,transcrib]'s ,notes3 ,und]scores 80 be=e & aft] a ^w or phrase indicate italics 9 ! orig9al text4 ,equal signs 80 be=e & aft] a ^w or phrase indicate bold 9 ! orig9al text4 ,small capitals h be5 conv]t$ to ,,solid capitals4 ,illu/rations h be5 mov$ s !y d n break up p>agraphs4 ,typographical & punctuation errors h be5 sil5tly correct$4 ,hoi/+ ,appliances ,by ,i4,c4,s4 ,,/aff ,,hoi/+ ,p>ts #c-d #ddg ,publi%$ by ,,int]national ,,textbook ,,company ,,scranton1 ,,pa4 ,hoi/+1 ,p>ts #c & #d3 ,copyright1 #aijf1 by ,,int]national ,,textbook ,,company4 ,ent]$ at ,/ation]s' ,hall1 ,london ,all rights res]v$ ,pr9t$ 9 ,u4 ,s4 ,a4 ,,int]national ,,textbook ,,press ,scranton1 ,pa4 ,,cont5ts ,,note4--,?is book is made up ( sep>ate p>ts1 or sections1 z indicat$ by _! titles1 & ! page numb]s ( ea* usually beg9 ) #a4 ,9 ?is li/ ( cont5ts ! titles ( ! p>ts are giv5 9 ! ord] 9 :i* !y appe> 9 ! book1 & "u ea* title is a full synopsis ( ! subjects treat$4 ,,hoi/+1 ,,"p #c ,pages ,hoi/+ ,appliances #a-dc ,hoi/ ,indicators #a-e ,column indicators2 ,dial indicators2 ,special indicators4 ,drums & ,reels #f-bj ,cyl9drical ,drums #g-h ,conical ,drums #i-af ,hoi/+ ) cyl9drical drums2 ,hoi/+ ) conical drums2 ,comp>ison ( cyl9drical & conical drums4 ,flat ,rope ,reels #ag-bj ,rope ,:eels #ba-bf ,koepe sy/em2 ,:it+ sy/em2 ,modifi$ ,:it+ sy/em4 ,rope ,fa/5+s #bg ,clut*es #bh-ca ,jaw clut*2 ,b& friction clut*es2 ,beekman friction clut*4 ,brakes #cb-dc ,block brake2 ,po/ brake2 ,/rap brake2 ,diff]5tial brake2 ,p[] = brakes2 ,diff]5tial lev]2 ,p[] brakes2 ,crank brake4 ,,hoi/+1 ,,"p #d ,hoi/+ ,appliances #a-ea ,%eaves #a-e ,ca/-iron %eave2 ,wood-l9$ %eaves2 ,diamet] ( %eave2 ,roll]s & c>ry+ %eaves4 ,cages = ,v]tical ,%afts #f-aa ,con/ruction ( cage2 ,safety cat*es2 ,multiple-deck cages4 ,automatic ,dump+ ,cages #ab-af ,def9ition2 ,slope1 or incl9$ %aft hoi/+2 ,slope c>riage4 ,skips1 or ,gunboats #ag-bb ,def9ition2 ,me?od ( load+ skips2 ,me?od ( dump+ skips2 ,skip cage4 ,buckets #bc ,c> ,locks #bc-bd ,cage ,guides #be ,l&+ ,fans1 or ,keeps #bf-bh ,common =ms ( fans2 ,hydro/atic fans2 ,pneumatic fans2 ,cage *airs4 ,head-,frames #bi-de ,head-frames 9 g5]al2 ,types ( head-frames2 ,examples ( v>i\s types2 ,head-frame specification4 ,deta*+ ,hooks #df-dg ,signal+ #dh-ea ,hamm]-&-plate signal2 ,electric bells2 ,speak+ tubes2 ,pneumatic gong signal2 ,telephones4 ,,hoi/+ ,s]ial #hea;,c 7,,"p #c7 ,edition #a ,,hoi/+ ,,appliances ,,hoi/ ,,indicators #a4 ,! hoi/ indicator is a me*anism atta*$ to ! drum %aft ( a hoi/+ eng9e to %[ ! hoi/+ eng9e] ! position ( ! cage or skip 9 ! %aft ?r\gh\t ! "t ( hoi/+4 ,! use ( su* indicators is sometimes requir$ by law1 b !re is a great div]sity ( op9ion z to ! advisability ( us+ !m4 ,! objections to !m are t !y are liable to get out ( ord]1 & t 9 g5]al ! use ( any automatic device t t5ds to relieve ! hoi/+ eng9e] ( responsibility & con/ant att5tion to 8 eng9e is n to be comm5d$4 ,a hoi/+ eng9e]1 h[ev]1 dep5ds = 8 /opp+ po9t ma9ly on a m>k made on ! rope1 or on ! drum1 or on bo?1 & uses an indicator mo/ly z a guide = ! position ( ! cage dur+ ! hoi/4 ,,types ,,( ,,indicators #b4 ,column ,indicators4--,a v simple indicator1 & "o t 0 =m]ly v commonly us$1 is made by ins]t+ a p9 into ! c5t] ( ! end ( ! drum %aft & us+ ?is z a m9iature drum on :i* to w9d & unw9d a *a9 or cord1 :i* corresponds to ! hoi/+ rope z ! p9 corresponds to ! drum4 ,?is *a9 or cord is l$ ov] a pulley plac$ at ! top ( a pair ( guides1 repres5t+ ! %aft1 & c>ries at its end a weight1 po9t]1 or gong1 repres5t+ ! cage or c>1 z %[n 9 ,fig4 #a4 ,illu/ration3 ,,fig4 #a ,illu/ration3 ,,fig4 #b ,! diff]5t l&+s 9 ! %aft are m>k$ on ! guide2 & z ! po9t] or gong rises & falls x indicates ! position ( ! cage 9 ! %aft4 ,if a gong is us$1 po9t] also may be add$ & ! gong s arrang$ t x w r+ at a po9t "s di/ance be=e ! l&+ is rea*$ & ?us attract ! eng9e]'s att5tion4 ,indicators ( ?is k9d1 ?\gh *eap & easily con/ruct$1 are n reliable1 = ! cord & *a9 may /ret* or !y may ov]lap 9 w9d+ on ! p91 or may b9d 9 ! pulley & ?us indicate a wrong position ( ! cage4 #c4 ,an indicator %\ld h a positive motion & be driv5 by ge>+ or by l9k belts4 ,fig4 #b %[s a column indicator t consi/s ( a screw a work+ inside ( a slott$ pipe b1 :i* may be ( any l5g? necess>y4 ,?is screw is revolv$ by means ( ! ge>s c1 :i* are rotat$ by ! sprocket :eel d4 ,a nut e travels up & d[n ! screw a & ! po9t] f atta*$ to ! nut indicates ! position ( ! cage 9 ! %aft4 ,! pipe /&>d b is usually pa9t$ a dead black & ! diff]5t levels may be m>k$ on x ) *alk or :ite pa9t4 ,*alk m>ks are n safe1 z !y may be tamp]$ ) & ! eng9e] ?us misl$4 ,illu/ration3 ,,fig4 #c ,! po9t] a1 ,fig4 #c1 is mov$ by ! rotation ( ! screw %aft b1 :i* is revolv$ by ! bevel ge>s c & d4 ,?is indicator also regi/]s ! numb] ( hoi/s by means ( ! dials e1 = at ea* hoi/ ! l[] end ( ! po9t] a engages a rat*et :eel beh9d ! two dial faces %[n & ?us regi/]s on ! dial4 ,illu/ration3 ,,fig4 #d #d4 ,dial ,indicators4--,fig4 #d %[s a positive-motion indicator t is op]at$ z foll[s3 ,a worm a on ! drum %aft b engages ) ! worm-:eel c on ! small %aft d t is support$ by ! be>+s e4 ,! po9t] f is rigidly atta*$ to ! %aft d & revolves 9 front ( ! prop]ly m>k$ dial g4 #e4 ,fig4 #e %[s a dial indicator atta*$ to drum hoi/s :]e ! spe$ ( rope is con/ant = ea* revolution4 ,! :eel a ( ?is indicator may be a worm-:eel work+ 9 a worm on ! drum %aft1 z describ$ 9 connection ) ! indicator %[n 9 ,fig4 #d1 or x may be a sprocket :eel driv5 by a l9k belt f a sprocket :eel on a drum1 or x may be a ge>-:eel driv5 directly f ano!r ge>-:eel on ! drum4 ,! ge>-:eels b revolve a v]tical %aft c fitt$ at ! upp] end ) a worm d t drives ! worm-:eel e plac$ on ! end ( ! po9t] sp9dle4 ,! diff]5t levels f :i* hoi/+ is to be done may be pa9t$ on ! dial1 or bett]1 !y may be plac$ on movable t>gets t are clamp$ to ! dial & c ?us be mov$ z occasion requires4 ,illu/ration3 ,,fig4 #e ,,example4--,an indicator is desir$ = a %aft #hjj feet deep at :i* ! drum ( ! hoi/+ eng9e to be us$ is #aj feet 9 diamet]2 :at ratio ( ge>+ mu/ be us$ s t ! po9t] w make "o revolution dur+ ! hoi/8 ,,solution4--,! circumf]5ce ( ! drum is #ca4db ft4 7,d #aj #c4adaf #ca4daf ft472 h5ce1 ! revolutions p] hoi/ are #hjj #ca4db #be4df revolutions4 ,!n1 if ! po9t] is to make "o revolution p] hoi/1 ! ratio ( ! ge>+ w be #be4df to #a4 ,ans4 #f4 ,special ,indicators4--,"o fault ( ne>ly all indicators is t !y give a regul> movem5t ?r\gh\t ! w9d+1 & ! space ov] :i* ! po9t] travels is too small to enable ! eng9e] to l& ! cage accurately4 ,indicators h be5 made ) a diff]5tial motion to ! po9t]1 ! motion be+ great] at ! "t ( l&+ & less dur+ ! middle ( ! hoi/4 ,!y are also made ) two po9t]s1 "o op]at+ l ! dial indicator above describ$ & ! o!r rema9+ /ation>y dur+ all ! hoi/ b ! la/ few feet1 :5 x moves ar\nd its circle4 ,illu/ration3 7a7 7b7 ,,fig4 #f #g4 ,:]e flat ropes are us$ or :]e r\nd ropes w9d on a conical drum1 ! l5g? ( rope w\nd or unw\nd is diff]5t = ea* turn ( ! drum4 ,) all ! indicators ?us f> describ$1 :ile ! spe$ ) :i* ! indicator moves is proportional to ! spe$ at :i* ! drum & ! drum %aft revolve1 x is n proportional to ! spe$ ( ! rope :5 w9d+ & unw9d+ on a conical drum or on a flat rope reel4 ,fig4 #f 7a7 & 7b7 %[s two views ( a comp5sat+ dial indicator4 ,by means ( ! spiral =m ( %eave c1 ! h& d is made to move equal di/ances ar\nd ! disk e = equal di/ances ( cage movem5t 9 ! %aft4 ,! rope f passes ab\t ! spiral %eave & "o end is atta*$ at ! small end g ( ! spiral1 :ile ! o!r end is fa/5$ to ! p]iph]y ( ! %eave h1 :i* takes its motion f ! drum %aft or crank-%aft ( ! hoi/+ eng9e by means ( ! bevel ge> i4 ,consequ5tly1 :ile ! %eave h has a regul> motion dep5d5t directly on ! revolution ( ! hoi/+ drum1 ! po9t] d moves irregul>ly1 dep5d+ on ! position ( ! spiral %eave c2 t is1 :e!r a small or l>ge diamet] ( ! spiral is pres5t$ to ! rope4 ,! rope j c>ry+ ! c\nt]weight k is atta*$ to a small circul> drum l t is on ! same %aft z ! spiral %eave4 ,! purpose ( ?is cord & c\nt]weight is to keep ! indicator l9e f taut & to br+ ! indicator back to position z ! cord f unw9ds f ! %eave h4 #h4 ,9 ord] t ! po9t] may n /& at exactly ! same po9t on ! dial :5 ! cage is at ! top & at ! bottom1 & s t ! eng9e] may be able to di/+ui% betwe5 ! top & ! bottom positions ( ! cage by ! po9t]1 ! ratio ( ! ge>+ is usually increas$ by all[+ "o or two extra tee? on ! worm-:eel4 ,9 ! example 9 ,art4 #e1 assume a ratio ( #bg3 #a2 t is1 if a worm-ge> is us$1 ! worm-:eel w h #bg tee?4 ,if ! pit* ( ! tee? is in*1 ! circumf]5ce ( ! pit* circle w be #bg #bj4be in*es & ! diamet] #f4dd in*es4 ,! pit* ( ! worm w1 ( c\rse1 be ! same z t ( ! :eel1 & its diamet] w be :atev] is necess>y to give suffici5t /r5g? outside ( ! %aft1 s9ce x be>s no relation to ! ratio ( ! ge>+4 ,,drums ,,& ,,reels #i4 ,! drum1 or reel1 ( a hoi/+ eng9e is ! "p on :i* ! rope w9ds4 ,x is ei!r key$ fa/ to ! eng9e %aft or is connect$ to ! %aft by means ( a clut*1 ! %aft be+ made extra heavy to c>ry ! /ra9 due to ! weight ( ! drum & ! pull ( ! rope4 ,,cyl9drical ,,drums #aj4 ,! out] "p1 or %ell1 ( a drum a1 ,fig4 #g1 is support$ on rims b1 & ^! rims are connect$ by arms or spid]s c ) ! hubs d4 ,! brake r+s e are = ! b& brakes1 ( :i* !re may be "o or two4 ,! "p a may be lagg$ ) /rips ( wood bolt$ to ! rims b1 ! heads ( ! bolts be+ c\nt]sunk4 ,fig4 #h %[s ! detail$ dim5sions ( a drum #h feet 9 diamet] hav+ a #d-;foot face design$ to c>ry heavy loads & a l>ge am\nt ( rope4 ,! %ell is ( boil] plate & ! spid]s ( ca/-/eel4 ,illu/ration3 ,,fig4 #g #aa4 ,! %ell may be ca/ 9 "o piece = small drums or built up 9 sections = l>ge drums1 z 9 ,figs4 #g & #h4 ,! %ell may h a smoo? surface1 ,fig4 #h1 or x may h grooves1 ,fig4 #g1 = ! rope to lie 9 z x is w\nd on ! drum4 ,on an iron drum )\t grooves1 ! rope w *afe sidewise2 & fur!rmore if ! rope w9ds on a h>d flat surface x be>s "h & !re on a s+le wire & t5ds to flatt51 caus+ int]nal we> betwe5 ! wires2 :ile1 9 ! case ( a rope w9d+ 9 a groove1 x is support$ on ab\t "o-qu>t] ( its circumf]5ce1 br++ _m m wires to be> on ! drum & divid+ ! pressure betwe5 !m4 ,a wood5-lagg$ drum causes less we> on a rope ?an an ungroov$ iron-%ell drum1 z grooves are gradually worn 9 ! lagg+1 b is n s good z a groov$ iron drum4 ,x is n good practice to all[ a rope to w9d on itself1 & ! drum %\ld be long en\gh to take ! full l5g? ( ! rope requir$ = ! hoi/4 ,at lea/ two turns ( ! rope %\ld be on ! drum :5 ! load is at ! bottom1 z ! friction betwe5 ! rope & drum ?us greatly less5s ! /ra9 com+ on ! rope at ! po9t :]e x is fa/5$ to ! drum4 ,all[ance = two or ?ree additional turns ( ! rope %\ld also be made s t ! cage may be hoi/$ above ! l&+4 ,illu/ration3 ,,fig4 #h ,! %ell usually has a flange at ea* end1 z %[n 9 ,figs4 #g & #h1 b x may h a flange at "o end only1 or may be )\t flanges entirely4 ,if1 h[ev]1 ! flanges are n us$1 ! drum mu/ be extra long to prev5t ! rope runn+ (f ! end4 ,if ! drum is v long1 a ?ird spid] is add$ midway betwe5 ! o!r two to /iff5 x aga9/ collapse4 ,,example4--,f9d ! l5g? ( a drum #f feet #c in*es 9 diamet] necess>y to hold #a1jjj feet ( #a-;in* wire-rope4 ,,solution4--,! diamet] f c5t] to c5t] ( ! rope :5 w\nd on ! drum is #f ft4 #c 94 plus #a 941 or #f ft4 #d 941 :i* is equal to #ai4if ft4 7approximately #bj ft47 ( circumf]5ce4 ,!n1 to w9d #a1jjj ft4 w require 1_/ #ej turns on ! drum4 ,all[+ two turns ( ! rope to protect ! fa/5+ & ?ree turns 9 case ( ov]w9d+1 gives fifty-five turns to be all[$ = on ! drum4 ,if ! drum is ( iron ) grooves turn$ 9 x1 94 mu/ be left betwe5 adjac5t p>ts ( ! rope1 or #a 94 f ! c5t] ( "o turn to ! c5t] ( ! next4 ,!n1 #ee #a #hb 94 plus 94 at ea* end #hd 941 or #g ft4 = ! l5g? ( ! drum betwe5 ! flanges4 ,ans4 ,if ! drum has wood5 lagg+1 cle>ance ne$ n be all[$ betwe5 two adjac5t coils ( rope1 z 9 ?is case ! rope w9ds aga9/ itself & s takes up only #a 94 ,x w !n be #ee #a 94 #fh 941 or #e ft4 #h 94 long 7say #e ft4 #i 9474 ,ans4 ,,conical ,,drums #ab4 ,9 hoi/+ 9 balance f deep %afts ) cyl9drical drums1 if no tail-rope is us$1 or 9 hoi/+ f a s+le %aft ) an unbalanc$ cage1 ! hoi/+ eng9e is n load$ equally at diff]5t po9ts ( ! hoi/ ow+ to ! gradually *ang+ weight ( ! unbalanc$ rope4 ,! foll[+ illu/rations w fur!r expla9 ?is4 #ac4 ,hoi/+ ,) a ,cyl9drical ,drum4--,suppose t1 f a s+le-comp>tm5t v]tical %aft #a1jjj feet deep1 x is requir$ to hoi/ ea* trip a load1 includ+ friction1 ( #aa1jjj p\nds made up z foll[s3 ,,p\nds ,weight ( mat]ial #d1jjj ,weight ( c> #c1jjj ,weight ( cage #c1jjj ,friction1 #aj p] c5t4 #a1jjj ------ ,total #aa1jjj ,if a #a-;in* ca/-/eel rope weigh+ #c p\nds p] foot is us$1 w9d+ ab\t a drum #g feet 9 diamet]1 ! weight ( rope is !n #c #a1jjj #c1jjj p\nds & ! load on ! rope1 :5 ! cage is at ! bottom1 is #aa1jjj #c1jjj #ad1jjj p\nds1 :ile at ! top ! load on ! rope is only #aa1jjj p\nds4 ,! mom5t ( ! load at ! bottom is !n ! load #ad1jjj multipli$ by ! radius #c1 or #ad1jjj #c #di1jjj foot-p\nds2 & at ! top1 #aa1jjj #c #ch1ejj foot-p\nds4 ,?is %[s t ! load aga9/ ! eng9e is mu* great] at ! beg9n+ ?an at ! end ( ! hoi/4 #ad4 ,take n[ a d\ble-comp>tm5t v]tical %aft ( ! same dep? z 9 ,art4 #ac & assume ! same am\nt ( mat]ial hoi/$ at a trip1 9 ! same m9e c> & on ! same cage2 b t an empty c> & cage are l[]$ 9 "o comp>tm5t :ile ! load$ c> & cage are hoi/$ 9 ! o!r4 ,! two c>s & ! two cages w balance ea* o!r1 & ! loads w be z