Part 18

At Manhattan the sand and stone were received from the bins in chutes at a small hopper built on the permanent upper platform of the intercepting arch. Bottom-dumping cars, divided by a partition into two portions, arranged to hold the proper quantities of sand and stone for a 4-bag batch of concrete, were run on a track on this upper platform, filled with the proper quantities of sand and stone, and then run back and dumped into the hoppers of the mixer. After mixing, the batch was run down chutes into the tunnel cars standing on the track below. The water was brought in pipes from the public supply. It was measured in barrels by a graduated scale within the barrels. The water was not put into the mixer until the sand and stone had all run out of the mixer hopper. The mixture was revolved for about 1½ min., or about 20 complete revolutions.

At Weehawken Shaft the mixing plant was entirely rebuilt. Four large bins, two for sand and two for stone, were built in the shaft. Together, they held 430 cu. yd. of stone and 400 cu. yd. of sand. The sand and stone were dumped directly into the bins from the cars on the trestle which ran from the wharf to the shaft. The materials were run through chutes directly from the bins to the hoppers of the mixers, where they were measured. Two No. 6 Ransome mixers, electrically driven, were used here, as at New York, and, as there, the water was led into measuring tanks before being let into the mixer.

The quantity of water used in the various parts of the concrete cross-section, for a 4-bag batch consisting of 1 bbl. (380 lb.) of cement, 8.75 cu. ft. of sand, and 17.5 cu. ft. of stone, is given in Table 31.

TABLE 31.--QUANTITY OF WATER PER 4-BAG BATCH OF CONCRETE, IN U.S. GALLONS.

==========================+==========+==========+========== Portion of cross-section. | Maximum. | Minimum. | Average. --------------------------+----------+----------+---------- Invert | 40 | 20 | 26 Duct bench | 36 | 21 | 27 Arch (excluding key) | 37 | 19 | 25 Key of arch | 27 | 15 | 20 Face of bench | 31 | 22 | 27 ==========================+==========+==========+==========

The maximum quantities were used when the stone was dry and contained more than the usual proportion of fine material, the minimum quantity when the sand was wet after rain.

The resulting volumes of one batch, for various kinds of stone, are given in Table 32.

TABLE 32.--VOLUME OF CONCRETE PER BATCH, WITH VARIOUS KINDS OF STONE.

========+===========+================+===========+==================| | | Resulting | | | DESCRIPTION OF STONE. |volume per | | Mixture.|-----------+----------------| barrel of | Remarks. | | | |cement, in | | | Passed | Retained on | cubic | | | screen. | screen. | yards. | | --------+-----------+----------------+-----------+------------------| 1:2½:5 | 1½-in. | 3/8-in. | 0.815 | Measured in air | 1:2½:5 | 2½-in. |Run of crusher. | 0.827 | " " " | 1:2½:5 | -- |General average.| 0.808[D]|Measured from plan| 1:2½:5 | 2-in. | 1½-in. | 0.768[E]| " " " | ========+===========+================+===========+==================|

[D] Average for whole of River Tunnel section.

[E] Average from 7,400 cu. yd. in Land Tunnel section.

The sand used was practically the same for the whole of the river tunnel section, and was supposed to be equal to "Cow Bay" sand. The result of the mechanical analysis of the sand is shown on Plate XLVI. The stone was all trap rock. For the early part of the work it consisted of stone which would pass a 2-in. ring and be retained on a 1½-in. ring, in fact, the same as used for the land tunnels. This was found to be too coarse, and for a time it was mixed with an equal quantity of fine gravel or fine crushed stone. As soon as it could be arranged, run-of-crusher stone was used, everything larger than 2½ in. being excluded. About three-quarters of the river tunnel concrete was put in with run-of-crusher stone. The force was:

_At Manhattan._

1 Foreman @ $3.00 per shift 4 Men on sand and stone cars " 1.75 " " 4 Men handling cement " 1.75 " " 2 Men dumping mixers " 1.75 " "

_At Weehawken._

1 Foreman @ $3.00 per shift 2 Men hauling cement " 1.75 " " 2 Men dumping mixers " 1.75 " "

The average quantity of concrete mixed per 10-hour shift was about 117 batches, or about 90 cu. yd. The maximum output of one of the mixers was about 168 batches, or 129 cu. yd. per 10-hour shift.

Transportation.

_Surface Transportation._--At Manhattan the stone and sand were received in scows at the wharf on the river front. For the first part of the work, the wharf at 32d Street and North River was used, and while that was in use the material was unloaded from the scows into scale-boxes by a grab-bucket running on an overhead cable, and then teamed to the shaft. For the latter part of the work, the wharf used was at 38th Street and North River, where facilities for unloading were given to the contractor by the Pennsylvania Railroad Company which was the permanent lessee of the piers. The material was unloaded into scale-boxes by a grab-bucket operated by a derrick, and teamed to the shaft. When the scale-boxes arrived at the shaft they were lifted from the trucks by derricks and dumped into the bins.

