2011.005

Lukacs, Claire

Gift

Museum Collections. Gift of a friend of the Museum.

Tudsberry, J.H.T.Jacobs, Charles Mattathias

1910 - 2011

Date: 1910

Notes: Scanned text as found 2011 at: http://quod.lib.umich.edu/m/moa/AJS1987.0001.001?rgn=main;view=fulltext [note OCR text is uncorrected, but many portions are readable.] The Hudson river tunnels of the Hudson and Manhattan railroad company ... With an abstract of the discussion upon the paper. Edited by J.H.T. Tudsbery ...Jacobs, Charles Mattathias, 1850-1919. List of all pages | Add to bookbagPage [unnumbered] Transportation Library -T: r > -, oz JACOBS ON THE HUDSON RIVER TUNNELS OF THE HUDSON AND MANHATTAN RAILIPOAD COMPANY. Page [unnumbered] Page 1 THE HUDSON RIVEiR TUNNELS OF THE HUDSON AND MANHATTAN RAILROAD COMAPANY. BY CHARLES MIATTATHIAS JACOPS, Ml. INsT. C.E. WITH AN ABSTRACT OF THlE DISCUSSION UPON THE PAPER'. EDITED BY J. II. T. TUDSBERY, D.Sc., M11. INST. C.E., sllCIRZETAR J Y. By permission of the Council. Excerpt Minutes of Proceedings of The Institution of Civil Engineers. Vol. clxxxi. Session 1909-1910. Part iii. LONDON: V~ublisfjub bp TJjc Enstitution, GREAT GEORGE STREET, WESTMINSTER, S.W. TEERM,"INSTvrUTiON, Lo\D N-." TLIIWES~T MINSTERC 77."] 1910. [The right of Publication (nd (j) TJr(nslslion is reserved.) Page 2 Mlnsportation Libra ry ADVERTISEMENT. The Institution as at body is not responsiblIe either for the statements made, or for the opinions expressed, in the following" pages. LONDON: PRINTED BY WILLIAM CLOWES AND SONS, LIMITED, DUKE STREET, STAMFORD STREET, S.E., AND GREAT WINDMIILL STREET, W. Page 3 THE INSTITUTION OFl CIVIL ENGINEERS. SECT. I.-MINUTES OF PROCEEDINGS. 22 February, 1910. JAMES CHARLES INGLIS, President, in the Chair. (Paper No. 3859.) "The Hudson River Tunnels of the Hudson and Manhattan Railroad Company." By CHARLES MATTATIIAS JACOBS, M. Inst. C.E. IT is not often that so many years elapse between the inception and the completion of an engineering project as has been the case with the construction of the tunnels under the IHudson (North) River at New York City. This work has been suspended on several occasions and taken up again under new management, with a different method of operation in view; and the existing system is a very considerable development from the project originally planned. HISTORY. The Hudson River is tidal as far as Troy, a distance of 150 miles from its mouth. It flows in a submerged valley, and it is estimated by geologists that a subsidence of about 200 feet has occurred since the glacial period; before that time the river was non-tidal, discharging into the ocean at a point many miles seaward of its present mouth. The river and glacial action have cut a deep channel in the rock, which has been gradually filled with material eroded from the area within the watershed, forming a silt stratum which extends from the bed of the river to the underlying rock and varies in thickness from a few feet to 250 feet. The character of this silt varies with the depth; it is very dark in colour, and contains about 30 per cent. of water. A sample obtained from the " up-town" tunnel at about the deepest point had the following characteristics: specific gravity wet, about 1 '65; dry, about 2-50; weight per cubic fi' u: 2 Page 4 4 JACOBS ON TIIE HUDSON RIVER TUNNELS. [Minutes of foot wet, about 103 lbs.; dry, about 156 lbs. In its natural state it is very soft and flows readily through minute apertures, but when the contained moisture is partially excluded by compressed air, it has many of the characteristics of a stiff clay. It has been used in its natural condition with great success to plaster a heading or shield-face, in order to prevent the escape of air when tunnelling in sand and gravel; and it is practically impervious to water, the tunnels through silt showing less seepage than in any other material met with in the river-tunnels in this vicinity. The Hudson River is about 1 mile in width and 40 to 60 feet in depth. The greatest depth to rock is near the west side where it is 250 to 300 feet below mean tide, although the deepest waterchannel is near the east side. From the east shore to a line about 1,500 feet therefrom the rock is 40 to 60 feet below mean tide. On the New Jersey side the rock is a soft mica schist, while on the New York side it is gneiss: the strike is approximately parallel to the river and the dip is nearly vertical. For many years no means of crossing this river existed south of Albany, 145 miles up-stream, except by ferry-boats, and continuous land transportation between the New England States and the States to the west and south was tlus interrupted. In 1889 the Poughlkeepsie bridge was built, crossing the river 75 miles from its mouth. The desire for some means of crossing the river at New York City, other than by ferry, had long been felt, and as aL bridge in the state of the engineering art at tlat time seemed out of the question, a tunnel was considered to be tle only means of solving