foll[s3 ,at ! beg9n+ ( ! hoi/1 :5 ! load$ c> & cage are at ! bottom1 ! gross load is #ad1jjj p\nds1 made up z foll[s3 ,,p\nds ,weight ( mat]ial #d1jjj ,weight ( m9e c> #c1jjj ,weight ( cage #c1jjj ,friction1 #aj p] c5t4 ( above #a1jjj ,weight ( rope #c1jjj ------ ,total #ad1jjj ,multiply+ ?is by ! radius ( ! drum1 ! gross turn+ mom5t is #ad1jjj p\nds #c feet #di1jjj foot-p\nds1 z be=e1 b !re is a c\nt]balanc+ load ( #f1jjj p\nds1 made up z foll[s3 ,,p\nds ,weight ( m9e c> #c1jjj ,weight ( cage #c1jjj ----- ,total #f1jjj ,less friction1 #aj p] c5t4 #fjj ----- #e1djj ,?is means a c\nt]balanc+ load mom5t ( #e1djj p\nds #c feet #ah1ijj foot-p\nds4 ,! net load mom5t to be ov]come by ! eng9e at ! beg9n+ ( ! hoi/ is1 !re=e1 #di1jjj-ah1ijj #cj1ajj foot-p\nds4 ,at ! end ( ! hoi/ !re is a gross load on ! load$ side ( #aa1jjj p\nds1 made up z foll[s3 ,,p\nds ,weight ( mat]ial #d1jjj ,weight ( m9e c> #c1jjj ,weight ( cage #c1jjj ,friction1 #aj p] c5t4 #a1jjj ------ ,total #aa1jjj ,?is is equal to a gross load mom5t ( #aa1jjj p\nds #c feet #ch1ejj foot-p\nds1 b !re is a c\nt]balanc+ load ( #h1ajj p\nds1 made up z foll[s3 ,,p\nds ,weight ( m9e c> #c1jjj ,weight ( cage #c1jjj ,weight ( rope #c1jjj ----- ,total #i1jjj ,less friction1 #aj p] c5t4 ( #f1jjj #fjj ----- #h1djj ,?is is equal to a c\nt]balanc+ load mom5t ( #h1djj p\nds #c feet #bi1djj foot-p\nds1 & leaves a net load mom5t aga9/ ! eng9e ( #ch1ejj-bi1djj #i1ajj foot-p\nds4 ,9 o!r words1 ! load mom5t t ! eng9e has to ov]come v>ies f #cj1ajj foot-p\nds at ! beg9n+ ( ! hoi/ to #i1ajj foot-p\nds at ! end ( ! hoi/4 #ae4 ,hoi/+ ,) ,conical ,drums4--,conical drums are design$ to make ! "w ( ! eng9e z ne>ly uni=m z possible ?r\gh\t ! hoi/4 ,to accompli% ?is1 :5 ! cage is at ! bottom ( ! %aft1 & ! load is !re=e heavie/1 ! rope w9ds on t "p ( ! drum hav+ ! smalle/ diamet]4 ,z hoi/+ cont9ues1 ! rope w9ds on a gradually increas+ diamet] ( drum1 & :5 ! cage is at ! top ( ! hoi/1 & ! load !re=e lea/1 ! rope is w9d+ on t "p ( ! drum hav+ ! greate/ diamet]2 9 ?is way1 ! mom5t ( ! load at e po9t ( ! hoi/ is approximately ! same4 ,! great diff]5ce 9 ! loads at diff]5t p>ts ( ! hoi/ is due ma9ly to ! v>iation 9 ! weight ( ! rope hang+ f ! drum2 h5ce1 ! less ! weight ( ! rope 9 proportion to ! total load on ! eng9e1 ! m ne>ly uni=m is ! load on ! eng9e4 ,illu/ration3 ,,fig4 #i #af4 ,fig4 #i 7a7 %[s ! condition at ! beg9n+ ( ! hoi/ :5 conical drums are us$4 ,cage a is at ! bottom & c>ries a load$ c>2 cage b is at ! top & c>ries an empty c>4 ,! net mom5t t ! eng9e mu/ ov]come is ! sum ( ! weight ( ! mat]ial to be hoi/$1 weight ( ! cage & c> at a1 & ! weight ( ! rope atta*$ to a1 multipli$ by ! small radius r ( ! drum1 m9us ! weight ( ! c> & cage at b1 multipli$ by ! l>ge radius ,r ( ! drum4 ,fig4 #i 7b7 %[s ! condition ( ?+s at ! end ( ! hoi/1 :5 ! cage a is at ! top & cage b at ! bottom4 ,! load$ c> & cage a1 ^: rope 9 ,fig4 #i 7a7 0 w9d+ on ! smalle/ diamet] ( ! drum1 is n[ at ! top & ! rope is w9d+ on ! l>ge/ diamet] ( ! drum4 ,! cage b ) ! empty c> is n[ at ! bottom & ! rope is unw9d+ f ! smalle/ diamet] ( ! drum4 ,! net mom5t t ! eng9e mu/ ov]come 9 ?is position is equal to ! sum ( ! weight ( ! mat]ial hoi/$1 ! weight ( ! cage a & ! c>1 multipli$ by ! l>g] radius ,r ( ! drum1 m9us ! sum ( ! weights ( ! cage b1 ! c>1 & ! rope1 multipli$ by ! small radius r ( ! drum4 #ag4 ,if ! mom5t ( ! load aga9/ ! eng9e at ! beg9n+ ( ! hoi/ is to equal t at ! end ( ! hoi/1 x is possible to det]m9e :at relative diamet]s ( drum w produce su* an effect1 z foll[s3 ,let ,w weight ( mat]ial hoi/$2 ,w weight ( cage & c>2 ,w weight ( rope2 ,r l>ge radius ( drum2 r small radius ( drum4 ,! load mom5t may be calculat$ by includ+ friction z ( ! total weight hoi/$1 except ! weight ( ! rope1 z %[n 9 ,art4 #ad2 or ! friction may be disreg>d$ )\t s]i\s error4 ,!n1 "u ! conditions %[n 9 ,fig4 #i 7a71 & disreg>d+ friction1 ,load mom5t 7,w,w,w7r - ,w,r 7#a7 & "u ! conditions %[n 9 ,fig4 #i7;b71 ,load mom5t 7,w ,w7,r - 7,w ,w7r 7#b7 ,plac+ =mula #a =mula #b1 7,w,w7,r - 7,w,w7r 7,w,w,w7r - ,w,r1 & 7,w #b,w #b,w7 ,r r ------------------- 7#c7 7,w #b,w7 ,s9ce ! diamet] ( a drum is g5]ally giv5 in/ead ( ! radius1 x foll[s t if ,d l>g] diamet]1 d small] diamet]1 & !n1 s9ce ,d #b,r & d #br1 =mula #c may be writt5 7,w #b,w #b,w7 ,d d ---------------------- 7#d7 7,w #b,w7 ,=mula #d gives only approximate results1 :i* are1 h[ev]1 suffici5tly accurate = ! m9e sup]9t5d5t's use1 & = ?is reason friction has be5 omitt$1 z x w\ld make ! =mula mu* m complex4 ,x may be express$ z a rule z foll[s3 ,rule4--,to f9d ! l>ge diamet] ( a conical drum1 multiply ! small diamet] by ! sum ( ! weight ( ! mat]ial to be hoi/$1 twice ! weight ( ! cage & c>1 & twice ! weight ( ! rope2 divide ?is product by ! sum ( ! weight ( ! mat]ial1 & twice ! weight ( ! cage & c>4 ,illu/ration3 ,,fig4 #aj ,apply+ ?is rule to ! problem giv5 9 ,art4 #ad & omitt+ friction1 #g7d1jjj #ab1jjj #f1jjj7 ,d ------------------------- #i4f feet 7#d1jjj #ab1jjj7 ,! drum w\ld !n be #g feet 9 diamet] at ! small end & #i feet #g in*es at ! l>g] end4 #ah4 ,fig4 #aj %[s a special =m ( comb9$ conical & cyl9drical drum design$ = hoi/+ a total balanc$ load ( #be tons ?r\gh a v]tical height ( #eej feet4 ,fig4 #aa %[s a comb9$ conical & cyl9drical drum2 an unusual feature is ! rope reel %[n at ea* end ( ! drum1 :i* p]mits ( prop]ly /or+ a few hundr$ feet ( extra rope1 all[+ ! rope to be l5g!n$1 :5 ne$$1 )\t splic+4 ,illu/ration3 ,,fig4 #aa #ai4 ,comp>ison ( ,cyl9drical & ,conical ,drums4 ,! disadvantages ( ! cyl9drical drum lie entirely 9 ! fact t ! load on ! eng9es is v>iable1 b x is possible to ov]come ?is disadvantage by add+ a tail-rope to ! cages to balance ! weight ( ! rope4 ,?is sy/em gives its be/ results :]e hoi/+ is done f "o level only1 b 9 deep hoi/+ x is impracticable because ( ! extra weight add$ & because ( possible excessive sway+ ( ! rope4 ,! conical drum has two /rong po9ts 9 its favor3 fir/1 ! load on ! eng9e may be ne>ly equaliz$ dur+ ! entire hoi/+ p]iod2 &1 second1 ! />t+ ( ! eng9es ) ! load requires less p[]4 ,! disadvantages ( ! conical drum are z foll[s3 ,to ma9ta9 a c]ta9 av]age spe$ ( hoi/+1 ! spe$ t[>d ! end ( ! hoi/ is ( necessity high] ?an ! av]age & comes at a "t :5 a sl[+ up %\ld be tak+ place1 s t m c>e mu/ be ex]cis$ :5 mak+ ! l&+4 ,to prev5t ! rope f be+ drawn out ( ! grooves1 ! latt] mu/ be made deep & ) a l>ge pit*1 !reby increas+ ! wid? ( ! face or l5g? ( ! drum4 ,9 mak+ a l&+1 :5 ! rope is on ! conical face1 ! rope mu/ be kept taut1 z any slackness w p]mit ! rope to leave ! groove1 ) ! result t all ! rope w pile up 9 ! bottom grooves ( ! drum all[+ ! cage to drop into ! m9e1 unless x is re/+ on ! *airs4 ,if !re are sev]al levels to be hoi/$ f1 ! equaliz+ ( ! load on ! eng9es c only be realiz$ = "o level2 = all o!r levels ?is advantage w be lo/4 ,= l>ge dep?s1 conical drums become v long & require correspond+ly long leads f head-frame to drum4 ,to hold ! same am\nt ( rope1 conical drums are heavi] ?an cyl9drical ones1 & z a result1 ! p[] requir$ 9 />t+ ! load is some:at increas$ ow+ to ! great] in]tia ( ! rotat+ p>ts4 ,"s ( ^! disadvantages h be5 ov]come by mak+ a comb9ation ( cone & cyl9drical drums4 ,! drums are s design$ t ! l&+ takes place only :5 ! rope is on ! cyl9drical portion ( ! drum4 ,= deep hoi/+1 ! great] diamet] ( ! drum & its l5g? mu/ be inconv5i5tly l>ge if ! load is equaliz$4 ,! l5g? & diamet] c be r$uc$ by mak+ "o-half ( ! drum cyl9drical & by hav+ ! rope f ea* end w9d on ! same cyl9drical portion ( ! drum4 ,9 all cases1 h[ev]1 ^! modifications are made at ! exp5se ( ! equalization ( ! load on ! eng9es1 & x is n possible to obta9 ! latt] )\t includ+ "s s]i\s disadvantage4 ,!re are c]ta9 objections to bo? cyl9drical & conical drums3 _! great size & weight1 = l>ge hoi/s1 make !m v exp5sive2 _! wid? necessitates plac+ ! eng9es f> ap>t1 :i* adds to ! co/ ( ! eng9es1 f\ndations1 & build+s2 ! great weight ( ! drums is also objectionable1 because x =ms a l>ge "p ( ! mass to be put 9 motion & br\ght to re/ at ea* hoi/4 ,,flat ,,rope ,,reels #bj4 ,to ov]come ! objections to conical & cyl9drical drums1 sev]al o!r sy/ems ( hoi/+ h be5 tri$1 among !m be+ "o t uses a reel1 ,fig4 #ab1 & a flat rope4 ,! hub a is increas$ 9 diamet]1 above :at is necess>y = /r5g?1 to su* a size z is suitable to w9d ! rope on4 ,x is !n cor$ out f ! inside1 s z n to conta9 too great a mass ( metal4 ,illu/ration3 ,,fig4 #ab ,! arms b ( ! reel ext5d radially f ! hub to conf9e ! rope lat]ally :5 x is all w\nd on ! drum4 ,^! arms are connect$ at _! out] ends by a cont9u\s flange c1 :i* flange is fl>$ out1 z %[n at d1 s z to take 9 ! rope easily1 if x is deflect$ at all sidewise4 ,9 ! l>g]-siz$ reels1 ! arms are bolt$ to ! hub1 & (t5 ! out] rim connect+ ! arms is omitt$4 ,h>dwood l9+ 0 =m]ly us$ on ! arms "u ! impression t ! we> on ! rope w\ld be less ?an ) b>e iron arms1 b s& & grit become emb$d$ 9 ! wood & gr9d ! rope4 ,poli%$ iron arms ) r\nd$ corn]s & lubricat$ ) oil or t> are be/4 ,! end ( ! rope is fa/5$ 9 a pocket e provid$ = x 9 ! hub4 ,! rope w9ds on itself1 s t ! diamet] ( ! reel increases z ! hoi/ is made & z ! load due to ! weight ( ! rope decreases4 ,?is s]ves to equalize ! load due to ! rope 9 ! same mann] z ! conical drum4 ,two reels are g5]ally put on ! same %aft1 & :ile "o is hoi/+ f "o comp>tm5t ( ! %aft ! o!r is l[]+ into ano!r comp>tm5t4 ,! p]iph]y ( ! hub :]e ! rope w9ds %\ld n be r\nd b ( gradually increas+ radius1 = if a flat rope be wrapp$ ab\t a r\nd hub ! rope w h to abruptly m\nt itself at ! end ( ! fir/ revolution & s on = e revolution4 ,! radius ( ! hub %\ld increase at su* a rate z to raise ! rope an am\nt equal to its ?ickness 9 ! fir/ wrap1 s t x w w9d on itself )\t j> at ! po9t ( atta*m5t1 z well z on succe$+ wraps4 #ba4 ,9 ,am]ica1 x is cu/om>y to w9d on reels ( small diamet]1 t is1 />t+ at #c or #e feet & increas+ to #h or #ab feet2 b sev]al l>ge plants h be5 built ) reels />t+ at #h feet & increas+ to #ai feet4 ,9 ,engl&1 reels h be5 made />t+ at #af feet & increas+ to #bj or #bb feet4 ,su* l>ge reels are easi] on ! rope b require l>ge eng9es1 z hoi/+ 9 balance is us$ to only a slight ext5t4 ,! l>ge reel is easy on ! rope1 bo? f ! fact t x b5ds ! rope b little & also gives less pressure on ! bottom wraps1 z ea* wrap adds to ! pressure4 ,^! reels are driv5 by means ( pla9 jaw or friction clut*es4 ,! we> ( a flat rope is excessive & ! rope itself co/s m ?an a r\nd rope ( ! same /r5g?1 does n la/ z long1 & requires m c>e & att5tion4 #bb4 ,calculat+ ,size ( ,flat ,rope & ,reel4--,! calculation ( ! size ( a flat rope = giv5 "w is n s simple z t ( a r\nd rope1 z !re is a v>iable factor 9 ! wid? & ?ickness ( ! rope t mu/ be tak5 into acc\nt4 ,to illu/rate ! me?od ( calculation1 suppose t x is requir$ to hoi/ #e1jjj p\nds ( mat]ial 9 a #c1jjj-p\nd skip f a v]tical two-comp>tm5t %aft #b1jjj feet deep "u conditions requir+ a factor ( safety ( ab\t #i = ! rope4 ,! det]m9ation ( ! size ( ! rope & ! small & l>ge diamet]s ( ! reels mu/ proce$ toge!r4 ,! latt] calculations are p]=m$ 9 mu* ! same mann] z = conical drums4 ,ref]r+ to ,table relat+ to flat wire ropes 9 ,hoi/+1 ,"p #b1 x is f\nd t a flat /eel rope #f in*es by in* 9 size & ) a break+ /r5g? ( #aej1jjj p\nds weighs #e4a p\nds p] foot2 h5ce1 #b1jjj feet ( x weighs #b1jjj #e4a #aj1bjj p\nds4 ,! total load on ! rope w !n be #ai1jjj p\nds1 made up z foll[s3 ,,p\nds ,weight ( mat]ial #e1jjj ,weight ( skip #c1jjj ,friction1 #aj p] c5t4 #hjj ,weight ( rope #aj1bjj ------ ,total #ai1jjj ,?is rope gives a factor ( safety ( #aej1jjj_/ai1jjj #g4h1 :i* is n q en\gh :5 figur$ f ! dead load )\t t due to accel]ation4 ,an #h rope ) a break+ /r5g? ( #bjj1jjj p\nds weighs #f4i p\nds p] foot2 h5ce1 #b1jjj feet ( x weighs #b1jjj #f4i #ac1hjj p\nds4 ,! load on ! rope w !n be #bb1fjj p\nds1 made up z foll[s3 ,,p\nds ,weight ( mat]ial #e1jjj ,weight ( skip #c1jjj ,friction1 #aj p] c5t4 #hjj ,weight ( rope #ac1hjj ------ ,total #bb1fjj #bjj1jjj ,?is rope gives a factor ( safety ( -------- #h4h4 #bb1fjj ,sub/itut+ ! =ego+ weights ( mat]ial1 skip1 & rope 9 =mula #d1 9 ,art4 #ag1 gives 7#e1jjj #f1jjj #bg1fjj7 ,d d ------------------------ 4 7#e1jjj #f1jjj7 ,h5ce1 ! equation ( mom5ts is ,d #c4e;d4 ,9 o!r words1 ! l>ge diamet]1 or t ( ! la/ coil ( rope1 %\ld be #c4e times ! small diamet]1 or t ( ! reel hub4 #bc4 ,fig4 #ac repres5ts a coil ( flat rope ^: great] diamet] ,d & small] diamet] d are to be det]m9$4 ,! area ( ! hub ab\t :i* ! rope is to coil is 77d1 :ile ! area includ$ by ! out] coil ( rope is 77,d h5ce1 ! area ( annul> space occupi$ by ! rope is 77,d - 77d 777,d - d74 ,su* values = ,d & d mu/ be *os5 t ! equation ( mom5ts 9 ,art4 #bb is satisfi$1 :ile ! area 777,d-d7 mu/ correspond to ! space occupi$ by ! giv5 rope :5 roll$4 ,illu/ration3 ,,fig4 #ac ,,illu/ration4--#b1jjj feet ( rope in* ?ick requires #b1jjj #ab ---------- #ab1jjj #b squ>e in*es 9 :i* to be coil$4 ,to satisfy ! equation ( mom5ts1 ,d mu/ equal #c4e d2 h5ce1 to satisfy bo? ^! conditions 777#c4e;d7 - d #ab1jjj2 d #cg in*es1 or #c feet #a in*2 ,d #cg #c4e #abi4e in*es1 or #aj feet #i in*es4 ,! dim5sions ( ! reel w !n be3 diamet] ( hub #c feet #a in*2 wid? betwe5 flanges1 #h in*es1 all[+ in* on ea* side ( ! rope = cle>ance2 diamet] ( ! flanges :]e !y fl>e1 #aj feet #i in*es4 ,,rope ,,:eels ,illu/ration3 ,,fig4 #ad #bd4 ,koepe ,sy/em4--,9 its lighte/ =m1 