This Consolidation design is bigger than the Standard 160 and may have been specially built for the US Army Transportation Corps' operation in Alaska. Its cylinders are larger by 2" in diameter, the grate had 2 sq ft greater area, and the boiler was slightly larger as well.
The MRS diagram shows that the class had 10"-diameter piston valves. This diagram states that the tractive effort at 77% was 37,100 lb, which is true only if the driver diameter is 50" - the sketch shows 57". Since the Alaskan site gives 50" as the diameter, the diagram seems to have been in error in that dimension. In addition the driving wheelbase measures 15' 6". Clearly, the diagram must be referring to a variant with taller drivers.
The builder's numbers are consecutive as were the USATC numbers, but the ARR jumbled them a bit, to wit:
Lima USTC ARR
7875 6994 505
7876 6995 506
7877 6996 504
7879 6998 501
7880 6999 502
7881 10 503. Apparently this locomotive came later, in 1946-1947, possibly as a replacement for 6997?
The class was later renumbered 401-406.
| Specifications | |
|---|---|
| Class | 501 |
| Locobase ID | 6426 |
| Railroad | Alaska Railroad |
| Whyte | 2-8-0 |
| Road Numbers | 501-506 |
| Gauge | Std |
| Builder | Lima |
| Year | 1942 |
| Valve Gear | Walschaert |
| Locomotive Length and Weight | |
| Driver Wheelbase | 14.50' |
| Engine Wheelbase | 23.08' |
| Ratio of driving wheelbase to overall engine wheebase | 0.63 |
| Overall Wheelbase (engine & tender) | 56.74' |
| Axle Loading (Maximum Weight per Axle) | |
| Weight on Drivers | 161300 lbs |
| Engine Weight | 180000 lbs |
| Tender Light Weight | 124700 lbs |
| Total Engine and Tender Weight | 304700 lbs |
| Tender Water Capacity | 6500 gals |
| Tender Fuel Capacity (oil/coal) | 10 tons |
| Minimum weight per yard of rail on which locomotive could run | 67.21 lb rail |
| Geometry Relating to Tractive Effort | |
| Driver Diameter | 50" |
| Boiler Pressure | 210 psi |
| Cylinders (dia x stroke) | 21" x 26" |
| Tractive Effort | 40934 lbs |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 3.94 |
| Heating Ability | |
| Firebox Area | 156 sq. ft |
| Grate Area | 43 sq. ft |
| Evaporative Heating Surface | 1937 |
| Superheating Surface | 467 |
| Combined Heating Surface | 2404 |
| Evaporative Heating Surface/Cylinder Volume | 185.84 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 9030 |
| Same as above plus superheater percentage | 10784.16 |
| Same as above but substitute firebox area for grate area | 39123.94 |
| Power L1 | 11618.66 |
| Power MT | 635.21 |
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