,,american ,,society ,,of ,,civil ,,engineers ,,instituted #aheb ,,transactions ,paper ,no4 #aaea ,,the ,,new ,,york ,,tunnel ,,extension ,,of ,,the ,,pennsylvania ,,railroad4 ,,the ,,north ,,river ,,division4 ,,by ,,charles ,m4 ,,jacobs1 ,m4 ,,am4 ,,soc4 ,c4 ,e4 ,these observations are written with the purpose of outlining briefly1 as far as the writer was concerned1 the evolution of the scheme of bringing the ,pennsylvania ,railroad and the ,long ,island ,railroad into ,new ,york ,city1 and also1 as ,chief ,engineer of the ,north ,river ,division of the ,new ,york ,tunnel ,extension of the ,pennsylvania ,railroad1 to record in a general way some of the leading features of the work on this division1 which is that portion of the work extending from the east line of ,ninth ,avenue1 ,new ,york ,city1 to the ,hackensack ,portal on the westerly side of the ,palisades1 as an introduction to the papers by the ,chief ,assistant ,engineer and the ,resident ,engineers describing in detail the work as constructed4 ,it may be stated that1 since shortly after the year #ahga1 when the ,pennsylvania ,railroad system was extended to ,new ,york ,harbor through the lease of the ,new ,jersey ,lines1 the officers of that company have been desirous of reaching ,new ,york ,city by direct rail connection4 ,the writer's first connection with the tunneling of the ,north ,river was early in #ahij1 when he was consulted by the late ,austin ,corbin1 ,president of the ,long ,island ,railroad ,company and the ,philadelphia and ,reading ,railroad ,company1 as to the feasibility of connecting the ,long ,island ,railroad with the ,philadelphia and ,reading ,railroad 7or with the ,central ,railroad of ,new ,jersey1 which was the ,new ,york connection of the ,reading7 by a tunnel from the foot of ,atlantic ,avenue1 ,brooklyn1 under the ,battery and ,new ,york ,city1 and directly across the ,north ,river to the terminal of the ,central ,railroad of ,new ,jersey4 ,surveys1 borings1 and thorough investigations were made1 and the ,metropolitan ,underground ,railroad ,company was incorporated in the ,state of ,new ,york to construct this railroad4 ,mr4 ,corbin1 however1 was aware that1 in the transportation problem he had in hand1 the ,central ,railroad of ,new ,jersey and the ,philadelphia and ,reading ,railroad were not as important factors as the ,pennsylvania ,railroad1 and1 in consequence1 he abandoned the scheme for a tunnel to the ,central ,railroad of ,new ,jersey for a line direct to the ,pennsylvania ,railroad terminal in ,jersey ,city4 ,meantime1 the ,pennsylvania ,railroad ,company1 as a result of its investigation of the matter1 in ,june1 #ahia1 thought that the most feasible project seemed to be to build tunnels for rapid transit passenger service from its ,jersey ,city ,station to the lower part of ,new ,york1 connecting there with the rapid transit systems of that city1 and also extending under ,new ,york on the line of ,cortlandt ,street1 with stations and passenger lifts at the main streets and elevated railroads4 ,the late ,a4 ,j4 ,cassatt1 then a ,director of the ,pennsylvania ,railroad ,company1 and previous thereto as ,general ,manager and ,vice-,president 7and later as ,president7 of that company1 was deeply interested in obtaining an entrance into ,new ,york ,city1 but was not satisfied with the proposed rapid transit passenger tunnels which required the termination of the ,pennsylvania ,railroad trains at its ,jersey ,city ,station4 ,therefore1 upon his request1 in ,september of the same year1 another study and report was made by ,joseph ,t4 ,richards1 ,m4 ,am4 ,soc4 ,c4 ,e41 then ,engineer of ,maintenance of ,way of the ,pennsylvania ,railroad1 on a route beginning in ,new ,york ,city at #chth ,street and ,park ,avenue on the high ground of ,murray ,hill1 thence crossing the ,east ,river on a bridge1 and passing around ,brooklyn to ,bay ,ridge1 thence under the ,lower ,bay or ,narrows to ,staten ,island and across to the mainland1 reaching the ,new ,york ,division of the ,pennsylvania ,railroad at some point between ,rahway and ,metuchen4 ,mr4 ,cassatt also had in mind at that time a connection with the ,new ,england ,railroad1 then independent1 but now part of the ,new ,york1 ,new ,haven1 and ,hartford ,railroad system1 by means of the ,long ,island ,railroad1 and a tunnel under the ,east ,river1 which in later years1 as the result of further consideration of the situation1 has been covered by the proposed ,new ,york ,connecting ,railroad with a bridge across the ,east ,river and over ,ward's and ,randall's ,islands4 ,as a result of these investigations1 the late ,george ,d4 ,roberts1 who was then ,president of the ,pennsylvania ,railroad ,company1 authorized an expenditure of about #be1jjj for soundings to determine the nature of the strata for tunneling under water4 ,these soundings were carefully made by ,mr4 ,richards with a diamond drill1 bringing up the actual core of all rock found in crossing the waters of ,new ,york ,bay from the west to the east side and extending from the ,narrows to the ,jersey ,city ,station of the ,pennsylvania ,railroad4 ,after these investigations had been made1 early in #ahib1 ,mr4 ,roberts expressed himself as being favorable to the undertaking1 with the definite limitation that the tunnels must be for small cars doing local suburban business1 and for the transfer of ,pennsylvania ,railroad passengers to and from ,new ,york1 ,brooklyn1 and ,jersey ,city1 and not in any way to be tunnels for standard steam equipment1 the expense for terminals and the prohibited use of coal for fuel in such tunnels not warranting any broader consideration4 ,under such instructions1 the interests of the ,pennsylvania ,railroad ,company for effecting a physical entrance into ,new ,york ,city in that year were turned over to ,samuel ,rea1 ,m4 ,am4 ,soc4 ,c4 ,e41 then ,assistant to the ,president of that ,company1 who has been identified with the investigations1 and the progress and construction of this work since that time1 ,mr4 ,cassatt also working in conjunction with him on the plans then and since considered by the ,pennsylvania ,railroad ,management4 ,on ,october #eth1 #ahib1 ,mr4 ,rea1 under special direction of ,president ,roberts1 made an extended investigation of the various routes which had then been projected for extending the system into ,new ,york ,city by rail or transport1 and reported to ,mr4 ,roberts that1 in his opinion1 because of the limitation of the tunnel scheme to rapid transit trains and the consequent transfer of passengers and traffic carried in passenger trains1 and because of the drawbacks caused by the use of steam locomotives in full-sized tunnels1 and the objection to cable traction or any system of transportation which had not then stood