a drum requires a l>ge am\nt ( p[] to set x 9 motion1 :i* p[] is absorb$ by ! brake & lo/ :5 x is br\ght to re/ aga94 ,fur!rmore1 ) deep %afts requir+ long drums1 ! fleet1 or angle t ! rope makes ) ! head-%eave due to its travel+ f "o end ( ! drum to ! o!r1 is n only a disadvantage & possible cause ( accid5t1 b x is a s\rce ( we>4 ,to ov]come ^! objections & also ! great co/ ( l>ge cyl9drical or conical drums1 ! ,koepe sy/em ( hoi/+1 %[n 9 ,fig4 #ad1 0 devis$ by ,mr4 ,fr$]ick ,koepe4 ,a s+le groov$ driv+ %eave a is us$ 9 place ( a drum4 ,! w9d+ rope b passes f "o cage ,a up ov] a head-%eave1 !nce ar\nd ! %eave a & back ov] ano!r head-%eave1 & d[n to a second cage ,b2 x encircles a little ov] half ! p]iph]y ( ! driv+ %eave & is driv5 by ! friction betwe5 ! %eave & rope4 ,a balance rope c b5ea? ! cages & pass+ ar\nd ! %eave d gives an endless-rope arrangem5t ) ! cages fix$ at ! prop] po9ts4 ,! driv+ %eave is /rong] ?an an ord9>y c>ry+ %eave1 z x has to d ! driv+ & is usually l9$ ) h>dwood1 :i* is groov$ to receive ! w9d+ rope1 ! dep? ( ! groove be+ g5]ally equal to twice ! diamet] ( ! rope4 ,in/ead ( be+ plac$ p>allel1 ! head-%eaves are plac$ at an angle ) ea* o!r1 ea* po9t+ to ! groove 9 ! driv+ %eave1 ?us r$uc+ ! side friction ( ! rope on ! %eaves4 ,! sy/em has be5 9 successful op]ation s9ce #ahgg1 & exp]im5ts made on x h det]m9$ t1 ) a rope pass+ only "o-half turn ar\nd ! drum %eave1 ! coeffici5t ( adhesion ) clean ropes is ab\t 4#c4 ,if ! ropes are oil$1 ! adhesion becomes less1 & sometimes slippage occurs1 produc+ n only we> ( ! driv+ %eave l9+ b giv+ an incorrect read+ ( ! hoi/ indicator & ?us possibly produc+ ov]w9d+1 unless ! position ( ! cage is indicat$ by m>ks on ! rope1 or unless ! eng9e] c see ! cage4 ,at ! end ( ! hoi/1 if ! upp] cage is all[$ to re/ on ! keep1 its weight & ! weight ( ! tail-rope are tak5 f ! hoi/+ rope1 & !re is !n n en\gh pull on ! hoi/+ rope to produce suffici5t friction ) ! drum %eave to />t ! next hoi/4 ,to prev5t ?is tr\ble1 ! keeps are disp5s$ )1 or ! rope is made cont9u\s & indep5d5t ( ! cage4 ,to d ?is1 cros%eads are plac$ above & bel[ ea* cage & connect$ by ropes or *a9s outside ( ! cages4 ,! bridle *a9s are !n hung f ! top cros%ead1 & :5 ! cage re/s on ! keeps1 ! weight ( ! w9d+ & tail-ropes rema9s on ! driv+ %eaves4 #be4 ,advantages & ,disadvantages ( ! ,koepe ,sy/em4--,) ?is sy/em1 only "o driv+ %eave is necess>y = ! op]ation ( two comp>tm5ts1 & x is light1 inexp5sive to build1 & v n>r[1 admitt+ ( a %ort %eave %aft & small f\ndations4 ,?is sy/em p]mits a p]fect balance ( rope & cage1 s t ! "w to be done by ! eng9e is uni=m1 except = ! accel]ation1 & consi/s only 9 lift+ ! mat]ial & ov]com+ ! friction4 ,!re is no fleet+ ( ! rope betwe5 ! driv+ %eaves & ! head-%eaves4 ,! sy/em has ! foll[+ disadvantages1 :i* prev5t its be+ us$ to any consid]able ext5t3 ,liability to slippage ( ! rope on ! drum2 if ! rope breaks1 bo? cages may fall to ! bottom2 hoi/+ f diff]5t levels _c be well done1 =1 s9ce ! cages are at fix$ di/ances f ea* o!r1 ! l5g? ( ! rope is su* t :5 "o cage ,a is at ! top1 ! o!r cage ,b is at ! bottom4 ,if hoi/+ is to be done f ! bottom1 ?is is satisfactory1 b if hoi/+ is to be done f "s upp] level1 cage ,b1 :i* is at ! bottom1 mu/ be hoi/$ to t level to be load$ be=e x c g to ! top4 ,!n1 :5 cage ,b goes to ! top ) its load1 cage ,a mu/ g to ! bottom1 wait !re :ile cage ,b is be+ unload$1 & !n be hoi/$ to ! upp] level to receive its load4 ,= ea* trip1 !re=e1 ! "t requir$ = a cage to g f ! bottom to ! upp] level & be load$ is lo/2 & two movem5ts ( ! eng9es are necess>y = a hoi/ in/ead ( "o4 #bf4 ,! ,:it+ ,sy/em4--,?is is a sy/em ( hoi/+ ) r\nd ropes1 9 :i* two rope :eels plac$ t&em are us$ 9 place ( cyl9drical or conical drums4 ,z %[n 9 ,fig4 #ae1 = a two-comp>tm5t %aft ! rope passes f "o cage a up ov] a head-%eave c1 d[n "u a guide %eave d1 & is !n w\nd ?ree times ab\t ! rope :eels e & f1 to secure a good hold1 !n ar\nd a fleet %eave g1 & back "u ano!r guide %eave h1 up ov] ano!r head-%eave i1 & d[n to ! o!r cage b4 ,:5 ! sy/em is to be us$ = a s+le-comp>tm5t %aft1 "o end ( ! rope c>ries ! cage & ! o!r end c>ries a balance weight1 :i* is run up & d[n 9 a corn] ( ! %aft4 ,a balance rope bel[ ! cages1 z %[n1 is g5]ally us$1 ?\gh x is n ess5tial to ! work+ ( ! sy/em1 z x is 9 ! ,koepe sy/em4 ,:5 s9k+ a %aft1 a balance rope _c be us$ z x int]f]es ) ! "w at ! bottom ( ! %aft4 ,illu/ration3 ,,fig4 #ae ,! drums or :eels e1 f are light1 inexp5sive1 & n>r[1 ?us p]mitt+ %ort %eave %afts & small f\ndations4 ,!y are l9$ ) h>dwood blocks1 ea* l9+ hav+ ?ree rope grooves turn$ 9 x4 ,! ma9 :eel e is driv5 by a hoi/+ eng9e1 :i* may be ei!r fir/ or second motion4 ,! foll[+ :eel f is c\pl$ to ! ma9 :eel by a pair ( p>allel rods1 "o on ea* side1 l ! driv]s ( a locomotive4 ,z ! rope wraps ab\t ! :eels e1 f ?ree times1 !re are six semi-circumf]5ces ( driv+ contact ) ! rope1 z comp>$ ) ! "o semi-circumf]5ce 9 ! ,koepe sy/em1 & !re is no slipp+ ( ! rope on ! :eels4 ,! foll[+ :eel f is be/ tilt$ or incl9$ f ! v]tical an am\nt equal1 9 ! diamet] ( ! :eels1 to ! pit* ( ! rope on ! :eel1 s t ! rope may n run out ( its groove & may run /raight f "o :eel to ! o!r )\t any *af+ betwe5 ! ropes & ! sides ( ! grooves4 ,! capacity ( ! :eels e1 f is unlimit$1 :ile groov$ cyl9drical drums1 conical drums1 & reels w hold only ! fix$ l5g? ( rope = :i* !y are design$4 ,z %[n by ! dott$ l9es1 ! fleet %eave g is arrang$ to travel backw>ds & =w>ds1 9 ord] to *ange ! work+ l5g? ( ! rope f "t to "t to provide = an increas$ dep? ( %aft1 & = ! *anges 9 ! l5g? ( rope due to /ret*+ & :5 ! ends are cut (f to resocket ! rope4 ,! fleet %eave g is mov$ a di/ance equal to half ! *ange 9 ! l5g? ( rope4 #bg4 ,hoi/+ f int]m$iate levels c be readily done ) ! ,:it+ sy/em2 = in/ance1 if ! cage a is at ! top & cage b at ! bottom1 & hoi/+ is to be done f "s upp] level1 x is only necess>y to run ! fleet %eave g out1 & ?us %ort5 ! work+ l5g? ( ! rope until cage b comes up to ! upp] level4 ,x c !n be load$ & g to ! top4 ,:ile cage b goes to ! top1 cage a desc5ds to ! same level1 :]e x c be load$ :ile cage b is be+ unload$1 & c !n g directly to ! top )\t any ( ! lo/ "t1 z is ! case 9 ! ,koepe sy/em4 ,! sy/em p]mits a p]fect balance ( rope & cage1 s t ! "w to be done by ! eng9es is uni=m1 except = ! accel]ation1 & consi/s only 9 lift+ ! mat]ial & ov]com+ ! friction4 ,!re is no fleet+ ( ! rope1 s ! rope :eels c be plac$ z close to ! %aft z may be desir$4 #bh4 ,?is sy/em 0 tri$ z e>ly z #ahfb 9 ,ea/]n ,p5nsylvania1 b x 0 n us$ ext5sively because hoi/+ f great dep?s 0 n necess>y1 s9ce1 = dep?s ( less ?an #a1jjj feet1 cyl9drical & conical drums are q satisfactory4 ,9 ! ,lake ,sup]ior copp] region1 !re are n[ ?ree ,:it+ hoi/s1 two ( :i* are probably ! l>ge/ hoi/+ plants 9 ! _w4 ,ea* plant consi/s ( a pair ( triple-expansion1 v]tical1 inv]t$-beam eng9es1 driv+ direct a pair ( #ai-;foot drums4 ,! high-pressure cyl9d]s are #bj in*es 9 diamet]1 ! int]m$iate cyl9d]s #cb in*es1 & ! l[-pressure cyl9d]s #ej in*es1 & all six ( !m h a #gb-;in* /roke4 ,! rope us$ is a #b-;in* pl[-/eel rope & hoi/s #aj tons ( mat]ial at a trip1 9 "o case f a dep? ( #d1ihj feet1 ! deepe/ %aft 9 ! _w4 ,sev]al plants on ! ,:it+ sy/em h be5 built 9 ,engl&1 & two or m are work+ 9 ,s\? ,africa4 #bi4 ,modifi$ ,:it+ ,sy/em4--,a modification ( ! ,:it+ sy/em is sometimes us$ 9 :i* a l>ge drum key$ to ! crank-%aft replaces ! small t&em drums1 & ev5 ! slight probability ( ! rope slipp+ 9 ! ,:it+ sy/em is ?us obviat$4 ,"o rope is fa/5$ to "o end ( ! drum1 & ! o!r rope to ! o!r end 9 su* a way t :ile "o is w9d+ on ! o!r w be w9d+ (f ! drum4 ,"o rope passes directly to ! head-%eave :ile ! o!r passes fir/ ar\nd a fleet %eave1 simil> to t us$ = ! ,:it+ sy/em1 b pref]ably plac$ horizontal1 & !nce to ! head-%eave4 ,?is sy/em possesses ! same advantages z ! ,:it+ sy/em except t ! dep? ( hoi/ is limit$ by ! size ( ! drum1 & t !re is a fleet ( ! rope4 ,up to ! limit+ dep?1 z det]m9$ by ! size ( ! drum1 ?is sy/em c be us$ ) equal economy = any dep?4 ,?is hoi/1 z well z ! ,:it+1 is !re=e especially suitable = a place :]e "o m9+ company op]ates sev]al m9es1 = x enables ! company to select "o size = all _! p]man5t "w1 ) all ! advantages t come f duplicate ma*9]y4 ,,rope ,,fa/5+s ,illu/ration3 ,,fig4 #af #cj4 ,a common me?od ( fa/5+ a rope to a drum1 ,fig4 #af 7a71 is to pass ! rope ?r\gh a hole 9 ! drum rim & !n ar\nd ! %aft1 clamp+ ! end to ! rope betwe5 ! %aft & %ell1 z %[n4 ,c>e %\ld be tak5 to make ! radius ( curvature ( ! hole at a z l>ge z possible s t ! rope w n be b5t any %>p] ?an is necess>y4 ,:5 an iron drum is us$1 ! ?ickness ( ! rim does n af=d en\gh dep? 9 :i* to b5d ! rope & x is necess>y to build 9 a pocket = ! purpose1 z %[n at ,fig4 #af 7b74 ,x is well to make bo? sides ( ?is pocket ) a long radius to avoid damag+ ! rope 9 case all ! rope is accid5tally unw\nd & ! drum back$ s z to br+ ! rope aga9/ ! o!r side ( ! pocket4 ,,clut*es #ca4 ,x is (t5 desir$ to h ! drum ( a hoi/+ eng9e run loosely on ! eng9e %aft1 s t x may run indep5d5tly ( ! eng9e4 ,) su* loose-runn+ drums1 ! eng9e g5]ally runs only 9 ! direction requir$ to hoi/ ! load1 :ile ! cage is l[]$ entirely by means ( ! brake4 ,9 ?is way1 "o eng9e provid$ ) sev]al drums may be us$ = hoi/+ f sev]al %afts or f sev]al levels 9 ! same %aft at ! same "t4 ,su* a loose-runn+ drum is connect$ to ! eng9e %aft :5 a load is to be hoi/$ by means ( a clut*1 ( :i* !re are two =ms commonly us$ = hoi/+ ma*9]y3 jaw or pi/on clut*es & friction clut*es4 ,illu/ration3 ,,fig4 #ag #cb4 ,jaw ,clut*4--,fig4 #ag %[s a jaw clut*1 "o-half a ( :i* is %[n ready to be bolt$ to a drum or flat rope reel1 :i* is loose on ! %aft b4 ,! o!r half c ( ! clut* is mov$ back s t ! jaws d are n 9 contact ) ! jaws e on ! "p a4 ,! half c slides freely on a fea!r key f1 :i* is driv5 tightly into a deep key seat 9 ! %aft b2 a coll> g1 fitt+ loosely 9 a groove 9 ! hub ( c1 is provid$ ) trunnions h on ea* side2 lev]s i connect ^! trunnions ) ! lev] j atta*$ to a suitable h&le1 by means ( :i* ! clut* is made to slide endwise on ! %aft s t ! jaws d engage or dis5gage ! jaws e & ?us connect or disconnect ! drum or reel f ! clut*4 ,!re are g5]ally f\r or six jaws d t engage ! same numb] ( jaws e on ! drum1 & x is necess>y to h little or no play betwe5 d & e :5 ! clut* is connect$ or !re w be too mu* %ock4 ,! clut* is ab\t #b feet 9 diamet]1 & ! jaws are #c or #d in*es deep = ! av]age #bj #dh fir/-motion hoi/+ eng9e4 ,in/ead ( ! clut* be+ fa/5$ to ! %aft by fea!r keys1 ! %aft may be hexagonal :]e ! clut* slides on x & ! clut* is ma*9$ to mat*4 ,jaw clut*es are made ( ei!r ca/-iron or ca/-/eel1 & %\ld be 9 halves1 = conv5i5ce ( repair1 & securely bolt$ toge!r4 ,illu/ration3 ,,fig4 #ah #cc4 ,b& ,friction ,clut*es4--,fig4 #ah %[s a b& friction clut* t is atta*$ to & revolves ) ! %aft a4 ,! w9d+ drum runs loosely on ! same %aft & has a driv+-b& r+ or seat b on "o end2 :5 ! r+ c ( ! clut* is tight5$ by means ( ! me*anism %[n1 ! clut* & driv+ b& become practically "o piece & ! drum revolves ) ! clut*4 ,! clut* is con/ruct$ z foll[s3 ,! driv+ disk d key$ to ! driv+ %aft a is connect$ to "o end ( ! r+ c by a fix$ arm e1 :i* is bolt$ firmly to ! disk d & revolves ) x2 a movable arm f t connects ) ! o!r end ( ! b& c turns on ! p9 g4 ,:5 ! b& c is loose1 x c revolve ab\t ! seat b )\t t\*+ x1 b ! b& c be tight5$ & made to clamp b ei!r :5 revolv+ or /&+ /ill1 z foll[s3 ,! slid+ sleeve h may be caus$ to slide ab\t #f in*es along ! hub ( ! disk d by lev]s 7n %[n7 t take hold ( trunnions i on a r+ on ! slid+ sleeve2 ?is sleeve is connect$ to ! movable arm f by a l9k j1 & :5 ! sleeve is on ! end ( ! hub ! l9k /&s at an angle ( ab\t #fj ) ! %aft2 by slid+ ! sleeve t[>d ! disk d1 ! l9k is made to move ! arm f ab\t #a in*es at its out] end & to ?us tight5 ! driv+-b& c1 s t x grips ! r+ b4 ,! adju/+ nuts k take up ! we> ( ! wood5 blocks ) :i* ! r+ c is l9$4 ,b& lift]s l hold ! b& cle> ( ! r+ :5 x is loose4 ,! clut* %[n is built to run 9 ! direction indicat$ by ! arr[1 b su* clut*es may be built to run 9 ei!r direction2 !y %\ld always be run 9 ! direction = :i* !y are design$1 s t ! load may always come on ! fix$ arm4 ,if ! b& be tight5$ sl[ly1 !re w be no sudd5 />t or j]k on ! rope1 z ! slip ( ! b& w prev5t ! entire =ce ( ! grip tak+ effect at once2 & aft] ! drum rea*es full spe$1 !re is little or no slipp+ ( ! driv+-b&4 ,x is be/ to keep ! b& only j tight en\gh to d ! "w1 = %\ld ! c> get (f ! track1 or be ov]w\nd1 or %\ld a cage /ick 9 ! %aft = any reason1 ! b& w slip & ?us become a safety appliance1 & n /ra9 or break ! rope1 %aft timb]+1 or ma*9]y1 z w\ld be ! case if a positive clut*1 ,fig4 #ag1 7 us$4 #cd4 ,! ,beekman ,friction ,clut*4--,a simple friction clut* is %[n 9 ,fig4 #ai1 9 :i* a is a section ( ! drum %ell4 ,! wood5 blocks b bolt$ to ! side ( ! ge>-:eel c are made ( suitable %ape to con=m to ! ,v-%ap$ groove d 9 ! side ( ! drum4 ,! /eel spr+ e betwe5 ! two /eel wa%]s f1 f dis5gages ! clut*1 z soon z ! pressure is reliev$1 by rev]s+ ! motion ( ! lev] g & screw h f ! opposite end ( ! drum4 ,:5 ! lev] g is turn$1 ! screw h is =c$ aga9/ ! end ( ! p9 i1 :i*1 9 turn1 presses ! cross-key j aga9/ ! coll> k1 =c+ ! drum aga9/ ! blocks b & frictionally engag+ ! ge>-:eel c4 ,?is drum %aft is prev5t$ f mov+ endwise by means ( ! coll> l & ! grooves m 9 ! babbitt$ pill[-block4 ,! wide be>+s ( ! drum on its %aft are lubricat$ by means ( ! pipes n4 ,illu/ration3 ,,fig4 #ai ,a clut* is (t5 us$ to *ange ! l5g? ( ! hoi/+ rope :5 hoi/+ f two or m lifts or levels4 ,9 ?is case ! %aft c>ries two drums1 "o ( :i* is fix$ to ! %aft1 :ile ! o!r is provid$ ) a friction clut*4 ,:5 x is desir$ to *ange ! l5g? ( ! rope1 ! cage atta*$ to ! loose drum is br\ght to1 say1 ! upp] l&+4 ,! cages bo? re/+ on ! w+s1 ! clut* is loos5$ & ! o!r cage atta*$ to ! fix$ drum is n[ br\ght to ! desir$ level1 :5 ! clut* is aga9 tight5$ & hoi/+ proce$s4 ,! *ange is made 9 #b or #c m9utes4 ,,brakes #ce4 ,a brake is a device by means ( :i* ! motion ( a hoi/+ drum may be ret>d$ or /opp$4 ,?is is accompli%$ by friction ( ! brake aga9/ ! circumf]5ce ( ! brake :eel4 ,!re are ?ree types ( brakes1 kn[n z block brakes1 po/ brakes1 & /rap brakes4 ,illu/ration3 ,,fig4 #bj #cf4 ,! ,block ,brake4--,! block brake1 ,fig4 #bj1 consi/s ( "o or m wood5 blocks or %oes b atta*$ to a lev] hav+ a fulcrum at d1 & connect$ by a rod to ! lev] c4 ,block brakes are object$ to ma9ly because !y ?r[ a great load on ! j\rnals ( ! drum :5 !y are appli$2 !y _c be reli$ on :5 !re is a heavy load on ! drum1 & !y require ! application ( great =ce to ! lev] c = a giv5 brak+ p[]4 ,!y are1 h[ev]1 *eap & easily appli$ to a drum1 & ! %oe is readily replac$ :5 worn4 #cg4 ,! ,po/ ,brake4--,! po/ brake1 ,fig4 #ba1 is compos$ practically ( two block brakes appli$ at two places on ! drum diametrically opposite ea* o!r1 ?us equaliz+ ! pressure on ! j\rnals4 ,! blocks are g5]ally some:at long] ?an 9 ! block brake1 or ab\t "o-qu>t] ( ! circumf]5ce ( ! drum on ea* side4 ,9 ,fig4 #ba1 a is ! drum2 b are wood5 brake blocks2 c are ! po/s :i* 9 ! brake %[n are ( massive1 built-up1 /eel con/ruction2 d are ! fulcrums on ! plates e1 :i* plates are adju/able by means ( ! nuts f2 by means ( ^! nuts1 ! fulcrums may be br\ght clos] toge!r z ! wood5 blocks b we> away2 g is a t5sion rod g5]ally furni%$ ) a turnbuckle to adju/ its l5g? z ! wood5 blocks we> away4 ,p[] is appli$ at ! end ( ! b5t lev] h1 z %[n by ! arr[4 ,illu/ration3 ,,fig4 #ba ,! /ops i are adju/$ s t ! blocks b on ea* side are equally di/ant f ! drum :5 ! brake is (f4 ,! fulcrums d %\ld be "s di/ance bel[ ! drum & brake r+1 = if !y are too ne> ! drum x w be difficult to sw+ ! l[] end ( ! wood5 blocks f> en\gh to cle> ! drum4 ,illu/ration3 ,,fig4 #bb #ch4 ,improv$ ,po/ ,brake4--,9 ord] to h an equal cle>ance at top & bottom1 & to h a m p[]ful lev]age ?an 9 ! ord9>y po/ brake1 ! po/s may be made movable at bo? top & bottom1 ,fig4 #bb4 ,! tops ( ! po/s a a are mov$1 z 9 ,fig4 #ba1 by ! t5sion rod b & ! lev] c1 ! latt] be+ connect$ by rod d to lev] e4 ,?is lev] is pivot$ at f & motion is transmitt$ to ! fulcrums j by ! l9k g1 ! lev] h1 & ! t5sion rod i4 ,! back po/ a is support$ by ! uprights k1 :i* are pivot$ at l & sw+ backw>ds & =w>ds l a p>allel rul]4 ,! front po/ a is support$ by ! s+le upright m1 pivot$ at n4 ,! setscrews o regulate ! motion ( ! bottom ( ! po/s s z to give equal cle>ance to ! bottom & top ( ! po/s4 ,an objection to bo? ! block & ! po/ brake is ! fact t1 if ! drum surface to :i* ! brake is appli$ is n p]fectly r\nd1 ! resi/ance ( ! brake w n be uni=m :5 appli$ :ile ! drum is 9 motion4 #ci4 ,! ,/rap ,brake4--,a /rap brake consi/s ( a wr\ght-iron b& or /rap t p>tly encircles ! drum & is connect$ at its free ends to lev]s ) :i* ! b& may be tight5$ on ! brake :eel & ! drum ?us firmly held4 ,! iron or /eel b& ei!r lies directly aga9/ ! wood5 lagg+ ( ! drum or on wood5 blocks bolt$ to ! drum2 or else x has bolt$ to x a l9+ ( wood5 blocks t be> on ! drum :5 ! b& is tight5$4 ,! mo/ effici5t =ms ( /rap brakes are ^? 9 :i* ! /rap or /raps are 9 contact ) #bgj or m ( ! circumf]5ce ( ! drum4 ,! great] ! arc ( contact1 ! m securely is ! drum held by ! brake4 ,a s+le /rap is sometimes us$1 b ?is is only satisfactory ) small drums1 say #h feet or less 9 diamet]2 on l>ge drums two /raps are g5]ally us$1 ea* ext5d+ half way ar\nd ! drum4 ,! lev]s = transmitt+ ! p[] f ! h& lev] or treadle to ! brake /rap are v>i\sly arrang$4 ,9 "s cases1 ! =ce is multipli$ by sev]al %ort lev]s2 9 o!rs1 by "o long lev]4 ,! treadle or foot-lev]1 h[ev]1 has be5 replac$ almo/ entirely by ! h& lev]4 ,illu/ration3 ,,fig4 #bc #dj4 ,! simple/ =m ( /rap brake1 ,fig4 #bc1 consi/s ( a s+le /rap a1 ) "o end an*or$ at b & ! free end atta*$ to ! brake lev] c4 ,?is brake acts on ! same pr9ciple z ! block brake & is op5 to ! objection t x br+s an undue load on ! j\rnals1 b x is m effici5t & holds ! drum m firmly "u a heavy load ?an a block brake4 ,illu/ration3 7a7 7b7 7c7 ,,fig4 #bd ,block brakes are usually run dry1 b 9 b& brakes & po/ brakes ) ample surfaces & prop] lev]age ! wood may be occasionally slightly oil$ ) black oil1 :i* greatly adds to ! durability ( ! blocks )\t unduly less5+ ! p[] ( ! brake4 #da4 ,a two-/rap brake is %[n 9 ,fig4 #bd4 ,"o end ( ea* /rap a1 b is fa/5$ to ! p$e/al c by ei!r ( ! me?ods %[n 9 ,fig4 #bd 7a71 7b71 & 7c74 ,9 ! me?od %[n 9 ,fig4 #bd 7a7 & 7b71 ! =g+s d1 d1 drawn out to ! =m ( bolts1 are rivet$ to ! ends ( ! /raps & pass$ ?r\gh a ca/+ c t is secur$ to ! f\ndation4 ,! object 9 giv+ "o bolt to "o /rap & two bolts to ! o!r /rap is to all[ ! /raps to pass ea* o!r & yet h _! l9es ( action int]sect4 ,! bolts are fa/5$ to c by f\r nuts on ea* bolt1 i4 e41 two pr9cipal nuts & two locknuts4 ,?is gives a means ( adju/m5t 9 ! l5g? ( ! /rap to take up ! we>4 ,a second me?od ( secur+ or an*or+ ! back ends ( ! /raps is %[n at 7c74 ,9 ?is case1 a wr\ght-iron angul> piece is rivet$ to ea* /rap1 & ^! pieces are pass$ ov] ! bolt e t takes ! place ( ! ca/+ ( ! =m] arrangem5t4 ,nuts are us$1 z %[n1 to adju/ ! /raps = we>4 ,! bolt %\ld be %ort & /iff1 s z to be well able to /& up to its "w :5 ! drum is mov+ or t5d+ to move 9 ! direction %[n by ! arr[4 ,:5 ! brake is appli$1 ! friction betwe5 ! brake /rap & ! circumf]5ce ( ! brake :eel produces a great /ra9 on ! p$e/al c1 :i* mu/ be securely an*or$4 ,! front ends ( ! /raps are work$ into eyes1 z %[n at f1 & by ^! eyes & suitable p9s pass+ ?r\gh !m ! ends are fa/5$ to ! brake lev] g4 ,?is lev] is support$ on & rotates ab\t a p9 h1 s t :5 ! brak+ =ce is appli$ at i1 9 ! direction ( ! arr[1 ! brake lev] rotates1 pull+ d[n on /rap a & up on /rap b2 &1 if ! /raps are held firmly at ! back end1 ! m =ce t is appli$ at i ! tight] w ! drum be gripp$ by a & b4 ,! ends ( ! /raps %\ld be br\ght 9 z close to ! drum z is practicable1 bo? front & back1 s z to give ! greate/ am\nt ( contact betwe5 ! drum & ! /raps & to get ! be/ effect f ! =ce appli$4 ,! spr+s j are us$ ) /raps t are n /iff en\gh to cle> ! drum :5 ! brake is releas$4 #db4 ,! rotation ( ! drum may assi/ or ret>d ! action ( ! lev] 9 apply+ ! drop brake4 ,= in/ance1 if1 9 ,fig4 #bc1 ! drum revolves 9 ! direction indicat$ by ! arr[1 ! pull ( ! drum at ! brake /rap is 9 ! same direction z ! pull ( ! lev] :5 apply+ ! brake & ! action ( ! lev] is !n assi/$ by ! motion ( ! drum4 ,on ! o!r h&1 if ! drum is revolv+ 9 ! opposite direction1 x opposes ! action ( ! lev] & a great] =ce mu/ be appli$ to ! lev] to ov]come ?is oppos+ pull ( ! drum4 ,h5ce1 9 ! case ( /rap brakes1 if possible1 t end %\ld be an*or$ :i* w cause ! revolution ( ! drum to assi/ ! lev] 9 apply+ ! brake & ?r[ ! /ra9 on ! an*or bolt in/ead ( on ! lev]4 ,illu/ration3 ,,fig4 #be #dc4 ,if a brake is requir$ to "w ) ! drum runn+ 9 ei!r direction1 !re are sev]al ways ( br++ ! /ra9 due to ! load on ! an*orage 9 :i*ev] way ! drum runs4 ,"o ( ! simple/ ( ^! is %[n 9 ,fig4 #be1 :]e a is a drum ) a /rap brake b embrac+ ne>ly ! entire circumf]5ce2 c is a lev] b> t is atta*$ to ! ends ( ! brake /rap by p9s d & e1 :i* "w 9 ! slots f 9 ! iron an*or plates g4 ,"o an*or plate is on ea* side ( ! lev]1 & bo? are bolt$ to ! f\ndation4 ,if ! b& is kept ( ! prop] l5g?1 !n1 no matt] :i* way ! drum is turn+1 ! pull ( ! drum w come on ! an*orage1 & ! pull on ! lev] ne$ be only suffici5t to take up ! slack end ( ! b&4 ,to illu/rate3 ,if ! drum is turn+ 9 ! direction indicat$ by ! arr[1 ! p9 e hold+ ! l[] end ( ! b& w be on ! bottom ( its slot & ! p9 d w be free 9 its slot & engag$ 9 tight5+ ! slack end ( ! b& ?r\gh ! motion ( ! lev] c4 ,7 ! drum runn+ ! o!r way1 ! p9 d connect$ ) ! upp] half ( ! b& w\ld move to ! upp] end ( its slot & take ! ma9 load1 :ile ! p9 e at ! l[] end ( ! b& w\ld only h to take up ! slack4 ,! out]1 or long1 end ( ! lev] moves d[nw>ds 9 all cases to tight5 ! b&4 ,provision mu/ be made to lift ! b& cle> ( ! drum :5 slack1 b no an*orage o!r ?an at g %\ld be attempt$4 ,illu/ration3 ,,fig4 #bf #dd4 ,! ,diff]5tial ,brake4--,! diff]5tial brake has bo? ends ( ! brake /rap atta*$ to %ort lev] arms op]at$ by ! brake lev]1 b ^! arms are ( diff]5t l5g?s & are s arrang$ t z ! long] arm tight5s ! brake /rap ! %ort] arm yields & loos5s ! /rap4 ,! tight5+1 h[ev]1 is m ?an ! loos5+ or yield+ &1 z a result1 ! brake b& is tight5$ ab\t ! brake :eel4 ,! =m ( ! lev] arm is immat]ial s long z ! diff]5tial pr9ciple is reta9$1 t is1 t ! %ort] arm yields :5 ! long] pulls1 :5 ! brake is ?r[n into action4 ,?is pr9ciple is illu/rat$ 9 ,fig4 #bf4 ,9 ?is brake1 no provision is made = an*or+ ei!r end ( ! brake /rap1 b ! entire load is ?r[n on ! lev] arms a & b4 ,^! lev] arms are connect$ ) ! arm c1 :i* revolves on ! same %aft d & is op]at$ by ! rea* rod e4 ,! revolution ( ! drum is ?us resi/$ by ! %aft d4 ,?is brake is self-act+ :5 ! drum revolves s z to pull on ! %ort] arm1 z indicat$ by ! arr[s2 t is1 ! motion ( ! drum helps to set ! brake :5 ! latt] is once appli$4 ,:51 h[ev]1 ! drum revolves 9 ! opposite direction1 ! action ( ! brake is oppos$1 in/ead ( be+ assi/$1 by ! motion ( ! drum4 ,z a consequ5ce1 ?is p>ticul> =m ( brake is n adapt$ to hoi/+ drums t revolve 9 opposite directions at ea* alt]nate hoi/4 ,diff]5tial brakes are n g5]ally us$4 ,illu/ration3 ,,fig4 #bg #de4 ,p[] = ,brakes4--,= small drums & light loads1 ! brakes are usually appli$ by h& p[] ?r\gh suitable lev] connections4 ,! =ce t a man c ex]t c be multipli$ indef9itely by lev]s & comb9ations ( lev]s2 b :ile ! =ce is multipli$1 ! di/ance ?r\gh :i* x c act is divid$ 9 ! same ratio4 ,a c]ta9 am\nt ( motion is requir$ to free ! brake b& f ! drum1 :5 ! brake is (f2 ?is1 !n1 limits ! lev]age t a man c use4 ,suppose1 = in/ance1 t ) a /rap brake ! b& moves f ! drum in*1 ?us increas+ ! diamet] #a in*1 or ! circumf]5ce ab\t #c in*es4 ,!n1 suppos+ t a man c ex]t 8 =ce to advantage ?r\gh #c feet1 or #cf in*es1 ! available lev]age is _/ #ab4 ,t is1 if a man c pull #ej p\nds on 8 h& lev]1 he c ex]t #ej #ab #fjj p\nds circumf]5tially on ! brake b&1 ) simple lev]s4 ,if any =m ( diff]5tial lev]s is us$1 ! ratio by :i* ! =ce appli$ at ! h& lev] c be increas$ w be consid]ably l>g]4 ,a diagram w expla9 ?is m cle>ly4 #df4 ,9 ,fig4 #bg1 a is ! h& lev]1 ) a fulcrum at b & a p9 at c by :i* x takes hold ( a rea* rod or connection d4 ,?is rod is connect$ to ! end h ( ! brake lev] e1 :i* is connect$ by p9s at f1 g to ! brake b&s4 ,if ! lev]age ( ! h& lev] a is made #f to #a1 t is1 if ab #f ----- --- 1 cb #a & a =ce ( #ej p\nds is appli$ at a1 a pull ( #cjj p\nds w be ex]t$ at ! p9 c &1 consequ5tly1 along ! rod d to ! end ( ! brake lev] e4 ,!n1 if ! brake lev] is made ) a ratio ( #d to #a1 t is1 if eh #d eh ----- --- ---- 1 eg #a ef a pull ( #cjj p\nds #d #a1bjj p\nds w be ex]t$ at ! p9 f or g4 ,?is total pull mu/ be divid$ equally betwe5 ! arms eg & ef1 giv+ #fjj p\nds pull on ea*4 ,accord+ to ! pr9ciple ( ! lev]1 ! di/ances ?r\gh :i* ^! =ces act are inv]sely proportional to ! =ces act+4 ,x is assum$ t ! brakeman c ex]t ! =ce ( #ej p\nds ?r\gh #cf in*es2 if ?is is ! motion ( ! end ( ! h& lev] a1 "o-six? ( ?is1 or #f in*es1 w be ! motion at c &1 !re=e1 at h2 "o-f\r? ( #f in*es or #a in*es w be ! motion at f & g2 t is1 f w increase its half ( ! brake b& #a in*es 9 circumf]5ce1 & g w d likewise ) its half1 mak+ ! total circumf]5ce #c in*es m1 or ! diamet] #a in* m1 & !reby mov+ ! b& away f ! drum in* radially4 ,! lev]s are all %[n 9 mid-position to make ! figure m simple1 b ! relative lev]ages rema9 ! same at all po9ts 9 ! motion4 ,?is is an example ( simple lev]s1 b ! =ce appli$ at ! h& lev] may be increas$ 9 a mu* great] ratio by ! use ( a device kn[n z a diff]5tial lev]4 ,illu/ration3 ,,fig4 #bh #dg4 ,! ,diff]5tial ,lev]4--,! pr9ciple ( ! op]ation ( ! diff]5tial lev] ) :i* a con/antly increas+ =ce c be appli$ to ! brake /rap is illu/rat$ 9 ,fig4 #bh4 ,let a o repres5t a /raight lev] ^: fulcrum is at o2 & let ! rea* rod be atta*$ at e4 ,9 ?is position1 if a o #f ------ --- 1 e o #a ! effective lev] is #f to #a4 ,if1 n[1 ! lev] is mov$ ?r\gh #cj to ! position b o1 ! =ce appli$ at a moves ?r\gh ! di/ance a b1 & ! rea* rod ?r\gh ! horizontal di/ance k f1 s t ! effective lev]age is increas$ a small am\nt e k & ! ratio ( ! arms becomes a o ------- 4 k o ,:5 ! lev] is mov$ ano!r #cj to ! position c o1 ! rea* rod moves a di/ance i g1 :i* is less ?an k f1 s t ! effective lev]age is increas$ by ! am\nt k l & ! ratio ( ! arms becomes a o ------ 4 l o ,aga91 mov+ ! lev] #cj m to ! position d o1 ! rea* rod moves ?r\gh ! /ill %ort] di/ance j h1 :i* is less ?an i g1 & ! effective lev]age becomes v great4 ,x is evid5t f ?is t ! f>!r ! lev] is mov$ t[>d d ! great] becomes ! effective lev]age4 ,9 practice1 x w\ld be impossible to move ! lev] ?r\gh ! entire quadrant to advantage1 & !re w\ld