the raising rope1 is unshackled4 ,the anchor is then taken aboard in the usual manner4 ,as soon as the mines are taken aboard they are disconnected1 the ropes are coiled1 and all matriel placed so as not to interfere with subsequent work4 ,as soon as the matriel is unloaded on the wharf it should be cleaned thoroughly and stored4 ,if the multiple cable is to be left down1 the ends of the conductors are insulated1 the lid replaced1 and the box lowered by means of a raising rope1 the end of which is made fast to the bight of the bowline of the anchor rope4 ,if the multiple cable is to be taken up1 the end is passed to the planter1 run through a large snatchblock on the bow1 and coiled on a cable-reel as it is raised4 ,whenever a multiple cable is coiled on a reel it should be secured so that both ends will be available for test when the cable is stored4 ,unloading mines4--,should any of the mines be loaded with dynamite the utmost care must be exercised in unloading them4 7,see p4 #gf47 ,some contrivance must be rigged up so that the first few turns of the compound plug may be accomplished by the operator at a distance1 as there is great liability of explosion1 due to leakage of nitroglycerin into the screw threads4 ,after the compound plug is removed the precautions to be observed are given in ,appendix ,no4 #a4 ,should the mine be loaded with guncotton or trotol1 no danger is to be apprehended in unloading2 the usual precautions in handling high explosives must1 of course1 be observed4 ,,chapter ,,viii4 ,,the ,,mine ,,command4 ,a mine command consists of the mine groups and rapid-fire batteries specifically assigned for their protection1 which are controlled by a single individual4 ,the mine commander is in direct command of the elements of the mine defense during drill and action4 ,his station is at the mine primary1 which is connected by telephone to the battle commander's station4 ,he bears the same relation to the battle commander as do the fire commanders1 and his duties are similar to theirs4 ,the mine commander is responsible that the property officer requests for all matriel necessary to carry out the approved scheme for mining the harbor2 he is responsible1 further1 that the property officer keeps this matriel in proper condition for immediate service4 ,the senior company officer of the mine command is the property officer and obtains from the district artillery engineer all necessary matriel for the mine defense4 ,he has direct charge of the storeroom1 cable tanks1 loading room1 wharves1 boats1 boathouses1 and mining casemate4 ,the personnel of the mine companies are subject to his orders for service in connection with caring for and maintaining this matriel4 ,the officers of the companies of the mine command will be assigned by the mine commander in accordance with their special fitness4 ,the enlisted personnel of mine companies will be divided into sections1 detachments1 and details1 as follows3 7a7 ,fire-control and power section4 7b7 ,planting and loading section4 7c7 ,gun and ammunition sections4 7d7 ,reserve section4 ,these will be subdivided as follows3 7a7 ,fire-control and power section3 #a4 ,observing detachment-- a4 ,m detail4 b4 ,m detail4 c4 ,m detail4 #b4 ,plotting detachment-- a4 ,plotting board detail4 b4 ,communication detail4 #c4 ,power detachment-- a4 ,casemate detail4 b4 ,searchlight detail4 7b7 ,planting and loading section3 #a4 ,planting detachment-- a4 ,planter detail4 b4 ,small-boat details4 #b4 ,loading detachment-- a4 ,loading room detail4 b4 ,explosive detail4 c4 ,cable detail4 7c7 ,gun and ammunition section3 a4 ,gun details4 b4 ,projectile detail4 c4 ,powder detail4 7d7 ,reserve section3 ,as required4 ,in each company assigned to the mine defense1 a permanent manning table will be made out and always kept up to date4 ,a copy of this manning table will be posted in the mine commander's station4 ,in addition1 a copy of such portion of this table as pertains to any particular station will be posted therein4 ,plotting board4--,the plotting board differs from that used for guns in that it requires no gun arm and corresponding attachments4 ,furthermore1 since the distance at which mines are planted will in general be small1 the board1 without any change in size1 may be used with a much larger scale1 say1 #aej yards or even #ajj yards to the inch1 and the arms graduated accordingly4 ,the stations are manned during the planting of mines and the location of distribution boxes1 as well as during operations4 ,illustration3 ,,fig4 #ae4--,,prediction ,,ruler4 ,for planting buoys signals may be made from the primary1 from the secondary1 or from both1 as conditions warrant4 ,observations are taken on each mine as planted1 the data are recorded1 and the position of each mine is plotted4 ,during operations vessels may be tracked by the vertical or by the horizontal method of position finding4 ,if by the former1 either the command 8,fire0 may be given when the vessel is on the cross wires of the instrument set at the range and azimuth of a mine1 or the time from any point to the instant of passing over a mine may be found by means of the prediction ruler 7see below7 and the command 8,fire0 be given at the proper instant1 as indicated by the stop watch4 ,for the horizontal base system the latter method must be used4 ,prediction ruler 7fig4 #ae74--,this is a #aj-;inch white celluloid slide rule with a beveled edge4 ,the slide is graduated in 8,yards in #ae seconds10 and on the left and right of the runway1 respectively1 are a 8,fire at time0 and a 8,yards to mine0 scales4 ,the beveled edge is graduated from the center outward in both directions with 8#j0 in the center of the scale and 8#ejj0 at either end4 ,each #ej and #ajj has its value engraved on the scale4 ,method of using4--,plot the position of the target for a #ae-second interval4 ,with the beveled edge find the distance the target has passed over during the interval2 and also determine the distance from the last plotted position to the mine4 ,move the slide until the graduation corresponding to the 8,yards in #ae seconds0 is opposite the graduation corresponding to the 8,yards to mine10 and read the 8,fire at time0 scale opposite the arrow on the slide4 ,the reading will be the number of seconds from the last plotted position to the mine which the vessel is approaching4 ,a stop watch is started at the time of the last observation on the target1 and at the expiration of the time obtained from the 8,fire at time0 scale the command 8,fire0 may be given4 ,observation firing4--,the mine commander's station is connected with the casemate by telephone4 ,at the command 8,observation firing0 sent to the casemate1 the casemate operator will see that all automatic switches are up1 and that all firing switches are open4 ,he will then close the double circuit breaker1 and switches #d and #i1 which will energize the busses of the power panel4 ,at the command 8,group ----1 mine ----10 the operator will close switches #c and #h on the power panel1 thereby putting both ,d4 ,c4 and ,a4 ,c4 power on the operating boards4 ,at the command 8,ready10 given from the mine commander's station at the proper time1 the operator will stand ready to trip the corresponding automatic switch4 ,at the command 8,fire0 the automatic switch will be tripped and the firing switch will be closed4 ,without delay1 after the mine is fired1 the firing switch and the power switch will be opened1 the automatic switch closed up1 and the mine switch opened on the mine block4 ,if the mine is struck before the command 8,fire0 is given1 the automatic switch will fall1 and the mine should be fired by closing the firing switch unless there are positive orders to the contrary4 ,contact firing4--,for contact firing the mine system will be set so that a signal will be sent to the casemate and the mine will be fired when the latter is struck by a passing vessel4 ,this is the normal method of firing in actual service4 ,at the command 8,contact firing10 which may be given for all groups1 or certain individual ones1 the casemate operator will see that all automatic switches are up1 power and mine switches closed1 and firing switches open2 he will then close the double circuit breaker1 and switches #d1 #i1 #c1 and #h on the power panel4 ,this puts both ,d4 ,c4 and ,a4 ,c4 on the operating boards4 ,he will then close the firing switches on all the boards or on such as may have been indicated4 ,when a mine has been fired1 the corresponding mine block will be cut out4 ,if it is desired to delay the firing of a mine after being struck1 the command 8,delayed contact firing0 is given4 ,the operations are the same as for contact firing except that the firing switch is closed by the operator a short time after the mine has been struck or when directed to do so4 ,after the mine has been fired the firing switch will be opened1 and the corresponding mine block will be cut out4 ,,appendix ,,no4 #a4 ,,explosives4 ,the latest adopted explosive for submarine mines is trinitrotoluol1 also called trotol4 ,the commercial names for this explosive are trinol1 trotyl1 and triton4 ,wet guncotton is used extensively for submarine mines and in emergency other commercial high explosives may be employed1 preferably dynamite4 ,trotol is a fine crystalline yellow powder1 much resembling brown sugar4 ,it is manufactured by nitrating toluol4 ,it is very insensitive to shock or friction1 insoluble in water1 very stable in storage1 and very powerful when detonated4 ,its melting point is about #ha ,c41 its ignition point is about #aig ,c41 its specific gravity in powdered form is about #a4ee2 it has no dangerous chemical action on metals4 ,the priming charge is a fuse can full of crystalline trotol4 ,trotol is supplied in wooden boxes doubly lined with wax paper1 each box containing about #ej pounds of explosive4 ,the date of receipt at the post and the name of the explosive shall be painted on each box4 ,the boxes should be stored in tiers with the marked end out1 the bottom tier resting on skids4 ,the explosive is not dangerous to handle1 but the same care should be observed in storing and handling as with other high explosives4 ,it should be stored in a perfectly dry place1 preferably in a magazine4 ,if it is impracticable to store in a magazine1 the explosive may be stored in the driest place available where it is protected thoroughly from all fire risks4 ,if from any cause the boxes of explosive are wet and there is reasonable assurance that the interior has become wet1 a box should be selected and opened4 ,if the interior is wet1 a full report of the circumstances shall be made to the ,war ,department4 ,boxes should be opened and the contents dried in open air out of the direct rays of the sun4 ,trotol may be stored with wet guncotton1 explosive ,d1 and dynamite4 ,inspection at posts will be limited to seeing that the rules for storage and care are strictly observed4 ,technical inspections will be made1 when required1 by the ,ordnance ,department4 ,wet guncotton in the form of compressed cakes is supplied in boxes lined with zinc1 the lid being screwed down upon a rubber gasket so as to prevent the loss of water by evaporation4 ,each box contains #ajj pounds of dry guncotton4 ,in the lid is a small flush cap which screws down upon a rubber washer and closes a tube communicating with the interior of the box4 ,upon each box there is painted by the manufacturer the net and total weights4 ,shipping regulations require that guncotton should be wet with water so that the water is #bj per cent of the weight of guncotton and water4 ,this is too much water for full detonation1 and the guncotton upon receipt at a post should be dried out so that the weight of water is from #ab to #ae per cent of that of the dry guncotton4 ,the guncotton is dried by opening the box and pyramiding the guncotton on the lid and in the box so that there will be free circulation of air between the cakes4 ,the use of an electric fan in this connection will ordinarily materially facilitate the operation4 ,by weighing pilot cakes it may be determined when the proper amount of water has evaporated4 ,the guncotton is then repacked1 lid screwed down1 and the weight chalked upon the end of the box4 ,the guncotton should be placed while drying so that it is not in the sunlight and should be handled with clean cotton or rubber gloves4 ,in addition to the regular monthly inspection the boxes are reweighed quarterly under the supervision of the officer responsible for submarine mine explosive1 and the gross weight so found chalked upon the end4 ,should any box show any decided decrease in weight the screw cap in the lid is removed1 enough fresh water1 preferably distilled or rain water1 added to bring it up to its original weight1 and the screw cap replaced4 ,magazines in which guncotton is stored should not be allowed to attain a temperature as high as #ajj ,f4 for any length of time4 ,guncotton which is kept wet may deteriorate after long storage1 but will not become dangerous4 ,wet guncotton can not be ignited by a flame1 but gradually smoulders away as the outer portions in contact with the flame become dried4 ,a brownish or reddish shade is sometimes seen in cakes of guncotton4 ,this is due to the presence of iron in the wash water and does not indicate decomposition4 ,when storing guncotton in the magazine the piles of boxes should be made so as to give free circulation of air and the greatest convenience in handling consistent with the capacity of the magazine4 ,in the event of damage to any case1 which may cause loss of water by evaporation1 the contents shall be removed at once1 repacked in a guncotton box which has been washed with soda solution1 the proper amount of water added to the contents1 and the box closed4 ,the gross weight shall be marked on the case4 ,in repacking avoid as much as possible handling the cakes with the bare hands4 ,this is for the protection of the guncotton from oil or acid of any kind4 ,clean cotton or rubber gloves are suitable covering for the hands when engaged on this work4 ,if for any reason the cases are subjected to dampness sufficient to cause unusual deterioration of the cases1 they should be removed from the magazine and dried1 out of the direct rays of the sun4 ,guncotton containing #ab or #ae per cent of moisture may be stored with explosive ,d1 trotol1 and dynamite1 but never with dry guncotton4 ,empty cases1 before being placed in storage1 must be washed thoroughly to remove all traces of guncotton4 ,for a charge of wet guncotton1 the priming charge is dry guncotton4 ,this may be either of crumbled guncotton or cakes made to fit the fuse can4 ,the compressed primer cakes are supplied wet and bored with holes to receive the fuses and the loading wire4 ,should the supply of guncotton primers become exhausted fresh ones may be prepared as follows3 ,two blocks of soft pine are used1 one #c inches square1 the other circular and #b4i inches in diameter4 ,a cake of wet guncotton is clamped between these blocks4 ,using a fine joiners' saw and the circular block as a gauge1 a cylinder is sawed from the cake4 ,the cylinder is then smoothed down with a rasp4 ,four of these are prepared for each charge and in each one of them a hole about _/ inch in diameter is bored4 ,while boring the hole the cake must be tightly clamped between