At Weehawken all the stone and sand, with the exception of the stone crushed on the work, was received by water at the North slip. Here it was unloaded by a 2-cu. yd. grab-bucket and dumped into 3-cu. yd. side-tipping cars, which were hauled by a small steam locomotive over the trestle to the shaft, where they were dumped directly into the bins.

Before beginning the concrete lining, the 2-ft. gauge railway, which had been used for the surface transportation during the driving of the iron-lined tunnels, was taken up and replaced by a 3-ft. gauge track consisting largely of 30-lb. rails. The cars were 3-cu. yd. side-dumping, with automatic swinging sides. Two steam locomotives which were being stored at Weehawken (part of the plant from another contract), were used for hauling the cars in place of the electric ones used with the 2-ft. gauge railway.

_Tunnel Transport._--The track used in the tunnel was of 2-ft. gauge, laid with the 20-lb. rails previously used in driving the iron-lined tunnels. The mining cars (previously mentioned in describing the driving of the iron-lined tunnels) were used for transporting the invert concrete, although, for most of the work, dumping buckets carried on flat cars were used. Several haulage systems were considered for this work, but not one of them was thought to be flexible enough to be used with the constantly changing conditions, and it was eventually decided to move all the cars by hand, because, practically all the work being down grade, the full cars could be run down by gravity and the empty ones pushed back by hand. Two men were allotted to each car, and were able to keep the traffic moving in a manner that would have been perhaps impossible with any system of mechanical haulage. This system was apparently justified by the results, for the whole cost of the tunnel transport, over an average haul of about 2,000 ft., was only about 50 cents per cu. yd., which will be found to compare favorably with mechanical haulage on similar work elsewhere, provided full allowance is made for the use of the plant and power.

_Force Employed._--The average force employed on transport, both on the surface and in the tunnel, is shown in Table 33.

Costs.

During the work, careful records of the actual cost to the contractor of carrying out this work were kept by the Company's forces; these costs include all direct charges, such as labor and materials, and all indirect charges such as head office, plant depreciation, insurance, etc., but do not include the cost of any financing, of which the Company had no information.

TABLE 33.--AVERAGE FORCE PER SHIFT FOR TRANSPORTATION IN TWO TUNNELS.

========+==================+=====+==========+============+===========+ Location|Grade |Rate | WORK IN PROGRESS | | | |----------+------------+-----------+ | | | Two |Two arches, |Four arches| | | | inverts |two inverts,| and one | | | | and two |and two duct| face of | | | | duct | benches | bench | | | | benches | | | --------+------------------+-----+----------+------------+-----------+ {|Foreman |$3.00| 2 | 2 | 2 | Tunnel {|Laborer | 1.75| 24 | 28 | 70 | {|Switchmen | 2.00| | 2 | 2 | {|Hoisting engineers| 3.00| 2 | 4 | 5 | {|Foreman | 3.00| 1 | 1 | 2 | Surface{|Laborers | 1.75| 8 | 8 | 15 | {|Teams | 6.50| 1 | 1 | 2 | ========+==================+=====+==========+============+===========+

Field Engineering Staff.

The field staff may be considered as divisible into five main divisions:

(_A_).--Construction, including alignment,

(_B_).--Cost records,

(_C_).--Testing of cement and other materials of construction,

(_D_).--Photography,

(_E_).--Despatch-boat service.

(_A_).--_Construction_ (_Inspection and Alignment_) _Staff._--A comparatively large staff was maintained by the Company, and to this two causes contributed. In the first place, the contractor maintained no field engineering staff, because, early in the proceedings, it was arranged that the Company would carry out all this work, and thus avoid the overlapping, confusion, and lack of definite responsibility which often ensues when two engineering forces are working over the same ground. Even had the contractor maintained an engineering force, it would have been necessary for the Company to check most of the contractor's work.

In the second place, this work gave rise to a number of special surveys, tests, borings, and observations of various kinds, most of which were kept up as a part of the regular routine work, and this necessitated a staff. Also, for a whole year, active progressive work was at a standstill while the pile tests were going on.

(_B_).--_Cost Records Staff._--A distinct feature was made of keeping as accurately as possible detailed records of the actual cost to the contractor of carrying out the work. A small staff of clerks, retained solely for this purpose, tabulated and recorded the information furnished by the members of the construction staff. About $12,000, altogether, was spent in salaries in this department, and it may be considered an extremely wise investment, for, not only is the information thus obtained of great value and interest in itself, but it also puts the Company in an excellent position should any claim or discussion arise with the contractor.