the test of years of practical service1 the plan of the ,north ,river ,bridge for reaching ,new ,york ,city and establishing a terminus therein was the best that had been evolved up to that time4 ,the plan provided a direct rail entrance into ,new ,york ,city for all railroads reaching the west side of the ,hudson ,river1 and also for the ,new ,york ,central and ,hudson ,river ,railroad1 as well as adequate station facilities in that city4 ,this bridge would have had one clear span of #c1ajj ft4 between pier heads1 landing on the ,new ,york side at the foot of ,west #bc;d ,street1 and thence the line would have passed diagonally to the terminus at ,sixth ,avenue and #beth ,street4 ,the location of the terminus was subsequently changed to the vicinity of ,seventh ,avenue and #cfth ,street4 ,the bridge was designed with three decks3 ,the first or lower deck was to accommodate eight steam railroad tracks2 the second was to have six tracks1 four of which could be assigned for rapid transit trains operating with electric power1 and the other two for steam railroad trains2 the third deck1 reached by elevators1 was to be a promenade extending from anchorage to anchorage4 ,a connection with the ,eleventh ,avenue tracks of the ,new ,york ,central and ,hudson ,river ,railroad was to bring the trains of that road into the ,union ,station4 ,the ,bridge ,company had a ,federal charter--granted in #ahhh--with broad powers4 ,gustav ,lindenthal1 ,m4 ,am4 ,soc4 ,c4 ,e41 was ,chief ,engineer1 and he and ,mr4 ,rea were corporators and among its early promoters4 ,the ,pennsylvania ,railroad ,management looked with favor on its construction at that time1 as subaqueous tunnels1 with standard railroad equipment with steam traction1 were not regarded as a final or attractive solution of the problem1 from the standpoint of the ,management1 and at a subsequent period the ,pennsylvania ,railroad ,company agreed to use the ,north ,river ,bridge provided the other roads reaching the west bank of the ,hudson ,river would join4 ,these roads1 however1 did not avail themselves of the opportunity which in its broadest scope was laid before them in #aijj1 after the ,board of ,directors of the ,pennsylvania ,railroad ,company had approved the scheme at the instance of ,mr4 ,cassatt4 ,the scheme of ,mr4 ,corbin for a subway connection1 between ,flatbush ,avenue and the ,jersey ,city ,station of the ,pennsylvania ,railroad1 for local transit1 took form in #ahib1 and1 jointly with the ,pennsylvania interests1 railroad companies were incorporated in the respective ,states to build a tunnel from under the ,jersey ,city ,station1 under the ,hudson ,river to ,cortlandt ,street1 ,new ,york ,city1 thence under ,maiden ,lane1 the ,east ,river1 and ,pineapple and ,fulton ,streets1 ,brooklyn1 to a location at or near ,flatbush and ,atlantic ,avenues4 ,on ,may #ith1 #ahic1 these companies were merged into the ,brooklyn1 ,new ,york and ,jersey ,city ,terminal ,railroad ,company1 and estimates and reports on the construction were made ready by the writer in association with ,mr4 ,rea1 pending application for the franchises4 ,the panic of #ahic1 occurring about that time1 checked further progress on this scheme1 and1 before it could be revived again1 other important projects for reaching ,new ,york ,city were given consideration4 ,that part of ,mr4 ,corbin's plan contemplating a subway under ,atlantic ,avenue in ,brooklyn to the present ,flatbush ,avenue ,terminal was not a new idea1 as a tunnel had been built in #ahde and operated under a portion of ,atlantic ,avenue1 but later it was filled up4 ,plate ,,iv1 reproduced from a crayon sketch which was the property of the late ,william ,h4 ,baldwin1 ,jr41 is a view of this tunnel4 ,in conjunction with schemes for river tunnels1 complete plans for rapid transit subways for ,new ,york ,city1 very much on the line of the present rapid transit subways1 were also prepared for ,mr4 ,corbin by the writer4 ,these plans provided a system of deep tunnels in rock1 entirely below the plane of quicksand1 and at the ,battery the lines were to connect directly into the tunnels to ,long ,island and ,new ,jersey1 respectively1 and the stations throughout1 where the rock was at a deep level1 were to be fitted with elevators1 grouped as suggested in ,plate ,v1 using private property on each side of the street at station locations--one side for north-bound and the other side for south-bound traffic4 ,these plans were submitted to the first ,rapid ,transit ,commission1 and1 after long consideration1 were rejected by that ,commission because they provided for the construction of the tunnels by a private company1 notwithstanding ,mr4 ,corbin gave the ,commission assurances of ample financial means to carry the work to completion4 ,during the years #ahib-ic ,mr4 ,corbin was convinced that it was necessary to get better facilities for handling the baggage and express matter of the ,long ,island ,railroad and the ,long ,island ,express ,company across the ,east ,river between ,long ,island ,city and ,new ,york ,city1 and he instructed the writer to investigate and report on the feasibility of building a tunnel1 along the lines of the ,east ,river ,gas ,tunnels1 then nearly completed1 between the foot of ,east #cdth ,street1 ,new ,york ,city1 and the ,long ,island ,city ,station of the ,long ,island ,railroad4 ,in #ahic an investigation was made for such a tunnel1 to be of similar size to the ,east ,river ,gas ,tunnel 7#h by #aj ft471 solely for the purpose of handling baggage and express matter4 ,investigation was made and estimates prepared1 but the cost was considered to be prohibitive in view of the possible earnings solely from the handling of baggage and express1 and the matter was not considered further4 ,illustration3 ,,plate ,,iv4--,,tunnel ,,under ,,part ,,of ,,atlantic ,,avenue1 ,,brooklyn4 7,from a ,crayon ,sketch47 ,while ,mr4 ,corbin was deeply interested in the down-town river tunnels1 the up-town situation was of great importance to the ,long ,island ,railroad1 and1 having allied himself with ,mr4 ,charles ,pratt1 they took up generally the franchise owned by ,dr4 ,thomas ,rainey for a bridge over ,blackwell's ,island4 ,mr4 ,corbin became interested with ,dr4 ,rainey in #ahid1 and the actual construction proceeded on this bridge4 ,the design provided for four railroad tracks1 besides highways for tracks1 pedestrians1 etc41 with a terminal station at ,third ,avenue and #fdth ,street1 ,new ,york ,city1 which1 under the franchise1 was the limit to which the railroad could proceed4 ,at this period there were two projects for bridging the ,hudson or ,north ,river3 the ,new ,york and ,new ,jersey ,bridge ,company at about #eith ,street1 and the ,north ,river ,bridge ,company at #bc;d ,street1 