two pine blocks to prevent it from splitting2 to insure that all the holes will be in alignment it is advisable that the upper wooden block be provided with a _/-inch hole and be thick enough to enable this hole to serve as a guide for the bit4 ,the boring is done with the ordinary bit1 which must be sharp1 so as to cut clean4 ,it is not safe to saw or bore a dry guncotton cake4 ,it is essential that the guncotton primer be thoroughly dry4 ,the primers may be dried by exposure to the air or by means of drying ovens supplied especially for the purpose4 ,to air-dry a primer1 it is placed on edge upon a shelf of wire gauze or netting which is hung up indoors where there is a free circulation of dry warm air4 ,drying should continue until weighings on two successive days show no appreciable loss4 ,this may require a week or more4 ,in drying with an oven the cakes are laid on edge on the shelves and the temperature of the oven is kept at about #ajj ,f42 it should not exceed #ajd ,f4 ,the heat is provided by means of a bank of lamps placed under the hood and the current of warm air regulated by the size of the lamp bank and the openings in the top of the oven4 ,under no circumstances must an open flame be used as a source of heat4 ,the drying in this case also is continued until successive weighings of samples show no appreciable loss4 ,whenever it is necessary to dry more than #ej pounds of guncotton primers for immediate use the guncotton should be placed in the drying oven and exposed to the action of an electric fan placed about #d feet in front of the open door until the moisture content is reduced to about #f per cent1 when the drying should be completed by the use of the bank of lamps as described in the preceding paragraph4 ,in each case1 to test the dryness of the primers1 take a cake and split it in four or five pieces and detonate each separately with a fuse4 ,it has been determined that about #e per cent of water is the maximum content for unconfined guncotton capable of detonation by a ,du ,pont ,no4 #cj fuse4 ,priming charges are not to be prepared until just previous to the time they are to be used in loading4 ,when the primers have been dried1 they should be kept in well-sealed jars unless they are to be used very soon after drying1 in which case they will be stored in assembled fuse cans2 when thus stored the assembled fuse cans should be kept in a cool1 dry1 and secure room away from other explosives4 ,if1 however1 the primers are to be stored for any length of time1 two strips of blue litmus paper are inserted between the cakes1 which are inspected from time to time4 ,if the litmus paper shows decided redness1 it should be removed and fresh strips inserted4 ,if these strips turn red in a few hours1 the primers should be thoroughly wet with fresh water4 ,in general1 the period of storage will be short and no particular examination of the dry guncotton will be required4 ,dry guncotton should be handled as little as possible1 to prevent crumbling and scattering of guncotton dust4 ,finely divided guncotton is difficult to remove by brushing and if allowed to collect about a room may give serious trouble by flashing should a portion become ignited4 ,this dust may be removed with a damp sponge or cloth4 ,dry guncotton which is not used as contemplated shall be rewet with the proper amount of water and repacked4 ,samples of each lot of guncotton issued to the service are preserved in the laboratory of the ,ordnance ,department for chemical test4 ,these retained samples are subjected regularly to technical inspection and test by that department to determine their condition as to stability4 ,this will insure the detection of lots that are deteriorating and their removal from the posts or their destruction before they have deteriorated to such an extent that they become dangerous4 ,dynamite4--,dynamite cartridges are packed ordinarily in sawdust in wooden boxes4 ,each cartridge is wrapped in paraffin paper4 ,the cartridges are arranged in the box so that when they are transported all cartridges will lie on their sides and never on their ends4 ,usually the amount of explosive in a single package will not exceed #ej pounds4 ,the boxes must never be allowed to stand so that the cartridges will be vertical4 ,like other nitroglycerin1 dynamite freezes at about #dj ,f41 and in its frozen condition is1 under ordinary circumstances1 less liable to explosion from detonation or percussion than when thawed1 but more susceptible to explosion by simple ignition4 ,should any of the nitroglycerin be exuded1 the dynamite cartridges are much more sensitive to explosion by a blow4 ,it is important that dynamite cartridges be kept dry4 ,if exposed to a moist atmosphere1 there is a tendency of the water1 condensed from the air on all exposed surfaces1 to displace the nitroglycerin4 ,the cases should be raised from the floor on skids and the floor underneath covered with clean sawdust4 ,the sawdust should be removed from time to time1 the old sawdust being burned in the open air4 ,rubber gloves should be worn in handling this explosive1 or in the absence of rubber gloves cover the hands with grease and wear cotton gloves4 ,this is for the protection of the skin from the injurious effect of nitroglycerin4 ,dynamite may be stored with wet guncotton1 explosive ,d1 and trotol4 ,date of receipt at post shall be marked on each box4 ,the priming charge for dynamite is a pound of loose dynamite contained in a small bag which fits easily into the fuse can4 ,in filling the bag rubber gloves must be worn4 ,to insert the fuses the bag is opened and the fuses embedded in the explosive1 the choke being tied around the fuse wires4 ,at the monthly inspection all boxes shall be examined to see if they are dry4 ,if not dry1 all shall be exposed to the dry air out of the direct rays of the sun4 ,the principal source of danger from dynamite is in the exudation of the nitroglycerin4 ,exudation is indicated by the presence of small white1 oily1 lustrous globules of liquid1 either among the particles of dynamite or on the packages4 ,if such globules are discovered1 they may be identified positively as nitroglycerin by absorbing a drop in a piece of unglazed paper1 which should be placed on an anvil or other piece of metal1 and striking it a sharp blow with a hammer4 ,if it be nitroglycerin1 an explosion will occur4 ,another test is to set fire to the paper1 and if the liquid be nitroglycerin it will burn with a crackling noise and a greenish-yellow flame4 ,if exuded nitroglycerin has stained floors or other material not readily destroyed1 the nitroglycerin may be decomposed and rendered harmless by washing with 8sulphur solution40 ,this solution may be made by boiling #ej pounds of lime in a barrel of water and adding powdered sulphur until the solution will take up no more4 ,this will require about #bj pounds of sulphur4 ,the resulting bright orange-colored solution should be filtered and only the filtrate used4 ,a suitable filter for this purpose is a piece of thin cheese-cloth4 ,sodium carbonate may be used in the place of lime4 ,dynamite may be destroyed by burning in small quantities at a time4 ,slit the cartridge with a knife1 spread out the contents over some straw or shavings1 and ignite carefully4 ,do not attempt to burn frozen dynamite4 ,mine fuses4--,these are regular commercial electric fuses1 extra quality1 and each contains about #be grains of mercury fulminate4 ,fuses are supplied in pasteboard boxes containing #ej each1 pasteboard boxes being shipped in suitable wooden boxes4 ,they are supplied with long leads which are cut to proper length when the mines are loaded4 ,they must not be stored with other explosives4 ,loading mines4--,in loading mines the following precautions are observed3 7a7 ,funnels are used to cover the screw threads4 7b7 ,trotol is poured through the funnels4 7c7 ,cakes of guncotton or packages of dynamite are passed through the funnels by hand4 7d7 ,the screw threads are wiped carefully before the compound plug is inserted4 7e7 ,pieces of canvas or paulins should be spread upon the floor of the loading room4 ,after the loading has been completed the canvas should be removed and thoroughly cleaned4 ,the floor of the loading room should be scrubbed and all refuse destroyed4 ,unloading mines4--,mines charged with trotol or wet guncotton may be unloaded without danger2 the compound plug being unscrewed1 the cakes of wet guncotton are removed by hand1 repacked in the original boxes1 a little fresh water added1 and the boxes closed4 ,if loaded with trotol1 the charge is poured out into the boxes1 which are then closed4 ,trotol should be inspected carefully when removed from the case1 and if there is indication that any of it has undergone a change while the mine was loaded1 a report should be made to the ,war ,department4 ,in unloading mines charged with dynamite too many precautions can not be taken4 ,the mine should be held either in an opening in a raft or behind an earthen traverse and the compound plug removed by some arrangement which may be operated from a safe distance4 ,if the mine has been planted for some time the recovered dynamite is usually destroyed4 ,sometimes the interior of the mine case may be found coated with an extremely thin film of exuded nitroglycerin4 ,this film may be destroyed by filling and thoroughly rinsing the case with 8sulphur solution40 ,,appendix ,,no4 #b4 ,,the ,,hornsby-,,akroyd ,,oil ,,engine ,,and ,,generator4 7,see also ,artillery ,notes1 ,no4 #ab47 ,the engine4--,this is a horizontal1 single-acting1 single-cylinder kerosene engine1 having a flyball governor and operating on a four-stroke cycle4 ,this cycle consists in turn of the explosion on the first outstroke1 the expulsion of the products of the explosion on the following instroke1 the intake into the cylinder of a mixture of air and oil vapor on the following outstroke1 and the compression of this explosive mixture on the next instroke4 ,this cycle therefore requires two complete revolutions of the crank shaft for one complete set of operations4 ,on one side of the cylinder near the closed end is a valve box containing two valves1 the air-inlet valve and the exhaust valve4 ,the air-inlet and the exhaust valves are actuated by separate levers1 each lever being moved by a cam mounted on a horizontal shaft1 driven by the crank shaft through worm gearing4 ,this horizontal shaft makes but one revolution while the crank shaft makes two2 thus the air-inlet and the exhaust valves are each opened once every two revolutions of the flywheel4 ,at the back of the cylinder1 in prolongation of its axis1 is a cast-iron box called the vaporizer1 which is always open to the cylinder4 ,before starting the engine this vaporizer must be heated by an external lamp1 so that it will vaporize the oil when it is first pumped into it4 ,after the engine has started running1 the lamp is no longer required1 as the vaporizer is kept at a sufficient heat by the internal explosions4 ,a small oil pump1 worked by the air-valve lever1 draws oil from the oil tank under the engine and forces it into the vaporizer at the proper time4 ,the oil1 on its way from the pump to the vaporizer1 passes through a valve box attached to the vaporizer2 this valve box has two valves in it1 a horizontal one1 kept closed by a spring which the oil forces open as it goes into the vaporizer2 the other1 a vertical one1 also kept closed by a spring4 ,should the engine run too fast1 the governor opens this latter valve and allows some of the oil to flow back to the oil tank through the waste pipe4 ,this valve can also be opened by turning the little regulating handle1 which will stop the supply of oil to the vaporizer and thus stop the engine4 ,,instructions ,,for ,,working4 ,frosty weather4--,if there is danger of freezing1 on shutting down drain the water from the circulating pipes and cylinder jacket1 and valve box if water-jacketed2 otherwise they may burst or crack4 ,caution4--,before starting1 see that the cocks which admit water to the water jacket of the vaporizer valve box are open2 that the cock on the main water pipe from the bottom of the water tank is open2 that the water in the tank is above the upper circulating pipe2 that the drain cock is closed2 and that the oil tank is filled with kerosene4 ,gasoline must not be used with this engine4 ,heating the vaporizer4--,open the relief cock on top of the engine cylinder4 ,place the lamp on the stand under the vaporizer2 fill the lamp with oil by means of the filling pipe till the oil is #a inch below the pipe2 and put a piece of wick into the cups which are formed around the pipes4 ,these wicks1 which should consist of a piece of ordinary asbestos packing1 will last for several weeks4 ,place the lid of the vaporizer cover crosswise on the cover to allow the escape of heated gas and air4 ,a little alcohol or kerosene should be poured into the cup under the coil and lighted4 ,the cups may be filled with kerosene by closing the air-escape valve and working the air pump4 ,the pressure forces oil out through the vapor nozzle and it will run down into the cups4 ,when this is nearly burned out pump up the reservoir with air by the air pump4 ,oil will issue from the small nozzle and give a clear flame4 ,when it is desired to stop the lamp1 turn the thumbscrew on the reservoir filling nozzle to let the air out4 ,should the nozzle become choked it should be cleaned with the small needles for that purpose4 ,the heating of the vaporizer is one of the most important things to be attended to1 and care must be taken that it is hot enough at starting4 ,the attendant must see that the lamp is burning properly and that a good clear flame is given off for from #e to #aj minutes1 according to the size of the engine4 ,if1 however1 the lamp is burning badly1 it may take longer to become heated sufficiently4 ,it is important that this should be carefully attended to1 for though the engine may start1 if the vaporizer is not as hot as it should be the engine will run badly and perhaps soon stop altogether4 ,failures of engines to run properly can in most cases be traced to this source4 ,no time should be lost in starting the engine after the vaporizer has been sufficiently heated1 as the engine may not run satisfactorily if the vaporizer is allowed to cool after heating it4 ,the lamp should be left burning a few minutes after starting4 ,oiling the engine4--,oiling the engine should always be done during the heating-up of the vaporizer4 ,see that the oil cups on the two main crank shaft bearings are fitted with proper wicks and filled with oil4 ,adjust the lubricator on the large end of the connecting-rod and oil the small end which is inside the piston4 ,oil also the following3 ,the bearings on the horizontal shaft and the skew gearing1 the rollers at the ends of the valve levers and their pins1 the pins on which the levers rock1 the governor spindles and joints and the bevel wheels which drive the same1 and the joints that connect the governor to the vertical valve of the overflow4 ,for such bearings none but the best engine oil should be used4 ,it is necessary that a suitable oil should be used for lubricating the cylinder1 and unless such an oil be used for this purpose the engine may run badly and perhaps stop altogether4 ,under no circumstances must a