the problem. Before the completion of the tunnel the traffic crossing the river was handled by large steam ferry-lboats, most of which were worked by the railway-lines terminating on the west side of the river. To meet the demands of the traffic a very efficient type of ferry-boat has been developed. These boats are built to move in either direction and load and unload from the ends: access to the shore is had by bridges, the shore end being hinged and the other end resting on a floating pontoon. The vessels have steel hulls, overhanging decks, and a double carriageway for vehicles in the middle, with large cabins on the sides. The more modern boats have an upper deck also, with a large cabin, and provision is made for loading and unloading from both decks. The older boats have side paddle-wheels driven by engines of the diagonal or workingbeam type, but the more recent ones have screw-propellers, but fore and aft on a rigid shaft extending from end to end of tile vessel. The principal dimensions are: Page 5 Proceedings.] JACOBS ON THE HUDSON RIVER TUNNELS. I Length over all......... 206 feet.,, of hull......... 200 Beam over guards......... 65,,,, of hull.. 46, Depth of hull......... 17, Draught.......... 10,, 10 inches. Displacement......... 890 tons. Power............ 1,016 I.HP. Speed, per hour.......... 12 knots. Capacity:Passengers, seating 500 standing.. 1,500 Vehicles (about)........ 18 In 1895 the Author was invited to report upon the practicability of completing the old Hudson River tunnels and to submit an estimate of the cost. The tunnels, which had filled with water to within 4 feet of the top of the shaft in Jersey City, were pumped out in order to make careful investigation of the condition of the structure. The two special difficulties relating to the continuation of the work were: first, 500 feet of cast-iron lining was closely timbered with 12-inch vertical timbers, and tied with three rows of horizontal turn-buckles to about 4-foot centres to preserve the structure from collapse; and secondly, within 136 feet of the point where the work had been suspended, there was a reef of rock which extended for a length of 750 feet on the line of the tunnel and gradually rose to about 16 feet above the incline of the bottom of the tunnel, the presence of this rock being clearly indicated by numerous borings. The Author stated in his report that the weakness in the metal lining could, in his opinion, be remedied, by an internal lining of reinforced concrete, and also that the shield could be carried through the reef if an apron were added to the front of it for the protection of the men when drilling the rock, the Author's previous experience in meeting similar difficulties in the construction of the East River tunnel for gas-mains in 1892 having indicated that this was feasible. Although the report was favourably considered, nothing was done until the 6th February, 1902, when a new company was incorporated under the name of the New York and Jersey Railroad Company, and the Author was retained as Chief Engineer. Plans and specifications were drawn up to cover the construction of tunnels extending to a station in Christopher Street, New York City, adjoining the Ninth Avenue elevated railroad station, and leading contractors were invited to tender for the execution of the work. Only one tender was submitted, which was entirely unacceptable; consequently, the whole of the work, including the entire system of tunnel-lines, was carried out by a construction Page 6 6 JACOBS ON TI1E IUDSON RIVER TUNNELS. [Minutes of force organized and directed by the Author, with the exception of a short length of the land tunnels built by cut-and-cover methods under contract. When the New York and Jersey Railroad Company took up the completion of the old tunnels, the length of tunnel already constructed was: North tunnel from New Jersey shaft...... 3,916 feet.,,,,,, New York....... 160,, South,,, New Jersey... 570,, The former plans contemplated the use of the tunnels by ordinary steam-trains, but this idea was abandoned on the resumption of work, as it was intended to use vehicles propelled by electricity, for passenger-traffic only. The first plan considered was the completion of the north tunnel only, and the use therein of special narrow carriages on two lines of railway! However, a reconsideration of this plan led to the decision that the capacity of such a line would be insufficient, and it was therefore decided to complete both tunnels and place a standard-gauge line in each. It was further decided to extend the New Jersey approach to a connection with the surface, thus enabling the electric tramcars of Jersey City and Hoboken to cross the river to an underground station to be built at Christopher and Greenwich Streets, New York City. No connection with the electric tramways on the New York side was contemplated; the New Jersey lines are equipped with an overhead contact-wire, while the New York City lines have an underground