In 1930, 14 Class S-2s (road numbers 2575 through 2588) came from Baldwin with 80" drivers. With 73" drivers, the S-1s were better suited for dual service, but the S-2s were truly passenger locomotives. The Class S-2s had 29 x 29 cylinders, a 225 psi boiler pressure, a weight of 420,900 lbs and a tractive effort of 58,300 pounds.
There is only one surviving GN "Northern", number 2584 at a depot in Havre, MT.
Class | Road Numbers | Year Built | Builder |
---|---|---|---|
S-1 | 2550-2555 | 1929 | Baldwin |
S-2 | 2575-2588 | 1930 | Baldwin |
Data from 1930 Locomotive Cyclopedia; see also DeGolyer, Vol 81 pp. 503+ . Works numbers were 60781-60782 in April 1929, 60807-60810 in May.
Heavy dual-service oil-burning engines. GN's signature improved Belpaire firebox was joined to a combustion chamber that contributed 108 sq ft (10.03 sq m) to the firebox heating surface. Unlike many other large superpower engines of the time, this design had no arch tubes or syphons. And the Elesco exhaust steam injector was less common than feed water heaters. It was rated at 10,000 US gallon capacity. Steam admission came through 14" (356 mm) piston valves. Only six built before design changed to lighter engine with high drivers (Locobase 262). They were nonetheless highly serviceable locomotives that remained in service until 1956 (2553), 1957, and 1958.
Data taken from DeGolyer, Vol 82, pp. 283+ and Great Northern locomotive diagram reproduced on Ben Ringnalda's [] website, last accessed 16 February 2007. See also Charles R Wood, Lines West (New York: Bonanza Books, 1967), pp. 88 inter alia; and The Great Northern Empire Then and Now website at [
], last accessed 3 July 2015.(Thanks to Chris Hohl for his 24 April 2015 email noting the use of coal in some GN S-2s and for callling attention to the high weights shown in the specs.) Data differs slightly from the 1930 Locomotive Cyclopedia specs. Works numbers were 61211-61216, 61224-61225, 61237-61242 in February and March 1930.
Principal Dimensions by Steve Llanso of Sweat House Media | ||
---|---|---|
Class | S-1 | S-2 |
Locobase ID | 261 | 262 |
Railroad | Great Northern (GN) | Great Northern (GN) |
Country | USA | USA |
Whyte | 4-8-4 | 4-8-4 |
Number in Class | 6 | 14 |
Road Numbers | 2550-2555 | 2575-2588 |
Gauge | Std | Std |
Number Built | 6 | 14 |
Builder | Baldwin | Baldwin |
Year | 1929 | 1930 |
Valve Gear | Walschaert | Walschaert |
Locomotive Length and Weight | ||
Driver Wheelbase (ft / m) | 19 / 5.79 | 20.75 / 6.32 |
Engine Wheelbase (ft / m) | 45.50 / 13.87 | 47.75 / 14.55 |
Ratio of driving wheelbase to overall engine wheelbase | 0.42 | 0.43 |
Overall Wheelbase (engine & tender) (ft / m) | 94.90 / 28.93 | 91.17 / 27.79 |
Axle Loading (Maximum Weight per Axle) (lbs / kg) | ||
Weight on Drivers (lbs / kg) | 273,700 / 124,148 | 247,300 / 112,174 |
Engine Weight (lbs / kg) | 472,120 / 214,150 | 420,900 / 190,917 |
Tender Loaded Weight (lbs / kg) | 375,780 / 170,451 | 326,560 / 148,125 |
Total Engine and Tender Weight (lbs / kg) | 847,900 / 384,601 | 747,460 / 339,042 |
Tender Water Capacity (gals / ML) | 22,000 / 83.33 | 17,250 / 65.34 |
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 5800 / 21,953 | 5800 / 21,953 |
Minimum weight of rail (calculated) (lb/yd / kg/m) | 114 / 57 | 103 / 51.50 |
Geometry Relating to Tractive Effort | ||
Driver Diameter (in / mm) | 73 / 1854 | 80 / 2032 |
Boiler Pressure (psi / kPa) | 250 / 17.20 | 225 / 15.50 |
High Pressure Cylinders (dia x stroke) (in / mm) | 28" x 30" / 711x762 | 29" x 29" / 737x737 |
Tractive Effort (lbs / kg) | 68,466 / 31055.69 | 58,305 / 26446.73 |
Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.00 | 4.24 |
Heating Ability | ||
Tubes (number - dia) (in / mm) | 61 - 2.25" / 57 | 38 - 2.25" / 57 |
Flues (number - dia) (in / mm) | 210 - 3.5" / 89 | 195 - 3.5" / 89 |
Flue/Tube length (ft / m) | 22 / 6.71 | 22 / 6.71 |
Firebox Area (sq ft / m2) | 401 / 37.25 | 401 / 37.25 |
Grate Area (sq ft / m2) | 102 / 9.48 | 97.75 / 9.08 |
Evaporative Heating Surface (sq ft / m2) | 5405 / 502.32 | 4781 / 444.33 |
Superheating Surface (sq ft / m2) | 2444 / 227.14 | 2265 / 210.50 |
Combined Heating Surface (sq ft / m2) | 7849 / 729.46 | 7046 / 654.83 |
Evaporative Heating Surface/Cylinder Volume | 252.81 | 215.65 |
Computations Relating to Power Output (More Information) | ||
Robert LeMassena's Power Computation | 25,500 | 21,994 |
Same as above plus superheater percentage | 33,405 | 29,032 |
Same as above but substitute firebox area for grate area | 131,328 | 119,097 |
Power L1 | 41,835 | 36,767 |
Power MT | 1347.90 | 1311.08 |