thick cylinder oil be used1 and the oil must not be used over again on the piston4 ,do not use ordinary lubricating oil4 ,a high-grade gas-engine oil especially suited to this engine should be used and the piston should be kept flooded with it4 ,starting the engine4--,throw the hand lever to 8,to start40 ,turn the small crutch-handle regulator ,y to the position 8,shut0 and work the pump lever up and down until oil is seen to pass the overflow freely4 ,turn the regulator back to 8,open10 work the pump lever up and down a few strokes4 ,vapor should issue with some force from the relief cock on the cylinder4 ,this indicates sufficient heat4 ,close the relief cock and pump a few strokes4 ,man the flywheel and start the flywheel backward1 using the weight of the body if necessary1 bringing the piston up against compression as sharply as possible1 and then release the wheel1 when an explosion should take place and the engine start forward4 ,as soon as the engine has sufficient speed to carry it past a full compression1 throw the lever to 8,to work40 ,when full speed is obtained1 cut down the pump stroke to correspond to the load1 open the oil feeders1 and go over the engine carefully1 seeing that the cylinder oil feed is working4 ,oil pump4--,when the cylinder is working at its full power the distance between the round flanges on the pump plunger should be such that the hand gauge 7supplied with the engine1 and to be found in the tool box7 will allow the part stamped 8#a0 just to fit in between the flanges2 if at any time the positions of these flanges be altered they can be readjusted to this gauge4 ,the other lengths on the hand gauge are useful for adjusting the pump to economize oil4 ,when running on a medium load1 use length marked #b2 on a light load1 use length marked #c4 ,see that the pump packing is not too tight4 ,running the engine light4--,when the engine is to run light--that is1 with no load or with a light load--it is best to alter the stroke of the pump to the amount of oil that will keep the engine running4 ,this amount can be reduced so that the speed of the engine is a few revolutions under the normal1 which will allow the vaporizer to get a small charge each time and keep it from cooling4 ,the cock on the return of the water circulating pipe may be nearly closed to keep the cylinder warmer4 ,these remarks do not apply when the load is intermittent and the engine is running light for a short time only4 ,air-inlet and exhaust valves4--,see that the air-inlet and the exhaust valves are always working properly and drop onto their seats4 ,they can at any time1 if required1 be made tight by grinding with a little flour of emery and oil4 ,to insure a good seat to the valves when the stems are expanded by heat the stems should clear the set-screws on the levers at least _/ inch when the air and the exhaust levers are clear of the cams4 ,a greater clearance is undesirable1 as it prevents the full opening of the valves4 ,if at any time the air-inlet or the exhaust valves appear to be opening or closing at the wrong time1 take off the nut on the end of the lay shaft which holds the skew-wheel on and see that the chisel cuts on the shaft are opposite to one another4 ,the lay shaft is coned where the skew wheel is fixed on and it is held on simply by friction1 the nut being tightened against it4 ,should it at any time become necessary to take out the crank shaft1 always be sure that the skew-wheel gearing is put together so that the tooth marked 8#j0 on the crank shaft skew-wheel fits in between the two teeth marked 8#j0 on the oil-shaft skew-wheel4 ,vaporizer valve box and pipes attached to vaporizer4--,in this box there are two valves4 ,the vertical one is regulated by the governor1 and when the engine runs faster than its proper speed the governor pushes it down1 thus opening it and allowing some oil to return to the oil tank4 ,the horizontal valve in this box is a back-pressure valve4 ,if at any time this valve is not working properly1 vapor will be seen coming out of the overflow pipe2 in this case the valve should be examined4 ,by screwing off the outside cap the tail of this valve can be seen2 if the valve is turned around a few times it will probably dislodge any dirt that may be under it2 if1 however1 this does not stop the leakage the valve should be taken out for inspection4 ,if the horizontal valve and sleeves are taken out at any time1 great care must be taken in replacing them to use the same thickness of jointing material as before or the distance the valve opens will be altered4 ,see that the pipe from the pump to the vaporizer valve box is inclined upward all the way from the pump4 ,if this is not so1 an air pocket will be formed in which a certain amount of air will be compressed upon each stroke of the pump4 ,this will cause the oil to flow in slowly and not suddenly as it should4 ,if the oil tank be emptied of oil at any time1 air will get into the suction and delivery pipes of the pump and it will take some time before the oil going through the pump and pipes will be free of this air2 for awhile thereafter1 the engine will not work properly1 as the air1 by being compressed as the pump works1 will interfere with oil being pumped in suddenly4 ,it is best1 if the oil gets below the filter in the tank1 to work the pump by hand for about #aj minutes1 holding the relief valve 7on the vaporizer box7 so as to get air well out of the pipes4 ,to stop the engine4--,turn the crutch-handle regulator to 8,shut40 ,close the automatic lubricator4 ,if it is desired to stop the engine for a short time only1 put the lamp back under the vaporizer to keep it hot4 ,setting the oil engine and the generator4--,the engine and generator should be so located that the distance from center to center of pulleys should be as nearly correct as possible when the generator is at the middle point of the base rails1 so that the proper tension of the belt may be obtained within the limits of adjustment allowed by the rails4 ,the two pulleys should be accurately in line and the belt not too tight4 ,the generator base should rest on a wooden frame to separate it from the concrete pier4 ,both engine and generator should be held firmly in position by anchor bolts4 ,for the generator bearings a quantity of the best dynamo oil is furnished2 the commutator should be clean and smooth1 and the brushes should fit the surface4 ,the commutator should be cleaned occasionally with a little paraffin on canvas1 and the brushes should be adjusted1 so that when running at full load no sparking occurs4 ,all electrical connections should be firmly made and kept thoroughly clean4 ,a cover should be kept on the generator when not in use4 ,if the machine be damp it should be allowed to dry before running at full load4 ,,note4--,a few new installations have been supplied with #e-kw4 gasoline electric sets1 and future installations will be similarly equipped4 ,wherever installed1 pamphlets on the care and operation of the gasoline sets have been furnished1 containing full instructions for the guidance of those concerned4 ,,appendix ,,no4 #c4 ,,the ,,storage ,,battery4 7,see pamphlets issued by the ,electric ,storage ,battery ,co41 ,philadelphia1 ,pa41 on ,general ,instructions for the ,operation and ,care of the ,chloride ,accumulator47 ,unpacking material4--,great care should be taken in the unpacking and subsequent handling of the various parts of the battery1 as many of them are easily broken or bent out of shape by rough handling4 ,open the crates or packing boxes on the side marked 8,up0 and carefully lift contents out2 never slide them out by turning the crate on its side4 ,upon opening the crates and boxes1 carefully count the contents of each package1 and check with the shipping list4 ,a number of small parts will usually be found in each shipment1 and care should be taken to examine the packing materials to determine that no parts have been overlooked4 ,immediately upon opening the crates the materials should be carefully examined for breakage4 ,cracked jars1 whether of glass or rubber1 should not be set up1 for if put into use leakage of electrolyte may cause annoyance or trouble4 ,location of battery room4--,the proper location of the battery is important4 ,it should be in a separate room1 which should be well ventilated1 dry1 and of moderate temperature4 ,extremes of temperature affect the proper working of a battery4 ,the air should be dry1 for if damp there is danger of leakage due to grounds4 ,the ventilation should be free1 not only to insure dryness1 but to prevent chance of an explosion1 as the gases given off during charge form an explosive mixture if confined4 ,for this reason never bring an exposed flame near the battery when it is gassing4 ,direct sunlight should not fall on the cells4 ,the trays1 the benches on which the cells rest1 and all metal work 7iron and copper7 should be painted with asphaltum varnish4 ,assembling and placing cells in position4--,place the jars1 after they have been cleaned1 in position on the stands1 which should be provided for the purpose and which should be so situated in the room that each cell will be easily accessible4 ,the jars are set in the trays1 which previously should be filled with fine dry sand even with the top1 the trays resting on the glass insulators4 ,place the elements as they come from the packing cases on a convenient stand or table 7the elements are packed positive and negative plates together2 the positive has plates of a brownish color1 the negative of a light gray--the negative always has one more plate than the positive71 cut the strings that bind them together1 and carefully pull the positive and negative groups apart1 throwing the packing aside4 ,after carefully looking over both groups and removing any dirt or other foreign matter1 assemble them1 with separators between each positive and negative plate4 ,when putting into the jars be careful that the direction of the lugs is relatively the same in each case1 thus causing a positive lug of one cell always to connect with a negative of the adjoining one1 and vice versa4 ,this insures the proper polarity throughout the battery1 bringing a positive lug at one free end and a negative at the other4 ,before bolting or clamping the lugs together1 they should be well scraped at the point of contact to insure good conductivity and low resistance of the circuit2 this should be done before the elements are taken apart and directly after unpacking1 if the battery is to be set up at once4 ,the connections should be gone over and tightened several times after the lugs are first fastened together to insure good contact4 ,connecting up the charging circuit4--,before putting the electrolyte into the cells1 the circuits connecting the battery with the charging source must be complete1 care being taken to have the positive pole of the charging source connected with the positive end of the battery4 ,electrolyte4--,the electrolyte is dilute sulphuric acid of a specific gravity of #a4baj or #be ,baum1 as shown on the hydrometer at temperature of #gj ,f4 ,the electrolyte should cover the top of the plates by one-half inch to three-fourths inch1 and must be cool when poured into the cells4 ,the jars should be numbered with asphaltum varnish and a line made with the same material to indicate the height at which the electrolyte should be kept4 ,initial charge4--,the charge should be started at the normal rate as soon as the electrolyte is in the cells and continued at the same rate1 provided the temperature of the electrolyte is well below #ajj ,f41 until there is no further rise or increase in either the voltage or specific gravity over a period of #aj hours1 and gas is being given off freely from all the plates4 ,also1 the color of the positive plates should be a dark brown or chocolate and that of the negatives a light neutral gray4 ,the temperature of the electrolyte should be closely watched and1 if it approaches #ajj ,f41 the charging rate must be reduced or the charge stopped entirely until the temperature stops rising4 ,from #de to #ee hours at the normal rate will be required to complete the charge2 but if the rate is less1 the time will be proportionately increased4 ,the specific gravity will fall rapidly after the electrolyte is added to the cells1 and may continue to fall for some time after charging begins4 ,it will finally rise as the charge progresses1 until it is again up to #a4baj or possibly slightly higher4 ,the voltage for each cell at the end of charge will be between #b4e and #b4g volts1 and for this reason a fixed or definite voltage should not be aimed for4 ,it is of the utmost importance that this charge be complete in every respect4 ,at the end of the first charge it is well to discharge the battery about one-half and then immediately recharge it4 ,repeat this treatment two or three times and the battery will be in proper working condition4 ,after the completion of a charge 7initial or with the battery in regular service7 and the current off1 the voltage will fall immediately to about #b4bj volts per cell1 and then to #b volts when the discharge is started4 ,if the discharge is not begun at once1 then the pressure will fall quite rapidly to about #b4je volts per cell1 and there remain while the battery is on open circuit4 ,battery in regular service4--,a battery must not be repeatedly overcharged1 undercharged1 overdischarged or allowed to stand completely discharged4 ,after the initial charge is completed1 the battery is ready to be put into regular service4 ,a cell should be selected as a 8pilot cell02 that is1 one that is in good condition and representative of the general condition of the battery4 ,the height of the electrolyte in this cell must be kept constant by adding a small quantity of water each day4 ,this cell is to be used particularly in following the charge and indicating when it should be stopped4 ,when the battery is in regular service1 the discharge should not be carried below #a4ge volts per cell at full load4 ,standing completely discharged will cause permanent injury2 therefore the battery should be immediately recharged after a heavy discharge4 ,in usual service1 with the normal rate1 it is advisable to stop the discharge at #a4ij volts per cell4 ,if the discharge rate is considerably less than normal1 the voltage should not be allowed to fall as low as #a4ij volts per cell1 for the reason that with a very low rate of discharge the voltage will not begin to fall off until the limit of capacity is almost reached4 ,the fall in specific gravity of the electrolyte also serves as an indication of the amount taken out and is in direct proportion to the ampere-hour discharge1 thereby differing from the drop in voltage1 which varies irregularly for different rates and degrees of discharge4 ,for this reason1 under ordinary conditions1 the fall in specific gravity is to be preferred in determining the amount of discharge4 ,the actual amount of variation in the specific gravity of the electrolyte between a condition of full charge and a complete discharge is dependent upon the quantity of solution in the containing vessel compared with the bulk of the plates4 ,when cells are equipped with the full number of plates1 the range will be about #ce points 7#j4jce sp4 gr472 for instance1 if the maximum specific gravity reached