Transcribers' Notes:
Some tables don't sum to the numbers indicated; no corrections have been made. All numbers are from the original.
Minor inconsistencies in hyphenation have been retained.
[A]Presented at the meeting of June 1st, 1910.
The section of the Pennsylvania Railroad Tunnel work describedin this paper is that lying between Tenth Avenue, New York City,and the large shaft built by the Company at Weehawken, N. J., andthus comprises the crossing of the North or Hudson River, the barrierwhich has stood for such a long time between the railroads and theirpossession of terminal stations in New York City. The general planand section, Plate XXVIII, shows the work included.
This paper is written from the point of view of those engaged bythe Chief Engineer of the Railroad Company to look after the workof construction in the field. The history of the undertaking is notincluded, the various phases through which many of the designs andplans passed are not followed, nor are the considerations regardingfoundations under the subaqueous portions of the tunnels and thevarious tests made in connection with this subject set out, as allthese matters will be found in other papers on these tunnels.
This paper only aims to describe, as briefly as possible, the actualdesigns which were finally adopted, the actual conditions met on theground, and the methods of construction adopted by the contractors.
For easy reference, and to keep the descriptions of work of asimilar character together, the subject will be treated under the fourmain headings, viz.: Shafts, Plant, Land Tunnels, and River Tunnels.
It is not intended to give much length to the description of theShafts or the Land Tunnels, as more interest will probably center inthe River Tunnels.
The shafts did not form part of the regular tunnel contract, butwere built under contract by the United Engineering and ContractingCompany while the contract plans for the tunnel were being prepared.In this way, when the tunnel contracts were let, the contractor foundthe shafts ready, and he could get at his work at once.
Two shafts were provided, one on the New York side and one on the NewJersey side. Their exact situation is shown on Plate XXVIII. They wereplaced as near as possible to the point at which the disappearance ofthe rock from the tunnels made it necessary to start the shield-drivenportion of the work.
The details of the shafts will now be described briefly.
The Manhattan Shaft.—The Manhattan Shaft is located about 100ft. north of the tunnel center; there was nothing noticeable about itsconstruction. General figures relating to both shafts are given inTable 1.
The Weehawken Shaft.—The Weehawken Shaft is shown in Fig. 1.This, as will be seen from Table 1, was a co