Transactions of the American Society of Civil Engineers, Vol. LXVIII, Sept. 1910 / The New York Tunnel Extension of the Pennsylvania Railroad. / The North River Tunnels. Paper No. 1155

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.
AMERICAN SOCIETY OF CIVIL ENGINEERS
INSTITUTED 1852
Paper No. 1155
By B. H. M. Hewett and W. L. Brown, Members, Am. Soc. C. E.
This paper is written from the point of view of those engaged by the Chief Engineer of the Railroad Company to look after the work of construction in the field. The history of the undertaking is not included, the various phases through which many of the designs and plans passed are not followed, nor are the considerations regarding foundations under the subaqueous portions of the tunnels and the various tests made in connection with this subject set out, as all these matters will be found in other papers on these tunnels.
This paper only aims to describe, as briefly as possible, the actual designs which were finally adopted, the actual conditions met on the ground, and the methods of construction adopted by the contractors.

For easy reference, and to keep the descriptions of work of a similar character together, the subject will be treated under the four main headings, viz.: Shafts, Plant, Land Tunnels, and River Tunnels.
It is not intended to give much length to the description of the Shafts or the Land Tunnels, as more interest will probably center in the River Tunnels.
The shafts did not form part of the regular tunnel contract, but were built under contract by the United Engineering and Contracting Company while the contract plans for the tunnel were being prepared. In this way, when the tunnel contracts were let, the contractor found the shafts ready, and he could get at his work at once.
The details of the shafts will now be described briefly.