on the preceding overcharge is #a4bji1 the extreme limit beyond which the discharge should not be carried is about #a4agd4 ,if the cells have less than the full number of plates1 this range in specific gravity is proportionately reduced1 except in the case of the 8pilot cell10 which should be equipped with a device for displacing the excess electrolyte4 ,the available capacity is temporarily reduced at low temperatures2 with a return to normal temperature the capacity is regained4 ,the battery should preferably be charged at the normal rate4 ,it is important that it should be sufficiently charged1 but the charge should not be repeatedly continued beyond that point4 ,both from the standpoint of efficiency and life of the plates the best practice is the method which embraces what may be called a regular charge1 to be given when the battery is from one-half to two-thirds discharged1 and an overcharge to be given weekly if it is necessary to charge daily1 or once every two weeks if the regular charge is not given so often4 ,the regular charge should be continued until the specific gravity of the pilot cells has risen to within five points of the maximum1 as shown on the last previous overcharge4 ,for example1 if on the previous overcharge the maximum is #a4baj1 then on the following regular charges the current should be cut off when the specific gravity of the pilot cell reaches #a4bje4 ,the pilot cell method of noting the end of charge should not be used with a battery unless all the cells are approximately in the same condition4 ,with an old battery whose plates are not uniform1 readings should be taken on each cell to determine the end of charge4 ,the overcharge should be prolonged until all the cells gas freely and until no rise in the specific gravity and voltage of the pilot cell is shown for five successive #ae-minute readings4 ,just before the overcharge the cells should be carefully examined to see that they are free from short circuits4 ,if any short circuits are found they should be removed with a stick or a piece of hard rubber2 do not use metal4 ,as the temperature affects the specific gravity this must be considered and correction made for any change of temperature4 ,the temperature correction is one point 7#j4jja sp4 g47 for #c degrees change in temperature4 ,for instance1 electrolyte1 which is #a4baj at #gj1 will be #a4bac at #fa and #a4bjg at #gi4 ,inspection4--,in order that the battery may continue in the best condition it is essential that specific gravity and voltage readings be taken on all cells in the battery at least once a week2 the specific gravity readings on the day before the overcharge and the voltage reading near the end2 the voltage readings must always be taken when the current is flowing1 open circuit readings being of no value4 ,also1 at the end of each charge it should be noted that all of the cells are gassing moderately and at the end of the overcharge very freely4 ,unevenness of cells2 cause and remedy4--,if any of the cells should read low at either time and do not gas freely with the others at the end of charge1 examine them carefully for pieces of scale or foreign matter which may have lodged between the plates4 ,if any are noted1 remove them by pushing down into the bottom of the jar with a strip of wood4 ,never use metal of any kind for this purpose4 ,if1 after the cause of the trouble has been removed1 the readings do not come up at the end of the overcharge1 then the cell must be cut out of circuit on the discharge1 to be cut in again just before beginning the next charge1 during which it should come up all right4 ,impurities in the electrolyte will cause a cell to work irregularly and the plates to deteriorate4 ,should it be known that any impurity has gotten into the electrolyte1 steps should be taken to remove it at once4 ,the solution should be replaced with new immediately1 thoroughly flushing the cell with water before putting in the new electrolyte4 ,the change should be made when the battery is discharged1 for the impurities will be in the electrolyte when the battery is discharged4 ,immediately after the change the cell should be charged4 ,if in doubt as to whether the electrolyte contains impurities1 a half-pint sample1 taken at the end of discharge1 should be submitted for test4 ,sediment4--,the accumulation of sediment in the bottom of the jars must be watched and not allowed under any circumstances to get up to the plates2 if this occurs1 rapid deterioration will result4 ,to remove the sediment1 the simplest way1 if the cells are small1 is to lift the elements out after the battery has been fully charged1 draw off the electrolyte1 and then dump the sediment1 and clean the jar with water1 getting the elements back and covered with electrolyte again as quickly as possible1 so that there will be no chance of the plates drying out4 ,electrolyte1 not water1 will be required to complete the filling of the cells1 the specific gravity being adjusted to standard 7#a4baj at the end of charge74 ,evaporation4--,do not allow the surface of the electrolyte to get down to the top of the plates2 keep it at its proper level 7one-half inch to three-fourths inch above the top of the plates7 by the addition of pure water1 which should be added at the beginning of a charge1 preferably the overcharge4 ,it will not be necessary to add electrolyte except at long intervals or when cleaning1 as noted above4 ,electrolyte added to replace loss should be of specific gravity #a4baj4 ,battery used but occasionally4--,if the battery is to be used at infrequent periods1 it should be given a 8freshening0 charge every two weeks4 ,putting the battery out of commission4--,if it is thought best to put the battery out of commission for a time1 then it must be treated as follows3 ,after thoroughly charging1 syphon off the electrolyte 7which may be used again7 into convenient receptacles1 preferably carboys which have been previously cleaned and have never been used for other kinds of acid1 and as each cell becomes empty immediately fill it with fresh1 pure water4 ,when water is in all the cells allow them to stand #ab to #ae hours1 then draw off the water2 the battery may then stand without further attention until it is again to be put into service2 then proceed as in the case of the initial charge1 as described above4 ,if for any reason any cell becomes discharged before the others1 it should be cut out on discharge and worked up to normal before being used4 ,should the battery sulphate1 charge and discharge frequently1 not using less than one-half normal rate at any time and increasing to full rate as the plates show signs of recuperation2 keep the temperature of the cells below #ajj ,f4 ,frequent exercise will clear the plates in a badly sulphated battery4 ,keep careful records of all charging voltages1 specific gravities1 and troubles with the cells4 ,the following is a recapitulation of the important points in operating a storage battery3 ,,condensed ,,instructions4 #a4 ,excessive charging must be avoided4 ,a battery should not be undercharged1 overdischarged1 or allowed to stand completely discharged4 #b4 ,keep the electrolyte at the proper height above the top of the plates4 #c4 ,the daily and weekly readings should be regularly and accurately taken and recorded4 #d4 ,inspect each cell of the battery carefully at regular intervals4 #e4 ,if any low cells develop do not delay in bringing them back to condition4 #f4 ,do not allow the sediment to get up to the plates4 #g4 ,do not allow impurities1 either solid or liquid1 to get into or remain in the cells4 #h4 ,have the battery room well ventilated1 especially while charging4 #i4 ,never bring an exposed flame into the battery room during or shortly after the gassing period of a charge4 #aj4 ,keep the floor and other parts of the battery room clean and dry4 #aa4 ,keep the iron1 copper1 or other metal work about the battery room free from corrosion4 #ab4 ,keep all connections clean and tight4 #ac4 ,post a copy of these condensed instructions in a conspicuous place4 ,,appendix ,,no4 #d4 ,,submarine ,,mine ,,cable4 ,submarine mine cable is shipped on reels having an outer sheathing for protection in transit1 with at least #ab feet of both ends of the cable brought out and coiled on the head of the reel for test purposes4 ,if the cable is not for immediate use1 it should be moved to the cable tank1 and by means of the overhead trolley and cable tongs put in its position in the tank1 the two ends being properly tagged and firmly fixed so as to allow it to be tested4 ,in arranging the multiple cable in the tanks that which is to be used first should be most readily accessible4 ,the cable tank should be provided with a cover to keep it clean1 as well as to lessen as much as possible variations of temperature4 ,enough clean water to cover by several inches the outer sheathing of the cable reels should be kept in the tanks1 but in climates where the water in the cable tanks would normally freeze to a depth exceeding #b feet1 the water should be let out of the tanks before ice begins to form and not again admitted until the following spring4 ,in localities where the tanks may become a breeding place for mosquitoes1 as a preventive measure1 salt water from the ocean or bay should1 when practicable1 be used for filling the tanks1 or where it is necessary to use fresh water sufficient salt should be added to produce a #c per cent solution4 ,no oil or kerosene should be used in the tanks4 ,the methods of recording tests and of classifying and transferring submarine mine cable are prescribed by orders from the ,war ,department4 ,the tests of submarine mine cable at posts will consist in determining the insulation and conductor resistances4 ,the insulation surrounding the conductor of a cable is supposed to be uniform in regard to quality of material1 density1 and thickness4 ,the resistance which it offers to the passage of a current through it will then vary inversely with its length4 ,in comparison the insulation resistance of #a mile of cable is taken as the standard4 ,this insulation has a large negative temperature coefficient2 that is1 an increase of temperature lowers its resistance4 ,it is customary to reduce all insulation resistance to that at a standard temperature of #fj ,f41 and for this purpose reduction factors applicable to the particular insulation compound should be furnished with the cable4 7,note3 ,it has been found that for most compounds1 if the logarithms of the resistance are plotted as ordinates against the temperature in degrees ,f4 as absciss1 the resulting curve will be very nearly a straight line47 ,the ordinary methods of measuring resistance--that is1 by means of a ,wheatstone bridge1 or by fall of potential1 or by voltmeter--can not be used in measuring resistance as high as that of the insulation of a submarine cable4 ,for this the direct deflection method is employed4 ,in brief1 this consists of the following steps3 ,first4 ,the deflection produced in a galvanometer by a current from a battery through a known resistance1 usually #ajj1jjj ohms1 is determined1 whence is calculated the resistance through which this same battery would produce a deflection of one point using the unity shunt4 ,this is expressed in megohms and is called the galvanometer 8constant0 under the conditions4 ,second4 ,the deflection produced by the current from the same battery through the insulation of the cable is determined1 whence1 from 8,first10 the corresponding number of megohms is calculated4 ,third4 ,this multiplied by the length of the cable in miles and corrected for temperature gives the required insulation resistance per mile4 ,this testing can be made most satisfactorily on dry days1 but a close adherence to the instructions herein given relative to the preparation of the cable ends1 the insulation of the cable lead and of the battery1 and the drying out of the test room and instruments should enable satisfactory work to be done under adverse conditions of weather or climate4 ,the following apparatus is required3 ,reflecting galvanometer1 universal shunt1 special testing key1 #ajj1jjj-ohm resistance box1 battery of dry cells giving approximately #ajj volts1 and stop watch4 ,figure #af shows diagrammatically the arrangement of the apparatus for testing a reel of cable4 ,as a rule the instruments should be so placed that one person may manipulate the key and the shunt while at the same time observing the galvanometer4 ,the #ajj1jjj-ohm box1 as a protection to the galvanometer in testing1 is always kept in the circuit and its value should be subtracted from the resistance determined1 except in the case of high insulation resistance when it will not be necessary to make the subtraction4 ,the universal shunt is always employed with the galvanometer and is used both to vary the current through the latter and to protect it from a violent throw at the instant of making or breaking the circuit at the testing key4 ,this last is accomplished by having the shunt on zero at such times4 ,the galvanometer being a very sensitive instrument must be solidly supported so as to be free from jars or vibrations4 ,the special testing key1 shown diagrammatically in the figure1 has its binding posts plainly marked4 ,it is a double-throw key and has two positions upon each side4 ,when completely closed to the right1 the cable is charged through the galvanometer from the positive pole2 when to the left1 from the negative pole of the battery4 ,in each case the deflection of the galvanometer is in the same direction4 ,when partly closed on either side1 the cable is discharged to earth through the galvanometer4 7,note3 ,it will be observed that the connections are such that the galvanometer is always connected to the cable core and never to the ground4 ,with this connection1 so long as the lead ,,px is free from leaks or grounds1 the galvanometer measures only the current actually passing through the core and not that leaking through any imperfect insulation in the battery and leads47 ,cable testing is a very simple operation1 but extreme care is necessary in all operations4 ,illustration3 ,,fig4 #af4--;,,cable ,,testing4 ,the following is a detailed description3 ,i4 ,preparing the cable for testing4--#a4 ,closely examine each conductor end4 ,look particularly for unusually hard or brittle insulation and for torn1 pinched1 or punctured insulation1 especially near the ends of the armor wires4 ,if any of the ends are not in perfect condition1 cut off enough cable to secure good ends4 7,caution4--,do not cut off more than enough to secure good ends1 for after three or four tests it may be necessary to unreel the whole cable to secure enough of the inner end above water47 #b4 ,verify the tagging4 ,remember that the 8shore end0 is the end from the outer coils on the reel and is numbered clockwise4 ,the other end is numbered contraclockwise4 #c4 ,the 8ground0 should be made by taking several turns of bare copper wire around the armor of the cable to be tested and soldering them in position4 ,one such ground in each tank is sufficient4 ,whenever 8ground0 or 8earth0 is subsequently spoken of1 this ground in the tank is meant1 and not a connection to ground at some point outside the tank4 #d4 ,the leads ,,px and ,,by 7fig4 #af7 should be of loading or other heavily insulated wire4 ,they