The
object of these tests was the determination of coal economy.
Tests with a Prony brake showed that the motor developed 128
H.P. The piece of track on which the experiments were conducted
embraced 2,200 ft. of level track and 1-8/10 miles of gradients,
varying from 11-3/10 to 98-7/10 ft. per mile, while at Thirtieth
street the station is at the foot of the steepest grade, thus
testing to the utmost the tractive capacity of the motor. The
experiments were begun in October, 1888, and carried on between
the hours of 9 P.M. and 4 A.M., beginning with one or two cars,
the load being increased nightly until it was finally made up of
eight coaches of 12 tons each, which were hauled up the 98 ft.
grade at a speed of 71/2 miles per hour, the entire distance being
covered at the rate of 14-6/10 miles per hour. The maximum speed
obtained on level with that train was 16.36 miles per hour.
Seventy trips were subsequently made with a 70 ton train
operated between the steam trains under 3 minutes headway, but
the work was considered too critical on account of the absence
of suitable brakes. A number of experiments made about this time
showed that the mean speed with a three-car train running
express on the up-town track was about 24 miles per hour,
although the ability of the motor on a level with a similar
train was nearly 28 miles per hour.
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