as hereinbefore described4 ,several studies were made by the writer1 with the idea of making a rail connection between the ,long ,island ,rainey bridge and a bridge over the ,north ,river4 ,an overhead structure connection was prohibitory1 as no franchise could be obtained to cross ,fifth ,avenue with an overhead structure4 ,sketches were prepared for a subway construction to connect with the bridges1 but a final plan was not worked out4 ,the failure to carry out the joint undertaking with the ,pennsylvania ,railroad ,company in #ahic led ,mr4 ,corbin to revive the scheme of extending the ,long ,island ,railroad from ,flatbush ,avenue1 ,brooklyn1 to ,new ,york ,city1 therefore consideration was given to a relocation of the route for ,mr4 ,corbin during the early months of #ahif1 the idea being that the entire up-town outlet for the ,long ,island ,railroad would be by ,blackwell's ,island ,bridge1 and the tunnel project would give the down-town outlet4 ,at this time a commission had been appointed by the ,legislature to investigate the conditions on ,atlantic ,avenue1 ,brooklyn1 and evolve some scheme for the elimination of grade crossings on that avenue4 ,early in #ahif plans were prepared and presented to this ,commission2 first1 for a subway from ,flatbush ,avenue ,terminal for the entire distance to the limits of the ,city of ,brooklyn at ,eldert's ,lane2 second1 for a subway from the ,flatbush ,avenue ,terminal to ,east ,new ,york1 ,manhattan ,crossing1 the railroad to remain as it previously existed at grade through the #bfth ,ward of ,brooklyn4 ,each of these schemes contemplated an extension through ,brooklyn to ,new ,york ,city at ,cortlandt ,street and ,broadway1 and surveys and borings for this work were made across the ,east ,river4 ,in the summer of #ahif1 on the decease of ,mr4 ,corbin1 all projects and work were immediately stopped2 but1 after some months1 ,mr4 ,w4 ,h4 ,baldwin1 ,jr41 when elected ,president of the ,long ,island ,railroad ,company1 took up actively the reconsideration of the means whereby the ,long ,island ,railroad could reach ,new ,york ,city4 ,after the fullest consideration1 he decided that the ,blackwell's ,island ,bridge was by no means a suitable1 adequate1 or convenient entry for the ,long ,island ,railroad into ,new ,york ,city1 as it involved too great a cost and altogether too rigid a connection2 it was also a very inconvenient location1 inasmuch as it was cut off from convenient access to the west side of ,new ,york ,city by ,central ,park4 ,for the down-town connection1 ,mr4 ,baldwin became enthusiastic1 but he had in mind1 throughout1 the all-important necessity for the ,long ,island ,railroad to reach the ,pennsylvania ,railroad across the ,north ,river4 ,at the same time ,mr4 ,baldwin took up energetically the ,atlantic ,avenue ,improvement with the ,atlantic ,avenue ,commission1 and1 on consideration1 decided it was essential that it should extend through the #bfth ,ward above or below grade4 ,the better plan1 of course1 was obviously to make it a subway throughout1 but1 further1 the residents of this ward objected to the subway through that section1 and that construction would have made any change of the ,manhattan ,beach ,division at ,manhattan ,crossing very difficult for the future2 besides this1 the controlling factor was the absolute limitation by the ,city of ,brooklyn of the amount of expenditure therefor in which they would participate1 therefore a composite scheme1 which is the plan as carried out1 was agreed upon1 being in part subway and part elevated4 ,this scheme reached a focus early in #ahig1 and the law constituting the ,board for the ,atlantic ,avenue ,improvement was passed1 with a provision in the last paragraph of the ,act1 for the construction of a tunnel from ,flatbush ,avenue ,terminal under ,flatbush ,avenue and ,fulton ,street to ,pineapple ,street1 crossing the river to ,broadway and ,maiden ,lane 7,cortlandt ,street71 ,new ,york ,city1 and with the understanding that it would be extended beyond the ,new ,york ,state ,line to the ,pennsylvania ,railroad ,station in ,new ,jersey4 ,this gave the legal right for the construction of this tunnel1 and1 on ,june #bjth1 #ahii1 the ,new ,york and ,long ,island ,terminal ,railroad ,company was incorporated for the purpose1 ,mr4 ,baldwin being ,president and ,j4 ,v4 ,davies1 ,m4 ,am4 ,soc4 ,c4 ,e41 ,chief ,engineer4 ,application was immediately made to the ,boards of ,aldermen of ,brooklyn and of ,new ,york ,city4 ,the latter acted favorably on the application1 but the ,board of ,aldermen of ,brooklyn held the matter up1 while the ,rapid ,transit ,commission laid out and promulgated the plan for ,contract ,no4 #b of the ,rapid ,transit ,subway4 ,with the understanding that the ,rapid ,transit ,brooklyn extension would be constructed to the ,flatbush ,avenue ,terminal1 ,mr4 ,baldwin withdrew the application for the independent franchise1 and agreed to proceed with the ,atlantic ,avenue ,improvement1 on the basis of the ,city proceeding with the ,brooklyn extension of the ,rapid ,transit ,subway4 ,this provided for the ,long ,island ,railroad entry down town4 ,illustration3 ,,plate ,v4--,,new ,,york ,,underground ,,railway ,,company ,section ,through ,surface and ,underground ,stations ,subsequently1 however1 it was proved that ,mr4 ,baldwin had not been fully satisfied that this was the proper solution of the matter1 for on ,april #abth1 #aija1 and upon his recommendation1 the ,board of ,directors of the ,long ,island ,railroad ,company took over from the ,pennsylvania ,railroad ,company its entire interests in the old ,brooklyn1 ,new ,york1 and ,jersey ,city ,terminal ,railway ,company1 thus giving him control of the route from ,flatbush ,avenue via ,maiden ,lane and ,cortlandt ,street to underneath the ,jersey ,city station4 ,in the early part of #aijj active consideration was being given by the ,pennsylvania ,railroad and other railroads terminating in ,new ,jersey to the proposed ,north ,river ,bridge1 as hereinbefore stated1 and1 for the ,long ,island ,railroad1 ,mr4 ,baldwin organized a new company to construct a tunnel from the ,long ,island ,railroad at ,sunnyside ,yard1 diving under the streets of ,long ,island ,city by two tracks under the ,east ,river to the foot of #cc;d ,street and then proceeding under #cc;d ,street as far as ,seventh ,avenue4 ,a station was to be located at ,fourth ,avenue below the ,rapid ,transit ,subway ,station and also a large ,terminal ,station at ,broadway4 ,for this purpose an option was obtained on the property of the ,newbold ,lawrence ,estate1 at ,broadway1 ,sixth ,avenue1 #cc;d and #cdth ,streets1 now occupied by ,saks' ,store4 ,mr4 ,baldwin1 however1 considered that the amount of the investment 7#a1fjj1jjj7 for