must be carefully insulated from each other1 from the ground1 and from the walls or other parts of buildings4 ,this is especially true of the cable lead ,,px4 ,in damp weather porcelain-knob insulators and porcelain tubes 7the latter for use in passing through walls or partitions7 may not be sufficient to afford proper insulation for the cable lead4 ,in such case the latter should be suspended in the air from the testing switch to the cable tank by means of several chains of paraffined porcelain insulators suspended by marline or protective tape which has been boiled in paraffin4 ,these suspensions should be in each case under cover and should be kept as dry as possible4 ,the length of the leads is immaterial4 ,if loading wire is used1 the distance between supports should be short 7not over #ej feet71 as this wire stretches considerably from its own weight1 pulling out the insulation and giving a very thin wall1 particularly at points of support4 ,extreme care should be taken to tighten up on the knob insulators1 in case they are used1 just enough to hold the wire without pinching the insulation4 #e4 ,using a double connector1 join the lead ,,by to the ground wire on the cable above the surface of the water4 ,put a connector on the end of the other lead so that it can be readily attached in turn to each conductor4 #f4 ,any protective covering1 such as armor1 jute1 etc41 should be removed from the ends of the conductors for a distance of about #ab inches1 thus laying the insulation coating bare4 ,this latter should not be handled and must be kept scrupulously clean4 ,with a clean dry knife prepare each conductor of the cable to be tested by cutting off about #a inch of the insulation from each end of the wire and then tapering the end of the insulation for about #a inch1 leaving a perfectly clean surface4 ,in damp weather dip each end of each conductor into melted paraffin 7not boiling1 but heated above #bab ,f474 ,secure one end of the cable so that it is well separated from the surrounding objects and separate the conductors so that no ends are touching4 #g4 ,take one strand of a loading wire about #d feet long and wrap it two or three times around the projecting copper end of each conductor at the other end of the cable1 then connect it to earth4 ,see that the conductors at this end are dry4 ,leave the lead ,,px disconnected and suspended in the air4 ,,ii4 ,setting up the testing apparatus4--#a4 ,select a light1 dry room as near the cable tank as practicable4 #b4 ,use dry cells for the battery4 ,the voltage of the battery should be such as to give a full scale deflection of the galvanometer through the resistance employed for taking the constant 7with shunt at _/74 ,large galvanometer throws are essential for reliable results4 ,set up the cells on shelves in a small closed closet or box1 with narrow strips of wood or heavy cardboard laid between each row of cells1 lengthwise and crosswise4 ,the height of each strip should be about half the height of a cell1 so that the two layers of strips will come nearly to the tops of the cells and keep them well separated4 ,wire the cells in series and bring the terminals out to a double-pole single-throw switch1 which should be on a heavy porcelain or slate base and rated for at least #bej volts4 7,it may be found desirable to install some electric lamps in the closet to keep the battery dry47 ,if difficulty is experienced in eliminating grounds from the battery set up in this manner1 the battery box should be suspended in air by means of chains of paraffined cleats4 #c4 ,set up the galvanometer on a pier or on a window sill if the building is of masonry4 ,it should be insulated by placing its feet on a slate or ebonite slab1 or in glass insulators4 ,remove the cover4 ,adjust the level until the suspended coil hangs freely4 ,maneuver the suspended coil1 by means of the knob at the top of the tube1 until its face is parallel with the face of the instrument4 ,then adjust the level until the upper suspension hangs in the center of the supporting tube1 and the air gap between the coil and armature is symmetrical4 ,replace the cover4 ,put on the scale and the telescope4 ,turn the mirror so that it reflects the #j of the scale approximately1 getting exact adjustment by moving the scale4 ,be careful 7particularly in dry weather7 not to touch the glass of the cover or to do anything which will produce a static charge on the glass4 ,the galvanometer scales are usually graduated in equal divisions corresponding to #a millimeter on the circumference of a circle whose radius is #a meter4 ,each tenth division is usually marked with a number4 ,this number is sometimes #a instead of #aj1 #b instead of #bj1 and so on4 ,the number of divisions to read and record is the number of smallest 7millimeter7 divisions4 ,do not try to read closer than of one division4 ,the larger the throw the less the personal error4 ,no accurate conclusion can be drawn from a very small throw4 #d4 ,place a table or low shelf conveniently to one side and place the shunt1 the testing key1 the megohm box1 and a voltmeter on it4 ,the apparatus should be insulated by an ebonite or slate slab1 or glass insulators4 ,fasten the shunt and the key securely to the table or the shelf4 7,the use of paraffin paper for insulating instruments is a makeshift at best4 ,it soon gets soiled and creased1 then it has to be replaced47 ,the use of lamps to keep the apparatus dry may be desirable1 or it may be found convenient to expose the apparatus to the sun for a few minutes before beginning the test on any day4 ,the use in the testing room of a small stove or of a gasoline torch for two or three hours before the beginning of the testing will ordinarily prove very advantageous4 #e4 ,wire up as in figure #af1 except that the leads from the testing key should be carried to the battery through the double-pole single-throw switch above referred to4 7,the battery switch should be opened whenever any connections are made or altered47 ,all leads used in connecting up the instruments should be of heavy copper1 and stiff enough to hold permanently any shape to which they are bent4 ,they should be supported at points of connection only1 and should not lie on the table or within an inch of each other4 ,,iii4 ,testing the insulation of the apparatus4--#a4 ,voltmeter test of battery insulation4--,this is a rough test1 but should be included4 ,a serious ground can be much more quickly located with a voltmeter than with the galvanometer4 7a7 ,disconnect the battery leads at the battery switch2 connect lead of battery to post of the voltmeter2 connect the ,b end of the lead ,,by to - post of the voltmeter2 - lead of the battery should be in the air4 ,close the voltmeter switch and read4 7b7 ,disconnect the voltmeter4 ,connect - lead of the battery to - post of the voltmeter4 ,connect the ,b end of the lead ,,by to post of the voltmeter2 lead of the battery should be in the air4 ,close the voltmeter switch and read4 ,if any deflection is obtained in either case1 the battery or its connections are grounded4 ,locate and remove the ground4 7,see ,foster or some other practical handbook47 #b4 ,testing the battery voltage4--,connect the voltmeter across the battery terminals4 ,read and record the voltage4 7,if there is no voltmeter available which will read as high as the battery voltage1 take the voltage of the battery in sections and add1 or make a multiplier of one of the resistance coils in the megohm box47 #c4 ,testing the battery and the apparatus for grounds with the galvanometer4--,with a camel's-hair brush go over all the instruments and carefully remove dust4 ,see that the instruments and connections are dry4 ,do not blow on the instruments4 ,open the battery switch4 ,connect the battery leads to the battery switch4 ,disconnect lead ,,px at ,p and connect the earth leads ,,by and ,,ey to the key at 8cable post40 7,y is grounded47 ,both battery leads are left connected to the key4 ,the shunt should be on #j4 ,close the battery switch4 ,close the testing key to the right4 ,turn the shunt gradually to the unity post4 ,the galvanometer deflection should be zero4 ,turn the shunt to #j4 ,reverse the testing key4 ,turn the shunt to the unity post4 ,the deflection should be zero4 ,if any deflection is obtained1 there is a ground in the battery1 the apparatus1 or the connections4 ,the test of the cable should not proceed if a deflection is obtained in either position of the key4 ,in reporting the voltage to earth and - to earth as 8zero0 on form1 it will be understood that this means zero using the galvanometer1 as herein described4 #d4 ,insulation of leads4--,turn the shunt to #j4 ,open the battery switch4 ,connect the earth leads ,,by and ,,ey to their proper posts4 ,connect the cable lead1 ,,px1 to 8cable0 post4 ,see that the cable tank ends of the lead ,,px is disconnected at ,x and suspended in the air4 ,close the battery switch4 ,close the key and turn the shunt to the unity post4 ,deflections should be as small as possible and in any case must be steady and uniform for several trials4 ,turn the shunt to #j4 ,reverse the key1 stopping at the discharge position4 ,turn the shunt to the unity post and wait until the galvanometer rests at #j1 indicating that the leads are discharged4 ,turn the shunt to #j4 ,close the key all the way down4 ,turn the shunt to the unity post4 ,the deflection should not differ materially from that noted above4 ,if there is a deflection1 the trouble is in the lead ,,px or its connections4 ,go over these1 carefully examining for dust and moisture and noting particularly the proximity of all wires of opposite potential which cross or lie near each other4 ,if there is a small deflection which can not be removed1 a correction must be applied subsequently to the deflection obtained in the test for the insulation resistance of the conductor4 ,using proper care1 there are very few days when perfect insulation of the instruments can not be secured4 ,the lead leakage with well-insulated wire put up properly will be noticed rarely4 #e4 ,use of ,price guard-wire4--,as an additional precaution against surface leakage across the insulation at the ends of the conductor it will sometimes be advisable to install an additional lead 7not necessarily as carefully insulated as ,,px7 running from the testing switch to the cable under test4 ,this lead should be connected in at the testing switch to the post carrying the lower blade between 8,d0 and 8,c0 7fig4 #af72 the tank end should be bare of insulation for a sufficient distance to enable the bare wire to be wrapped firmly1 without pinching1 around the insulation at each end of the particular conductor under test1 just below the tapered portion4 ,the potential difference between the cable core and this guard-wire is thus made practically nil1 so that any leakage will be from the guard-wire to the tank1 consequently this leakage will not be measured by the galvanometer4 ,,iv4 ,take the galvanometer constant as follows3 ,open the battery switch4 ,with a short piece of wire connect the hinge post of the testing key marked 8cable0 to either 8earth0 post of the key1 the leads to the cable tank being disconnected at ,e1 ,b1 and ,p4 ,turn the shunt to #j4 ,examine the megohm box and see that all the resistance coils are in the circuit4 ,close the battery switch and the testing key4 ,turn the shunt to the _/ post4 ,watch the swing of the galvanometer and when it has come to rest1 read and record4 ,turn the shunt to #j4 ,the galvanometer should return exactly to #j4 ,if it does not1 readjust and repeat until it does4 ,the galvanometer constant is numerically equal to the total throw in smallest divisions of the scale multiplied by #ajj4 ,remove the connecting wire and replace the leads to the tank4 ,if at any subsequent time during the test the galvanometer adjustment is disturbed--that is1 if it does not return accurately to zero when the shunt is at #j--the constant should be redetermined4 ,testing the cable4--#a4 ,see that the testing key is open and the shunt at #j4 ,connect the earth lead to ground on the cable armor4 ,remove the earth connection from ,no4 #a conductor and connect the cable lead to this conductor2 in wet weather the connector joint should be dipped in melted paraffin4 7,in using paraffin to insulate joints or ends bring it just above #bab ,f4 to evaporate any moisture present4 ,it should not be boiling4 ,the paraffin coating should be at least as thick as the rubber insulation and extend back over the rubber for an inch or more47 #b4 ,close the testing key to the left 7 to earth71 stopping at the discharge position1 and turn the shunt to the unity post4 ,there should be no deflection4 ,if there is1 it is due either to a charge on the cable1 which will disappear after a moment1 or to earth currents4 7,it is assumed that the testing apparatus has been thoroughly tested for insulation47 ,if due to earth currents1 the conductor is probably a poor one4 ,earth currents are readily recognizable by their fluctuating character4 ,before assuming that the trouble can not be removed1 the joint between the lead and the conductor should be examined again4 ,moisture on the cable end will give a path for earth currents4 ,note the value and direction of the throw of the galvanometer and record it4 #c4 ,turn the shunt to #j1 close the testing key all the way down 7 to earth71 noting the time to the second1 or starting the stop watch at the same time1 if one is available4 ,the time must be accurately noted4 ,the insulation resistance at the end of one minute's electrification is the resistance to be reported4 #d4 ,when #ce seconds have elapsed1 turn the shunt to the _/-post and watch the galvanometer throw2 if small1 move the shunt successively to the _/-post1 to the _/-post1 and to the unity post4 ,this operation must be completed before #de seconds have elapsed from the time the key was closed4 ,with good cable the unity post will always be reached without danger of throwing the galvanometer reading off the scale4 ,remember that each successive post should give #aj times the throw of the preceding post4 #e4 ,at the end of one minute read the deflection1 correct for the leakage of the leads and the earth currents1 and record4 7,see example following47 #f4 ,at the end of two minutes read the deflection1 correct and record it4 ,for good cable it should be less than the deflection observed at the end of one minute4 #g4 ,turn the shunt to #j1 and reverse the key1 stopping at the discharge position4 ,turn the shunt on gradually until the unity post is reached and wait until the reading is #j1 indicating that the conductor is discharged4 ,if earth currents are present1 #j will not be reached or will be passed4 ,in this case proceed as before described4 ,a submarine mine cable conductor a mile long will discharge ordinarily in about three minutes4 #h4 ,turn the shunt to #j1 stop and start the stop watch2 at the same time close the key all the way down 7- to earth74 #i4 ,after #ce seconds1 start turning the shunt1 ceasing at #de seconds4 7,see paragraph #d1 above47 #aj4 ,at the end of one minute read the deflection1 correct and record it4 ,for good cable it should be substantially the same as the deflection observed at the end of one minute with of the battery to earth4 #aa4 ,turn the shunt to #j1 and reverse