timating the number of the box which has been pulled.
Automatic recording devices in train dispatchers' offices and in the
office of the General Superintendent also note the number of the box
pulled.

The photograph on page 120 shows a typical fire alarm box.

CHAPTER VIII

ROLLING STOCK--CARS, TRUCKS, ETC.

The determination of the builders of the road to improve upon the best
devices known in electrical railroading and to provide an equipment
unequaled on any interurban line is nowhere better illustrated than in
the careful study given to the types of cars and trucks used on other
lines before a selection was made of those to be employed on the
subway.

All of the existing rapid transit railways in this country, and many
of those abroad, were visited and the different patterns of cars in
use were considered in this investigation, which included a study of
the relative advantages of long and short cars, single and multiple
side entrance cars and end entrance cars, and all of the other
varieties which have been adopted for rapid transit service abroad and
at home.

The service requirement of the New York subway introduces a number of
unprecedented conditions, and required a complete redesign of all the
existing models. The general considerations to be met included the
following:

High schedule speeds with frequent stops.

Maximum carrying capacity for the subway, especially at times of rush
hours, morning and evening.

Maximum strength combined with smallest permissible weight.

Adoption of all precautions calculated to reduce possibility of damage
from either the electric circuit or from collisions.

The clearance and length of the local station platforms limited the
length of trains, and tunnel clearances the length and width and
height of the cars.

The speeds called for by the contract with the city introduced motive
power requirements which were unprecedented in any existing railway
service, either steam or electric, and demanded a minimum weight
consistent with safety. As an example, it may be stated that an
express train of eight cars in the subway to conform to the schedule
speed adopted will require a nominal power of motors on the train of
2,000 horse power, with an average accelerating current at 600 volts
in starting from a station stop of 325 amperes. This rate of energy
absorption which corresponds to 2,500 horse power is not far from
double that taken by the heaviest trains on tru