A radical departure from the usual design for a coal-burning steam
locomotive, and the first of its type built in this country, was the
noncondensing geared steam-turbine locomotive built jointly by The
Baldwin Locomotive Works and the Westinghouse Electric and Manufacturing
Co. Constructed in 1944 at Baldwin’s Eddystone plant (Westinghouse
manufactured the turbines and gears), it was designated Pennsylvania
Railroad Co. class S-2 locomotive _No. 6200_.
This locomotive, combining the work of two pioneers in the railroad
equipment field, is represented in the Museum collection by a
nonoperable model (figure 80) made especially for the Museum (USNM
312935) and presented to it by The Baldwin Locomotive Works early in
1946. The locomotive and tender, together 30 inches long, were built to
a scale of ¼ inch to the foot by Minton Cronkhite of Pasadena, Calif.
Two steam turbines, similar to the type that drive the larger fighting
ships of the U.S. Navy, powered the original locomotive. The more
complex and powerful of the two, the forward-drive turbine, developed a
maximum of 7,250 horsepower and was at all times engaged with the
wheels. (Although 6,500 horsepower has usually been the quoted figure
for the forward-drive turbine, 7,250 was actually developed on October
22, 1946, at the Altoona Locomotive Testing Plant.) The simpler one, for
reverse only, developed 1,500 horsepower and was normally disengaged
from the driving wheels except while actually being used.
The boiler, frame, trucks, and driving wheels were of the conventional
type, the most notable visible difference between the locomotive and
those of other types being the absence of cylinders, valve motion, and
their accompanying parts. Because of the elimination of piston rods and
other reciprocating parts it was possible to balance almost perfectly
the driving wheels, thus permitting a higher operating speed than
normally practical with a conventional locomotive.
The weight of the locomotive alone was 580,000 pounds, and its forward
tractive force was 70,500 pounds. A 6-8-6 wheel arrangement was
employed, the driving wheel diameter was 68 inches, and a speed of 100
miles an hour was possible. The working steam pressure was 310 pounds
per square inch. Bituminous coal served as the fuel. A detailed and well
illustrated description of this locomotive appears in the magazine
“Baldwin” (for the fourth quarter of 1944).
The locomotive covered 103,050 miles in passenger service, and was then
set aside on June 11, 1949, because it was in need of repairs to the
firebox and flues, and also to the turbines, oil pumps, and gears. At
that time all passenger service on the Pennsylvania was being changed to
diesel-electric operation, so the locomotive was ultimately scrapped on
May 29, 1952.
[Illustration: Figure 80.—Model of Baldwin-Westinghouse geared
steam-turbine locomotive, 1944.]