the key1 stopping at the discharge position4 #ab4 ,disconnect ,no4 #b conductor from ground4 ,disconnect ,no4 #a from the lead and connect up ,no4 #b4 ,connect ,no4 #a to ground4 ,it is not necessary to wait for ,no4 #a to be discharged completely before disconnecting it4 #ac4 ,proceed with ,no4 #b as with ,no4 #a and repeat with each conductor4 #ad4 ,on the completion of the test all conductor ends should be carefully taped4 #ae4 ,to determine the correct value of the insulation resistance it is essential that the negative pole of the battery be connected to the core of the cable1 otherwise the products of electrolysis will tend to seal up any fault which may exist and will cause the conductor to appear better than it really is4 ,with the negative pole of the battery to the core the tendency is to deposit copper on the core and thus to lay bare any fault4 ,the insulation resistance of any conductor is therefore found by multiplying the corrected deflection at the end of one minute1 with of battery to earth1 by the denominator of the shunt used1 and then dividing the galvanometer constant by this product4 ,the resistance of the _/-megohm box is neglected unless the insulation resistance determined is very low1 say1 under #a megohm1 when the #ajj1jjj ohms should be subtracted from the above quotient4 #af4 ,to determine the insulation resistance per mile at #fj ,f41 multiply the actual insulation resistance found by the length of the cable in miles1 and this result by the multiplier furnished by the torpedo depot for the particular make of cable1 corresponding to the temperature of the water in the tank observed during test4 ,example4--,leakage of the leads found to be one-half division4 ,earth currents found to give #a divisions in a negative direction from #j of the scale4 ,galvanometer throw at the end of one minute 7 to earth71 #ae divisions4 ,the corrected deflection is1 #ae - #a #af divisions4 ,the galvanometer constant 7#dej divisions through _/ megohm1 shunt at _/71 #de1jjj megohms4 ,that is1 the battery will give _/ of #dej divisions #de through #a megohm1 the shunt at _/2 or1 what is the same thing1 one division through #de megohms1 the shunt at _/2 therefore with the shunt at unity the battery will give one division through #de #a1jjj #de1jjj megohms4 ,the insulation resistances #de1jjj #af #b1hac megohms4 ,if the cable is three-fourths mile long1 the insulation resistance in megohms per mile is #b1hac #b1aaj megohms4 ,manufacturer1 ,safety ,insulated ,wire ,cable ,co4 ,temperature of water in tank1 #hj ,f4 ,multiplier1 #a4gjef2 #b1aaj #a4gjef #c1eii megohms insulation resistance per mile at #fj ,f4 ,this result is recorded on the form4 ,,vi4 ,copper resistance4--#a4 ,the drop of potential method is quicker than the bridge method under the usual conditions and should be used if the apparatus is available4 ,apparatus required4--7a7 ,source of power 7#aaj volts ,d4 ,c4 lighting circuit1 casemate battery or generator72 7b7 a double-pole single-throw switch to which the power leads are attached2 7c7 a bank of ten #aaj-volt lamps in parallel2 7d7 a ,d4 ,c4 ammeter of not more than #j-be scale2 7e7 a ,d4 ,c4 voltmeter1 #j-aej scale4 ,place the lamp bank and the ammeter in one side of the power line from the switch to the conductor1 and the other end of the conductor to the other side of the power line4 ,connect the voltmeter across the ends of the cable so as to measure the drop of potential between the ends of the conductor being tested4 ,close the switch1 take simultaneous readings on the voltmeter and the ammeter and calculate the resistance4 ,with the apparatus described a conductor #a mile long will receive about #b amperes and show a drop of about #ej volts4 ,the lamps are inserted as a safety precaution4 ,in no case should the current through the conductor exceed #f amperes4 ,if the cable has been tested for insulation resistance and all the conductors show high insulation1 the lamps are not necessary1 provided the cable is at least a mile long4 #b4 ,the copper resistance found is reduced to that at #fj ,f4 by multiplying by the coefficient found in the following table with the temperature of the water in the tank at the time of the test as an argument3 ,reduction of copper resistance to #fj ,f4 ---------------------------------------- ---- ,temperature4 ,temperature4 ---------------------------------------- ---- ,f4 ,f4 #aj #a4abeb #ee #a4jaac #aa #a4abbd #ef #a4jjij #ab #a4aaif #eg #a4jjfh #ac #a4aafh #eh #a4jjde #ad #a4aada #ei #a4jjbc #ae #a4aaac #fj #a4jjjj #af #a4ajhf #fa 4#iigh #ag #a4ajei #fb 4#iief #ah #a4ajcb #fc 4#iicc #ai #a4ajje #fd 4#iiaa #bj #a4jigh #fe 4#ihhi #ba #a4jieb #ff 4#ihfg #bb #a4jibe #fg 4#ihdf #bc #a4jhii #fh 4#ihbd #bd #a4jhgc #fi 4#ihjb #be #a4jhdf #gj 4#igha #bf #a4jhbj #ga 4#igei #bg #a4jgid #gb 4#igch #bh #a4jgfi #gc 4#igag #bi #a4jgdc #gd 4#ifie #cj #a4jgag #ge 4#ifgd #ca #a4jfib #gf 4#ifec #cb #a4jffg #gg 4#ifcb #cc #a4jfda #gh 4#ifaa #cd #a4jfaf #gi 4#ieia #ce #a4jeia #hj 4#iegj #cf #a4jeff #ha 4#iedi #cg #a4jedb #hb 4#iebi #ch #a4jeag #hc 4#iejh #ci #a4jdib #hd 4#idhh #dj #a4jdfh #he 4#idfh #da #a4jddc #hf 4#iddh #db #a4jdai #hg 4#idbh #dc #a4jcie #hh 4#idjh #dd #a4jcga #hi 4#ichh #de #a4jcdg #ij 4#icfh #df #a4jcbc #ia 4#icdh #dg #a4jcjj #ib 4#icbh #dh #a4jbgf #ic 4#icjh #di #a4jbeb #id 4#ibhh #ej #a4jbbi #ie 4#ibfi #ea #a4jbjf #if 4#ibej #eb #a4jahb #ig 4#ibca #ec #a4jaei #ih 4#ibaa #ed #a4jacf #ii 4#iaib ---------------------------------------- ---- ,the true length of a cable should be that of its center conductor4 ,from the size of the conductor and its copper resistance the length of the cable may be computed by use of the following wire table3 ,table of resistances of pure copper wire at #fj ,f4 ------------------------------- ,size ,dia4 in ,ohms per ,b4 ,s4 mils4 #a1jjj feet4 ------------------------------- #a #bhi #j4aaiii #b #beh 4#aeacj #c #bbi 4#aijhj #d #bjd 4#bdjeh #e #ahb 4#cjcch #f #afb 4#chbef #g #add 4#dhbde #h #abh 4#fjhca #i #aad 4#gffif #aj #ajb 4#ifgdj #aa #ia #a4baifj #ab #ha #a4ecgi #ac #gb #a4icic #ad #fd #b4ddec #ae #eg #c4jacd #af #ea #c4hhhj #ag #de #d4ijcj #ah #dj #f4ahbg #ai #cf #g4hjbd #bj #cb #i4hcaf #ba #bh4e #ab4cig #bb #be4c #ae4fbe #bc #bb4f #ai4gab #bd #bj4a #bd4heg #be #ag4i #ca4cdc #bf #ae4i #ci4ece #bg #ad4b #di4hci #bh #ab4f #fb4hdh #bi #aa4c #gi4bej #cj #aj4j #ii4icb ------------------------------- ,the objections to the use of a bridge for measuring copper resistance are the difficulty of eliminating the resistance of the plug contacts and the time required to secure balance4 ,the resistance of the plug contacts may often be as high as #bj ohms1 particularly if used at the tank4 ,if the bridge is used at all1 it should be placed in the testing room1 and the same leads employed for testing insulation should be used4 ,the resistance of these leads should first be determined by connecting them together and measuring2 this resistance is subtracted from each resistance measured4 ,,vii4 ,general4--,the key to success in cable testing is great care in every detail4 ,the cable now being furnished is all tested with galvanometers having constants from #bjj1jjj to #bej1jjj megohms4 ,it has all been accepted after most careful test4 ,the chances are that it is good when it arrives at the post1 unless it has been mechanically injured in transit1 which should be ascertained by careful inspection when delivered at the post4 ,do not accept a single measurement if it shows low resistance1 but repeat until certain of results4 ,the time between trials on the same conductor should be as great as practicable4 ,for example3 ,measurements showing low resistance made in the morning should be repeated in the afternoon2 those made in the afternoon should be repeated the next day2 the conductor being connected to earth during the interval between tests4 ,,appendix ,,no4 #e4 ,,care ,,and ,,preservation ,,of ,,submarine ,,mine ,,mat,,riel4 ,frequent inspections of all articles of submarine mine equipment should be made1 not only to check up the property1 but also to determine the condition of all matriel1 and especially to see if it has been affected by dampness4 ,these inspections should be thorough and detailed1 as only in this manner can there be impressed on those directly charged with the care of the property the importance of ventilation1 dryness1 and the proper use of preservatives4 ,the generating set1 storage battery1 motor-generators1 casemate transformers1 power panel1 and operating boards will be installed in the mining casemate1 and such tools1 appliances1 and materials as may be used when this apparatus is in commission will also be kept there4 ,the explosive will be kept in the magazines and tested and cared for in the manner prescribed in ,appendix ,no4 #a4 ,the multiple and single conductor cable will be kept in the cable tanks as described in ,appendix ,no4 #d4 ,all other articles of equipment will ordinarily be kept in the storehouse1 and a noncommissioned officer will be placed directly in charge4 ,it shall be his duty to keep the matriel in the best possible condition1 using such details from the submarine mine detachment from time to time as may be necessary to assist him in this work4 ,he shall check up all articles taken from the storehouse during practice and report at the end of the day's work any shortage in tools or appliances that he may discover4 ,paints and oils should be kept separate from other stores1 and the floor where kept should be covered with #b or #c inches of sand1 to be renewed occasionally4 ,sawdust should never be used for this purpose4 ,cotton waste which has become unfit for use should be promptly burned4 ,fuses must not be stored with other explosives4 ,gasoline in considerable quantities should be stored in tanks underground and never inside of buildings4 ,small quantities should be kept outside of buildings in some safe place4 ,when oil engines or generators are out of commission1 their bright parts should be covered with light slushing oil4 ,brass screw threads and parts of tools that are liable to rust should be covered also4 ,in all cases the light slushing oil should be applied in a thin coat1 since this is all that is necessary to give good protection4 ,before applying the light slushing oil to any surface it should be thoroughly cleaned1 so as to be free from rust1 water1 kerosene and lubricating oil1 as their presence will cause rusting underneath the slushing oil4 ,the protected surfaces should be occasionally inspected and the coating of slushing oil renewed as often as required4 ,screw threads of mine cases1 steel screw threads of compound plugs1 bolts1 nuts and washers1 and surfaces of flat joints should be kept coated with the light slushing oil or a mixture of machine oil and graphite4 ,no oils or grease should ever be placed on points where metallic contact of electrical instruments is necessary1 nor on india rubber1 ebonite1 or slate4 ,mine cases should rest on racks or skids1 and where space permits should not be in contact with each other4 ,in handling mine cases care must be taken not to damage the bails and bolts4 ,they should be arranged so that the holes in the mine cases can be seen easily2 these holes should be fitted with a wooden plug which has been thoroughly greased all over its surface4 ,new mine cases1 if galvanized1 usually will not need painting until they have been in the water4 ,when taken from the water they should be thoroughly dried1 and if they should show signs of rust they should be gone over thoroughly with steel wire brushes until the rust is removed4 ,parts which can not be reached with the brush should be cleaned with three-cornered steel scrapers4 ,a heavy coat of red lead should then be applied4 ,seven gallons of this paint can be made by mixing #ajj pounds of red lead ground in oil with #e gallons of raw linseed oil4 ,this mixture should be applied within two or three weeks after mixing4 ,one gallon of paint should give #aj mine cases one coat4 ,after this coat has been allowed to dry there should be applied a coat of white lead toned down to a neutral gray4 ,seven gallons of this paint can be made by mixing #ajj pounds white lead1 #b gallons raw linseed oil1 #b gallons turpentine1 #a gallon liquid drier1 and adding about #a pound of lampblack to tone down the mixture4 ,mines treated in this way1 if kept in a dry storehouse1 and not put in the water1 should not require repainting for several years4 ,frequent inspection should be made1 however1 for in handling the cases and changing their positions on the racks1 it will often happen that an abrasion will be made in the surface of the paint1 which if neglected may serve as the starting point of a progressive corrosion1 which may extend rapidly under the surface of the paint4 ,should loose paint or rust be seen the case should be repainted4 ,a small wooden mallet may be used to tap the case at all points to loosen scales of rust or paint2 then the surface should be thoroughly wire brushed or scraped and the cases repainted as stated above4 ,the inside of mine cases must be inspected to see that the interior surfaces are kept free from rust4 ,ground mines and ground mine buoys should be treated in the manner just described for buoyant mine cases4 ,if the oil engine has not been painted1 it should be given a priming coat of red lead mixed in oil4 ,this should be rubbed down with pumice stone and two coats of steel-colored paint applied4 ,the second coat should be rubbed down and two coats of varnish then applied4 ,after this the engine should not need repainting for a couple of years4 ,when1 however1 repainting is necessary1 the engine should be rubbed down until all the varnish is removed and a coat of steel-colored paint applied4 ,this coat should be rubbed until no brush marks remain1 and one or two coats of varnish should then be applied4 ,the steel-colored paint should be applied flat2 that is1 the color which is ground in ,japan should be mixed with turpentine4 ,one gallon of this paint is more than sufficient to give an engine two coats4 ,the motor-generators and the casemate transformers usually will not need the priming coat of red lead1 as they come from the factory painted4 ,when it is necessary to paint them1 one coat of the steel-colored paint and one of varnish will usually be found sufficient4 ,anchors1 distribution boxes1 junction boxes1 mooring sockets1 shackles1 sister hooks1 and the ironwork of operating boards and power panels should be painted with asphaltum varnish4 ,paint brushes when new1 and before use1 should be wrapped or bridled with strong twine and soaked in water to swell4 ,after use they should be cleaned with turpentine and put away in water to keep them from drying and becoming unpliable4 ,large ropes should be stored on skids1 allowing a free circulation of air4 ,small ropes should be hung on wooden pins4 ,ropes should be uncoiled semiannually in dry seasons and stretched out for several days to dry4 ,wire rope must be stored in a dry place where it will not rust4 ,marline-covered wire rope should be stored where there is a fair circulation of air4 ,the date of receipt should be stenciled on each reel4 ,if not used at the end of five years it should be run through a bath of pure distilled tar oil4 ,this may be done by setting up an empty reel #bj feet in front of the full reel and placing