US Army Transportation Corps 2-8-2 "Mikado" Locomotives in the USA

Class Details by Steve Llanso of Sweat House Media

Class S155 (Locobase 16330)

Data from 1947 Locomotive Cyclopedia and from CN's Newfoundland Railway locomotive diagram books supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also Joseph Bykofsky and Harold Larson, The Transportation Corps: Operations Overseas,United States Army in World War Two - The Technical Services (Washington, DC: Center for Military History, 1990), pp. 9-10.(Thanks to Steve Low for his 30 December 2017 email noting the transfer of five of the locomotives to the US Army Transportation Corps. Low followed up on 19 January 2018 with additional information from Tim Moriarity) .) Alco's works numbers were 69736-69740 in 1941.

Data is given for the firebox with two syphons contributing 38 sq ft (3.55 sq m) to the direct heating surface area; without the syphons, firebox heating surface was 118 sq ft (10.96 sq m)..

Steve Low reports (citing Tourette's United States Army Transportation Corps Locomotives) that locomotives originally meant for the Newfoundland Railway were instead bought for USATC service before delivery. Originally projected as NFLD 1009-1013, the quintet was delivered as USATC500-504, but were shipped to Newfoundland as planned after their completion in October 1941.

(For the rest of the class, see Locobase 960.)

By that time, says Bykovsky and Larson's account, the US Army had been creating bases on the island for about nine months and finding that a tough task. Among other problems, the NFLD was the "principal means of clearance from the ports to Army stations and to the main airport at Gander." But the railway was "of small capacity, its rolling stock was old and in poor condition, and heavy snowstorms from January to April often hampered the operation of trains."

As part of the Army's upgrade of Newfoundland facilities, the Army contributed "significant American financial assistance and a modest amount of equipment were furnished for the rehabilitation of the railway." Obviously, this quintet of modern Mikes met the needs handily, as they were specificially designed for the Newfoundland Railway.

Tim Moriarty's research at the US Army's Center of Military History found that $2.1 million was conveyed in November 1941 to the Newfoundland Railway through the Defense Supply Corporation. The five locomotives were funded under this agreement. Although they remained US Army property, a further agreement assigned the responsibility for maintaining them to the NFLD, "thus eliminating possible confusion which might have resulted from operations by two separate agencies."

Compared to the standard designs developed for overseas operations, however, they were smaller and ran on a unique gauge. At the end of the war, the USATC turned the engines over to the NFLD. They were all scrapped in the first half of 1957.

Principal Dimensions by Steve Llanso of Sweat House Media
Locobase ID16,330
RailroadUS Army Transportation Corps
Number in Class5
Road Numbers500-504
Number Built5
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)12.75 / 3.89
Engine Wheelbase (ft / m)29.25 / 8.92
Ratio of driving wheelbase to overall engine wheebase 0.44
Overall Wheelbase (engine & tender) (ft / m)55.75 / 16.99
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)117,400 / 53,252
Engine Weight (lbs / kg)151,570 / 68,751
Tender Loaded Weight (lbs / kg)104,000 / 47,174
Total Engine and Tender Weight (lbs / kg)255,570 / 115,925
Tender Water Capacity (gals / ML)5000 / 18.94
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)9 / 8.20
Minimum weight of rail (calculated) (lb/yd / kg/m)49 / 24.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)48 / 1219
Boiler Pressure (psi / kPa)200 / 13.80
High Pressure Cylinders (dia x stroke) (in / mm)18" x 24" / 457x610
Tractive Effort (lbs / kg)27,540 / 12491.95
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.26
Heating Ability
Firebox Area (sq ft / m2)153 / 14.21
Grate Area (sq ft / m2)35.20 / 3.27
Evaporative Heating Surface (sq ft / m2)1768 / 164.25
Superheating Surface (sq ft / m2)426 / 39.58
Combined Heating Surface (sq ft / m2)2194 / 203.83
Evaporative Heating Surface/Cylinder Volume250.12
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation7040
Same as above plus superheater percentage8378
Same as above but substitute firebox area for grate area36,414
Power L114,412
Power MT1082.55

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