Alco delivered the first 15 S (700-714), works numbers 68646-68653 in September 1934, 68654-68658 in October, and 68659-68660 in November.
Eight years later, Lima began producing three more sub-classes, which differed from the S class in little more than weight.:
S-1 (715-739), works numbers 7860-7867 in June 1942, 7868-7874 in July,
8003-8007 in March 1943, 8008-8009 in April, and 8010-8012 in May
S-2 (740-769), works numbers 8414-8428 in January 1944, 8663- 8670 in August,
and 8671-8677 in September. Roller bearings on the driving axles.
S-3 (770-779), works numbers 9371-9373 in March 1949, 9374-9376 in April, and 9377-9380 in May.
Firebox had two thermic syphons offering a total of 98 sq ft (9.3 sq m) of heating surface and two arch tubes with an additional 19 sq ft (1.75 sq m). Piston valves measured 14" (356 mm) in diameter, had 8" (203 mm) of travel, a lead of 3/16" (5.1 mm), and lap of 1 11/16"(42.9 mm). S-3 weight on drivers 266,000 lb (120,656 kg), engine weight 444,300 (201,531 kg), Factor of adhesion slightly higher.
The NPS study notes that William Black designed several of the best-known and most highly regarded freight engines of the Superpower era. After designing the Erie's 2-8-4s, he moved to the Chesapeake & Ohio and drafted the lines for the C&O's T1 2-10-4s (which would be duplicated by the Pennsylvania as their J1s). He headed the Van Swearingen Roads' Advisory Mechanical Committee, which oversaw design for the Chessie, its subsidiary the Hocking Valley, the Nickel Plate, and the Pere Marquette.
The Nickel Plate's Berkshire design emerged from the AMC in 1934 as a "mathematically scaled-down version of the C&O's 2-10-4." The NPS account quotes Gene Huddleston's verdict that the S class was "the greatest 2-8-4 ever to take the rails."
All of the S class had Worthington Type 5 SA feed water heaters, Elesco Type E superheaters, Standard Type MB stokers, Precision Type F-3 reverse gear, and 14" (356 mm) piston valves.
See Railfan & Railroad, March 1994, for a long article by Rich Melvin in which he recounts excursion runs with 765 that demonstrate just how powerful this class was. Melvin underscores the slogan coined by Lima's Will Woodard to explain the SuperPower concept: "Horsepower at Speed." The article contains an excellent analysis of the strengths of a steam horsepower curve (there's more the faster you go) and diesel horsepower (there's plenty at the low end, but the system reaches its upper limit at a speed well below an equivalent steam engine).
|Specifications by Steve Llanso of Sweat House Media|
|Railroad||New York, Chicago & St Louis (Nickel Plate)|
|Number in Class||80|
|Locomotive Length and Weight|
|Driver Wheelbase (ft)||18.25|
|Engine Wheelbase (ft)||42|
|Ratio of driving wheelbase to overall engine wheebase||0.43|
|Overall Wheelbase (engine & tender) (ft)||87.73|
|Axle Loading (Maximum Weight per Axle) (lbs)|
|Weight on Drivers (lbs)||251,100|
|Engine Weight (lbs)||428,500|
|Tender Loaded Weight (lbs)||356,000|
|Total Engine and Tender Weight (lbs)||784,500|
|Tender Water Capacity (gals)||22,000|
|Tender Fuel Capacity (oil/coal) (gals/tons)||22|
|Minimum weight of rail (calculated) (lb/yd)||105|
|Geometry Relating to Tractive Effort|
|Driver Diameter (in)||69|
|Boiler Pressure (psi)||245|
|High Pressure Cylinders (dia x stroke) (in)||25" x 34"|
|Tractive Effort (lbs)||64,135|
|Factor of Adhesion (Weight on Drivers/Tractive Effort)||3.92|
|Firebox Area (sq ft)||460|
|Grate Area (sq ft)||90.30|
|Evaporative Heating Surface (sq ft)||4772|
|Superheating Surface (sq ft)||1992|
|Combined Heating Surface (sq ft)||6764|
|Evaporative Heating Surface/Cylinder Volume||247.04|
|Computations Relating to Power Output (More Information)|
|Robert LeMassena's Power Computation||22,124|
|Same as above plus superheater percentage||28,539|
|Same as above but substitute firebox area for grate area||145,383|