(_C_).--_Cement-Testing Department._--As the Company furnished the cement to the contractor, it became incumbent to make careful tests of the quality. A cement-testing laboratory was established at the Manhattan Shaft offices, under the charge of a cement inspector who was furnished with assistants for sampling, shipping, and testing cement. All materials used on the work, such as bricks, sand, stone, water-proofing, etc., were tested here, with the exception of metals, which were under the charge of a metal inspector reporting directly to the head office. This department cost about $10,000 for salaries and $3,000 for apparatus and supplies, or about $13,000, in all.

There were 800,000 bbl. of cement tested, and samples from 2,100,000 brick. A large amount of useful information has resulted from the work of this laboratory.

(_D_).--_Photography._--It was desired to keep a complete photographic record of the progress of the work, and therefore a photographer was appointed, with office room at the Manhattan Shaft. The photographer took all the progress photographs on the work of the North River Division, made photographic reductions of all drawings and plans, made lantern slides of all negatives of a more important nature, and, in addition, during the period of compressed air, analyzed the samples of compressed air, brought into the office for the purpose, for the amount of CO_{2} present. About $8,000 was spent on this department.

(_E_).--_Despatch-Boat Service._--To provide access to the New Jersey side, a despatch boat was purchased. This boat was at first (June, 1904) chartered, and in May, 1905, was bought outright, and ran on regular schedules, day and night. It continued in the service until April, 1909, when it was given up, as the tunnels were so far completed that they provided easy access to New Jersey. The cost of the boat (second-hand) was about $3,000. It was then thoroughly overhauled and the cabin remodeled. The monthly cost, when working a 12-hour shift, was $270 for manning, $65 for supplies, and $64 for coal. On two 12-hour shifts, the monthly cost was $533 for manning, $100 for supplies, and $96 for coal. About 100,000 passengers were carried during the boat's period of service, and the total cost was about $37,500.

For the major part of the period embraced by this paper, B. H. M. Hewett, M. Am. Soc. C. E., served as General Resident Engineer, in charge of the Field Work as a whole.

W. L. Brown, M. Am. Soc. C. E., was at first Resident Engineer of the work constructed from the Manhattan Shaft, while H. F. D. Burke, M. Am. Soc. C. E., was Resident Engineer of the work constructed from the Weehawken Shaft. After the meeting of the shields, Mr. Burke left to take up another appointment, and from that time Mr. Brown acted as Resident Engineer.

It may be said, without reflecting in any way on the manufacturers, that the high standard of all the metal materials also testified to the efficient inspection conducted under the direction of Mr. J. C. Naegeley.

It is impossible to close this brief account of these tunnels without recording the invaluable services at all times rendered by the members of the Company's field staff. Where all worked with one common aim it might seem invidious to single out names, but special credit is due to the following Assistant Engineers: Messrs. H. E. Boardman, Assoc. M. Am. Soc. C. E., W. H. Lyon, H. U. Hitchcock, E. R. Peckens, H. J. Wild, Assoc. M. Am. Soc. C. E., J. F. Sullivan, Assoc. M. Am. Soc. C. E., and R. T. Robinson, Assoc. M. Am. Soc. C. E. Mr. C. E. Price was in charge of the cement tests throughout the entire period, and brought to his work not only ability but enthusiasm. Mr. H. D. Bastow was in charge of the photographic work, and Mr. A. L. Heyer of the cost account records, in which he was ably seconded by Mr. A. P. Gehling, who, after Mr. Heyer's departure, finished the records and brought them into their final shape. The organization of the Company's field engineering staff is shown graphically by Fig. 24.

FIELD ORGANIZATION OF THE O'ROURKE ENGINEERING CONSTRUCTION COMPANY FOR THE BUILDING OF THE PENNSYLVANIA RAILROAD TUNNELS INTO NEW YORK CITY--NORTH RIVER DIVISION. SECTIONS GY EAST, GY WEST SUPPLEMENTARY, GY WEST, AND CO.

