Transactions of the American Society of Civil Engineers, Vol. LXVIII, Sept. 1910 | Page 2

account of the restricted area
at the shaft sites, where a steam plant would have occupied
considerable space of great value for other purposes. The installation of
a steam plant at the Intermediate Shafts, which were located in a
high-class residential district, would have been highly objectionable to
the neighboring property owners, on account of the attendant noise,
smoke, and dirt, and, in addition, the cost of the transportation of fuel
would have been a serious burden. Except for the forges and, toward
the last, the steam locomotives, not a pound of coal was burned on the
work. The use of the bucket and telpher also eliminated most of the
objectionable noise incident to the transfer of spoil from tunnel cars to
ordinary wagons at the shaft sites. Power plants were installed at the
North Shaft near First Avenue and at the rear of the 33d Street
Intermediate Shaft.
First Avenue Plant.--Fig. 1, Plate LVIII, is a general view of the First
Avenue plant. The power-house at the corner of 34th Street and First
Avenue supplied compressed air for operating drills, shovels, pumps,
and hoists in the tunnels driven from the river shafts, and in it three
Laidlaw-Dunn-Gordon compressors were installed. The largest was a
32 by 20 by 30-in., two-stage, cross-compound, direct-connected to a
Fort Wayne 480 h.p., 230-volt, direct-current, constant-speed motor run
at 100 rev. per min. This compressor was rated at 2,870 cu. ft. of free
air per minute at a pressure of 100 lb. It was governed by throttling the
suction, the governor being controlled by the pressure in the air
receiver and the motor running continuously at a constant speed. The
two others were of similar type, one was 22-1/2 by 14 by 18-in., rated
at 1,250 cu. ft. of free air at a pressure of 100 lb., the other was 16 by
10 by 18-in., rated at 630 cu. ft. They were fitted with 9-ft. fly-wheels,
and were driven at 150 rev. per min. by 105-h.p., General Electric,
220-volt, compound-wound, direct-current motors running at 655 rev.
per min. The larger of these two compressors was driven by two of the
motors belted in tandem, and the smaller was belt-connected to a third

motor. The compressors were water-jacketed and had small
inter-coolers, the water supply for which was itself cooled in a Wheeler
Condenser and Engineering Company's water-cooling tower. The pump
and the blower operating it were electrically driven.
The telphers, used for hoisting muck from the tunnels and for lowering
supplies, were each hung from single rails on a timber trestle, about 40
ft. high, spanning and connecting the two shafts. One machine was
provided for each shaft, and where their tracks crossed 33d Street they
were separated sufficiently to permit the machines to pass each other.
At this point, and covering the street, a large platform was provided, on
which the trucks were loaded and unloaded (Fig. 2, Plate LVIII), and
from which they descended by an incline on First Avenue leading south
to 32d Street. The platform also covered practically all the yard at the
South Shaft and materially increased the available working area. The
telphers were built by the Dodge Cold Storage Company, and were
operated by a 75-h.p. General Electric motor for hoisting and a 15-h.p.
Northern Electric Company motor for propulsion. Their rated lifting
capacity was 10,000 lb. at a speed of 200 ft. per min.
The carpenter shop and machine-shop, both of which served the entire
work, were conveniently located in small buildings on the loading
platform. In the former the saws were each run independently by small
electric motors suspended under the platform. The heavy forms and
form carriages used in lining the tunnels with concrete were fabricated
and stored on the platform outside. The machine-shop lathes, etc., were
all belted to one shaft driven by an 8-h.p. General Electric motor.
Above the machine-shop was a locker-room and below it on the street
level was the main blacksmith shop for the work. Subsidiary
blacksmith shops were located at each of the other shafts. The
storeroom and additional locker-rooms were located above the
power-plant in the North Shaft yard, and isolated from the other
structures was a small oil-house. Additional storage space was provided
by the contractor on 32d Street just west of First Avenue by renting
three old buildings and the yards in the rear of them and of the Railroad
Company's cement warehouse adjacent. Here electric conduits, pipe,
castings, and other heavy and bulky supplies were stored.

During excavation the headings were supplied with forced ventilation
through 12-in. and 14-in. No. 16, spiral-riveted, asphalted pressure
pipes, canvas extensions being used beyond the ends of the pipes. A No.
4 American Blower, located at the top of each shaft and driven by a
15-h.p. General Electric motor, supplied the