The "A" unit, described in this article, has a
total weight of about 381,000 pounds and is car-
ried in two six-wheel trucks. The starting tractive
force, at 30% adhesion, is 76,200 pounds. The total
length of the unit, over coupler knuckles, is 80
feet; the distance between truck center pins is 49
feet; and the total wheel base is 64 feet 4 inches.
The two power plants consist of 1,000-hp, Bald-
win diesel engines, direct-connected to Westing-
house generators. Traction motors and electrical
control equipment are products of Westinghouse
The two 1,000-hp power plants are located one
ahead of the other, on the center line of the loco-
motive, with the two generators facing each other.
An air compressor is located at the rear end of
each engine and the necessary air reservoirs and
intercooler are mounted beneath the underframe
of the locomotive. This system provides air for
operation of the brakes, pneumatic control equip-
ment and horn. Starting the diesel engine is ac-
complished by motoring the generator, using
current from the batteries.
Blowers for cooling the traction motors are
V-belt driven from the engine crankshaft. Fuel
and water tanks are suspended beneath the loco-
Motor driven fans, taking current from the main
generators, provide air for the engine cooling
system. Radiator shutters are thermostatically
controlled, eliminating the human element and
insuring proper operating temperatures for the
diesel engine, regardless of whether the locomo-
tive is operating in desert heat or arctic cold,
hauling a 50-car train or running light.
The engineman's operating compartment is lo-
cated in the nose of the "A" unit and at the oppo-
site end is the steam heat generating equipment
for cab and train heating.
The underframe of the locomotive is a welded
structure fabricated from steel plates and shapes.
The principal longitudinal and transverse mem-
bers are I section. The superstructure is of the
truss type, welded to the underframe to form an
integral unit, and the steel cab sheets are welded
to the framing.
Hatches in the roof permit the removal of either
power plant, and added maintenance conve-
nience is provided by hinged covers which permit
piston and liner removal without the necessity of
taking off the main hatches. A hatch is provided
for removal of the steam generator.
The operator's compartment has fixed front win-
dows and combination hinged and sliding side
windows, all fitted with shatterproof glass. Front
windows are equipped with windshield wipers,
defroster fans and sun visors. The cab floor is cov-
ered with linoleum and comfortable heat is main-
tained, even during the coldest weather, by means
of steam radiators. Upholstered, adjustable seats