also be m movem5t ( ! rea* rod at ! beg9n+ ( ! /roke & less at ! end ?an is ne$$ to produce ! desir$ effect4 ,illu/ration3 ,,fig4 #bi ,f ! pr9ciple j giv51 x is pla9 t1 if p o1 ,fig4 #bh1 repres5ts a brake lev] ) ! rea* rod atta*$ at q1 a small] pull w be ex]t$ on ! brake b& if ! lev] is mov$ to ! position b o ?an w\ld be ex]t$ if a lev] 7 mov$ ?r\gh ! same angle f b o to d o4 ,! movem5t f p o to b o is a conv5i5t & easy "o = ! eng9e] to make1 :ile ! movem5t f b o to d o is inconv5i5t4 ,to ov]come ! inconv5i5ce & /ill to obta9 ! advantage ( ?is latt] movem5t1 ! diff]5tial lev] %[n 9 ,fig4 #bi is us$4 ,by means ( an arm plac$ on ! lev]1 ! po9t ( atta*+ ! rea* rod is at l in/ead ( p2 h5ce1 :5 ! h&le r b is mov$ to ! position s b1 ! po9t l moves to m1 ?us secur+ a great] & gradually increas+ pull ) ! easi] movem5t ( ! h&le4 ,a diff]5tial lev] may be advantage\sly us$ 9 connection ) any b& or po/ brake & on a drum runn+ 9 ei!r direction4 ,su* lev]s are consid]$ by _m pref]able to ! diff]5tial brake4 #dh4 ,p[] ,brakes4--,l>ge drums & heavily load$ drums _c be controll$ by h&-p[] brakes1 & 9 su* a case "s o!r =m ( p[]1 su* z /eam1 compress$ air1 or wat]1 mu/ be us$4 ,illu/ration3 ,,fig4 #cj ,fig4 #cj %[s1 9 outl9e1 h[ su* p[] is appli$4 ,! movem5ts ( ! h& lev] ,a1 in/ead ( be+ directly communicat$ to ! lev] op]at+ ! brake1 m]ely control ! valve v connect$ ) ! cyl9d] a4 ,by means ( ?is valve1 /eam1 compress$ air1 or wat] is admitt$ to ei!r end ( ! cyl9d] & ?is moves ! pi/on 9 ! direction necess>y to apply or release ! brake4 ,!re are a numb] ( v>ieties ( su* p[] brakes1 diff]+ 9 /ructural details1 b ! action ( all is ess5tially ! same4 ,) /eam or air p[]1 ! brake w\ld be appli$ ) its full =ce almo/ in/antane\sly1 ?us subject+ ! v>i\s p>ts ( ! me*anism to v sev]e & objectionable /ra9s1 unless ! valves 7 modifi$ s z to regulate ! admission ( ! /eam or air4 ,"o me?od ( controll+ ?is action is ! use ( a valve t requires a long travel to give x a full op5+4 ,su* a valve c be op5$ a little1 s z to all[ ! /eam to leak ?r\gh & !reby increase ! pressure 9 ! cyl9d] gradually4 ,z ! motion is difficult to regulate1 a bett] me?od is by means ( a float+ valve1 describ$ 9 ,hoi/+1 ,"p #a4 #di4 ,crank ,brake4--,9 addition to ! brake appli$ to ! drum & int5d$ = use ma9ly 9 em]g5cies1 _m hoi/+ eng9es are also fitt$ ) a /rap brake appli$ to ! crank-disk4 ,9 "s /ates1 crank-brakes are requir$ by law4 ,9 ord] to give a l>ge be>+ surface1 ! crank-disk is made v l>ge4 ,,hoi/+ 7,,"p #d7 ,s]ial #hea;,d ,edition #a ,,hoi/+ ,,appliances ,,%eaves #a4 ,%eaves are groov$ iron or /eel :eels us$ to c>ry or guide a rope4 ,! g5]al me?od ( m\nt+ !m on a frame = hoi/+ light loads is %[n 9 ,fig4 #a4 ,! j\rnal boxes are s con/ruct$ z to be easily tak5 ap>t = inspection or repair4 ,= hoi/+ heavy loads1 ! timb]s mu/ be brac$1 z is expla9$ "u ! head+ ,head-,frames 9 ?is ,section4 ,%eaves are ( two /yles--^? compos$ entirely ( ca/-iron & ^? ) ca/-iron hubs & rims & wr\ght-iron or s(t-/eel arms or spokes4 ,illu/ration3 ,,fig4 #a #b4 ,! ca/-iron %eave1 ,fig4 #b1 has arms ) a cross-section1 z %[n at a b1 & ) ! flanges ( ! arms tap]+ f ! hub to ! rim2 t is1 d is great] ?an c & f is great] ?an e4 ,! bottom ( ! groove g 9 ! rim %\ld be a circul> arc1 ^: radius is a little l>g] ?an t ( ! rope us$ ov] ! %eave1 to all[ = ! angl+ ( ! rope due to its fleet+ on ! drum4 ,! flanges h are made q deep to prev5t ! rope jump+ (f4 ,?is %eave is *eap] ?an a comb9$ ca/-iron & wr\ght-iron or /eel %eave1 & = _m purposes x is entirely satisfactory4 ,its great weight is an objection1 because x adds to ! weight on ! j\rnals & also (f]s consid]able resi/ance to be+ set 9 motion & /opp$4 ,illu/ration3 ,,fig4 #b ,if a %eave is m]ely us$ to c>ry ! rope or to deflect x only a little1 ! contact & pressure betwe5 ! rope & ! %eave is small2 consequ5tly1 ! p[] ( ! rope to turn ! %eave w be slight4 ,9 su* a case1 :5 ! rope />ts or /ops quickly1 z x usually does 9 mod]n hoi/+ plants1 ! heavi] ! %eave ! m w x lag beh9d ! rope & ! great] w be ! we> on ! rope due to slipp+4 #c4 ,! %eave ) a ca/-iron hub & rim & wr\ght-iron or s(t-/eel spokes1 ,fig4 #c1 is an excell5t & ext5sively us$ %eave1 especially ! l>g] diamet]s4 ,! spokes are screw$ into ! hub & rim & are c>ri$ to ! "r & to ! left ( ! hub alt]nately1 z %[n 9 ,fig4 #c 7b71 s z to take hold ( ! opposite ends ( ! hub1 !reby giv+ /iffness to ! %eave aga9/ any side /ress4 ,illu/ration3 ,,fig4 #c ,) a %eave hav+ ca/-iron arms1 ! load f ! rope is transmitt$ to ! %aft by a compressive /ress ?r\gh ! arms directly "u ! load2 t is1 if a rope runs ov] ! %eave1 ,fig4 #b1 putt+ a load on x f j to k1 ?is load w be transmitt$ z a compressive /ress ?r\gh ! arms l & m to ! hub & ! %aft4 ,( c\rse1 a "p ( ?is load is c>ri$ ar\nd ! rim to ! l[] arms & is support$ by !m 9 t5sion1 b ^! l[] arms are n consid]$ 9 design+ ! %eave because ca/-iron is ( comp>atively little value 9 t5sion1 :]eas x is ( great value 9 compression4 ,9 ! case ( ! %eave ) wr\ght-iron arms1 or spokes1 ,fig4 #c1 ! load is transmitt$ ar\nd ! rim to ! side opposite its po9t ( application & is c>ri$ f !re to ! hub & %aft by ! t5sion ( ! spokes2 9 fact1 f ! me?od ( con/ruction1 ! spokes 9 ?is %eave act only by t5sion4 ,! %eave is /rong & rigid1 & mu* light] ?an a ca/-iron %eave ( ! same /r5g?1 s t !re is less we> betwe5 x & ! rope due to any slipp+ action :5 x is />t$ or /opp$4 ,illu/ration3 ,,fig4 #d ,illu/ration3 ,,fig4 #e #d4 ,sometimes1 ! spokes1 in/ead ( be+ radial z 9 ,fig4 #c1 are made tang5t at ! c5t] ( ! :eel1 ,fig4 #d1 to an imag9>y circle1 :i* is ab\t #b in*es 9 diamet] = a #aj-;foot %eave4 ,alt]nate pairs ( spokes are made tang5t to ! opposite sides ( ! circle1 s t !y pull aga9/ ea* o!r1 & ?is makes ! %eave rigid 9 bo? directions4 ,t is1 spoke ,a is tang5t to ! "r side ( ! tang5t circle & ,a to ! left side1 :ile spoke ,b is tang5t to ! "r side ( ! circle & ,b to ! left side4 ,! pair ,b ,b is jo9$ to "o end ( ! hub1 :ile ! pair ,a ,a is jo9$ to ! o!r end1 ?us giv+ lat]al /iffness to ! %eave4 ,?is arranges ! spokes 9 gr\ps ( f\r1 s t ! total numb] mu/ be "s multiple ( f\r4 ,! tang5tial direction ( ! spokes is (t5 necess>y 9 v l>ge %eaves c>ry+ heavy loads1 because ) su* a %eave x requires consid]able =ce to turn ! %aft 9 its be>+s1 & :ile radial spokes act only z long lev]s 9 turn+ ! %aft1 ) tang5tial spokes !re is also a direct pull to d x4 #e4 ,wood-,l9$ ,%eaves4--,! rims ( all %eaves are made ei!r solid or ) wood5 l9+1 z %[n 9 section 9 ,fig4 #e4 ,"o flange a ( ! rim is a sep>ate piece t is held on by bolts b4 ,! wood5 l9+ is 9 ! =m ( blocks plac$ ) ! gra9 ( ! wood runn+ radially & held securely by clamp+ toge!r ! two flanges ) bolts1 z %[n4 ,) su* a %eave1 !re is mu* less we> on ! rope ?an !re is ) "o t has a pla9 ca/-iron rim4 ,! we> ( ! %eave prop] is also avoid$1 because z ! blocks we> d[n !y are tak5 out & replac$ by new ones4 #f4 ,diamet] ( ,%eave4--,! size ( a %eave ab\t :i* a rope b5ds is det]m9$ g5]ally by ! size ( ! rope to be us$1 z expla9$ "u ,wire ,ropes 9 ,hoi/+1 ,"p #b2 b1 if ! rope is simply to be support$ 9 a /raight l9e1 ! space available = sett+ ! %eave & its co/ & weight usually det]m9e ! size us$4 ,! m9imum all[able diamet] ( %eave %\ld n be us$ unless x is necess>y to d s1 = ! l>g] ! %eave ! less w be ! we> ( ! rope due to ! b5d+1 & ! long] ! life ( ! rope1 b ! co/ ( ! %eave1 :i* increases ) ! size1 puts a limit 9 ! o!r direction4 #g4 ,roll]s & ,c>ry+ ,%eaves4--,wood5 or iron roll]s are sometimes us$ = rope c>ri]s or guides1 in/ead ( light %eaves1 :5 ! rope has m]ely to be support$ & !re is no b5d+ ( ! rope1 except+ ! slight am\nt due to ! sagg+ betwe5 ! roll]s4 ,! diamet] ( ! roll]s is ( little importance 9 su* cases s f> z ! rope is conc]n$4 ,if !y are = use on a slope to keep ! rope f dragg+ on ! gr\nd1 !y mu/ be small1 because ! c>s mu/ run ov] !m1 & m9e c>s are usually made l[ because ( re/rict$ headroom 9 ! m9e4 ,roll]s & c>ry+ %eaves are fully describ$ & illu/rat$ 9 ,haulage4 ,if a hoi/+ rope *anges its c\rse f a /raight l9e1 ev5 if ! deflection is only a small am\nt1 a roll] is n advisable & a %eave %\ld be us$1 if possible4 ,,cages ,,cages ,,= ,,v]tical ,,%afts #h4 ,a cage is a c>riage us$ = hoi/+ m9e c>s & _! cont5ts1 m51 timb]1 etc41 9 bo? v]tical & incl9$ %afts4 ,cages are built ( wood /r5g!n$ ) iron or /eel1 or entirely ( iron or /eel4 ,illu/ration3 ,,fig4 #f #i4 ,! cage %[n 9 ,fig4 #f is mu* us$ 9 ! an?racite region ( ,p5nsylvania4 ,x is made l>gely ( oak /r5g!n$ ) iron & ! size v>ies to suit ! %aft1 be+ sometimes z l>ge z #f feet wide by #ab feet long4 ,! g5]al con/ruction ( ! cage is evid5t f ! figure1 b sev]al appliances t %\ld be common to all cages 9 "s =m or o!r require detail$ explanation4 ,a cov]+ a1 call$ a bonnet1 protects p]sons on ! cage f objects fall+ d[n ! %aft1 & is requir$ by law 9 "s ,/ates4 ,?is bonnet is made ( /eel plate ) flanges or angle irons to /iff5 x1 & is usually incl9$4 ,to prev5t objects ( mod]ate size f w$g+ betwe5 ! edge ( ! bonnet & ! %aft l9+1 ! =m] is sometimes made %ort] ?an ! cage1 s t a space ( ab\t a foot is left betwe5 its l[] edge & ! %aft l9+4 ,a %ort bonnet ( ?is "* does n1 h[ev]1 fully protect p]sons on ! cage4 ,! upp] "p ( ! bonnet is fa/5$ to ! upp] cross-b> ( ! cage by two h+es & is held up by rods b t are atta*$ to ! bonnet & h sockets at _! l[] ends1 :i* fit ov] p9s bolt$ to ! uprights ( ! cage4 ,by rais+ ! rods f ! p9s ! bonnet c be l[]$ s t pipes or long timb]s may be l[]$ on ! cage4 #aj4 ,safety cat*es are int5d$ to prev5t a cage fall+ 9 case ! hoi/+ rope breaks4 ,a common =m1 %[n at c1 ,fig4 #f1 & 9 detail 9 ,fig4 #g1 consi/s ( a pair ( too!d cams j1 ,fig4 #g1 fa/5$ on ea* side ( ! cage ne> ! %aft guides4 ,! drawb> b to :i* ! rope is atta*$ ext5ds ?r\gh ! top cross-piece ( ! cage & ?r\gh ! cyl9d] d1 at ! bottom ( :i* is a plate c suppli$ ) lugs = ! rods f t connect x ) ! lev]s g4 ,inside ! cyl9d] are ?ree p[]ful rubb] spr+s1 :i* are 9 compression s long z ! cage hangs f ! rope1 b are ext5d$ if ! rope breaks1 draw+ ! rods f d[n & ) !m ! ends ( ! lev]s g to :i* !y are atta*$2 &1 s9ce ! lev]s are pivot$1 _! o!r ends are mov$ upw>ds & ) !m ! rods k4 ,! cams j are ea* atta*$ to "o end ( ! rods k 9 su* a mann] t z ! rods move upw>ds !y rotate ! cams inw>ds until !y come 9 contact ) ! %aft guides4 ,! tee? ( ! cams grasp ! wood5 %aft guides & /op ! desc5t ( ! cage4 ,! cams are provid$ ) projections a & l t /rike ! guide & ?us prev5t ! cams turn+ entirely ar\nd4 ,fig4 #g 7a7 %[s ! spr+s ext5d$ & ! dogs j j ab\t to grasp ! %aft guides1 :ile ,fig4 #g 7c7 %[s ! position ( ! dogs :5 ! spr+s are compress$ z !y are :5 hoi/+4 ,at e 9 cyl9d] d1 ,fig4 #g 7b71 !re are slots = ! lugs ( plate c to move up & d[n z ! spr+ is compress$ or ext5d$4 ,in/ead ( rubb] spr+s1 helical /eel spr+s are sometimes us$1 & ) a some:at diff]5t design flat /eel spr+s are us$4 ,illu/ration3 7a7 7b7 7c7 ,,fig4 #g ,illu/ration3 ,,fig4 #h ,! cams1 or dogs1 may be plac$ at any po9t along ! upright po/ ( ! cage1 & 9 "s cases two sets ( cams are us$ on ea* side1 "o set at ! top & ano!r 9 ! middle1 bo? sets be+ connect$ by rods s t !y "w toge!r4 ,practical te/s ( ^! cat*es1 made by all[+ ! cage to drop1 %[ t !y are1 z a rule1 v effici5t devices4 ,! cams usually take hold at once1 ! cage dropp+ only a few in*es1 or1 at mo/1 a few feet if ! guides are dry & free f oil4 ,:5 ! guides are v greasy or wet1 ! cage may drop sev]al feet be=e ! cams take a firm hold & /op x1 & ) ice-cov]$ guides1 in/ances are giv5 :]e ! cage has fall5 #ae feet be=e ! cams pl\gh$ _! way ?r\gh ! ice & took firm hold ( ! guides2 b 9 s do+ ! mom5tum ! cage acquir$ 0 s great t ! guides 7 de/roy$4 ,=tunately = ! utility ( safety cat*es1 ropes are usually brok5 :ile a load$ cage is be+ rais$1 & ! cage has an upw>d mom5tum2 if a rope breaks :5 ! cage is desc5d+ at a spe$ ( #cj or #dj feet a second1 its mom5tum is s great t ei!r ! cat*es or guides break4 ,! cat*es g5]ally hold & ei!r ! guides or cage suff] m or less injury "u su* circum/ances4 ,in/ead ( be+ plac$ ne> ! top ( ! cage ! dogs are frequ5tly plac$ ne> ! c5t]1 or ne> ! bottom2 9 "s cases two sets ( dogs h be5 us$1 "o set be+ at ! top & ! o!r at ! bottom4 ,in/ead ( be+ cam-%ap$ ) a numb] ( small tee? on ! rim ( ! cam1 z %[n 9 ,fig4 #g1 ! dogs are n[ frequ5tly made consi/+ ( "o or m /rong /raight tee? on ea* side ( ! guide4 ,^! tee? are op]at$ simil>ly to ^? %[n 9 ,fig4 #g1 & are driv5 into ! guides if ! rope breaks1 ?us hold+ ! cage m firmly ?an ! cam-%ap$ guides1 p>ticul>ly :]e ! guides are wet4 ,,table ,i ,plat=m ,guides ---------------------------------------- -,safe ,load ,weight ,wid? ,l5g? ,size ,di/ance ,betwe5 ,p\nds ,p\nds ---------- ,feet ,in*es --------------- ,feet,in*es ,feet ,in*es ---------------------------------------- ---------------- #d #c #f #f #f #d #f #e1jjj #b1jjj #f #aj #f #aj #f #c #h1jjj #c1hjj #aa4 ,! ,heavy ,/eel ,cage4--,! cage t is %[n 9 ,fig4 #h is made ( iron & /eel except ! wood floor+1 :i* is laid 9 two c\rses1 "o l5g?wise & "o diagonal4 ,! jo9ts %\ld n be driv5 too tightly1 z ! wood is likely to swell4 ,! track is bolt$ to ! floor1 or deck1 ( ! cage4 ,! ca/-/eel safety dogs are op]at$ by /eel spr+s a1 coil$ ab\t ! b>s b1 :i* are connect$ to ! drawb> c by *a9s1 z %[n4 ,! drawb> drops if ! rope breaks & ?us assi/s ! action ( ! spr+s a4 ,?is cage is 9 use at bo? coal & iron m9es1 & is built to