conductor. Authority for this work was granted by certificate to the New York and Jersey Railroad Company by the Board of Rapid Transit Railroad Commissioners on the 10th July, 1902. Studies as to the number of passengers likely to use this pair of tunnels led to an investigation of the whole question of the traffic crossing the river by ferry-boats and its probable growth, with a view to carrying it in this and additional tubes. New York City, in its rapid increase in size and population, has followed the lines of least resistance as influenced by the lines of transportation. Politically, New York, with a population of 3,437,202, is divided into five boroughs, the most populous of which is Manhattan, conterminous with the island of the same name, having a population of 1,850,000 (census of 1900). This island has an average width of 1. mile and a length of 14 miles. Its growth has been from the south end northward, having been successively stimulated by improvements in transportation-facilities; first, by the elevated railways built between 1870 and 1880 and extended at Page 7 Proceedings.] JACOBS ON THE HUDSON RIVER TUNNELS. 7 various times; secondly, by the electrification of the surface tramways in the years 1895 to 1903; thirdly, by the improvement in speed and capacity of the elevated railways, due to the change in motive power from steam to electricity in 1902 and 1903; and, fourthly, by the opening of the Subway in 1904. While this development in Manhattan was progressing, improvements in transportation-facilities diverted large numbers to the boroughs of Brooklyn and Queens, across the East River. This was brought about by the construction of the Brooklyn bridge, opened in 1883, and over which the Brooklyn elevated railway trains have entered Manhattan since 1898, and the electric tramways later in the same year; and also by the Williamsburgh bridge, opened in 1903. Owing to insufficient transit-facilities the development of the cities and towns on the west bank of the Hudson River, opposite Manhattan, has not been as rapid as in the corresponding territory across the East River; and although these municipalities are not politically part of New York City, they are essentially part of the same community, and are influenced by the same natural forces which have caused a concentration of population around this great port. However, the fact that they are subject to the laws of another State has placed them beyond the jurisdiction of the various commissions which have been constituted by the State of New York to investigate the transit-facilities of the city and to devise means for improvement; and therefore improved facilities for crossing the river had to be brought about by private enterprise, subject to the laws affecting corporations in the two States and the Interstate Commerce Laws of the United States. The population of the suburban territory on the west side of the Hudson, within a radius of 20 miles, is about 1,000,000, according to the census of 1900. The volume of traffic crossing the river by the existing ferries, based on statistics for 1903, is about 90,000,000 passengers per annum, with an annual increase of about 5 per cent., of whom more than 75 per cent. cross at points 2- mile to 1 mile south of the tunnels of the original project. A study of these facts led to the conclusion that a single pair of tubes would not be sufficient to handle the existing traffic crossing the river, and that if additional tubes were to be built they would better serve the convenience of the public if situated about 1 mile southward of the earlier tunnels. A tunnel was therefore projected to cross the river on the line of Cortlandt Street to a terminus at the west side of Church Street, between Cortlandt Street and Fulton Street, New York City, returning by another tunnel on the line of Fulton Street, with a station in Page 8 8 JACOBS ON TIIE HUDSON RIVER TUNNELS. [Minutes of Jersey City under the terminus of the Pennsylvania Railroad. This pair of tunnels will, for convenience, be designated in this Paper " down-town " tunnels, and the older tunnels, so long under construction, will be called the "up-town" tunnels. A line was also projected on the New Jersey side to run parallel with the river, connecting the uptown and downtown systems. Authority for the construction of the downtown system was granted in the name of the Hudson and Manhattan Railroad Company by certificate of the Board of Rapid Transit Railroad Commissioners on the 24th November, 1903. A further development of the plan was also adopted, extending the up-town approach inland in New York City to a terminus at Sixth Avenue and Thirty-third Street, with six intermediate stations between the terminus and the river, and with a branch on Ninth Street, extending to Fourth Avenue. This branch would bring passengers to the heart of Manhattan Island (New York City), and also enable them to transfer to two of the elevated railway-lines and to the Interborough Rapid Transit