that property was too great for this purpose1 and allowed the option to expire4 ,the property was sold within a week thereafter to the ,morganthau ,syndicate for #b1jjj1jjj4 ,at this time 7,may1 #aijj71 the ,pennsylvania ,railroad obtained a controlling interest in the ,long ,island ,railroad1 and thereafter the two schemes became one4 ,mr4 ,baldwin and ,mr4 ,rea purchased two #be-;ft4 lots on #cc;d ,street just east of ,broadway for an entrance to the underground station4 ,plans were also prepared for extending this line from ,seventh ,avenue northward under ,seventh ,avenue to #deth ,street4 ,the investigation and preliminary work in connection with this project were carried out in the early part of #aijj4 ,reconsideration was given by ,mr4 ,baldwin to the proposed location of the up-town tunnels1 with the idea of connecting the ,new ,york ,central and ,hudson ,river ,railroad by a tunnel between ,long ,island ,city 7,long ,island ,railroad ,station7 and the foot of #db;d ,street and extending to the ,grand ,central ,station1 but nothing further than investigation and the preparation of estimates was done on this4 ,in the summer of #aija ,mr4 ,cassatt was in ,paris and was advised by ,mr4 ,rea of the opening of the extension of the ,orleans ,railway to the ,quai d',orsay ,station and its successful operation by electric power1 also of the possibility of the ,pennsylvania ,railroad reaching ,new ,york ,city in a similar way 7the other trunk lines not having joined in the promotion of the ,north ,river ,bridge project74 ,he at once examined the new line1 and then consulted the writer in ,london in relation to the possibility of building tunnels under the ,north ,river4 ,the writer returned to ,new ,york with ,mr4 ,cassatt1 and soon thereafter a conference of ,mr4 ,cassatt1 ,mr4 ,rea1 and ,mr4 ,baldwin with the writer and ,mr4 ,davies was held in the ,pennsylvania ,railroad ,company ,office in ,new ,york1 when ,mr4 ,cassatt outlined the scheme practically as it is now carried out1 the only difference being that he also proposed a station on property of the ,new ,york and ,harlem ,railroad ,company at #cc;d ,street1 which was soon abandoned on account of the grade from the ,east ,river1 and particularly because of the superior location of the adopted site at ,seventh ,avenue and #cc;d ,street1 this being central between the down-town commercial and financial district and ,central ,park1 which divides ,new ,york ,city4 ,on ,mr4 ,cassatt's instructions1 surveys and investigations were begun in ,november1 #aija1 and estimates1 drawings1 etc41 were made4 ,preliminary estimates were presented to him on ,november #hth1 #aija4 ,following this1 borings were continued1 and a plan was presented to ,mr4 ,cassatt for assisting the support of the ,north ,river tunnels on piles1 if necessary4 ,at the time of the appointment of the ,board of ,engineers and the general organization of the work1 the preliminary investigations and work had been carried to an advanced state4 ,one result of the determination of the ,pennsylvania ,railroad ,company to extend its lines into ,new ,york ,city and thus move its principal station from ,jersey ,city1 was that the down-town local and suburban as well as through business was not provided for properly4 ,mr4 ,william ,g4 ,mc,adoo1 appreciating this opportunity1 revived the scheme of an electric subway from ,jersey ,city to ,new ,york1 originally promoted by ,mr4 ,corbin and associates1 but not including the extension via ,maiden ,lane to ,brooklyn1 and entered into negotiations with the ,pennsylvania ,railroad ,company to provide for this down-town business by extensions of the tunnel lines of the ,new ,york and ,new ,jersey ,railroads to ,exchange ,place1 ,jersey ,city1 under the ,pennsylvania ,railroad ,station1 and thence across the ,hudson ,river to ,cortlandt and ,church ,streets4 ,as a result1 the ,hudson and ,manhattan ,railroad ,company was organized in #aijb1 and contracts were made with the ,pennsylvania ,railroad ,company for the sub-surface use of its station in ,jersey ,city1 and for the interchange of passenger business at that point between the trains of the ,pennsylvania ,railroad ,company and the tunnel of the ,hudson and ,manhattan ,railroad ,company4 ,later1 a further contract was made with the ,pennsylvania ,railroad ,company providing for the construction of the tunnel of the ,hudson and ,manhattan ,railroad ,company westward under the tracks of the ,pennsylvania ,railroad in ,jersey ,city to a junction with the latter at ,summit ,avenue1 at which point can be installed a joint station1 and the operation effected of a joint electric train service between ,church ,street1 ,new ,york ,city1 and ,newark1 ,n4 ,j41 the ,pennsylvania ,railroad tracks between ,summit ,avenue and ,newark to be electrified for that purpose1 with a transfer station established east of ,newark1 at ,harrison1 at which point the steam and electric locomotives will exchange4 ,by means of this1 all down-town passengers will transfer to the electric service at ,harrison ,station1 and thus the ,pennsylvania ,railroad ,company is expected to be relieved of maintaining a separate steam service for passenger traffic to ,jersey ,city and a large down-town station with extensive contingent facilities at that point4 ,from the foregoing it will be seen that the final decision to extend the ,pennsylvania ,railroad into and through ,new ,york ,city by a system of tunnels1 and erect a large station in that city on a most eligible site1 was not reached in a hurried or off-hand manner1 but after years of painstaking study and a full and extended investigation of all routes1 projects1 and schemes1 whether originating with the company or suggested by others4 ,illustration3 ,plate ,,vi4--,pennsylvania ,railroad ,extension3 ,map ,showing ,proposed ,lines ,leading to ,those ,finally ,adopted ,plate ,,vi is a map of ,new ,york ,city and vicinity on which are shown the various lines contemplated in the evolution of the ,new ,york ,tunnel ,extension of the ,pennsylvania ,railroad hereinbefore outlined4 ,the question of tunnels under the ,north ,river was an uncertain factor in the larger ,pennsylvania ,railroad scheme1 owing to the nature of the ground composing the river bed in which the tunnels would be constructed4 ,it is well known that about #ce years ago an attempt was made to construct a tunnel under the ,north ,river by using a ,pilot system under compressed air and forming the tunnels in brick masonry4 ,owing to the very soft nature of the materials through which it passed1 several serious accidents occurred1 and the work was abandoned after about #b1jjj ft4 of tunnel had been constructed4 ,later1 this work was taken up again1 when a shield was installed and an additional #a1hjj