house manufactured the turbines and gears), it was des- 

 ignated 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 espe- 

 cially for the Museum (USNM 312935) and presented to it 

 by The Baldwin Locomotive Works early in 1946. The loco- 

 motive and tender, together 30 inches long, were built to a 

 scale of ^A 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 de- 

 veloped 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 be- 

 tween 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 per- 

 fectly the driving wheels, thus permitting a higher operating 

 speed than normally practical with a conventional locomo- 

 tive. 



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 diam- 

 eter 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, 



101 



