Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Volume 11, p. 27. Works numbers were 6257, 6260 in June 1882; 6330 in August.
All three of these Moguls served for 25 years on the WM before being sold in April 1907 to Southern Iron & Equipment, the locomotive rebuilder/reseller that renumbered the trio 590-592. Each was then sold to a different lumber company beginning with 591 to Titusville Lumber in July 1907, then 592 to Henderson Lumber Company in August, and ending with 590 to Alexandria Lumber (Alexandria, La) in March 1908.
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | 21 |
| Locobase ID | 11794 |
| Railroad | Western Maryland (WM) |
| Country | USA |
| Whyte | 2-6-0 |
| Number in Class | 3 |
| Road Numbers | 21-23 |
| Gauge | Std |
| Number Built | 3 |
| Builder | Burnham, Parry, Williams & Co |
| Year | 1882 |
| Valve Gear | Stephenson |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 14.50 / 4.42 |
| Engine Wheelbase (ft / m) | 22.08 / 6.73 |
| Ratio of driving wheelbase to overall engine wheelbase | 0.66 |
| Overall Wheelbase (engine & tender) (ft / m) | |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | |
| Weight on Drivers (lbs / kg) | 66,000 / 29,937 |
| Engine Weight (lbs / kg) | 78,000 / 35,380 |
| Tender Loaded Weight (lbs / kg) | |
| Total Engine and Tender Weight (lbs / kg) | |
| Tender Water Capacity (gals / ML) | 2400 / 9.09 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 37 / 18.50 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 50 / 1270 |
| Boiler Pressure (psi / kPa) | 130 / 900 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 18" x 24" / 457x610 |
| Tractive Effort (lbs / kg) | 17,185 / 7794.99 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 3.84 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | 184 - 2" / 51 |
| Flues (number - dia) (in / mm) | |
| Flue/Tube length (ft / m) | 10.73 / 3.27 |
| Firebox Area (sq ft / m2) | 103 / 9.57 |
| Grate Area (sq ft / m2) | 16 / 1.49 |
| Evaporative Heating Surface (sq ft / m2) | 1135 / 105.48 |
| Superheating Surface (sq ft / m2) | |
| Combined Heating Surface (sq ft / m2) | 1135 / 105.48 |
| Evaporative Heating Surface/Cylinder Volume | 160.54 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 2080 |
| Same as above plus superheater percentage | 2080 |
| Same as above but substitute firebox area for grate area | 13,390 |
| Power L1 | 2528 |
| Power MT | 253.33 |