a tub of the tar oil midway between them4 ,as the rope comes off the full reel it is passed through the oil and the surplus oil slicked off with a piece of burlap1 thus returning the oil to the bath4 ,the freshly oiled reel will continue to drip for several days1 and sand should be put on the floor under the reel to take up the excess oil4 ,after use in water the marline-covered rope should be thoroughly dried out and then reoiled as above described4 ,,appendix ,,no4 #f4 ,,instructions ,,for ,,masters ,,of ,,mine ,,planters4 ,the matter contained in this appendix is primarily for the information of the masters of those vessels which are called into service for mine planting purposes upon the outbreak or threatening of hostilities4 ,the master shall request to be supplied with a copy of ,regulations for ,mine ,planters1 ,u4 ,s4 ,army4 ,to each vessel will be assigned a coast artillery officer1 who shall be the commanding officer of the vessel4 ,all orders for the vessel shall be given to and through him4 ,he shall have general charge of its business and be responsible for the proper care and disposition of all stores aboard1 leaving to the master of the vessel the full and unquestioned control and authority over all matters for which he is professionally responsible4 ,any orders to be given by the commanding officer concerning the vessel or its crew will be given to or through the master1 except that when planting mines or operating any of the mining appliances or machinery aboard the vessel1 the commanding officer1 or an officer designated by him1 may give instructions directly to any of the vessel's officers or to members of the vessel's crew who have duties directly connected with the mining work4 ,the duties and responsibilities of the master of a vessel engaged in submarine mine work do not differ materially from those devolving upon him when his vessel is otherwise employed4 ,with respect to every duty the vessel may be called upon to perform1 it may be stated that explicit directions as to where the vessel is to go and just what maneuvers it is to execute in the mine field will be given by the officer aboard1 and it is then incumbent upon the master to execute the maneuver according to his best judgment4 ,the duties that vessels employed as mine planters are likely to be called upon to perform are as follows3 #a4 ,to lay out the mine fields4 #b4 ,to lay the multiple cable4 #c4 ,to plant mines4 #d4 ,to take up mines 7including replacing defective mines by good ones where necessary74 #e4 ,to take up the cable4 ,the commanding officer of the vessel is responsible for the proper equipment of the vessel with the necessary apparatus for mine planting1 for the loading of all the matriel prior to the planting1 and for the method of procedure under the above heads4 ,the master of the vessel will carry out the orders of the commanding officer and is concerned only in the handling of his boat to prevent accidents to it and to the boats engaged in the planting4 ,the following precautions will be observed by masters3 #a4 ,if current flows across the mine field the planting vessel1 to avoid accidents1 should always pass on the downstream side of the yawl boat holding the measuring line4 #b4 ,the greatest care should be taken that the measuring line and buoy ropes are not caught in the propellers4 ,if the vessel has twin screws1 the upstream propeller should be stopped as soon as the measuring line has been passed to the marking boat4 ,in all cases a man with a boat hook should be posted near the anchor davits and another amidships1 to hold the measuring line above the water and clear of the sides of the vessel4 ,keg buoys1 and as much of the buoy rope as possible1 should be held on the rail near the stern1 letting the rope pay out slowly and under tension1 until the propellers are past the rope1 then the keg and the remainder of the rope may be thrown overboard4 #c4 ,a general rule is never to back either propeller when buoy ropes1 measuring lines1 or cables are being handled overboard at or near the stern of the vessel4 #d4 ,if it becomes absolutely necessary to reverse the propellers when paying out cable1 men paying it out must haul it in taut and keep it above the wheel and clear of it4 ,the planting vessel should not pass nearer than #be feet to the distribution box boat when cable is leading out from the latter1 nor should it pass over any cable1 if it can be avoided1 if the depth is less than #af feet4 #e4 ,the vessel should proceed after passing the distribution box boat on such a course that cable will pay off smoothly without becoming entangled4 ,if a cable becomes fouled and entangled1 the end should be 8let go0 at once at the distribution box boat--the planter should proceed on1 not stop nor back its propellers4 ,mine cable should never be made fast in the distribution box boat until after a mine is dropped4 ,it is much better to drop the mine out of position than to endanger the propellers of the vessel4 ,the propeller nearest the distribution box should be stopped the moment the bow of the vessel passes the distribution box boat on its course to drop a mine4 #f4 ,if1 in planting1 the vessel moves against the direction of the current1 there is little danger of overturning the distribution box boat if ordinary caution is observed4 ,should it be necessary to plant against a cross current or with it1 it is best to pass the cable end to the distribution box boat by a launch or small boat4 ,in this way the planter need not pass within #ej or #ge yards of the boat4 #g4 ,to avoid getting foul of the buoy rope or mine after the mine is dropped1 the helm should be put over so as to throw the stern away from the mine4 ,the vessel should be under good headway so that the propellers may be stopped until they are well past the buoy and buoy ropes of the mine4 ,these points are important2 failure to observe them will result disastrously4 ,in laying multiple cable1 the course of the vessel invariably should be against the current4 ,rather than lay cable with the current it is advisable to postpone laying the cable until a change of the tide causes a favorable direction of current4 ,in the end1 time will be saved by waiting4 ,cable should pay off on the upstream side of the vessel if any cross current is running4 ,all care should be taken that the cable does not get caught in the vessel's propellers4 ,this is of the greatest importance4 ,as the cable pays out over a chock near the bow of the vessel a man should stand by with a #c-;inch strap in readiness to stop the cable should it be necessary1 and two men should manipulate brakes to prevent the cable from paying out too rapidly4 ,this is especially necessary if the water is deeper than #ej feet4 ,especial care is necessary in planting mines to avoid3 7a7 ,colliding with yawl or distribution box boat2 7b7 picking up cable in the propeller2 7c7 getting the mine cable tangled2 7d7 drifting over the mine after it is dropped4 ,,appendix ,,no4 #g4 ,,manual ,,for ,,small ,,boats4 ,the left-hand side of a boat or ship1 looking toward the bow1 is the port side1 and the other is the starboard side4 ,the men who row on the port side are called the port oars and those rowing on the starboard side are called the starboard oars4 ,boats are called single or double banked1 according as they have one or two oarsmen to a thwart4 ,thwarts are the seats on which the crew sits2 the space abaft the after thwart is called the stern sheet4 ,floorings and gratings are the bottom boards of a boat4 ,they prevent the weight from bearing directly upon the planking4 ,the gunwale of a boat is the upper rail4 ,the yoke is an athwartship piece of wood or metal fitting over the rudderhead4 ,yoke lanyards are the small lines made fast to the ends of the yoke1 by which the rudder is turned and the boat steered4 ,the stem is the upturned portion of the keel at the bow of the boat1 to which the forward ends of the planks are secured4 ,oars are said to be double banked when two men pull one oar4 ,the blade of an oar is the broad flattened part4 ,the handle is the small part of an oar on the inboard end of the loom1 which the oarsman grasps when pulling4 ,the loom is the portion of an oar extending from the blade to the handle4 ,the leather is the portion of an oar which rests in the rowlock4 ,this is sometimes covered with canvas1 but is usually covered with leather2 hence the name4 ,feathering is the term applied to the operation of turning the blades nearly flat to the water after the stroke1 with the upper edge turned forward1 especially valuable in rowing against a head wind4 ,rowlocks are forked pieces of metal in which the leather of the oars rests while pulling4 ,swivel rowlocks are movable1 a pin on the rowlock fitting into a socket in the gunwale4 ,thole pins are pins set vertically in the gunwale and are used in place of rowlocks4 ,the steering rowlock is a peculiar form of swivel rowlock 7fitted near the stern of a boat7 in which the steering oar is shipped4 ,this is sometimes called a crutch4 ,the painter is a rope secured in the bow for towing or for securing the boat4 ,boat-falls are tackles made with two blocks and a length of rope2 used for hoisting boats4 ,the plug is the wooden stopper fitted into a hole in the bottom of a boat to let water in or out4 ,a boat breaker is a small keg used for carrying fresh water4 ,a boat-recall is an understood signal made to order a boat's return4 ,,boat ,,orders4 ,oars and rowlocks having been placed in the boat1 blades of oars toward the bow1 rudder and yoke1 if any1 stepped and the yoke lanyards clear1 the men board and take their proper seats4 ,the man pulling the bow-oar is ,no4 #a1 the next man is ,no4 #b1 and so on1 to the man pulling the stern-oar1 who is called the 8stroke-oar40 ,the men being seated1 with oars handy1 the bow-man1 who may be ,no4 #a or an extra man1 as convenient1 holds onto the wharf1 side1 or piling1 as the case may be1 with his boat hook4 ,shove off4--,at this command the bow-man shoves the boat clear1 giving her headway if possible4 ,he boats his boat hook and takes his seat4 ,up oars4--,the crew simultaneously seize and raise their oars smartly to the vertical 7guiding on the stroke-oar7 and hold them directly in front of them1 the blades fore-and-aft1 inboard hands grasping the handles1 holding the same well down between the knees1 outboard hands grasping the looms at the height of the chin4 ,let fall4--,the oars are eased down into the rowlocks together1 brought level with the gunwale1 blades horizontal and all trimmed on the after oars4 ,oars must not be allowed to splash4 7#a7 ,give way together1 7#b7 ,,give ,,way4 ,at the first command the men reach well forward1 blades nearly vertical1 ready for the stroke4 ,at the second command they dip their oars at the same time as the stroke-oar and commence rowing1 keeping stroke exactly and all lifting their blades to the height of the gunwale on the return4 7,or higher if waves render this necessary47 ,,to ,,make ,a ,,landing4 ,in running alongside a vessel or up to a float-stage or wharf1 when several lengths away from same1 give the command 7while the oars are in the water71 ,,in ,,bows4 ,the bow oarsman 7if there be no extra man in the bow7 finishes his stroke1 then 8tosses0 and 8boats0 his oar1 blade to the bow1 and stands ready with the boat hook to fend off and hold the landing4 ,when there is sufficient headway to carry the boat properly to the landing1 give the command1 ,,way ,,enough4 ,this order is given while the oars are in the water2 the men finish the stroke1 then toss and boat their oars with as little noise as possible4 ,the oars are next the rail1 the after oars outboard of the bow oars4 ,if the stroke oarsman is provided with a boat hook1 he grasps it and stands ready to help the bow man4 ,if it be desired to stop rowing temporarily1 give the preparatory command1 7#a7 ,stand by to lay on oars1 at which the crew pays strict attention4 ,then1 when ready1 give 7#b7 ,,oars4 ,at this command1 given while the oars are in the water1 the crew finishes the stroke and brings the oars level with the gunwale1 blades horizontal1 trimmed on the after oars4 ,this position is also used for salutes1 as noted hereafter4 ,if about to pass so close to another boat that a collision of oars seems probable1 command 7#a7 ,trail1 7#b7 ,,oars4 ,at the second command1 given while the oars are in the water1 the men finish the stroke1 and then1 while the oars are still in the water1 by lifting the handles with their outboard hands the looms are thrown out of the rowlocks4 ,the men carry their hands outboard till the backs of their wrists rest on the rails and the oars trail astern4 7,this movement is used in shooting bridges1 where lack of head room precludes tossing47 ,to bring the oars inboard1 command3 ,,oars4 ,at this command the men raise the handles1 lower the looms into the rowlocks1 and then raise the blades out of the water and swing the oars to the regular position of ,let fall4 ,in order to turn the boat short around 7being stationary or nearly so7 command3 7#a7 ,give way1 starboard2 back port1 7#b7 ,,give ,,way2 or 7#a7 ,give way1 port2 back1 starboard1 7#b7 ,,give ,,way4 ,the crew keeps stroke just as regularly as in pulling straight away4 ,as soon as the boat points in the desired direction command3 7#a7 ,give way together1 7#b7 ,,give ,,way4 ,if it be desired to check the boat's headway1 command3 ,,hold ,,water4 ,at this command the men drop their blades vertically into the water1 tops of blades inclined slightly forward1 inboard hands grasping the handles1 outboard arms over the looms to steady the oars against the chest4 ,to prepare the crew for rowing command ,,oars1 at which they resume the position described under the heading ,let fall4 ,to move the boat astern command ,,stern ,,all4 ,at this command the men back water1 keeping stroke as regularly as in ordinary rowing4 ,to resume the position of attention give the command ,,oars1 as before4 ,to toss oars command3 7#a7 ,stand by to toss1 7#b7 ,,toss4 ,the command of execution is given while the oars are in the water1 the stroke is completed and the oars raised smartly to the vertical1 with blades in fore-and-aft plane1 handles of oars on bottom boards1 the wrists of the inboard hands resting on the thighs1 outboard hands grasping the looms at the height of the chin1 crew sitting upright4 ,to place the oars in the boat give the command ,,boat ,,your ,,oars4 ,at this command the oars are lowered toward the bow 7not swung outboard7 and laid in the boat as before described4 ,this command may be given from the position of ,let fall1 in which case the men toss their oars and proceed as above4 ,,notes4 ,in rowing the blade of the oar should be raised as high as the gunwale after leaving the water and feathered by dropping the wrist4 ,a barely perceptible pause should be made1 and the oar next thrown well forward and dropped edgewise into the water1 taking care to avoid splashing and chopping4 ,now swing the oar smartly through the water without giving it any final jerk1 and repeat as above4 ,with green crews it may be found necessary for the coxswain to call stroke1 stroke1 in order to get the men to pull exactly together4 ,there should be a mark on the loom of the oar 7about the height of the eyes when the oar is at toss7 to show