suit any size ( %aft & guides4 ,/&>d sizes are giv5 9 ,table ,i4 #ab4 ,! ,light ,/eel ,cage4--,fig4 #i %[s a light /eel cage mu* us$ at gold & silv] m9es4 ,x has a spr+ drawb> & /eel safety dogs1 op]at$ by /eel spr+s1 z 9 ,fig4 #h1 b ! floor is ( /eel grat+ 9 ord] to give z little air pressure z possible aga9/ ! cage4 ,! op5+s a 9 ! side frames are provid$ s t ?r\gh !m ! nuts c be tight5$ on ! bolts t hold ! %aft guides4 ,! cage is provid$ ) bails b t sw+ d[n ov] ea* end ( a c> to hold x on ! cage4 ,illu/ration3 ,,fig4 #i #ac4 ,multiple-,deck ,cages4--,cages are sometimes built t h two or m decks or plat=ms "o above ! o!r1 ?us giv+ great] hoi/+ capacity to a %aft4 ,a two-deck1 safety1 hoi/+ cage is %[n 9 ,fig4 #aj4 ,! upp] deck is heavi] ?an 9 a s+le-deck cage ( simil> con/ruction4 ,! l[] deck is susp5d$ f ! upp] deck by means ( p9s s t x may be remov$ at any "t4 ,a d\ble-deck cage may be us$ by fir/ *ang+ ! c> on ! upp] deck & !n br++ ! l[] deck to ! track level & *ang+ ! o!r c>4 ,"t c be sav$ by hav+ two track levels1 bo? at ! load+ & l&+ /ations1 enabl+ bo? decks to be load$ & unload$ at ! same "t4 ,illu/ration3 ,,fig4 #aj ,multiple-deck cages h be5 ma9ly us$ at ore m9es 9 ,am]ica & v few coal m9es h be5 equipp$ ) !m4 ,cages are also built to accommodate two c>s plac$ ei!r side by side or end to end4 ,illu/ration3 ,,fig4 #aa ,,automatic ,,dump+ ,,cages #ad4 ,a dump+ cage is a cage s con/ruct$ t at ! prop] place x c be automatically tipp$ suffici5tly to dump ! cont5ts ( a c> t is on x & w !n "r itself = ! d[n trip1 ?us avoid+ ! necessity ( remov+ ! c> f ! cage1 & sav+ "t at ! head4 ,! con/ruction ( ! cage is su* t ! c> is held firmly 9 place :ile dump+4 ,! pr9ciple ( ! self-dump+ cage is illu/rat$ 9 ,fig4 #aa1 ! cage be+ %[n 9 its highe/ & l[e/ positions4 ,! cage is made 9 two p>ts a & b4 ,! fix$ frames b slide on ! guides k & h atta*$ to !m ! safety cat*es & hoi/+ ge>4 ,! movable "p a is unit$ to ! frame b by ! h+e c4 ,! plat=m d1 on :i* ! c> re/s1 is fa/5$ to ! movable "p a by ! support e & fur!r secur$ by ! braces f4 ,at ! top ( a is atta*$ ! :eel g t runs along ! rail h1 keep+ a 9 an upright position until x rea*es ! dump+ place i4 ,"h ! rail h is b5t z %[n & ! :eel g is made to foll[ x by means ( ! guide j4 ,?is ?r[s ! top ( a ov] s z to incl9e ! plat=m & dump ! c> t is on x4 ,on l[]+1 ! cage rights itself :5 g passes bel[ ! po9t i4 ,! "p b is kept 9 a v]tical position by means ( %oes t slide on ! ma9 guides k4 ,x is possible to disp5se ) ! guide rail h by atta*+ a flange to ! top ( a at ! back1 to slide on ! ma9 guide k4 ,?is flange %\ld be %ort] ?an ! %oe on b4 ,! ma9 guide is cut away at ! po9t :]e ?is flange comes :5 ! :eel g ent]s ! curv$ guide j1 leav+ an op5+ j l>ge en\gh to all[ ! flange on a to pass ?r\gh4 ,! %oe on b1 be+ long]1 completely spans ! space & _c pass ?r\gh1 b makes b move /raight up on ! ma9 guides4 ,! bottom ( ! cage 9 ,fig4 #aa has an int]rupt$ track1 & at ! bottom ( ! %aft ! track is also int]rupt$1 z %[n 9 ! plan at ! bottom ( ! figure1 b 9 su* a way t :5 ! cage is re/+ at ! bottom ?is portion ( ! track n projects up ?r\gh ! bottom ( ! cage & makes a cont9u\s track4 ,:5 ! cage is rais$ ! :eels ( ! c> drop into ! spaces n 9 ! cage bottom1 ?us prev5t+ ! c> f runn+ (f ! cage dur+ hoi/+ or dump+4 #ae4 ,slope1 or ,incl9$-,%aft1 ,hoi/+4--,9 a slope1 or incl9$ %aft1 ! m9e c>s are atta*$ directly to ! hoi/+ rope & hoi/$ s+ly or 9 tra9s = incl9ations less ?an #ce1 at :i* incl9ation ! mat]ial w beg9 to fall f ! top ( ! c>4 ,= /eep] slopes1 x is cu/om>y to use a slope cage or c>riage on :i* ! m9e c> is hoi/$1 or else to dump "o or m c>s ( ! mat]ial into a gunboat1 or skip1 at ! bottom ( ! slope or at "s l&+ along ! slope1 & to !n hoi/ ! gunboat1 or skip4 ,fig4 #ab %[s a cage = use 9 a slope or /eeply incl9$ %aft4 ,x is made ( /eel ) timb] plat=m & diff]s f a v]tical %aft cage ma9ly 9 hav+ its upp] frame incl9$ & 9 runn+ on f\r :eels a1 b4 ,^! :eels usually run on timb] guides1 s t ! safety dogs c w take hold ( ! guide 9 case ! rope breaks4 ,= slopes ( v>iable incl9ation1 ! plat=m d may be made adju/able by means ( a h& lev] s z to be always level4 ,illu/ration3 ,,fig4 #ab #af4 ,a slope c>riage is a frame s con/ruct$ t :5 rails are plac$ on ! top & a m9e c> run on !m ! c> w be practically horizontal4 ,! c>riage is m\nt$ on :eels & axles 9 ord] to foll[ ! slope tracks1 & is suppli$ ) a drawb>1 or ) hooks1 z %[n 9 ,fig4 #ac1 = atta*m5t to ! hoi/+ rope4 ,^! c>riages are sometimes built to run on a slope track ( ! same gauge z ! m9e c>s1 b to insure /ability !y h g5]ally a broad] gauge4 ,! headroom necess>y is gov]n$ n s mu* by ! =m ( ! c>riage z by ! l5g? ( ! c> & ! incl9ation ( ! seam4 ,?is height is less :5 ! c>s are plac$ on ! c>riage ) _! l5g? across ! slope ?an :5 !y are run on l5g?wise2 b ?is arrangem5t increases ! wid? ( ! slope4 ,:5 ! incl9ation is v /eep1 ! :eels are sometimes plac$ on ! sides ( ! c>riage & above its c5t] ( gravity & run betwe5 two tracks or guides1 on ea* side ( ! slope4 ,illu/ration3 ,,fig4 #ac ,! c>riage1 ,fig4 #ac1 is = use on slopes ( a uni=m incl9ation4 ,x is made almo/ entirely ( heavy timb]1 is /iff & simple ( con/ruction1 & is easy to repair4 ,its details w be readily und]/ood f ! illu/rations1 except p]haps1 ! device = lock+ ! c> to prev5t its runn+ (f dur+ ! hoi/4 ,! middle portion ( ! plat=m a hav+ a piece ( ! c> track on x1 may move v]tically up or d[n4 ,z %[n 9 ! side elevation1 x is re/+ on ! horizontal timb]s b ( ! c>riage 9 a position ready = hoi/+4 ,at ! end ( ! hoi/1 :5 ! cage settles on ! keeps c1 %[n 9 ! end elevation1 ?is plat=m rea*es !m fir/ & is support$ by !m :ile ! re/ ( ! c>riage desc5ds /ill f>!r until ! timb]s d re/ on ! keeps also4 ,! track on ! plat=m a is !n at ! same level z t on d1 & ! c> c be run (f & replac$ by ano!r4 ,:5 ! empty c> is on1 ! c>riage is lift$ f ! keeps1 b ! plat=m a rema9s until ! timb]s b pick x up1 :5 ! keeps are swung back out ( ! way & ! c>riage is l[]$4 ,slope c>riages usually h ! tracks runn+ crosswise s t ! c> is pu%$ on f ! side in/ead ( f ! end4 ,,skips1 ,,or ,,gunboats #ag4 ,skips are self-dump+ c>s us$ = hoi/+ mat]ial f %afts or slopes4 ,9 a v]tical %aft1 !y run 9 guide tracks2 b 9 a slope !y h :eels & run on a track l a c>4 ,9 ! an?racite region ( ,p5nsylvania1 skips are call$ gunboats4 ,z ! skip is n deta*$ f ! hoi/+ rope1 "t is sav$ at ! top ov] t ne$$ to unhook & hook ! c>s to ! rope or to remove & place ! c>s on ! cage4 ,b s9ce dump+ ! mat]ial into ! skip & aga9 on ! surface produces consid]able f9e mat]ial1 skips1 or gunboats1 are seldom us$ = any mat]ial1 su* z coal1 t is (t5 less5$ 9 value by be+ brok54 ,! skip1 or gunboat1 %[n 9 ,fig4 #ad is clos$ along ! top a & op5 at ! end b1 :i* is cut at ab\t ! angle ( ! slope 9 :i* x is to be us$1 s z to rema9 practically level dur+ ! hoi/4 ,x is made ( %eet iron1 ! bottom1 sides1 & top be+ /iff5$ by angle or ,t irons1 & ! back /iff5$ & protect$ by #c-;in* planks1 back$ by #c #f timb]s4 ,! :eels ( a skip are fix$ on ! axles1 :i* run 9 j\rnal boxes1 ?us insur+ smoo!r runn+ ?an is obta9$ ) loose :eels4 ,! details ( ! j\rnal be>+s1 z %[n 9 ,fig4 #ae1 consi/ ( ?ree ca/+s1 ! bracket a1 :i* is bolt$ or rivet$ to ! gunboat1 a pivot ca/+ b1 & ! be>+ prop] c4 ,! be>+ c re/s on ! axle & c>ries1 by means ( trunnions d1 ! pivot ca/+ b1 on ! top ( :i* is plac$ a rubb] cu%ion e to less5 ! %ocks betwe5 ! ca/+ & ! bracket4 ,illu/ration3 ,,fig4 #ad ,illu/ration3 ,,fig4 #ae #ah4 ,me?od ( ,load+ ,skips4--,9 ,fig4 #af1 a skip a is %[n 9 a slope /&+ imm$iately bel[ a level :]e a c> b is ready to h its load dump$ into ! skip4 ,in/ead ( dump+ ! m9e c> directly into ! skip1 a b9 is frequ5tly provid$ at ! level /ation1 or l&+1 into :i* ! m9e c>s are dump$ & f :i* ! mat]ial is load$ into ! skip ?r\gh suitable *utes4 ,! use ( su* b9s makes ! hoi/+ ( mat]ial l>gely indep5d5t ( ! work+ conditions on ! levels & ! hoi/+ c be m sy/ematically & satisfactorily c>ri$ on4 ,illu/ration3 ,,fig4 #af ,illu/ration3 ,,fig4 #ag ,if ! mat]ial comes to ! slope z %[n 9 ,fig4 #ag1 x is necess>y to let d[n a bridge a1 on :i* ! c> runs1 9 ord] to rea* ! skip4 ,aft] ! c> is dump$1 ! bridge is lift$ out ( ! way into ! dott$ position1 s z to leave ! slope unob/ruct$4 #ai4 ,me?od ( ,dump+ ,skips4 ,to dump a skip at ! surface1 ! tracks are ext5d$ above ! slope m\?1 z %[n 9 ,figs4 #ah & #ai1 & are arrang$ s t ! mat]ial may be dump$ directly into a b9 or into c>s z desir$4 ,9 ! arrangem5t %[n 9 ,fig4 #ah1 ! front :eel ( ! skip /rikes a /op a &1 s9ce ! bail ( ! skip is pivot$ f> d[n t[>d ! l[] end1 z ! rope cont9ues to pull1 ! re> ( ! skip is rais$ & ! mat]ial is dump$4 ,! objection to ?is me?od is t if ! rope is slightly ov]w\nd ! skip is pull$ (f ! track & does n !n "r itself on ! track :5 ! rope is releas$4 ,illu/ration3 ,,fig4 #ah ,9 ! ,lake ,sup]ior iron & copp] region1 _m ( ! dumps are built z %[n 9 ,fig4 #ai4 ,9 ?is dump1 ! rails ( ! ma9 track a are curv$ z %[n at b2 a %ort di/ance back ( ! beg9n+ ( ?is curve1 ano!r track c beg9s outside ! track a & runs 9 a /raight l9e p>allel to ! incl9ation ( ! hoi/4 ,! track c is ( a wid] gauge ?an a1 & ! re> :eels ( ! skip h a wid] tread ?an ! front1 s t !y w run on c :ile ! front :eels take ! curv$ track until !y /rike ! /op d4 ,! re> ( ! skip w ?us be rais$ & ! mat]ial dump$4 ,!re are b two tracks 9 ! ma9 "p ( ! slope4 ,illu/ration3 ,,fig4 #ai ,illu/ration3 ,,fig4 #bj ,illu/ration3 ,,fig4 #ba ,9 ! me?od illu/rat$ 9 ,fig4 #bj1 ! re> & front :eels h ! same tread1 b ! re> axle is long] ?an ! front & has roll]s a on ea* side4 ,^! /rike ! track b1 & :ile ! front :eels foll[ ! curv$ track c ^! roll]s run on ! track b & ?us raise ! re> end ( ! skip4 #bj4 ,skip ,cage4--,:]e a self-dump+ skip is to be us$ 9 a v]tical or highly incl9$ %aft & x is desir$ to use safety cat*es1 ! skip a is m\nt$ 9 a cage or frame b1 ,fig4 #ba1 simil> to ! self-dump+ cage1 ,fig4 #aa4 ,! skip be+ pivot$ at c "o side ( ! c5t]1 & re/+ on ! frame ( ! cage1 t5ds to rema9 upright until x rea*es ! dump2 b = safety x is sometimes lock$ 9 place by ! lat* d1 :i* hooks ov] ! p9 e4 ,:5 ne> ! top1 ! roll] f on ! end ( ! lat* d comes 9 contact ) a b> t depresses ! roll] & ?us unhooks ! lat*4 ,! roll] g ent]s & travels along ! guide rails h1 tipp+ ! skip4 ,!re are two roll]s g1 "o on ei!r side ( ! skip4 ,! nose i is tempor>ily caught on ! roll] j1 ?us /opp+ ! movem5t ( ! skip sidewise & away f ! upright guide4 ,,buckets #ba4 ,buckets1 su* z are us$ = hoi/+ mat]ial dur+ %aft s9k+1 are cont9u$ 9 use aft] m9+ beg9s :5 ! am\nt ( mat]ial to be hoi/$ is small4 ,,c> ,,locks #bb4 ,sev]al me?ods ( keep+ ! c> on ! cage h already be5 illu/rat$3 by *a9s1 ,fig4 #h2 by bails1 ,figs4 #i1 #aj1 & #ab2 by omitt+ sections ( ! rail "u ! c> :eels1 ,fig4 #aa2 & by dropp+ a portion ( ! plat=m1 ,fig4 #ac4 ,a v common way is m]ely to put a p9 ?r\gh ! hole 9 ! drawb> & into ! floor ( ! cage4 ,ano!r common device consi/s ( a brake block t fits betwe5 ! :eels & c be ?r[n 9 f ! side by a lev] :5 ! c> is 9 place4 ,ano!r device consi/s ( a yoke1 :i*1 by means ( a lev]1 is rais$ :5 ! c> is 9 place s t x passes ab\t ! axle & ?us holds ! c>4 ,a device frequ5tly us$ on self-dump+ cages is %[n 9 ,fig4 #bb4 ,illu/ration3 ,,fig4 #bb ,! curv$ b>s a ( iron1 :i* j fit ar\nd ! c> :eels z %[n1 are atta*$ to ! loose b>s b1 on ! ends ( :i* are ! weights c4 ,:5 ! cage is at ! bottom1 ^! weights /rike on a cross-piece & are rais$ to ! position %[n by ! dott$ l9es1 ?r[+ out ! b>s b1 z %[n by ! dott$ l9e1 ?us releas+ ! :eels4 ,! devices %[n 9 ,figs4 #aa1 #ac1 & #bb d n come into action until ! cage leaves ! l&+ & ! c>s mu/1 !re=e1 be wat*$ until t "t4 ,,cage ,,guides #bc4 ,guides are us$ 9 all v]tical %afts ( any consid]able dep? & 9 _m highly incl9$ %afts to keep ! cage f sw++ ab\t & /rik+ ! sides ( ! %aft4 ,!y are made ( wood5 rails1 iron rails1 or wire ropes4 ,9 ,am]ican m9es1 timb] guides pr$om9ate1 al?