Subway. Authority for this extension was granted by certificate of the Board of Rapid Transit Railroad Commissioners on the 2nd February, 1905. After the up-town tunnel had been completed and put in service as far as Twenty-third Street Station, the matter of the position of the New York terminus of this line was reconsidered, and, after careful study of the conditions, it was decided that the line should be extended from Thirty-third Street up Sixth Avenue to Fortysecond Street, and thence eastward in Forty-second Street to a terminus under Forty-second Street at Park Avenue, which would place the terminus at a point where passengers could readily transfer to the Rapid Transit subway, the Third Avenue elevated railway, the Forty-second Street tunnel under the East River, and also more especially to the trains of the New York Central and Hudson River Railroad Company and of the New York, New Haven and Hartford Railroad Company at their terminal at this point. Permission to extend the line to this point was granted under certificate of the Public Service Commission on the 4th May, 1909. Construction work will soon commence, and is to be completed within 2 years. Consideration of the annual increase in the passenger-traffic crossing the river and of the maximum capacity of the proposed tunnels led to the conclusion that they would have very little spare capacity for future growth, and therefore a third pair of tunnels to cross the river was projected, to be built at such times as the conditions should warrant. Rather than place this pair of tunnels parallel to either the up-town or down-town system, it was Page 9 Proceedings.] JACOBS ON TlE IUDSON RIVER TUNNELS. 9.LN3 1 u 3 d: I 1 AjVUJ. A ki u n oQH Page 10 10 JACOBS ON THE HUDSON RIVER TUNNELS. [Minutes of thought the traffic would best be handled by tunnels running from the Church Street terminus parallel to the down-town tunnels as far as the river's edge, and then crossing obliquely to the Erie Railroad Company's yards, where a connection with the line connecting the up-town and down-town systems, as well as a connection with the surface lines of the Erie Railroad Company, could be made. These tunnels will be referred to in this Paper as the Erie tunnels, and while they do not form part of the lines recently completed, the work is planned so as to admit of their construction at any time without interruption of traffic, the junction enlargements at junctions and points of crossing having been built as part of the present work. The completion of these tubes in the future will admit of an independent train-service between Church Street terminus and Hoboken or the Erie Railroad without passing through the Pennsylvania Railroad station. As the urban and suburban passenger-traffic in a great city is not uniformly distributed throughout the hours of the day, transportation lines only work to their maximum capacity for two short periods during the day. As this has a marked influence on the transportation problem, the habits of the population of New York in this respect may prove of interest. The percentage of passengers in each hour of the day is given by Fig. 1 (p. 9), from records of the Cortlandt Street and Desbrosses Street ferries. The foregoing considerations led to the abandonment of the plan of using single electric-tramcar units through the tunnel, in favour of a service of multiple-unit trains. This equipment, while making higher speed possible, rendered easier gradients and curves desirable. As, however, portions of the tunnel had been constructed before the final plan was adopted, and with regard to which the original scheme was not well located, it was necessary to adopt heavier grades and sharper curves than would otherwise have been the case had the points to be served and the character of the equipment been known from the start. Fig. 2, Plate 2, indicates the system as finally located, and Figs. 3 and 4 the profiles of the river-tunnels. On the 6th December, 1906, the corporations organized for the construction of the various portions of the work were consolidated into one corporation called the Hudson and Manhattan Railroad Company Page 11 Proceedings.] JACOBS ON TIIE IIUDSON RIVER TUNNELS. 11 RIVER-TUNNELS. Active constructional work was commenced in Februnry, 1902, the only plant used which was left by Messrs. Pearson and Son being the original shield in the old and uncompleted north tunnel. A change in the design of the cast-iron lining was made, the ring being made up of eleven segments and key as before. The dimensions were: skin, 1 inch thick; flanges, 8 inches deep; rings, 201 inches long; outside diameter, 19 feet 5a inches; inside diameter, 18 feet 1L inch; weight per lineal foot, 7,565 lbs. The first ring was erected on the 22nd October, 1902, and by the 29th November, 1902, 136 feet of tunnel had been constructed, when the cutting edge of the shield came in contact with the rock ledge before referred to. The unusual problem now presented itself of having