Data from DeGolyer, Vol 73, pp. 194. Works number was 57975 in September 1924.
Locobase 14952 describes the MW&S and the Consolidation Baldwin sold to the railroad in 1920. This Mikado increased the cylinder volume only slightly while rolling on taller drivers. The locomotive still traveled on 65 lb/yard (32.5 kg/metre) rail up 4.4% grades and around 18 degree curves (radii of 320 feet/97.5 metres).
A much longer boiler created more heating surface, both evaporative and superheater, which undoubtedly permitted longer, heavier hauls before running out of steam. Thirteen-inch (330 mm) piston valves supplied the cylinders.
Colonel Howard Hill's account of the development of the standard light 2-8-2 for the US Army says the S200 represented a conscious update of this engine after its suitability was suggested by Baldwin's Charles Krause; see Locobase 958.
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | 20 |
| Locobase ID | 15304 |
| Railroad | Montana, Wyoming & Southern |
| Country | USA |
| Whyte | 2-8-2 |
| Number in Class | 16 |
| Road Numbers | 20 |
| Gauge | Std |
| Number Built | 16 |
| Builder | Baldwin |
| Year | 1924 |
| Valve Gear | Walschaert |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 15 / 4.57 |
| Engine Wheelbase (ft / m) | 31.67 / 9.65 |
| Ratio of driving wheelbase to overall engine wheelbase | 0.47 |
| Overall Wheelbase (engine & tender) (ft / m) | 62.58 / 19.07 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | |
| Weight on Drivers (lbs / kg) | 154,000 / 69,853 |
| Engine Weight (lbs / kg) | 208,000 / 94,347 |
| Tender Loaded Weight (lbs / kg) | 143,000 / 64,864 |
| Total Engine and Tender Weight (lbs / kg) | 351,000 / 159,211 |
| Tender Water Capacity (gals / ML) | 7000 / 26.52 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 12 / 11 |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 64 / 32 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 56 / 1422 |
| Boiler Pressure (psi / kPa) | 190 / 1280 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 22" x 28" / 559x711 |
| Tractive Effort (lbs / kg) | 39,083 / 17727.77 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 3.94 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | 172 - 2" / 51 |
| Flues (number - dia) (in / mm) | 24 - 5.375" / 137 |
| Flue/Tube length (ft / m) | 19.25 / 5.87 |
| Firebox Area (sq ft / m2) | 187 / 17.37 |
| Grate Area (sq ft / m2) | 46.80 / 4.35 |
| Evaporative Heating Surface (sq ft / m2) | 2560 / 237.83 |
| Superheating Surface (sq ft / m2) | 533 / 49.52 |
| Combined Heating Surface (sq ft / m2) | 3093 / 287.35 |
| Evaporative Heating Surface/Cylinder Volume | 207.79 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 8892 |
| Same as above plus superheater percentage | 10,404 |
| Same as above but substitute firebox area for grate area | 41,570 |
| Power L1 | 11,935 |
| Power MT | 683.43 |