ft4 was built with cast-iron segmental lining1 but the work was again abandoned1 owing principally to financial difficulties while coincidentally before entering a rock reef which presented another serious difficulty in construction4 ,the experience then in the construction of this tunnel led capitalists and engineers to believe that1 owing to the very soft nature of the ground1 a tunnel could not be built that would be sufficiently stable to withstand the vibration due to heavy traffic1 and for this reason tunnels under the ,north ,river were not looked upon as practicable4 ,the writer devised a scheme to carry within the tunnel the rolling loads on bridging supported on piers or piles extending from the tunnel invert down to hard material4 ,these would be attached to the tunnel itself or would pass into it independently through sliding joints in the tunnel shell4 ,this scheme gained the confidence of the management1 as it was believed that1 by adopting such a plan1 tunnels could be built in the soft material underlying the ,hudson ,river and remain stable under all conditions of traffic4 ,after thus feeling assured that by this method the tunnels could be made safe beyond question1 orders were given to proceed with the great work of the extension into ,new ,york of the ,pennsylvania and ,long ,island ,railroad systems4 ,illustration3 ,,fig4 #a4--7;,full page image7 ,,engineering ,,staff ,,organization ,,chief ,,engineer ,,chief ,,assistant ,,engineer --7,,chief ,,office7 --,,office ,,engineer --,chief ,draftsman4 ,draftsmen4 ,messenger4 --,,mechanical ,,engineer --,mechanical ,draftsmen4 --,,assistant ,,engineer --,accountant4 ,clerks4 ,telephone ,operators4 ,messenger4 --7,,terminal ,,station ,,west7 ,,resident ,,engineer --,assistant ,engineer4 ,chief of ,party4 ,instrumentmen4 ,rodmen4 ,chainmen4 --,inspectors4 --,clerk4 ,janitors4 --7,,subaqueous1 #cb,,nd ,,street ,,and ,,weehawken ,,tunnels7 ,,general ,,resident ,,engineer --,cement ,inspectors4 ,ass't4 ,cement ,inspectors4 --,photographer4 --,recording ,clerk4 ,ass't4 ,recording ,clerks4 --,,dispatch ,,boat --,captains4 ,engineers4 ,deckhands4 ,messenger4 --,,resident ,,engineers --7,,construction7 --,ass't4 ,engineers4 ,chief ,tunnel ,inspectors4 ,tunnel ,inspectors4 ,surface ,inspectors4 ,clerks4 --7,,alignment7 --,ass't4 ,engineers4 ,chiefs of ,parties4 ,instrumentmen4 ,rodmen4 ,chainmen4 ,rear ,chainmen4 ,laborers4 --7,,office ,,staff7 --,draftsmen4 ,field ,office ,clerks4 ,cement ,warehousemen4 ,janitors4 ,messengers4 --7,,medical ,,department7 ,,chief ,,medical ,,officer ,ass't4 ,medical ,officer4 --7,,bergen ,,hill ,,tunnels7 ,,resident ,,engineer ,assistant ,resident ,engineer --,assistant ,engineer4 ,instrumentmen4 ,rodmen4 ,chainmen4 --,inspectors4 ,cement ,warehousemen4 --,clerk4 ,janitors4 --7,,metal ,,inspection7 ,,chief ,,metal ,,inspector ,metal ,inspectors4 ,clerks4 ,the organization of the engineering staff is shown on the diagram1 ,fig4 #a4 ,in the beginning of #aijb and during the period of making studies1 additional borings1 and preliminary triangulations1 and prior to making the contract plans and specifications1 ,james ,forgie1 ,m4 ,am4 ,soc4 ,c4 ,e41 was appointed ,chief ,assistant ,engineer by the writer4 ,to him all the ,resident ,engineers and other heads of the ,engineering ,departments reported4 ,the work was divided into three ,residencies3 #a4--,the ,terminal ,station-,west1 under the charge of ,b4 ,f4 ,cresson1 ,jr41 ,m4 ,am4 ,soc4 ,c4 ,e41 ,resident ,engineer1 comprising the work from the east side of ,ninth ,avenue to the east side of ,tenth ,avenue1 including excavation1 retaining and face walls1 and the extensive work of underpinning ,ninth ,avenue with its surface and elevated railroads and other structures4 #b4--,the ,river ,tunnels1 under the charge of ,b4 ,h4 ,m4 ,hewett1 ,m4 ,am4 ,soc4 ,c4 ,e41 ,general ,resident ,engineer1 and ,mr4 ,h4 ,f4 ,d4 ,burke and ,william ,lowe ,brown1 ,m4 ,am4 ,soc4 ,c4 ,e41 ,resident ,engineers1 including the land tunnels from the east side of ,tenth ,avenue1 ,new ,york ,city1 to the commencement of the iron-lined tunnels1 and extending westward from there to the ,weehawken ,shaft1 ,new ,jersey4 #c4--,the ,bergen ,hill ,tunnels1 under the charge of ,f4 ,lavis1 ,m4 ,am4 ,soc4 ,c4 ,e41 ,resident ,engineer1 including the rock tunnels from the ,weehawken ,shaft to the ,hackensack ,portal on the west side of the ,palisades1 all in ,new ,jersey4 ,paul ,a4 ,seurot1 ,m4 ,am4 ,soc4 ,c4 ,e41 acted as ,office ,engineer in charge of the drawing office1 and ,mr4 ,j4 ,soderberg as ,mechanical ,engineer in charge of the mechanical drafting4 ,prior to the construction of the above works ,mr4 ,c4 ,j4 ,crowley acted as ,resident ,engineer on the construction of the ,weehawken ,shaft1 and ,j4 ,f4 ,rodenbough1 ,assoc4 ,m4 ,am4 ,soc4 ,c4 ,e41 on that of the ,manhattan ,shaft4 ,table #a shows the quantities of certain materials and other statistics regarding this ,division4 ,,table #a4 ---------------------------------------- -------------------------------- ,bergen ,river ,term4 ,hill4 ,tunnels4 ,sta4-,w4 ------------------------------ ,excavation disposed of 7or displaced71 in cubic yards #bfc1jjj #bch1iie #eag1jjj ,cast metal used in tunnel1 including cast iron and cast steel1 in tons #fd1bfe ,steel bolts used1 in tons #b1fjf ,cement used 7concrete and grout71 in barrels #ie1jjj #ade1ejj #cc1jjj ,concrete1 in cubic yards #ie1jjj #ge1djj #ah1ejj ,dynamite for blasting1 in pounds #fjj1jjj #ajj1djj #bjf1jjj ,brickwork1 in cubic yards #d1ihj ,structural steel 7including ,pier #gb71 in pounds #ej1jjj #c1ada1jjj #a1dge1jjj ---------------------------------------- -------------------------------- ,the number of passengers carried on the ,elevated ,railroad and surface lines of ,ninth ,avenue during the underpinning of these structures was about #abe1jjj1jjj4 ,the ,board of ,engineers1 organized by the ,pennsylvania ,railroad ,company in ,january1 #aijb1 immediately took up the matter of route and grade4 ,the center line1 which had been assumed as the center line of #cb;d ,street extended westward1 was slightly changed4 ,the grade adopted was approximately #b descending westward from ,ninth ,avenue1 which would place the tunnel well below the ,government dredging plane of #dj ft4 below mean low water at the pier head line2 thence westward on a lighter grade still descending until the deepest portion of the river was reached where the top of the rail would be about #ij ft4 below mean high water1 this location giving sufficient cover over the tunnels to insure stability and guard against the possibility of shipwrecks settling on the tunnels4 ,from this point to the portal an ascending grade of #a4cj was adopted1 which gave the lines sufficient elevation to cross over the