to blast rock ahead of the cutting edge of the shield, varying from 1 foot to 16 feet above the cutting edge, superposed by a bed of soft silt saturated with water, with a cover varying from 10 to 15 feet above the crown of the shield and a depth of water above the silt rising from 60 to 65 feet. The heading in front of the shield was enlarged and solidly timbered to form a working-chamber for the purpose of attaching a steel apron just below the axis and extending across the shield, and projecting 5 feet beyond the cutting edge, so that workmen might have sufficient overhead protection in drilling the rock, and also to act as a material safeguard against the inflow of silt. This work of reconstruction occupied 47 days and was carried out under an airpressure of 42 lbs. The alterations to the shield being completed, on the 1st February, 1903, progress was resumed with the shield partly in rock and partly in silt. The surface of this rock ledge was very irregular, in some places passing below the line of the tunnel and again above. When not in rock, the shield was forced ahead by the jacks without any workmen being in advance of the diaphragm, the material encountered being forced into the tunnel through one or more doors in the diaphragm. If the shield would not advance with a hydraulic pressure of 3,000 lbs. per square inch on the jacks, the pockets of the shield were excavated and rock and other hard material found holding the shield was blasted away; this pressure on the jacks was determined as the safe thrust the shield would withstand without damage. In view of the probable disturbance of the river-bed which this blasting would involve, scows holding about 600 cubic yards of clay were held in readiness to be dumped over the point of disturbance Page 12 12 JACOBS ON THIE HUDSON RIVER TUNNELS. [Minutes of in case of a "blow," which precaution proved to be well justified. Nevertheless, two serious blows entailing the flooding of the tunnel did occur, but on dumping two scows over the break, the escape of air through the river-bed was stopped, enabling the water to be blown out. The workmen succeeded in recovering the heading in 11 hours and 23 hours, respectively, from the time that these blows occurred. The work of blasting the rock proceeded until the last few feet of the reef were reached, where the rock had now reached its highest point, 16 feet above the bottom of the cutting edge, on the east side of the ridge. The silt at this point was in a semi-fluid state and five barges of clay had been deposited to reinforce it. Very great difficulty was encountered here, due to the clay creeping through to the shield-doors, and all efforts by poling and other mining devices to hold the clay back far enough to enable the drillers to work were unavailing. An unusual method was then determined upon; namely, to bake the clay by means of intense heat. Two large tanks were sent into the tunnel, filled with kerosene under pressure; fine blow-pipes were attached to the tanks, and the fire from the blow-pipes impinged on the exposed clay until it became caked sufficiently dry and hard to overcome slipping. The time occupied in the application of the heat extended over a period of 8 hours and during this time water was played continually on the shield to avoid damage due to the high temperatures. This is believed to be the first time that soft material met with in tunnelling under the bed of a river has been solidified by means of fire while working under an air-pressure of 38 lbs. per square inch. Seven days after passing this high point, the rock disappeared and sand was reached. Construction proceeded regularly for a distance of 740 feet, when the bulkhead at the end of the brick-lined tunnel in New York was reached on the 11th March, 1904, thus completing the first tunnel under the Hudson River. Practically 30 years had elapsed since the work was first started. The time that elapsed from the date work was commenced under the direction of the Author was 505 days, in which 1,625 feet of tunnel were built, or an average of 3 * 2 feet per day. During this time, in addition to the delay caused by the alterations and repairs to the shield, work was hindered by a strike of the compressed-air workmen, and, in addition to the two blows of air previously described, nine minor blows occurred. The north tunnel was completed by cutting out the internal parts of the shield and constructing, inside the shell, cast-iron tunnel of the standard external diameter of 16 feet 7 inches, which was adopted for the remainder Page 13 Proceedings.] JACOBS ON TIIE IIUDSON RIVER TUNNELS. 