Data from VGN 8 - 1951 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also DeGolyer, Volume 68, pp. 377+. Works number was 55100 in September 1921.
After the 2-8-8-8-4 Triplex had proved a flat-footed failure (Locobase 3301), Baldwin took the huge boiler and placed it on a 2-8-8-0 engine unit. The cylinders matched those of the 1913 ADs, but the tube and flue layout remained that of the Triplex boiler. Firebox heating surface included 72 sq ft (6.7 sq m) of arch tubes. The firebox also had a Gaines combustion chamber and was fed by a Duplex automatic stoker. (For a full description of the Gaines combustion chamber's intended effect on combustion, see Locobase 4228.) The resulting combination of boiler and superheater put the AF in a very small class of steam locomotives with over 10,000 sq ft (929 sq m) of combined heating surface.
The high-pressure cylinders powering the rear driver set were fed by 16" (406 mm) piston valves while the low-pressure cylinders under the smokebox were supplied by Allen-Richardson balanced slide valves.
The ruling grade for AF service was the 12 mile (19.3 km) portion of the Elmore to Clark's Gap segment that inclined at 2.07%. The single AF gained a trailing truck in November 1942 to become a 2-8-8-2 and operated until 1953.
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | Triplex reborn - AF |
| Locobase ID | 3566 |
| Railroad | Virginian (VGN) |
| Country | USA |
| Whyte | 2-8-8-0 |
| Number in Class | 1 |
| Road Numbers | 610 |
| Gauge | Std |
| Number Built | 1 |
| Builder | Baldwin |
| Year | 1921 |
| Valve Gear | Baker |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 30.50 / 9.30 |
| Engine Wheelbase (ft / m) | 50.50 / 15.39 |
| Ratio of driving wheelbase to overall engine wheelbase | 0.60 |
| Overall Wheelbase (engine & tender) (ft / m) | 90.92 / 27.71 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | |
| Weight on Drivers (lbs / kg) | 487,400 / 221,081 |
| Engine Weight (lbs / kg) | 526,190 / 238,676 |
| Tender Loaded Weight (lbs / kg) | 235,000 / 106,594 |
| Total Engine and Tender Weight (lbs / kg) | 761,190 / 345,270 |
| Tender Water Capacity (gals / ML) | 13,000 / 49.24 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 12 / 11 |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 102 / 51 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 56 / 1422 |
| Boiler Pressure (psi / kPa) | 200 / 1380 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 28" x 32" / 711x813 |
| Low Pressure Cylinders (dia x stroke) (in / mm) | 44" x 32" / 1118x813 |
| Tractive Effort (lbs / kg) | 108,416 / 49176.73 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.50 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | 365 - 2.25" / 57 |
| Flues (number - dia) (in / mm) | 65 - 5.25" / 133 |
| Flue/Tube length (ft / m) | 25 / 7.62 |
| Firebox Area (sq ft / m2) | 430 / 39.95 |
| Grate Area (sq ft / m2) | 108.20 / 10.06 |
| Evaporative Heating Surface (sq ft / m2) | 8120 / 754.65 |
| Superheating Surface (sq ft / m2) | 2059 / 191.36 |
| Combined Heating Surface (sq ft / m2) | 10,179 / 946.01 |
| Evaporative Heating Surface/Cylinder Volume | 356.08 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 21,640 |
| Same as above plus superheater percentage | 25,968 |
| Same as above but substitute firebox area for grate area | 103,200 |
| Power L1 | 9546 |
| Power MT | 345.43 |