tracks of the ,new ,york1 ,susquehanna and ,western and the ,erie ,railroads1 which run along the westerly base of the ,palisades4 ,owing to the exigencies of construction1 these grades in the river were very slightly modified4 ,plate ,,vii is a plan and profile of the tunnels as constructed4 ,illustration3 ,plate ,,vii4--,plan1 ,profile1 and ,triangulation1 ,north ,river ,tunnels ,the ,board of ,engineers early in #aijb took up the question of supports for the tunnels under the ,north ,river1 and various plans and schemes were considered4 ,it was finally decided to support the tracks on screw-piles carried through the lining of the tunnels1 as originally proposed by the writer4 ,in order to know something of the capacity of screw-piles in the actual material to be passed through1 it was resolved to test them4 ,a caisson was sunk at the end of one of the ,erie ,railroad piers on the ,new ,jersey side near the line of the tunnels1 and1 to obtain parallel conditions as much as possible1 the excavation was carried down to the proposed grade of the tunnel4 ,various types of screw-piles were sunk therein and tests were made1 not only of the dead load carrying capacity1 but also with the addition of impact1 when it was found that screw-piles could be sunk to hard ground and carry the required load4 ,the final part of the test was the loading4 ,the screw-pile1 having a shaft #cj in4 in diameter and a blade #e ft4 in diameter1 was loaded with #fjj1jjj lb41 with the result that1 for a month--the duration of this loaded test--there was no subsidence4 ,again1 and after the iron tunnel lining had been constructed across the river1 tests were made of two types of supports3 ,one a screw-pile #bi-a_/b in4 in diameter with a blade #d ft4 #h in4 in diameter and the other a wrought-iron pipe #af in4 in external diameter4 ,tests were made1 not only for their carrying capacity1 but also for their value as anchorages1 and it was found that the screw-pile was more satisfactory in every way2 it could be put down much more rapidly1 it was more easily maintained in a vertical position1 and it could carry satisfactorily any load which could be placed on it as a support for the track4 ,the #af-;in4 pipe did not prove efficient either as a carrier or as an anchorage4 ,these tests will be mentioned in the detailed description of the work to follow4 ,figs4 #b and #c illustrate the general arrangement and details of the machine designed by the writer and used for sinking the test piles in the tunnels4 ,this machine had been used originally on the ,new ,jersey side on the test pile at ,pier ,c1 and the adaption was not exactly as shown on these drawings1 but if the screw-piles had been placed in the tunnels1 the arrangement shown would have been used4 ,surveys1 soundings1 and borings were commenced in the latter part of #aija on an assumed center line of tunnels which was the center line of #cb;d ,street extended westward4 ,the soundings were made from a float stage fastened to a tugboat1 the location being determined by transits on shore and the elevation by measuring from the surface of the water1 a tide gauge being continually observed and the time of soundings and gauge readings kept4 ,in the river wash-borings were made from a floating pile-driver on which was installed a diamond-drill outfit of rods1 pump1 etc4 ,fourteen borings were completed in the river4 ,considerable difficulty was found in holding the pile-driver against the current1 the material in the bottom being very soft1 and several borings were lost owing to the drifting of the pile-driver4 ,each boring was continued1 and the depth of several was more than #bej ft4 below the surface of the water4 ,the borings on land were mostly core borings1 and were generally made with the chilled shot boring machine4 ,base lines1 about #b1bej ft4 in length1 were measured on each side of the river1 and observation points established4 ,it was necessary to build a triangulation tower #fj ft4 high on the ,new ,jersey side as an observation point4 ,the base lines were measured with #ajj-;ft4 steel tapes which were tested repeatedly1 and the work was done at night in order to obtain the benefit of uniform temperature and freedom from traffic interruptions4 ,from the base line on the ,new ,jersey side1 which passed over the ,weehawken ,shaft1 an elevated point on the assumed center line on the side of ,bergen ,hill was triangulated to1 and from this point westward a closed polygon was measured along the streets to the top of the hill on the west side and thence along the assumed center line to the portal4 ,the level transfer across the river was made by sighting across in opposite directions simultaneously1 and also by tide gauges4 ,the outline of the final triangulation system is shown on ,plate ,,vii4 ,illustration3 ,,fig4 #b4--7;,full page image7 ,,hydraulic ,,screwing ,,machine ,,with ,,ratchet ,,drive ,,and ,,vertical ,,jack ,,general ,,arrangement ,illustration3 ,,fig4 #c4--7;,full page image7 ,,hydraulic ,,screwing ,,machine ,,with ,,ratchet ,,drive ,,and ,,vertical ,,jack ,,details ,the decision as to the locations of the shafts on both sides of the river1 for construction purposes and finally for permanent use1 was a comparatively simple matter1 and1 all circumstances considered1 they are unquestionably in the most suitable places4 ,on the ,new ,york side the shaft was as near as practicable to the line dividing the subaqueous iron-lined tunnels from the land tunnels1 and on the ,new ,jersey side the shaft was placed centrally on the line of the tunnels and on the nearest available ground to the river1 while at the same time beyond the other end of the river tunnels1 thus necessitating driving the subaqueous tunnels only from east and west to meet under the river4 ,a caisson shaft on the ,new ,york side1 on the line of the tunnels near the river bulkhead1 was at one time considered1 but was not adopted as it entailed the driving of two shields both east and west1 in addition to the two from ,new ,jersey1 adding to the plant outlay while not affording any material saving in the time of construction4 ,it was thought desirable to construct the shafts on the two sides of the river in advance of letting the main contracts for the tunnels4 ,the ,manhattan ,shaft is north of the line of the tunnels1 on the north side of #cb;d ,street1 east of ,eleventh ,avenue4 ,the ,weehawken ,shaft is on the line of the tunnels in the yards of the ,erie ,railroad on the ,new ,jersey side1 and the distance between the shafts is about #f1ege ft4 ,the contracts for these shafts were let in ,june1 #aijc1 to the ,united ,engineering and ,contracting ,company1 and they were completed and ready for use at the time of letting the main contract for the tunnels1 thus saving