when the blade is fore-and-aft1 thus avoiding the necessity of the men gazing up for the purpose of finding out when this is the case4 ,never allow a boat's crew to splash with the blades when executing ,let fall4 ,when resting on oars1 insist that they be kept level with the gunwale and at right angles to the keel4 ,talking among the crew and turning the heads to look at any object should never be allowed while the boat is under way4 ,in most cases1 boats should be permanently equipped with a small breaker of fresh water1 a spare oar and oarlock and a suitable anchor or grapnel4 ,the anchor rope to withstand a storm should be six 7#f7 times as long as the greatest depth liable to be used as an anchorage4 ,for any small boat in our service a #bj-pound anchor and #ab-thread 7about #a inch7 manila hawser should easily weather a hurricane4 ,a boat should never go out at night without a good1 well-filled lantern4 ,many a boat has been run down through its inability to make its presence known4 ,before leaving the shore in foggy weather1 provide the boat with some sort of a foghorn and a compass1 and calculate as nearly as possible the bearings of the landing you wish to make4 ,take the opposite of this upon returning1 making due allowance for tide and wind in both cases4 ,to ride out a gale of wind in an open boat1 lash the oars and grating together1 making them into a bulky bundle and weight them if possible2 span them with the painter and pitch them overboard4 ,this will keep the boat's head to the sea and prevent her from drifting fast4 ,assist the boat to take the seas head-on by means of a steering oar4 ,in rowing through a chop1 where the rudder is apt to be pitched clear of the water1 it should be unshipped and a steering oar used instead4 ,remember1 in making a landing1 that the heavier the boat is laden the longer she will keep her way4 ,if you are being towed by a steamer1 make her give you a line1 instead of using your own1 and belay it so it can be cast off in a hurry4 ,carefully avoid weighing down the bow2 always use a short towline when the boat is empty and a long towline when the boat is laden4 ,if the boat's painter is used for a towline1 have a knife ready for cutting it if it becomes necessary4 ,never go close under a steamer's stern unless it is absolutely unavoidable4 ,officers in boarding a ship1 use the starboard gangway1 although they may use the port gangway4 ,enlisted men use the port gangway or the booms1 unless otherwise ordered4 ,boat salutes4--,the following salutes should be exchanged between boats meeting or passing each other4 ,no junior should pass ahead of a senior without permission4 ,the junior should always salute first1 and the senior should return the salute by touching his cap4 ,salutes should be exchanged whenever boats pass near enough to each other for the senior officer to be recognized1 whether he be in uniform or not4 ,officers without a flag or pennant flying should be saluted with the hand only2 those with a flag or pennant flying should1 in addition1 be saluted by laying on oars4 ,when a noncommissioned officer is in a boat and meets another boat containing an officer he stands and salutes4 ,if the boat flies a flag or pennant1 the noncommissioned officer1 in addition1 lays on oars4 ,officers of the ,navy and ,marine ,corps and foreign officers in boats should always be saluted when recognized4 ,in laden boats1 towing boats1 or boats under sail the hand salute only is made on all occasions4 ,coxswains in charge of boats shall always rise and salute when officers enter or leave their boats4 ,boat keepers shall stand up and salute officers passing in boats and remain standing until the boat has come alongside or passed4 ,,appendix ,,no4 #h4 ,,supply ,,list4 ,,apparatus4 ,ammeters1 portable1 #j-be scale1 #a to each post4 ,anchors1 buoy1 #ejj pounds1 #e to each group of #ai mines4 ,anchors1 mine1 #a to each buoyant mine4 ,axle1 cable-reel1 #a to each cable-reel frame4 ,balances and weights1 #a set to each post4 ,battery1 storage1 #a to each casemate4 ,boards1 operating1 #a to each group of #ai mines4 ,boxes1 distribution1 #a to each group of #ai mines4 ,boxes1 distribution1 #a to each group of #g mines4 ,boxes1 junction1 large1 #c to each mile of multiple cable4 ,boxes1 junction1 small1 #a to each mile of single-conductor cable4 ,buoy1 distribution box1 #a to each distribution box4 ,buoy1 marking1 #e to each group of #ai mines4 ,buoy1 mine1 #a to each buoyant mine4 ,cable1 submarine1 #ai-;conductor1 according to project4 ,cable1 submarine1 #g-;conductor1 according to project4 ,cable1 submarine1 #a conductor1 according to project4 ,cases1 guncotton1 as required4 ,circuit closer1 #a to each mine transformer4 ,clips1 cable1 #b for each mine4 ,engine1 internal combustion1 #a to each casemate4 ,frame1 cable-reel1 #c to each post4 ,fuse can1 #a to each compound plug4 ,generator1 casemate1 #a to each casemate4 ,mine cases1 according to project4 ,motor generator1 ,d4 ,c4-,a4 ,c41 #b to each casemate4 ,panels1 power1 #a to each casemate4 ,planting equipment for emergency vessels1 #a to each vessel3 ,each planting equipment consists of-- #a axle1 cable-reel4 #d blocks1 snatch4 #d blocks1 triplex1 #b-ton4 #b come-alongs4 #b davits1 anchor4 #b davits1 mine4 #a frame1 cable-reel4 #d hooks1 trip4 ,plugs1 compound1 #a to each mine case4 ,reels1 cable1 according to cable on hand4 ,reel and frame1 measuring1 #a to each mine field4 ,shackles1 anchor1 #b to each anchor4 ,shackles1 mine1 #b to each mine4 ,sister hooks1 #a pair to each anchor4 ,sockets1 mooring1 #b to each buoyant mine1 for wire rope only4 ,springs1 automatic anchor1 #f extra for each group of #ai mines4 ,switches1 starting1 #a to each motor generator1 ,d4 ,c4-,a4 ,c4 ,telephones1 boat1 #d to each mine field4 ,testing set1 insulation1 #a to each post having a cable tank3 ,each testing set consists of-- #a box1 resistance1 #ajj1jjj ohms4 #b cases for instruments4 #a galvanometer1 ,d',arsonval1 reflecting4 #a key1 special insulation testing4 #a repair kit4 #a shunt1 ,ayrton ,universal4 ,transformer1 casemate1 #b to each casemate4 ,transformer1 mine1 #a to each mine4 ,voltmeter1 portable1 #j-c-volt scale1 #a to each storage battery4 ,voltmeter1 portable1 #j-aej-volt scale1 #b to each post4 ,weights1 distance1 for automatic anchor1 #f extra for each group of #ai mines4 ,,utensils4 7,supply for each post1 unless otherwise indicated47 #a anvil1 #ej-pound4 #c axes1 handled4 #f basins1 wash4 #bd binding posts 7to each casemate74 #b blocks1 tackle1 double4 #b blocks1 tackle1 single4 #f boxes1 tool4 #f brushes1 battery4 #f brushes1 dust4 #f brushes1 paint1 flat4 #f brushes1 paint1 oval4 #ab brushes1 sash4 #ab brushes1 scratch4 #f buckets1 galvanized iron4 #a chest1 carpenter's tool3 ,the chest contains the following tools-- #a bits1 set1 of #ac4 #a bit1 expansive1 #a brace1 ratchet4 #a chisels1 carpenter's1 set of #f4 #a hammer1 claw4 #a knife1 drawing4 #a level1 carpenter's4 #a oilstone4 #a plane1 jack4 #a plane1 smooth4 #a rule1 #b-;foot4 #a saw1 compass4 #a saw1 hand4 #a saw1 rip4 #a saw set4 #a square1 carpenter's4 #f chisels1 cold4 #d clips1 wire rope 7for each buoyant mine74 #d coppers1 soldering4 #c crowbars4 #f cups1 drinking4 #b cutters1 cable4 #a dies1 letters1 set4 #a dies1 numbers1 set4 #a drill1 breast4 #a drill points1 set of #ae4 #f files1 #f-;inch1 flat bastard4 #c files1 #f-;inch1 slim taper4 #f funnels1 loading1 large4 #f funnels1 loading1 small4 #a gloves1 rubber1 pair 7to each storage battery74 #a grindstone4 #bd hacksaw blades4 #d hacksaw frames4 #f hammers1 ball peen4 #f hammers1 smith's4 #b handles1 with tools4 #c hatchets4 #f hooks1 boat4 #b hydrometers1 battery 7to each storage battery74 #c irons1 calking4 #d irons1 grappling4 #abj knives1 submarine mine 7for each mine company1 to be issued as part of equipment74 #c ladles4 #f lamps1 alcohol4 #b lamps1 battery inspection 7to each storage battery74 #c lamps1 ,khotal4 #e leads1 sounding4 #ab levers for socket wrenches4 #ab life buoys4 #ab life preservers4 #b mallets1 large4 #b mallets1 small4 #ab marlinespikes4 #f megaphones4 #a oilers and tray1 set 7to each casemate74 #ab padlocks1 brass1 with chain4 #b pitchers1 acid 7to each storage battery74 #b plates1 earth4 #gj pliers1 side cutting1 #e inch 7for each mine company1 to be issued as part of equipment74 #ej pliers1 side cutting1 #h-;inch 7for each mine company1 to be issued as part of equipment74 #c pots1 melting4 #d pumps1 boat 7to each mine field74 #b scales1 extension spring1 reading #bjj pounds4 #a scales1 portable platform4 #f scissors1 #h-;inch4 #f scoops1 large1 for trotol only4 #f scoops1 small1 for trotol only4 #ab scrapers1 iron1 with handle4 #d screw-drivers1 large4 #d screw-drivers1 medium4 #d screw-drivers1 small4 #f switches1 assorted 7to each casemate74 #b syringes1 battery 7to each storage battery74 #c tapes1 measuring4 #b thermometers1 battery 7to each storage battery74 #b thermometers1 cable tank4 #b thimbles1 galvanized iron 7to each buoyant mine case74 #b tongs1 cable-reel4 #f torches1 gasoline1 hand4 #b trucks1 mine case4 #f vises1 bench1 large4 #f wrenches1 monkey1 #h-;inch4 #f wrenches1 monkey1 #ae-;inch4 #ab wrenches1 ,s4 #f wrenches1 socket4 #f wrenches1 spanner4 #c wrenches1 ,stillson4 #f wrenches1 ,t1 small4 ,,expendable ,,stores4 ,alcohol1 wood1 #e gallons to each post4 ,antimony for socket alloy1 #aj pounds to each #ai mines4 ,books1 record of cable test1 #a to each post4 ,books1 daily test1 #b to each post4 ,books1 note1 #bd to each post4 ,brushes1 carbon1 #d extra for each machine requiring them4 ,brushes1 wire1 #d extra for each machine requiring them4 ,cells1 dry1 large1 #be to each post4 ,cells1 dry1 small1 #ajj to each post4 ,cement1 rubber1 #c pounds to each #ai mines4 ,cleats1 porcelain1 #a-wire1 #ej to each casemate4 ,cleats1 porcelain1 #b-wire1 #ej to each casemate4 ,collars1 ,turk's-head1 large1 #aj to each mile of #g-;conductor cable4 ,collars1 ,turk's-head1 medium1 #aj to each mile of #ai-;conductor cable4 ,collars1 ,turk's-head1 small1 #e to each mine4 ,compound1 commutator1 #a stick to each casemate4 ,connectors1 double1 #be to each casemate4 ,cords1 telephone1 #d extra4 ,crayons1 marking1 #ab to each storehouse4 ,cut-outs1 porcelain1 #b to each casemate4 ,drier1 as required4 ,electrolyte1 specific gravity #abaj1 #d carboys to each casemate4 ,explosive1 according to project4 ,fuses1 service1 #d to each mine4 ,gasoline1 for torches1 #aj gallons to each post4 ,glands for compound plugs1 #b extra for each plug4 ,glue1 #e pounds to each post4 ,graphite1 as required4 ,handles1 assorted1 as required for repairing tools4 ,insulators1 glass1 #be to each storehouse4 ,jointers1 copper1 #a pound to each #ai mines4 ,keys1 distribution box1 flat1 #d extra to each box4 ,keys1 distribution box1 split1 #d extra to each box4 ,keys1 mine case1 #b extra for each mine case4 ,keys1 shackle1 #a extra to each shackle4 ,knobs1 porcelain1 #ajj to each post4 ,lampblack1 #b pounds to each #ajj pounds of white lead4 ,lamps1 incandescent1 white1 #aaj volts1 #af-;candlepower1 #ab to each casemate4 ,lamps1 incandescent1 white1 #hj volts1 #af-;candlepower1 #ab to each casemate4 ,lamps1 incandescent1 red1 #hj volts1 #h-;candlepower1 #c to each operating board4 ,lamps1 incandescent1 green1 #de volts1 #h-;candlepower1 #c to each operating board4 ,lamps1 incandescent1 green1 #de volts1 #af-;candlepower1 #c to each operating board4 ,lamps1 incandescent1 green1 #de volts1 #cb-;candlepower1 #c to each operatingboard4 ,lead1 for socket alloy1 #ij pounds for each #ai mines4 ,lead1 red1 as required4 ,lead1 white1 as required4 ,line1 cod1 #b1jjj feet to each post4 ,line1 measuring1 #b1jjj feet to each post4 ,line1 sounding1 #ejj feet to each post4 ,lye1 as required4 ,marline1 #a pound to each mine4 ,nails1 assorted sizes1 #be pounds to each post4 ,needles1 cleaning1 for ,khotal lamps1 #f to each post4 ,nipples1 soft rubber1 #a to each hard rubber fuse can4 ,oakum1 #ej pounds to each post4 ,oil1 cylinder1 #e gallons to each casemate4 ,oil1 dynamo1 #a gallon to each casemate4 ,oil1 lubricating1 #a gallon to each storehouse4 ,oil1 linseed1 as required1 #c gallons to #ajj pounds of lead4 ,oil1 slushing1 #e gallons to each post4 ,oil1 tar1 as required for marline-covered rope4 ,oil1 transformer1 #a gallon to each casemate transformer4 ,packing1 asbestos sheet1 #b pounds to each casemate4 ,packing1 asbestos wick1 #a pound to each casemate4 ,packings1 rubber1 #ajj to each #ai mines4 ,paint1 acid-resisting1 as required4 ,paint1 steel color1 for casemate apparatus1 as required4 ,paste1 soldering1 #a pound to each post4 ,paraffin1 #aj pounds to each post4 ,pencils1 lead1 #f dozen to each post4 ,plugs1 attachment1 #f to each post4 ,pomade1 ,putz1 #c pounds to each post4 ,primers1 explosive1 #a to each mine charge4 ,pumice stone1 #b pounds to each casemate4 ,resin1 #b pounds to each post4 ,rope1 for distance weight1 #bj feet for each automatic anchor4 ,rope for heaving lines1 #a1bjj feet to each post4 ,rope for lashings1 #a1bjj feet to each post4 ,rope1 marline-covered1 according to project4 ,rope1 raising1 #ej per cent more than of mooring rope4 ,rope1 wire mooring1 according to project4 ,rosettes1 #bd to each post4 ,ruberine1 #e gallons to each post4 ,sandpaper1 #dh sheets to each post4 ,sapolio1 #aj cakes to each post4 ,screws1 brass1 assorted sizes1 #a gross when required4 ,screws1 iron1 assorted sizes1 #a gross when required4 ,screws1 set1 for compound plugs1 #a extra set for each compound plug4 ,screws1 set1 for mine transformers1 #a extra set for each mine transformer4 ,shellac for insulation purposes1 #e pounds to each post4 ,soap1 #be cakes to each post4 ,sockets1 lamp1 #ab to each casemate4 ,solder1 wire1 #e pounds to each post4 ,staples1 large1 #bj pounds to each post4 ,staples1 small1 #a pound to each post4 ,suspensions1 galvanometer1 lower1 #c to each insulation testing set4 ,suspensions1 galvanometer1 upper1 #f to each insulation testing set4 ,tags1 brass1 #ej per group of #ai mines4 ,tags1 lead1 #ej per group of #ai mines4 ,tags1 linen1 #ej per group of #ai mines4 ,tape1 protective1 #e pounds to each #ai mines4 ,tape1 rubber1 #e pounds to each #ai mines4 ,tinfoil1 #a pound to each #ai mines4 ,towelling1 #aj yards to each post4 ,tubes1 porcelain1 #ab to each post4 ,turpentine1 as required4 ,twine1 #c pounds to each #ai mines4 ,varnish1 asphaltum1 as required4 ,varnish1 spar1 as required4 ,washers1 brass1 #ajj to each #ai mines4 ,washers1 lead1 #a extra set for each compound plug4 ,waste1 cotton1 #ej pounds to each post4 ,wire1 casemate1 extra1 #ajj feet each of black1 blue1 red1 and brown to each casemate4 ,wire1 fuse1 #a pound each of #c1 #ab1 and #be ampere to each casemate4 ,wire1 lamp-cord1 extra #ajj feet to each casemate4 ,wire1 loading1 #bj feet to each mine4 ,wire1 soft-drawn copper4 ,remarks3 7a7 ,clips and thimbles1 scales1 extension spring1 marline-covered rope1 and parts for automatic anchors are required only at posts supplied with automatic anchors4 7b7 ,loading scoops are required only at posts supplied with trotol4 7c7 ,in the case of articles to be supplied 8as required0 it is not contemplated that they shall be kept on hand in larger quantities than required for immediate needs4 ,illustration3 ,,fig4 #ag;a4--,,improvised ,,mine ,,target4 ,illustration3 ,,fig4 #ag;b4--,,improvised ,,mine ,,target4