\gh "s iron ones are us$1 & = small %afts at ore m9es wire-rope guides are common4 ,9 ,engli% m9es1 wire ropes1 call$ conductors1 are v l>gely us$4 ,?is diff]5ce 9 practice is probably due to ! fact t 9 ,engli% m9es ! %afts are usually r\nd & ! cages are rectangul>4 ,9 su* a %aft1 ! wire-rope conductors hang f ! head-frame )\t any cross-brac+1 b !y require a /rong support1 z bo? ! weight ( ! ropes & ! /ra9 to give ! necess>y t5sion come on ! head-frame4 ,:5 bo? ! %aft & ! cage are rectangul>1 z 9 mo/ ,am]ican m9es1 timb] guides are easily put 9 & !y (f] a good surface = ! safety cat*es to grip4 ,illu/ration3 ,,fig4 #bc ,wood5 guides are always rectangul> 9 cross-section & 9 ! ,unit$ ,/ates are usually made ( yell[ p9e or o!r long-gra9$ wood t does n spl9t] easily2 9 "s localities1 oak or "s ( ! o!r h>d] woods are us$4 ,!re is no fix$ size = cage guides1 b #d #d1 #f #h1 #h #aj1 & #d #aa timb]s are frequ5tly us$4 ,! guides are firmly fa/5$ to ! %aft buntons ) lagscrews or ) bolts c\nt]sunk into ! guide s z to be cle> ( ! %oes1 &1 to secure safety ) spe$ 9 hoi/+1 ! ends ( ! guides mu/ be put toge!r ) jo9ts t are n liable to displacem5t & t (f] no projections to ! %oes 9 pass+4 ,! buntons to :i* ! guides are secur$ mu/ be s firmly fa/5$ t !y _c get out ( place1 & ! guides mu/ be set z ne>ly z possible 9 a /raight l9e1 because if !y are crook$ ! cage is ?r[n back & =? z x travels along !m & ?is n only increases ! /ra9 on ! hoi/+ rope & eng9e1 b soon] or lat] loos5s & misplaces ! guide4 ,fig4 #bc %[s a plan ( a cage ) ! bunton ,a1 guides ,b1 & cage %oes ,c 9 _! normal positions4 ,,l&+ ,,fans ,,or ,,keeps #bd4 ,9 ord] to take ! /ra9 (f ! hoi/+ rope :ile a cage or skip is be+ load$ or unload$1 a me*anism to support ! cage is plac$ at ! top & at any level ( ! m9e :]e load+ is done1 except+ at ! bottom level :]e all t is usually requir$ are ! cross-timb]s = ! cage to re/ on4 ,^! supports h diff]5t names 9 v>i\s localities1 be+ kn[n z fans1 keeps1 cage re/s1 l&+ dogs1 l&+ *airs1 w+s1 etc4 ,_! use increases ! safety ( cag+4 #be4 ,a common =m ( keeps is %[n 9 ,fig4 #bd4 ,! cage a re/s on f\r squ>e b>s ( iron b1 "o "u ea* corn] ( ! cage4 ,^! b>s h an eye or hub at ! l[] end & are key$ to ! %afts d1 :i* re/ 9 ca/-/eel boxes4 ,! lev]s e & f1 :i* are also key$ to ! ends ( ! %afts d1 are connect$ by a rod g4 ,*a9s h prev5t ! fans f mov+ too f> "u ! cage4 ,:5 ! cage is to be l[]$1 x is fir/ lift$ cle> ( ! fans & ! lev] e is mov$ into ! dott$ position1 ?us mov+ ! fans b out ( ! way & p]mitt+ ! cage to be l[]$4 ,! inside ( ! fans h no projections1 & ! op]at+ me*anism is su* t no h>m w\ld come if !y 7 left 9 ! %aft & a hoi/ 7 made1 z ! cage w\ld op5 out ! fans & pass ?r\gh !m )\t any tr\ble4 ,if1 h[ev]1 ! fans are n drawn back at all ! head+s 9 ! %aft :5 ! cage is l[]$1 great damage results :5 ! cage /rikes ! project+ fans4 ,to avoid ! possibility ( su* an accid5t1 fans h be5 devis$ t fall back out ( l9e ( ! %aft z soon z ! weight ( ! cage is remov$ f !m4 ,illu/ration3 ,,fig4 #bd #bf4 ,hydro/atic ,fans4--,mo/ fans 9 use are built on ! same pr9ciple z ^? j describ$1 al?\gh ! details ( _! con/ruction may v>y4 ,an objection t c be rais$ aga9/ !m is t1 ) l>ge cages & heavy loads1 ! j> caus$ by lett+ ! cage d[n on su* a rigid support is v h>d on ! cage4 ,all cages1 p>ticul>ly heavy ones1 suff] mu* m we> f be+ l&$ too sudd5ly ?an f ! /ra9s ( hoi/+4 ,= ?is reason1 x is advisable to make ! upp] p>ts z light z compatible ) /r5g? & ! side pieces /rong] ?an ne$$ = ! actual /ra9s to :i* !y are subject$4 ,hydraulic fans1 ,fig4 #be1 h successfully ov]come ?is tr\ble4 ,! cyl9d] %[n is "o ( f\r on :i* ! cage re/s4 ,! eye at ! l[] end fits on a b> by means ( :i* ! cyl9d]s are mov$ backw>ds & =w>ds simil> to ! motion ( ! fans b1 ,fig4 #bd4 ,9 ,fig4 #be 7a71 ! cage is %[n z ab\t to re/ on ! jaw a4 ,z ! cage settles1 x pu%es ! plung] b d[nw>ds1 b ?is action is resi/$ by oil 9 ! cyl9d] at c4 ,at fir/1 ?is resi/ance is v slight1 because ! ,v-%ap$ grooves d 9 ! plung]1 :i* are ( consid]able size at ! end ( ! plung]1 all[ ! oil to escape freely into ! upp] *amb] e4 ,^! grooves1 h[ev]1 tap] d[n to no?+1 s t ! fl[ ( oil ?r\gh !m decreases until none c pass except by leakage ar\nd ! plung]4 ,?is all[s ! plung] ) its load to settle sl[ly to ! bottom1 z %[n 9 ,fig4 #be 7b74 ,illu/ration3 7a7 7b7 ,,fig4 #be ,if n[ ! cage is lift$ & ! weight ?us remov$ f ! jaw a1 ! spr+ g pu%es ! plung] b outw>ds & all[s ! oil to run f e back into c4 #bg4 ,pneumatic ,fans4--,a pneumatic fan1 %[n 9 section 9 ,fig4 #bf1 is "o 9 :i* ! %ock ( ! l&+ is p>tially reliev$ by a cu%ion ( compress$ air4 ,! fan is key$ at ! bottom to ! %aft a t rotates x1 z 9 ,fig4 #bd4 ,! cyl9d] b conta9s ! plung] c1 :i* is kept at ! top limit ( its motion by ! spr+ d4 ,:5 ! cage l&s 9 ! jaw e1 ! plung] desc5ds1 compress+ ! air 9 ! cyl9d] b4 ,! air escapes sl[ly ?r\gh ! _/-in* hole f1 ?us all[+ ! cage to settle into place ) v little %ock4 ,^! fans %\ld be made ( wr\ght-iron or ca/-/eel s z n to be easily brok54 ,illu/ration3 ,,fig4 #bf #bh4 ,cage ,*airs4--,9 ! case ( a cage requir$ to /op at a l>ge numb] ( levels1 x is exp5sive to provide fans at ea* level1 & to obviate ?is a /rong /eel b> or dog may be us$ "u ea* corn] ( ! cage1 all f\r b>s be+ connect$ to a lev] on ! cage1 by means ( :i* !y c be ?r[n out at w s z to re/ on supports provid$ at ea* level4 ,fig4 #bg %[s ,gray's pat5t cage *air1 :i* op]ates on ?is pr9ciple4 ,! slid+ b>s a are connect$ by ! cross-b>s b1 :i* are pivot$ at ! c5t] & op]at$ by ! b> c ?r\gh ! l9ks d4 ,by mov+ ! lev] e into ! position %[n1 ! b>s a are ?r[n out s z to re/ 9 not*es or on wall plates 9 ! %aft4 ,! spr+s f1 ?r\gh ! cross-b>s b1 =ce ! slid+ b>s a back "u ! cage :5 ! lev] e is releas$4 ,,head-,,frames #bi4 ,a head-frame ( wood1 iron1 or /eel is built ov] a %aft or slope m\? to c>ry ! %eaves ov] :i* ! hoi/+ ropes are conduct$ f ! m9e to ! drum ( ! hoi/+ eng9e2 x also usually c>ries ! upp] portion ( ! cage guides or1 9 ! case ( a slope1 ! tracks = c>s4 ,illu/ration ,illu/ration3 ,,fig4 #bg ,a head-frame mu/ be /rong en\gh to be> ! /ra9 br\ght on x due to ! total load hoi/$ & ! pull ( ! eng9e 9 hoi/+ ?is load2 x mu/ also be rigid 9 con/ruction to )/& ! sev]e vibration & %ock to :i* x is subject$ on acc\nt ( ! rapid hoi/+ & ! j> due to ! l&+ ( ! cages4 ,illu/ration3 ,,fig4 #bh ,! am\nt & direction ( /resses t a head-frame mu/ resi/ are usually det]m9$ by apply+ ! p>allelogram ( =ces z foll[s3 ,fig4 #bh is a simple head-frame at a slope2 a is ! drum ( ! hoi/+ eng9e ) ! rope com+ f its upp] side & runn+ ov] ! head-%eave b d[n to ! slope cage c4 ,assum+ t ! angles e1 f made by ! two portions ( ! rope ) ! horizontal are equal1 & t ! pull on ea* "p ( ! rope is #bj1jjj p\nds1 to det]m9e ! am\nt & direction ( ! resultant ( ! two rope pulls1 proce$ z foll[s3 ,ext5d ! rope l9es to ! po9t ( int]section g & f !re lay (f ! two l9es g h & g k1 to "s def9ite scale1 repres5t+ ! pull ( ! rope4 ,if a scale ( #b1jjj p\nds to in* is tak5 7 in* #b1jjj p\nds71 g h & g k w ea* be #a in* long4 ,complete ! p>allelogram by draw+ h l p>allel to g k & k l p>allel to g h4 ,! diagonal g l repres5ts ! direction & am\nt ( ! =ce act+ on ! head-frame due to ! pull ( ! two portions ( ! rope4 ,! diagonal1 by measurem5t1 is #a in*es or _/ in*es long1 & s9ce ea* t5? in* equals #b1jjj p\nds1 ! /ress on ! head-frame 9 ! l9e ( ! diagonal g l is #b1jjj #ae #cj1jjj p\nds4 ,! figure also %[s t ! direction ( ?is =ce is v]tical1 h5ce !re is no t5d5cy = ! frame to be pull$ ov] to ei!r side &1 !oretically1 side brac+ is n ne$$4 ,illu/ration3 ,,fig4 #bi #cj4 ,consid] n[ ! case ( a v]tical %aft1 ,fig4 #bi1 9 :i*1 z be=e1 a is ! drum1 b ! head-%eave1 c ! cage1 & d ! head-frame1 & assume ! same pull ( #bj1jjj p\nds on ea* "p ( ! rope4 ,z be=e1 ext5d ! l9es ( ! rope1 :i* are ! l9es ( =ce along :i* ! pulls due to ! eng9e & ! load act1 until !y int]sect at g4 ,f ?is po9t lay (f on ^! l9es di/ances repres5t+ ! /resses 9 ! rope to any scale4 ,us+ ! same scale z be=e1 in* #b1jjj p\nds1 ! l9es g h & g k repres5t+ ! two =ces w be ea* #a in* long4 ,complet+ ! p>allelogram by draw+ h l p>allel to g k1 & k l p>allel to g h1 & draw+ ! diagonal g l ?r\gh g1 ! resultant1 g l _/ in*es1 repres5ts a /ress ( #ch1jjj p\nds4 ,! direction ( ! resultant is also det]m9$1 be+ 9 ! l9e ( ! diagonal g l4 ,if ! head-frame %[n 9 ,fig4 #bh 7 us$ = ?is case1 x w\ld be ov]turn$ by ?is resultant =ce1 unless ! leg on ! opposite side ( ! %aft f ! eng9e 7 securely an*or$1 s an incl9$ brace m is add$ to resi/ ?is ov]turn+ action4 ,! resultant ( all =ces act+ on ! head-frame %\ld g5]ally fall )9 ! /ructure if ! greate/ /ability is to be secur$1 b :5 ?is _c be done x is necess>y to resi/ ! ov]turn+ pull by an*or+ ! head-frame to its f\ndations mu* m securely ?an is ! case :]e ! resultant falls )9 ! /ructure4 ,! direction ( ! resultant =ce may be obta9$ by draw+ a l9e ?r\gh ! int]section ( ! l9es ( action ( ! =ces at g & ! c5t] ( ! head-%eave b1 z may be se5 9 ,figs4 #bh & #bi4 ,illu/ration3 ,,fig4 #cj #ca4 ,9 ,figs4 #bh & #bi1 ! pull ( "o hoi/+ rope runn+ f ! top ( ! drum 0 consid]$1 b 9 mo/ cases x is necess>y to consid] ! pull f two hoi/+ ropes1 "o runn+ f ! top & "o f ! bottom ( ! drum f1 z %[n 9 ,fig4 #cj4 a b & a b repres5t ! directions ( action ( ! two =ces act+ on ! hoi/+ ropes1 :ile ! two v]tical =ces a c & a c act+ d[n ! %aft are approximately equal to ! two =ces act+ t[>d ! drum4 ,!re are1 !re=e1 two resultants a d & a d1 ! directions ( :i* are det]m9$ by l9es f a & a ?r\gh ! c5t] ( ! %eave e4 ,! am\nts ( ^! resultant =ces c be det]m9$ by ! p>allelogram ( =ces z %[n 9 ,figs4 #bh & #bi4 ,a resultant t is a mean betwe5 a d & a d1 bo? 9 position & am\nt1 is sometimes tak51 or ! great] value z det]m9$ f a d or a d & ! greate/ incl9ation z giv5 by a d may be us$1 z be+ ! wor/ !oretical conditions to :i* ! frame may be subject$4 ,a head-frame usually has a v]tical po/ approximately p>allel to ! v]tical pull ( ! rope 9 ! %aft1 & an incl9$ memb] g h approximately p>allel to ! resultant det]m9$ by ! p>allelogram ( =ces4 ,if g h1 ,fig4 #cj1 is p>allel to ! resultant1 ! v]tical leg h i is "u no /ra9 & m]ely supports ! end ( g h4 ,if ! resultant falls betwe5 g h & h i1 bo? ( ^! legs w be "u compression4 ,if ! resultant falls outside ( g h1 ! leg g h w be "u compression & h i w be "u t5sion4 ,! head frame w be mo/ /able :5 ! resultant falls betwe5 g h & h i1 b ?is _c always be accompli%$ 9 build+ ! frame on acc\nt ( ! conditions at ! head ( ! %aft2 nor is x always advisable to d s f /ructural consid]ations4 #cb4 ,s9ce wood is mu* bett] adapt$ to )/& compressive ?an t5sile /resses & s9ce /eel is adapt$ to )/& ei!r t5sile or compressive /resses1 x is mu* m important t ! memb]s ( timb] frame con=m z closely z possible to ! !oretical l9e work$ out 9 ,figs4 #bh1 #bi1 & #cj ?an 9 ! case ( a /eel frame4 ,take1 = in/ance1 ! case %[n 9 ,fig4 #ca1 :]e = "s local reason x is impossible to put an incl9$ /rut 9 or ne> ! l9e ( ! resultant /ress to )/& ! pull t t5ds to ov]turn ! head-frame4 ,9 a /eel /ructure1 a c v easily be made a t5sion memb] by an*or+ its l[] end to a heavy f\ndation4 ,?is resi/s ! t5d5cy to ov]turn & makes a v /able /ructure4 ,9 practice1 braces c g5]ally be locat$ p>allel to ! l9e ( resultant /ra91 ,fig4 #bi1 or outside ?is l9e1 z %[n 9 ,fig4 #cj1 s t ! /ra9 due to ! pull ( ! rope w come ma9ly on ! incl9$ brace & n on ! upright4 ,to di/ribute ! /ress on ! foot ( ! diff]5t p>ts ( ! frame1 an incl9$ brace is usually set f>!r f ! %aft ?an ! p>allelogram ( =ces locates x1 & s plac$ t ab\t two-?irds ( ! /ra9 due to ! pull ( ! rope comes on ! brace & "o-?ird on ! upright p>ts ( ! frame4 ,9 ord] to give ! frame a m /able base & because ! base mu/ be l>g] ?an ! top ( ! frame to br+ ! f\ndations back f ! %aft m\?1 usually ! memb]s h i are also slightly incl9$4 ,illu/ration3 ,,fig4 #ca ,:]ev] p]man5cy ( head-frames is requir$1 if /eel is obta9able at a price at all comp>able ) wood1 /eel /ructures are be+ us$1 z timb] frames rot4 ,,types ,,( ,,head-,,frames #cc4 ,!re are ?ree types ( head-frame con/ruction--! ,a type1 ! squ>e type )\t an incl9$ brace1 & ! squ>e type ) an incl9$ brace4 #cd4 ,a ,type ( ,head-,frame4--,fig4 #cb %[s ! con/ruction ( a triangul>1 or ,a-%ap$1 head-frame ( :i* 7a7 is a side elevation & 7b7 an end view4 ,?is p>ticul> frame is l>gely us$ at an?racite m9es1 b ! type is "o q commonly us$ = timb] frames1 ?\gh ! details ( con/ruction v>y 9 diff]5t localities4 ,! height ( ! frame is f #cj to #ej feet1 & ) direct-act+ eng9es ?is height %\ld be suffici5t to all[ a play ( at lea/ two-?irds ( a revolution betwe5 ! cage l&+ & ! ov]w9d+ po9t4 ,! po/s a are p>allel to ! hoi/+ rope b z x hangs d[n ! %aft & ! incl9$ brace c1 :i* resi/s any ?ru/ t w\ld t5d to rotate ! head-frame1 is p>allel to ! resultant pull ( ! two p>ts ( ?is rope b2 ! incl9$ braces d /iff5 ! frame & help support ! cross-timb]s m t support ! cage guides e4 ,! sills f are made ( ?ree pieces ( timb] #h in*es by #ad in*es 9 cross-section4 ,! po/s a re/ 9 ca/-iron %oes g t are firmly bolt$ to ! po/s & sills4 ,! incl9$ braces c1 d are fitt$ ) ca/-iron %oes h1 i4 ,! po/ a & ! two braces c1 d are held 9 place at ! top ( ! frame by ! ca/+ j1 :i* also supports ! pill[-block k4 ,! po/s a & ! brace c are made up ( two pieces ( timb] ea* #h in*es by #ad in*es 9 cross-section4 ,! brace d consi/s ( "o piece ( timb] #h in*es by #ad in*es 9 cross-section4 ,! transv]se braces l consi/ ( two pieces ( timb] #f in*es by #ad in*es 9 cross-section1 bolt$ ?r\gh ! timb]s a & c4 ,! supports m = ! guides are s+le pieces ( #h #h timb]4 ,! c5t] po/1 z %[n 9 ,fig4 #cb 7b71 is brac$ by ! two pieces n1 o1 :i* are support$ by two timb]s p1 q bolt$ to ! two outside po/s4 ,! po/s a & ! incl9$ braces c are fur!r brac$ by ! tie-rods r1 s1 t1 & u1 all ( :i* are fitt$ ) turnbuckles1 z %[n at v4 ,! diff]5t po/s are firmly bolt$ toge!r1 ! bolts be+ fitt$ ) ca/-iron wa%]s4 ,illu/ration3 7a7 7b7 ,,fig4 #cb ,illu/ration3 ,,fig4 #cc ,fig4 #cc %[s ! con/ruction ( ! ord9>y timb] gall[s frame us$ at _m ore m9es4 ,fig4 #cd %[s a /eel ,a frame1 ( :i* ! pr9cipal dim5sions are z foll[s3 height to %eave c5t] #dh feet2 base #cc feet #aj in*es by #ef feet4 ,legs a & b are made ( lac$ *annels1 z are also ! c5tral upright po/s & cross-braces4 ,! =w>d incl9$ legs are made ( ,i beams4 ,! weight ( ! frame is #ih1jjj p\nds )\t ! %eaves4 ,! advantages claim$ = ?is type ( design are t x gives a v /rongly brac$ frame :ile us+ a m9imum ( mat]ial4 ,also1 9 cases ( ov]w9d+1 ! cage goes ov] ! top ( ! frame )\t injury to ! frame1 & %\ld m5 be ov]w\nd !y w\ld fall only ! height ( ! frame in/ead ( be+ cru%$ aga9/ ! top4 #ce4 ,squ>e ,type ,)\t ,incl9$ ,brace4--,fig4 #ce %[s a /eel frame 9 :i* ! t5d5cy to be ov]turn$ by ! pull ( ! rope is resi/$ by a ne>ly v]tical t5sion leg z expla9$ 9 ,art4 #cb4 ,ea* leg ( ! frame is built ( *annel b>s connect$ by lattice brac+1 z %[n1 & ! legs are /iff5$ by horizontal *annel cross-b>s simil>ly brac$ & also by diagonal tie-rods1 provid$ ) turnbuckles4 ,illu/ration3 ,,fig4 #ce ,illu/ration3 ,,fig4 #cd ,spr+s are sometimes plac$ "u ! j\rnals ( ! head-%eaves to less5 ! /ra9 on ! rope :ile />t+ ! load2 ! #ae-;foot head-%eaves ( ! ,rob9son deep m9e at ,johannesburg h locomotive spr+s "u ! j\rnal boxes1 ! actual load on ea* spr+ due to ! weight ( ! %eave1 rope1 skip1 & rock be+ equal to ab\t #bj1jjj p\nds2 x 0 e/imat$ t ! %eave w\ld ?us be l[]$ by ! load on x1 ab\t #c in*es1 :i* w\ld be equal to an action ( a spr+ giv+ motion ( #f in*es at ! cage4 ,spr+s c (t5 be us$ bo? on ! rope & "u ! %eave 9 ! same plant to advantage4 ,illu/ration3 ,,fig4 #cf #cf4 ,squ>e ,type ,) ,incl9$ ,brace4--,fig4 #cf %[s a v sub/antial frame ) squ>e t[] & incl9$ brace4 ,illu/ration3 ,,fig4 #cg ,its pr9cipal dim5sions are z foll[s3 height to %eave c5t] #ei feet #f in*es2 base ( t[] #ae feet #h in*es by #ad feet2 di/ance ( bottom ( incl9$ leg f v]tical po/ #dh feet4 ,ea* end po/ a is compos$ ( two *annels1 d\ble-lattic$4 ,! horizontal memb]s b are ,i beams & ea* incl9$ memb] c is made up ( two angles4 ,! incl9$ leg d is truss$ z %[n & built ( *annel & angle beams1 ! ma9 memb] be+ made ( two *annels1 ! incl9e & base memb]s ( ! truss be+ made up ( two angles1 & ! %ort v]tical memb] ( two *annels4 ,! c5t] po/ ( ! t[] is simil> to ! end po/s1 except t ! uprights are ,i beams in/ead ( *annels4 ,! frame is design$ = a /atic weight ( #af1jjj p\nds & = a maximum /ra9 on ! cable ( #cb1jjj p\nds4 ,fig4 #cg %[s a frame ( simil> =m1 b 9 :i* ! l&+ plat=m is plac$ at a height above ! surface1 s t ! c>s hoi/$ c be run (f on a tre/le & ?us be deliv]$ at ! top ( a c>1 break]1 tipple1 or ore h\se4 ,its pr9cipal dim5sions are z foll[s3 height to %eave c5t] #ge feet2 base #dj feet #aa in*es by #ba feet #h in*es4 ,! leg a is made ( two angles4 ,! brac+ leg b is built ( two angles4 ,! diagonal braces c are s+le angles4 ,! horizontal braces are angles or *annels ( v>i\s sizes dep5d+ on ! /resses4 #cg4 ,! head-%eave is support$ directly on top ( ! ma9 frame1 z %[n 9 ,figs4 #cb1 #cd1 #cf1 & #cg1 or a small sup]/ructure a is built on top ( ! ma9 frame1 z %[n 9 ,fig4 #ch1 s t ! base ( ! %eave j\rnals is p]p5dicul> to ! resultant pull on ! frame1 t is1 to ! !oretical direction ( ! incl9$ leg ( ! frame if "o is us$4 #ch4 ,timb] frames are usually built by ! m9+ company f its own designs4 ,/eel frames are g5]ally built by ! /ructural /eel companies f detail$ plans & designs furni%$ by ! m9+ company1 or f a skeleton diagram furni%$ by ! m9+ company1 giv+ ! loads on ! rope & ! g5]al conditions ab\t ! %aft to :i* ! frame mu/ con=m1 ! frame be+ !n design$ & erect$ 9 detail by ! /eel company4 #ci4 ,enclos+ ,head-,frames4--,head-frames are sometimes :olly or p>tially enclos$ to protect !m & ! m5 f ! wea!r4 ,a cov]+ ( bo>ds is w>me/4 ,all woodwork %\ld be pa9t$ ) firepro( pa9t & ample means = ext+ui%+ fire %\ld be provid$4 ,a cov]+ ( corrugat$ %eet iron well pa9t$ on bo? sides to prev5t ru/+ is (t5 us$ in/ead ( wood & less5s ! dang] ( fire1 b is n z w>m a cov]+ z wood4 ,illu/ration3 ,,fig4 #ch #dj4 ,9 _m /ates1 x is requir$ by law t ! top ( ! %aft be protect$ by a f5ce or by gates to prev5t p]sons fall+ d[n ! %aft4 ,?is protection is secur$ at ! sides ( head-frames by extra timb]s or beams =m+ "p ( ! frame1 or by means ( a f5ce plac$ ne> ! sides ( ! frame4 ,! ends ( ! %aft are protect$ by a b> plac$ across uprights1 by gates t sw+ l an ord9>y door1 or m g5]ally by v]tical slid+ gates t are rais$ by ! cage :5 x comes to ! surface & drop into place :5 ! cage desc5ds4 ,simil> gates1 doors1 or b>s %\ld be us$ at all l&+s bel[ ! surface4 ,,head-,,frame ,,specifications #da4 ,! foll[+ is a sample set ( specifications = a /eel head-frame to be built f detail$ plans furni%$ by ! m9+ company4 ,?is head-frame to be made f draw+s to be furni%$ by !---- ,coal ,company1 & plac$ on f\ndations furni%$ by said company4 ,mat]ial4--,/ructure to be built ?r\gh\t ( s(t /ructural /eel1 net /r5g? #ee1jjj to #fb1jjj p\nds p] squ>e in*2 ela/ic limit n less ?an #cj1jjj p\nds p] squ>e in*2 elongation1 #be p] c5t42 b5d+ te/1 b5d flat on itself )\t fracture4 ,build] agrees to gu>antee /ructure to )/& /ra9s specifi$ on draw+s ) factor ( safety ( #aj1 to provide = possible ov]w9d+ or /ick+ 9 %aft4 ,no /eel %all be us$ less ?an in* ?ick except = l9+ or fill+ vacant places4 ,workman%ip4--,! t[] to be built 9 a neat & workman-l mann]4 ,! pit* ( ! rivets 7di/ance betwe5 c5t]s7 %all n exce$ #f in*es or sixte5 times ! ?9ne/ plate1 nor be less ?an ?ree diamet]s ( ! rivets4 ,! rivets us$ %all g5]ally be in*1 in*1 & in* 9 diamet]4 ,! di/ance betwe5 edges ( any piece & ! c5t] ( rivet hole %all n be less ?an #a in*es1 except = b>s less ?an #b in*es wide2 :5 practicable x %all be at lea/ two diamet]s ( ! rivet4 ,all rivet holes %all be spac$ & pun*$1 s t :5 ! sev]al p>ts are assembl$ toge!r a rivet ( _/ in* less diamet] ?an ! hole c be ent]$ hot into any hole1 )\t ream+ or drift+4 ,! rivets :5 driv5 %\ld fill ! holes4 ,! heads mu/ be r\nd$2 !y mu/ be full & neatly made1 & be conc5tric to ! rivet hole1 & ?or\ghly p9* ! connect+ pieces toge!r4 ,field rivet+ mu/ be r$uc$ to a m9imum4 ,all jo9ts & connections %all be neatly made1 ! sev]al p>ts to be br\ght toge!r )\t twi/s1 b5ds1 or op5 jo9ts4 ,inspection4--,all facilities = inspect+ ! mat]ial & workman%ip %all be giv5 by ! build]s dur+ ! erection ( ! head-frame4 ,! company res]ves ! "r to reject any or all p>ts n built 9 accordance ) ! plans or ^! specifications4 ,f9al inspection ( "w #a mon? aft] be+ 9 actual s]vice4 ,pa9t+4--,all "w1 be=e leav+ ! %ops1 %all be ?or\ghly clean$ f all loose ru/ & scale1 & be giv5 "o good coat ( pa9t well work$ into all jo9ts & op5 spaces4 ,9 rivet$ ironwork1 ! surfaces com+ 9 contact %all ea* be pa9t$ be=e be+ rivet$ toge!r4 ,bottoms ( be>+ plates & any p>ts t are n accessible = pa9t+ aft] erection %all h two coats ( pa9t4 ,aft] ! /ructure is erect$ 9 place1 x %all be giv5 "o coat ( pa9t4 ,all recesses t w reta9 wat]1 or ?r\gh :i* wat] c ent]1 mu/ be fill$ ) ?ick pa9t or "s wat]pro( cem5t be=e receiv+ ! f9al pa9t+4 ,! pa9t %all be a lampblack pa9t1 mix$ ) pure l9se$ oil1 or ( r$ lead mix$ ) raw l9se$ oil conta9+ ,japan dry]4 ,g5]al ,clauses4--,! specifications & draw+s are int5d$ to coop]ate & to indicate ! pr9cipal dim5sions & requirem5ts necess>y to ! complete /ructure4 ,x be+ und]/ood t :ile "s "w may be %[n 9 ! plans & n describ$ 9 ! specifications1 or vice v]sa1 & "s m9or details & fa/5+s are omitt$ f bo? plans & specifications1 ! "w is to be execut$ )\t extra *>ge !re=1 ! same z if ! m9ute/ details 7 set =? 9 full 9 bo? draw+s & specifications4 ,! contractor is to make good any defects ( mat]ial or workman%ip develop+ )9 #a ye> aft] f9al acceptance4 ,! contractor %all furni% a location plan & also two copies ( ! detail %op draw+s = conv5i5ce 9 mak+ future alt]ations & repairs4 ,erection4--,! head-frame is to be erect$ complete1 secur$ to f\ndations provid$ by !---- ,company4 ,contractor %all furni% all f\ndation bolts & wa%]s4 ,iron /airway ) h& rails beside ma9 back brac]s & plat=m ) wood5 floor "u %eaves1 also iron /airs f plat=m "u %eaves to back %eave p$e/al = oil+4 ,wood furni%$ by !---- ,company4 ,price includes all mat]ial = completion ( "w deliv]$1 erect$1 & rivet$ 9 place & pa9t$4 ,!---- ,company w furni% & place 9 position ! %eaves1 ) ! %afts & boxes belong+ to ! same1 also ! wood5 guides4 ,deliv]y4--,! head-frame to be erect$1 complete1 & secur$ to f\ndations 9---- weeks f date ( ord]4 ,,deta*+ ,,hooks ,illu/ration3 ,,fig4 #ci #db4 ,9 hoi/+1 !re is m or less dang] ( ov]w9d+ or lift+ ! cage too f>1 & da%+ x aga9/ ! top ( ! head-frame1 or if ! top is op5 ! cage may be pull$ entirely ov] ! top4 ,deta*+ hooks are int5d$ to prev5t ?is4 ,sev]al v>ieties ( su* hooks are made1 :i* diff] f ea* o!r only 9 _! small] details4 ,9 all ( !m1 deta*m5t is effect$ by pass+ ! rope ?r\gh a circul> hole 9 an iron plate or ?r\gh an iron cyl9d]1 ! diamet] ( :i* is suffici5t to all[ ! upp] portion ( ! hooks to pass ?r\gh :5 pass+ upw>ds1 b ! l[] portion is made l>g] & s arrang$ t :5 ?is l>g] "p /rikes ! plate ! upp] portion is =c$ op5 & ! hoi/+ rope releas$4 ,aft] ! upp] "p has be5 ?us op5$1 x is too l>ge to pass back ?r\gh ! op5+ & ! plate & ! cage is !re=e held susp5d$4 ,fig4 #ci %[s su* a hook4 ,x consi/s ( two outside fix$ plates slightly n>r[] at ! top ?an ! diamet] ( ! hole 9 ! dis5gag+ plate h4 ,betwe5 ! frame plates a are two inn] plates b t move ab\t a /rong p9 c pass+ ?r\gh bo? plates a & b1 b ne> ! bottoms !re are two projections d to prev5t ! hook f pass+ entirely ?r\gh ! hole4 ,! w9d+ rope is atta*$ to ! top %ackle e & ! cage to ! l[] %ackle f4 ,:5 ! two movable plates b are clos$ z tightly z possible at ! top ab\t ! p9 ( ! %ackle e1 !y are secur$ by a copp] p9 g4 ,9 case ( ov]w9d+1 :5 ! hook passes into ! hole ( ! dis5gag+ plate h1 ! two projections k on plates b are press$ inw>ds1 %e>+ (f ! copp] p9 g & all[+ ! plates b to turn ab\t ! c5tral bolt c1 ?us releas+ ! %ackle e4 ,! plates b are !n 9 su* a position t ! projections l on !m _c pass d[n ?r\gh ! hole4 ,! cage !n hangs by ! hooks f ! dis5gag+ plate1 & ! rope passes on4 ,an objection rais$ aga9/ ?is hook is t1 be+ con/ruct$ ( plates1 !re is consid]able surface 9 contact betwe5 ! mov+ p>ts1 & unless !y are regul>ly tak5 ap>t & oil$1 !re is dang] ( _! ru/+ firmly toge!r4 ,9 ,engl&1 deta*+ hooks are us$ q commonly1 & also 9 c]ta9 p>ts ( ! ,c5tral ,bas9 9 ! ,unit$ ,/ates1 b !y h n yet be5 g5]ally adopt$ ?r\gh\t ! ,unit$ ,/ates4 #dc4 ,x is claim$ by _m t su* devices inspire ! eng9e] ) a mislead+ feel+ ( security2 t !y are m or less complicat$ 9 con/ruction & s ne$ c>e1 & de/roy ! simplicity ( ! plant2 t !y may be ! direct cause ( accid5t by introduc+ new elem5ts ( dang]2 t !y add to ! co/2 & t !y are n ?or\ghly reliable4 ,aga91 x is held t ! sure/ prev5tion ( ov]w9d+ is obta9$ by ! employm5t ( a sob]1 reliable1 & compet5t eng9e]1 :o is held p]sonally responsible = ov]w9d+ accid5ts2 by hav+ a good brake & an eng9e ?or\ghly "u ! control ( ! eng9e]2 by a reliable me?od ( indicat+ ! position ( ! cage2 by suffici5t height to head-%eaves to all[ ( consid]able hoi/+ ov] & above t necess>y = l&+4 ,,signal+ #dd4 ,"s me?od mu/ be provid$ = communicat+ betwe5 ! bottom or any level ( a %aft & ! top l&+ or ! eng9e room1 also betwe5 ! top l&+ & ! eng9e room1 s t ! hoi/+ eng9e] may be notifi$ :5 bo? ! head-man & foot-man are ready = him to hoi/4 ,a common me?od ( signal+ is by means ( a gong1 bell1 or triangle plac$ 9 ! eng9e room & connect$ by a wire or small wire-rope ) ! po9t f :i* x is desir$ to signal4 ,attempts h be5 made 9 diff]5t localities & by diff]5t associations to adopt a /&>d code ( hoi/+ signals1 & :ile x w\ld be advantage\s if ?is c\ld be done1 none ( ! attempts made h be5 entirely successful4 ,al?\gh !re is no uni=m sy/em ( signals1 "o bell g5]ally means /op1 two bells l[]1 ?ree bells hoi/1 & f\r bells hoi/ m54 ,illu/ration3 ,,fig4 #dj #de4 ,hamm]-&-,plate ,signal4--,fig4 #dj %[s a hamm]-&-plate signal1 ! plate be+ a piece ( boil] iron or /eel4 ,! hamm] is (t5 locat$ b5ea? ! plate in/ead ( above1 z %[n4 ,ano!r /yle ( hamm]-&-plate is %[n 9 ,fig4 #da4 ,! hamm] is made ( #b-;in* squ>e iron & heavy en\gh to balance ! weight ( wire hang+ 9 ! %aft & to take ! sag out ( ! horizontal wire connect+ ! top ( ! %aft ) ! lev] a4 ,a simple dial turn$ by a rat*et motion atta*$ to ! lev] a is sometimes us$ to %[ ! numb] ( /rokes1 & ?us *eck ! numb] c\nt$ by ! eng9e]4 ,! dial is reset by ! eng9e] z soon z he und]/&s ! signal4 ,illu/ration3 ,,fig4 #da ,illu/ration3 ,,fig4 #db #df4 ,electric ,bells4--,electric bells op]at$ by pu% buttons are rapidly com+ into use = m9e signal+ on acc\nt ( ! ease & complet5ess ) :i* su* a sy/em c be in/all$4 ,electric fla% lights are also ext5sively us$ = signal+ purposes4 ,! pr9ciple ( action & details ( ! wir+ = electric signals & fla% lights h be5 describ$ 9 ,transmission1 ,signal+1 & ,light+4 #dg4 ,speak+ ,tubes4--,! laws ( c]ta9 /ates require speak+ tubes1 9 addition to ! ord9>y means ( signal+4 ,^! speak+ tubes are g5]ally made ( #b-;in* iron pipe & are f #cjj to #a1ejj feet long1 & are (t5 provid$ ) :i/les at ! end ( ! pipe & at ea* level ( ! m9e1 by :i* ! att5tion ( p]sons at any level c be attract$ or ! :i/le may be omitt$ & ! att5tion ( p]sons attract$ m]ely by rapp+ on ! pipe ) a piece ( iron4 ,illu/ration3 ,,fig4 #dc #dh4 ,pneumatic ,gong ,signal4--,fig4 #db %[s an atta*m5t t c be connect$ to a speak+ tube & t is widely us$ = signal+4 ,x consi/s ( a brass cyl9d] a fitt$ ) a pi/on b conta9+ valves c4 ,! gong d is atta*$ to ! cyl9d] e inside ( :i* ! clapp] f fits loosely4 ,:5 ! pi/on is pu%$ inw>ds1 z %[n by ! arr[1 by means ( ! h&le1 ! air 9 ! cyl9d] & 9 ! pipe h is compress$ & =ces ! clapp] f upw>ds aga9/ ! gong d4 ,! arrangem5t ( ^! gongs 9 ! m9e is %[n 9 ,fig4 #dc4 ,a cyl9d] & :i/le are usually plac$ at ea* l&+ & a gong & :i/le 9 ! eng9e room1 ?\gh1 if desir$1 a cyl9d]1 :i/le1 & gong may be plac$ at ea* l&+ & 9 ! eng9e room4 #di4 ,telephones4--,telephones connect+ ! diff]5t levels ) ! top & ! eng9e room are n[ frequ5tly us$ 9 connection ) o!r signal sy/ems1 b !y are n z well adapt$ z bells or gongs = rapid-hoi/+ signal+4