Transactions of the American Society of Civil Engineers, Vol. LXVIII, Sept. 1910

Transactions of the American
Society of
by James H. Brace
and Francis Mason

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Title: Transactions of the American Society of Civil Engineers, Vol.
LXVIII, Sept. 1910 The New York Tunnel Extension of the
Pennsylvania Railroad. The Cross-Town Tunnels. Paper No. 1158
Author: James H. Brace and Francis Mason
Release Date: August 13, 2006 [EBook #19037]
Language: English
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AMERICAN SOCIETY OF CIVIL ENGINEERS
INSTITUTED 1852
TRANSACTIONS
Paper No. 1158
THE NEW YORK TUNNEL EXTENSION OF THE
PENNSYLVANIA RAILROAD. THE CROSS-TOWN TUNNELS.[A]
BY JAMES H. BRACE AND FRANCIS MASON, MEMBERS, AM.
SOC. C. E.

In this paper, it is proposed to describe the construction of the tunnels
extending eastward from the easterly extension of the Terminal Station
to the permanent shafts east of First Avenue.
They were located under 32d and 33d Streets from the station to
Second Avenue, and thence, curving to the left, passed under private
property and First Avenue to the shafts, as described in a preceding
paper. Typical cross-sections of the tunnels are shown on Plate XII.[B]
On May 29th, 1905, a contract was entered into with the United
Engineering and Contracting Company for the performance of this
work. This contract provided that work on each pair of tunnels should
be carried on from two shafts. The first, here referred to as the First
Avenue Shafts, were located just east of that avenue and directly over
the line of the tunnels; the other two, called the Intermediate Shafts,
were located on private property to the north of each pair of tunnels in
the blocks between Fourth and Madison Avenues. It was originally
intended to do all the work of construction from these four shafts.
Workings were started both east and west from the Intermediate Shafts,

and those to the west were to be continued to the Terminal Station.
After the change of plans, described in a previous paper, it was decided
to sink a third shaft on each line. These were known as the West Shafts,
and were located between Sixth and Seventh Avenues. Finally, it was
found necessary to build a portion of the tunnels on each line west of
Sixth Avenue in open cut. The locations of the shafts are shown on
Plate XIV.[C]
The First Avenue shafts were built by S. Pearson and Son, Inc., for the
joint use of the two contractors, as described in the paper on the tunnels
under the East River. While the shafts were being sunk, the full-sized
tunnels were excavated westward by the contractor for the river tunnels
for a distance of 50 ft., and top headings for 50 ft. farther. By this
means, injury to the caissons and to the contractor's plant in the shafts
by the subsequent work in the Cross-Town Tunnels was avoided. The
west half of the shaft was for the exclusive use of the contractor for the
Cross-Town Tunnels.
CONTRACTOR'S PLANT.
The method of handling the work adopted by the contractor was,
broadly speaking, as follows: Excavation was usually carried on by
modifications of the top-heading and bench method, the bench being
carried as close to the face as possible in order to allow the muck from
the heading to be blasted over the bench into the full section. The spoil
was loaded into 3-yd. buckets (designed by the contractor and
hereinafter described), by steam shovels operated by compressed air,
and hauled to the shafts by electric locomotives. Electrically-operated
telphers, suspended from a timber trestle, hoisted the buckets, and,
traveling on a mono-rail track, deposited them on wagons for
transportation to the dock. Arriving at the dock, the buckets were lifted
by electrically-operated stiff-leg derricks and their contents deposited
on scows for final disposal. The spoil was thus transported from the
heading to the scow without breaking bulk.
When concreting was in progress, the spoil buckets were returned to
the shafts loaded with sand and stone. The concrete materials were
deposited in storage bins placed in the shafts, from which they were fed

to the mixers located at the foot of the shaft about on a level with the
crown of the tunnels. The concrete was transported to the forms in
side-dump, steel, concrete cars, hauled by the electric locomotives.
Electrical power was adopted largely on