The section of the Pennsylvania Railroad Tunnel work described in this
paper is that lying between Tenth Avenue, New York City, and the large
shaft built by the Company at Weehawken, N. J., and thus comprises the
crossing of the North or Hudson River, the barrier which has stood for
such a long time between the railroads and their possession of terminal
stations in New York City. The general plan and section, Plate XXVIII,
shows the work included.
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.