GENERAL SUPERINTENDENT. | +------------------------+-------+--+ | | | (General, Surface and Office) (Excavation | ---------------+------------- of Land | | Tunnels) | ASSISTANT GENERAL SUPERINTENDENT | | | GENERAL | | ROCK SUPT | +------------+------------+ | | | | | Tunnel | FIELD SURFACE DESPATCH Supts | OFFICE BOAT Tunnel | Foreman | Civil Head Captain Foremen | Engineer Carpenter Engineer Timbermen | Inspectors Foreman Deck Hands Timbermen | Bookkeepers Carpenter Timbermen's | Paymaster Carpenters Helpers | Head Carpenters' Foremen | Storekeeper Helpers Drillers | Storekeepers Blacksmiths Drillers | Timekeepers Blacksmiths' Foremen | Telephone Helpers Muckers | Operators Foreman Pipe Fitters | Office Boys Laborers Pipe Fitters' | Messengers Laborers Helpers | Janitors Disposal Electricians | Trimmers Hoist | Teamsters Engineers | Signalmen | Muckers | Nippers | Water Boys | | | -------------+--------+-------------------------+--------+----------+ | | | | (Shield Tunnel Driving) (Masonry (Power (Medical | Lining-Rock Plant) Supervision) GENERAL TUNNEL SUPERINTENDENT and River | | | Tunnels) MASTER CHIEF MED ASSISTANT SUPERINTENDENTS | MECHANIC OFFICER | | | | | | | +--------+------------+---------+ | Foreman | EXCAVATION | | GENERAL | Electrician | | IRON LINING CAULKING AND | | Electricians | General | GRUMMETING | | Engineers | Foremen Foremen | Pipefitters | Foreman Resident Foremen Erector Foremen Pipefitters' | Machinist Doctor Drillers Runners Caulkers Helpers | Machinists Drillers Ironmen Grummeters Electricians | Machinists' Powdermen Boltmen Electricians'| Helpers Foremen Helpers | Firemen Timbermen Trackmen | Oilers Timbermen Lockmen | Pumpmen Foremen Transport | Hoist Engineers Muckers Foreman | Signalmen Muckers Transport | Shieldmen Laborers | Laborers Watchmen | Nippers | Water Boys | GENERAL CONCRETE SUPERINTENDENT | TUNNEL SUPERINTENDENTS | +-----------+------------+----------------++-----------+ | | | | | CONCRETE BRICKWORK DUCTS WATER-PROOFING GENERAL

Foremen Foremen Foremen Foremen Pipefitters Carpenters Bricklayers Duct-layers Waterproofers Pipefitters' Carpenters' Bricklayers' Helpers Helpers Laborers Electricians Mixer Carpenters Electricians' Foremen Carpenters' Helpers Mixer Helpers Transport Laborers Foremen Concrete Transport Laborers Laborers Watchmen

FIG. 24.

_Contractor's Organization._--The contracting firm which did the work described in this paper was the O'Rourke Engineering Construction Company, of New York City. The President of this Company was John F. O'Rourke, M. Am. Soc. C. E., the Vice-President was F. J. Gubelman, Assoc. M. Am. Soc. C. E. The General Superintendent was Mr. George B. Fry, assisted by J. F. Sullivan, Assoc. M. Am. Soc. C. E. The duties of General Tunnel Superintendent fell to Mr. Patrick Fitzgerald. The generally pleasant relations existing between the Company and the contractor's forces did much to facilitate its execution.

The organization of the Contractor's field staff is shown on Fig. 25.

PENNSYLVANIA TUNNEL AND TERMINAL RAILROAD COMPANY. NORTH RIVER DIVISION.

SECTIONS GY EAST, GY WEST SUPPLEMENTARY, GY WEST, GJ, AND I, _I. E._, FROM 10TH AVENUE, MANHATTAN, TO THE WEEHAWKEN SHAFT, FIELD ENGINEERING STAFF ORGANIZATION.

GENERAL RESIDENT ENGINEER | +-----------------+------------+------------+---------+----+ | | | | | | (Material Testing) (Photography) | (Cost Records) |(Office) Cement Inspector Photographer | Recording Clerk | Clerks Asst Cement | Asst Recording |Messengers Inspectors | Clerks | (Construction) | | (Despatch Boat) +----------------+ Captain | Engineers RESIDENT ENGINEERS Deckhands (Two during driving of Shield-driven Messengers Tunnels, and one subsequently.) | +---------------------+---+------------------+ | | | (Inspection) (Alignment) (Office) Assistant Engineers Assistant Engineers Draftsmen Chief Tunnel Chiefs of Parties Field Office Inspector Instrumentmen Clerks Tunnel Inspectors Rodmen Cement Surface Inspectors Chainmen Warehousemen Clerks Laborers Janitors

FIG. 25

In conclusion, the writers cannot forego the pleasure of expressing their deep obligation to Samuel Rea, M. Am. Soc. C. E., as representing the Management of the Company, to the Chief Engineer, Charles M. Jacobs, M. Am. Soc. C. E., and to James Forgie, M. Am. Soc. C. E., Chief Assistant Engineer, for their permission to write this paper, and also to all the members of the field office staff for their great and unfailing assistance in its preparation.