considerable time4 ,the ,terminal ,station-,west4--,between ,ninth and ,tenth ,avenues4--,in the original design it was contemplated to have a four-track tunnel under #cb;d ,street from ,ninth to ,eleventh ,avenues1 but owing to the necessity for having additional yard facilities1 property was bought for about #ajj ft4 north and #ajj ft4 south of #cb;d ,street1 between ,ninth and ,tenth ,avenues1 and an open excavation1 lined with concrete retaining walls and face walls1 was made4 ,between ,ninth and ,tenth ,avenues1 #cb;d ,street was closed1 and the property formerly the street was bought by the ,tunnel ,company from the ,city of ,new ,york for a consideration by deed dated ,april #ahth1 #aijf4 ,the ,church1 ,rectory1 and ,school of ,st4 ,michael's1 which was located on the west side of ,ninth ,avenue between #cast and #cb;d ,streets1 was acquired by the ,tunnel ,company after it had acquired property for and had built a similar institution on the south side of #cdth ,street west of ,ninth ,avenue4 ,probably the most interesting feature of this contract was the support and maintenance of ,ninth ,avenue1 which has a three-track elevated railway structure and a two-track surface railway structure1 on which it was necessary to maintain traffic while excavation was made to a depth of about #fj ft41 and a viaduct was erected to carry ,ninth ,avenue4 ,the length of this viaduct is about #cge ft41 and the steelwork and its erection was done apart from the ,north ,river ,division work1 but all excavation and underpinning was included in this division4 ,the contract for this work on the ,terminal ,station-,west was let to the ,new ,york ,contracting ,company-,pennsylvania ,terminal1 on ,april #bhth1 #aijf1 and included about #eag1jjj cu4 yd4 of excavation1 about #hg being rock1 the construction of about #b1jjj lin4 ft4 of retaining and face walls containing about #ah1ejj cu4 yd4 of concrete1 and a large quantity of structural steel 7#a1dge1jjj lb47 for temporary use in underpinning ,ninth ,avenue4 ,fig4 #d shows cross-sections of the ,terminal ,station-,west yard1 and ,fig4 #e shows the general method of underpinning the ,ninth ,avenue structures4 ,illustration3 ,,fig4 #d4--,,terminal ,,station ,,west ,,typical ,,sections ,river ,tunnels4--,in the original plan a four-track tunnel was contemplated from the east side of ,tenth ,avenue to the east side of ,eleventh ,avenue1 but1 owing to the extension of the ,terminal ,yard1 previously noted1 this plan was changed1 and a two-track structure was built having a central wall between the tracks4 ,this was constructed in tunnel1 with the exception of #agb ft4 about midway between ,tenth and ,eleventh ,avenues1 where the rock dipped below the roof of the tunnel1 and there the construction was made in open cut4 ,these tunnels were lined with concrete with brick arches1 ,figs4 #f1 #g1 and #h being typical cross-sections4 ,this work was executed by the ,o',rourke ,engineering ,construction ,company1 under a contract dated ,november #ast1 #aijd4 ,it was possible to excavate in full rock cover about #bej ft4 of the tunnels eastward from the ,weehawken ,shaft and #bbe ft4 westward from the ,manhattan ,shaft4 ,at these points the rock cover was very thin1 and there shield chambers were made for the erection of two sets of shields1 about #f1ajj ft4 apart4 ,a typical cross-section of the ,weehawken ,land ,tunnel is shown on ,plate ,,viii4 ,illustration3 ,plate ,,viii4--,typical ,sections ,between ,manholes1 ,bergen ,hill ,tunnels ,the ,board of ,engineers decided1 and it was so stated in the contract and specifications1 that the river tunnels should be constructed by means of hydraulic shields1 but bidders were permitted to present to the ,board any scheme on which they might desire to bid1 but1 of course1 the decision as to the practicability of such plans rested with the ,board4 ,inasmuch as the shield method of construction was required1 the writer designed a shield for use in the ,north ,river ,tunnels4 ,the shield was about #ah ft4 long1 over all1 and was provided with a rigid but removable hood extending beyond the normal line of the cutting edge1 for use in sand1 gravel1 and ballast1 to be removed when the shield reached the silt4 ,the shields were thrust forward by twenty-four rams capable of exerting a pressure of #c1djj tons at a hydraulic pressure of #e1jjj lb4 per sq4 in4 ,taking into account #cj lb4 air pressure1 this pressure was increased to #d1djj tons4 ,the shield was fitted with a single hydraulic erector and hydraulic sliding platforms1 and when complete weighed #aid tons4 ,fig4 #i is a back elevation and section of the shield4 ,the contract for the river tunnels was let to the ,o',rourke ,engineering ,construction ,company on ,may #b;d1 #aijd4 ,the shields were built in accordance with the design previously referred to1 and proved entirely satisfactory4 ,generally1 the materials passed through were as follows3 ,starting out in full face rock1 from it into a mixed face of rock and sand1 thence into sand and gravel1 full face of sand1 piles1 rip-rap1 and the ,hudson silt2 and all were fully charged with water4 ,compressed air1 at an average gauge pressure of about #be lb4 and a maximum of #dj lb4 per sq4 in41 was used in the tunnels from the time the shields emerged from full rock face until the tunnel lining had been joined up and all caulking and grummeting had been done4 ,illustration3 ,,fig4 #e4--7;,full page image7 ,,arrangement ,,of ,,structures ,,supporting ,,ninth ,,ave4 ,,during ,,progress ,,of ,,excavation ,contractor's plants were established at the ,weehawken ,shaft and at the ,manhattan ,shaft1 including at each1 low-pressure air compressors of a capacity of #ac1jjj cu4 ft4 of free air per minute and also high-pressure air compressors for drills1 hydraulic pumps1 electric generators1 etc4 ,the river tunnels passed under ,pier #gb1 ,north ,river 7old ,no4 #fb71 which was occupied by the ,new ,york ,central and ,hudson ,river ,railroad ,company4 ,the ,tunnel ,company leased this pier and withdrew all the piles on the lines of the tunnels prior to the commencement of construction1 and on the remaining piles constructed a trestle for the disposal of the excavation from the tunnels and the terminal4 ,at the completion of the work this pier had to be restored1 and ,fig4 #aj shows the general arrangements of the location of the piles and the pier structure with reference to the tunnels4 ,in the tunnels which were constructed in silt farther down the river1 by the writer as ,chief ,engineer for the ,hudson ,companies1 it had been possible to shove the shield through the silt with all the doors closed1 displacing the ground and making great speed in construction owing to the absence of all mucking4 ,it was thought that this procedure