Small superheated, oil-burning Consolidation with 8" (203 mm) piston valves and relatively short tubes and flues.
Works 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.
This Consolidation design is bigger than the Standard 160 (Locobase 433) 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" (254 mm) 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" (4.72 m) . Clearly, the diagram must be referring to a variant with taller drivers.
Apparently the last locomotive came later, in 1946-1947, possibly as a replacement for 6997? In any case, the 503 was destroyed in a fire in 1951.
Spain's Ferrocarril de Langreo bought several cast-off ARR steam locomotives. Except for ARR 503, this entire class was sold to the FC de L and arrived at Gijon on 25 February 1958 and renumbered 401-406. 401 was kept as a spare, but the other four were quickly found to be too big for the Langreo's loading gauge, wrote , and the railway had to rework the locomotives: "Modifications included cut tender tops, cabs with lowered roofs and slope sides and front pilot substituted by Langreo hook couplings and buffers."
So converted, the locomotives went into service one by one with 404 starting in April 1960 and finishing with 402 ending its mods in March 1963. All ran up service "mileage" (kilometrage?) exceeding 36,700 km each (22,791 miles) with 405 accumulating 38,089 km (23,653 miles). All were withdrawn in 1968 when steam operations ended and were soon scrapped.
|Specifications by Steve Llanso of Sweat House Media|
|Railroad||American Railroad||Alaska Railroad|
|Number in Class||1||6|
|Locomotive Length and Weight|
|Ratio of driving wheelbase to overall engine wheebase||0.63||0.63|
|Overall Wheelbase (engine & tender)||46.31'||56.74'|
|Axle Loading (Maximum Weight per Axle)|
|Weight on Drivers||81000 lbs||161300 lbs|
|Engine Weight||88500 lbs||180000 lbs|
|Tender Light Weight||66500 lbs||124700 lbs|
|Total Engine and Tender Weight||155000 lbs||304700 lbs|
|Tender Water Capacity||3000 gals||6500 gals|
|Tender Fuel Capacity (oil/coal)||1500 gals||10 tons|
|Minimum weight of rail (calculated)||34 lb/yard||67 lb/yard|
|Geometry Relating to Tractive Effort|
|Boiler Pressure||160 psi||210 psi|
|Cylinders (dia x stroke)||16" x 20"||21" x 26"|
|Tractive Effort||18819 lbs||40934 lbs|
|Factor of Adhesion (Weight on Drivers/Tractive Effort)||4.30||3.94|
|Firebox Area||95 sq. ft||156 sq. ft|
|Grate Area||15 sq. ft||43 sq. ft|
|Evaporative Heating Surface||823 sq. ft||1937 sq. ft|
|Superheating Surface||155 sq. ft||467 sq. ft|
|Combined Heating Surface||978 sq. ft||2404 sq. ft|
|Evaporative Heating Surface/Cylinder Volume||176.83||185.84|
|Computations Relating to Power Output (More Information)|
|Robert LeMassena's Power Computation||2400||9030|
|Same as above plus superheater percentage||2784||10746|
|Same as above but substitute firebox area for grate area||17632||38984|