13 of the tubes througlhout the system. The annular space between the shell and the smaller lining was filled with concrete and cement grout. The defective iron lining installed in the early stages of the work was rendered efficient by an internal lining of concrete, and a longitudinal and circumferential reinforcement of twisted steel rods. The original tunnel being 3 feet 3 inches larger in internal diameter than the standard tunnel adopted for the remainder of the work, there was sufficient room to admit of this. The inside lining of concrete was continued until the junction with the standard diameter of tunnel was reached. In addition to the historic north tunnel of the up-town system, three other tunnels have been driven across the river; the south tunnel of the up-town system, and the two tunnels of the downtown system; one of the latter is on the line of Cortlandt Street and the other on the line of Fulton Street. A standard type of cast-iron lining was used (Figs. 5 and 6, Plate 2), consisting of a ring weighing 11,340 lbs. and made up of nine segments and a key. The metal is 17, inch thick. Each segment has six holes on the circumferential flanges and three holes on the longitudinal flanges. All joints were machined and were provided with a caulking-space 1I inch deep and I inch wide. In sand or rock each segment was provided with a grout-hole, and in silt one segment only of each ring. All cast-iron lining-plates were, while hot, immersed in a bath of coal-tar pitch. Where the tunnel was liable to be subjected to undue stresses, the lining was strengthened by reducing the width of the rings to 18 inches, the other dimensions remaining unaltered. The weight of an 18-inch ring was 9,522 lbs. The tunnels were also strengthened at points where extraordinary exterior loads were anticipated, by placing between the cast-iron lining-rings packing-rings consisting of two steel plates A- inch thick, the ring being made up of four segments, and the joints being so spaced as to break joint with those on the cast-iron lining. In addition to the cast-iron lining, short lengths of tunnel were built with cast-steel lining where there were liable to be concentrated loads due to piles supporting the seawall along the edge of the river. The dimensions were the same as for cast-iron lining, except that the bolt-holes were larger to permit of the use of thicker bolts. The standard bolts were of steel with a rolled thread 11 inch in diameter at the bottom of the thread. The bolts for the steel rings were: inclI larger. Page 14 14.ACOBS ON TlE IIUD)SON PIIVEI TUNNELS. [Minutes of SHIELDS. The shields used in driving the tube tunnels were all built to one design, with some slight exceptions. The outside diameter was 17 feet, the length 11 feet 5 inches. The diaphragmn was placed 5 feet 8 inches in rear of the cutting edge. The space in front of the diaphragm was divided into six pockets by one transverse girder and two vertical girders. The shields were advanced by sixteen 8-inch hydraulic jacks. Water at a pressure of 5,000 lbs. per square inch was taken to the shield from hydraulic pumps placed in the engine-rooms outside the tunnels. The weight of a shield complete with hydraulic machinery, etc., was 61 tons. Above the transverse girder were three sliding platforms actuated by hydraulic jacks, so that they could be advanced ahead of the cutting edge to provide cover for the men when drilling rock. A removable projecting hood was also provided on the upper cutting edge, extending downwards one-third of the circumference and outwards 2 feet 6 inches, so as to provide head cover for the drills when the surface of the rock was at a higher level than the sliding platforms, and to serve as a poling-board in soft ground. The first shields were built with the segment-erector attached, but afterwards the erectors were made independent of the shield and carried on a platform moving on rollers connected by brackets with the iron lining. Table I in the Appendix gives the records of the various shields. SOUTH TUNNEL (UP-TOWN SYSTEM). Work was commenced on the twin to the old north tunnel —i.e., the south tunnel of the up-town system-by building a shieldchamber at the end of the short section of brick tunnel built by the original company, and 500 feet from the shaft. On the 23rd January, 1903, work was commenced on the installation of the air-locks. The erection here of one of the typical shields started on the 17th July, and was completed on the 24th August, and the first ring of iron was put in on the 22nd September, 1903. The experience in the north tunnel having demonstrated the fact that the shield could be advanced by the admission of a small quantity of silt through a single door, the standard shields for the remainder of the work were designed with a view to withstand the full power of the sixteen 8-inch jacks, under a hydraulic pressure Page 15 Proceedings.].IJCOIBS ON TIIE IUDSON 1VERl TUNNELS. 15 of 5,000 lbs. per square inch. It was found that this shield could be easily advanced with the admission of no silt whatever. It was also found, when advancing the shield in the Hudson River silt without excavating, that the shield commenced to move with 1,600 lbs. per square inch on eleven jacks, which was equivalent to a pressure of 3,900 lbs. per square foot on the area of the face... [truncated due to length]