Data based on [] (visited 26 December 2004). Works numbers were 64996-64997 in November 1923.
The diagram indicates that these were based on the USRA heavy articulated (Locobase 330), but were intended to negotiate 22-deg curves. As a result, each set of drivers had a 3" (76.2 mm) longer wheelbase and the engine wheelbase measured a total of 3" longer. One source states that they were originally meant for the Clinchfield, which took ten with slightly shorter wheelbases (Locobase 1321).
The diagram is less informative about heating surfaces, giving only the total of evaporative and superheater combined as 8,332 sq ft (774.07 sq m). This is 737 sq ft (68.44 sq m) more than the USRA standard.
Principal Dimensions by Steve Llanso of Middle Run Media | |
---|---|
Class | 20 |
Locobase ID | 6441 |
Railroad | Interstate (IRR) |
Country | USA |
Whyte | 2-8-8-2 |
Number in Class | 2 |
Road Numbers | 20-21 |
Gauge | Std |
Number Built | 2 |
Builder | Alco-Brooks |
Year | 1923 |
Valve Gear | Walschaert |
Locomotive Length and Weight | |
Driver Wheelbase (ft / m) | 31.50 / 9.60 |
Engine Wheelbase (ft / m) | 58 / 17.68 |
Ratio of driving wheelbase to overall engine wheelbase | 0.54 |
Overall Wheelbase (engine & tender) (ft / m) | 94.25 / 28.73 |
Axle Loading (Maximum Weight per Axle) (lbs / kg) | 62,000 / 28,123 |
Weight on Drivers (lbs / kg) | 486,500 / 220,673 |
Engine Weight (lbs / kg) | 541,000 / 245,394 |
Tender Loaded Weight (lbs / kg) | 209,200 / 94,892 |
Total Engine and Tender Weight (lbs / kg) | 750,200 / 340,286 |
Tender Water Capacity (gals / ML) | 12,000 / 45.45 |
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 16 / 15 |
Minimum weight of rail (calculated) (lb/yd / kg/m) | 101 / 50.50 |
Geometry Relating to Tractive Effort | |
Driver Diameter (in / mm) | 57 / 1448 |
Boiler Pressure (psi / kPa) | 240 / 1650 |
High Pressure Cylinders (dia x stroke) (in / mm) | 25" x 32" / 635x813 |
Low Pressure Cylinders (dia x stroke) (in / mm) | 39" x 32" / 991x813 |
Tractive Effort (lbs / kg) | 101,465 / 46023.80 |
Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.79 |
Heating Ability | |
Tubes (number - dia) (in / mm) | |
Flues (number - dia) (in / mm) | |
Flue/Tube length (ft / m) | |
Firebox Area (sq ft / m2) | |
Grate Area (sq ft / m2) | 96.50 / 8.97 |
Evaporative Heating Surface (sq ft / m2) | |
Superheating Surface (sq ft / m2) | |
Combined Heating Surface (sq ft / m2) | |
Evaporative Heating Surface/Cylinder Volume | |
Computations Relating to Power Output (More Information) | |
Robert LeMassena's Power Computation | 23,160 |
Same as above plus superheater percentage | 23,160 |
Same as above but substitute firebox area for grate area | |
Power L1 | |
Power MT |