might be pursued in the larger tunnels of the ,pennsylvania ,railroad1 and it was tried1 but it was almost immediately found to be impossible to maintain the required grade without taking a certain quantity of muck into the tunnels through the lower doors1 the tendency of the shield being to rise4 ,by taking in about #cc of the excavation displaced by the tunnel1 the grade could be maintained4 ,it was considered desirable1 owing to this rising of the shields1 to increase the weight of the cast-iron lining1 and this was done1 making the weight of the completed tunnel more nearly equal to the weight of the displaced material4 ,the weight of the cast-iron lining 7with bolts7 was increased from #i1fji to #ab1abg lb4 per lin4 ft4 of tunnel4 ,the weight of the finished tunnel with this heavier iron is #ca1dfi lb4 per lin4 ft4 ,the weight of the silt displaced per linear foot of tunnel1 at #ajj lb4 per cu4 ft41 is #da1edh lb4 ,the weight of the completed tunnel with the maximum train load is #db1hfi lb4 per lin4 ft4 ,the maximum progress at one face in any one month was #ede ft41 working three #h-;hour shifts1 and the average progress in each heading while working three shifts was #ah ft4 per #bd hours2 while working one shift with the heavier lining referred to above1 the delivery of which was slow1 the average progress was #aa ft4 per #bd hours4 ,illustration3 ,,fig4 #f4--ae' #d ,span ,twin ,tunnels4 ,rock ,roof4 ,illustration3 ,,fig4 #g4--ai' #f ,span ,twin ,tunnels4 ,illustration3 ,,fig4 #h4--ba' #f ,span ,twin ,tunnels ,illustration3 ,,fig4 #i4--,,proposed ,,shield ,,for ,,subaqueous ,,tunneling ,,general ,,elevation ,illustration3 ,,fig4 #aj4--,,restoration ,,of ,,pier #gb 7,,old #fb7 ,,north ,,river ,,transverse ,,section ,,at ,,center ,,of ,,pier ,in order to permit the screw-piles to be put in place through the lining1 cast-steel bore segments were designed1 and placed in the invert at #ae-;ft4 centers2 these are of such a design as to permit the blade and shaft of the screw-pile to be inserted without removing any portion of the lining4 ,fig4 #aa is a typical cross-section of the river tunnel1 as originally planned1 with these pile supports4 ,after the shields had met and the iron lining was joined up1 various experiments and tests were made in the tunnel2 screw-piles1 and #af-;in4 pipes1 previously referred to1 were inserted through the bore segments in the bottom of the tunnel1 thorough tests with these were made1 levels were observed in the tunnels during the construction and placing of the concrete lining1 an examination was conducted of the tunnels of the ,hudson and ,manhattan ,railroad ,company under traffic1 and the result of these examinations was the decision not to install the screw-piles4 ,the tunnels1 however1 were reinforced longitudinally by twisted steel rods in the invert and roof1 and by transverse rods where there was a superincumbent load on the tunnels2 it might also be noted that on the ,new ,york side1 where the tunnels emerge from the rock and pass into the soft material1 the metal shell is of cast steel instead of cast iron4 ,fig4 #ab is a typical cross-section of the river tunnels as actually constructed4 ,illustration3 ,,fig4 #aa4--7;,full page image7 ,,cross-,,section ,,of ,,tunnel ,,showing ,,track ,,system ,,and ,,screw-,,pile4 ,illustration3 ,,fig4 #ab4--,,subaqueous ,,tunnels ,,cross-,,sections ,during the investigations in the tunnels1 borings were made to determine exactly the character of the underlying material1 and it was then found that the hard material noted in the preliminary wash-borings was a layer of gravel and boulders overlying the rock4 ,when the borings in the tunnels reached this material it was found to be water-bearing and the head was about equivalent to that of the river4 ,rock cores were taken from these borings1 and the deepest rock was found at about the center of the river at an elevation of #cjb4f ft4 below mean high water4 ,rods were then inserted in each bore hole and thereby attached to the rock and used as bench-marks in the tunnels4 ,from these bench-marks1 using specially designed instruments1 very accurate observations of the behavior of the tunnels could be made1 and from these the very interesting phenomenon of the rise and fall of the tunnels with the tide was verified1 the tunnels being low at high tide and the average variations being about #j4jjh ft4 in the average tide of about #d4ch ft43 the tidal oscillations are entirely independent of the weight of the tunnels1 since observations show them to have been the same both before and after the concrete lining was in position4 ,there was considerable subsidence in the tunnels during construction and lining1 amounting to an average of #j4cd ft4 between the bulkhead lines4 ,this settlement has been constantly decreasing since construction1 and appears to have been due almost entirely to the disturbances of the surrounding materials during construction4 ,the silt weighs about #ajj lb4 per cu4 ft4 7this is the average of a number of samples taken through the shield door1 and varied from #ic to #aji lb4 per cu4 ft471 and contains about #ch of water4 ,it was found that whenever this material was disturbed outside the tunnels a displacement of the tunnels followed4 ,the tunnels as above noted have been lined with concrete reinforced with steel rods1 and prior to the placing of the concrete the joints were caulked1 the bolts grummeted1 and the tunnels rendered practically water-tight2 the present quantity of water to be disposed of does not exceed #cjj gal4 per #bd hours in each tunnel #f1ajj ft4 long4 ,bergen ,hill ,tunnels4--,these are two single-track tunnels1 #cg ft4 from center to center1 and extend for a distance of #e1idj ft4 from the ,weehawken ,shaft to the ,hackensack ,portal4 ,they were built almost entirely through trap rock4 ,the contract was let on ,march #fth1 #aije1 to the ,john ,shields ,construction ,company1 but was re-let on ,january #ast1 #aijf1 to ,william ,bradley1 the ,shields ,company having gone into the hands of a receiver4 ,about #a1cfi ft4 of the tunnel excavation was done by the ,shields ,company1 but no concrete lining4 ,the maximum monthly progress for all headings was #fbb ft41 and the average progress was #cch ft4 ,a working shaft #baf ft4 deep was sunk from the top of the hill1 to facilitate construction4 ,the tunnels are lined with concrete throughout4 ,typical cross-sections of these tunnels are shown on ,plate ,,viii4 ,in conclusion it may be admissible for the writer after having1 in conjunction with ,mr4 ,samuel ,rea1 experienced the evolution and materialization of this ,pennsylvania ,railroad scheme1 to express his great sorrow for the untimely death of the father of the entire scheme1 the late ,president ,cassatt4