Working Sites.
Before beginning a description of the tunnel work, it may be well to set
out in some detail the arrangements made on the surface for conducting
the work underground.
All the work was carried on from two shafts, one at Eleventh Avenue and
32d Street, New York City--called the Manhattan Shaft--and one at
Baldwin Avenue, Weehawken, N. J.--called the Weehawken Shaft.
[Illustration: WEEHAWKEN SHAFT. EXCAVATION FIG. 2.]
The characteristics of the two sites were radically different, and
called for different methods of handling the transportation problem. The
shaft site at Manhattan is shown on Plate XXX. It will be seen that
there was not much room, in fact, the site was too cramped for comfort;
the total area, including the space occupied by the old foundry, used
for power-houses, offices, etc., was about 3,250 sq. yd. This made it
necessary to have two stages, one on the ground level for handling
materials into the yard, and an overhead gantry on which the excavated
materials were handled off the premises. The yard at Weehawken was much
larger; it is also shown on Plate XXX. Its area was about 15,400 sq. yd.
in the yard proper, and there was an additional space of about 750 sq.
yd. alongside the wharf at the "North Slip," on the river front,
connected with the main portion of the yard by an overhead trestle.
All the cars at Manhattan were moved by hand, but at Weehawken two
electric locomotives with overhead transmission were used.
Power-House Plant.
At the Manhattan Shaft the power-house plant was installed on the ground
floor of the old foundry building which occupied the north side of the
leased area. This was a brick building, quite old, and in rather a
tumble-down condition when the Company took possession, and in
consequence it required quite a good deal of repair and strengthening
work. The first floor of the building was used by the contractor as
offices, men's quarters, doctor's offices, and so on, and on the next
one above, which was the top floor, were the offices occupied by the
Railroad Company's field engineering staff.
On the Weehawken side, the plant was housed in a wooden-frame,
single-story structure, covered with corrugated iron. It was rectangular
in plan, measuring 80 by 130 ft.
At both sides of the river the engines were bedded on solid concrete on
a rock foundation.
The installation of the plant on the Manhattan side occupied from May,
1904, to April, 1905, and on the Weehawken side from September, 1904, to
April, 1905. Air pressure was on the tunnels at the New York side on
June 25th, 1905, and on the Weehawken side on the 29th of the same
month.
[Illustration: PLATE XXIX. TRANS. AM. SOC. CIV. ENGRS. VOL. LXVIII, No.
1155. HEWETT AND BROWN ON PENNSYLVANIA R. R. TUNNELS: NORTH RIVER
TUNNELS. FIG. 1. FIG. 2.]
The plants contained in the two power-houses were almost identical,
there being only slight differences in the details of arrangement due to
local conditions. A list of the main items of the plant at one
power-house is shown in Table 2.