USRA Light Mountain

The USRA Light Mountain was a USRA standard class of steam locomotive designed under the control of the United States Railroad Administration, the nationalized railroad system in the United States during World War I. This was the standard light freight locomotive of the USRA types, and was of 4-8-2 wheel arrangement in the Whyte notation, or 2′D1′ in UIC classification.

USRA Light Mountain
Type and origin Power type Steam Builder American Locomotive Company Baldwin Locomotive Works Total produced 47 (90 plus copies)
Specifications Configuration: ​  • Whyte 4-8-2  • UIC 2′D1′ h2 Gauge 4 ft 8 ^1⁄2 in (1,435 mm) Driver dia. 69 in (1,753 mm) Wheelbase Coupled: 18 ft 3 in (5.56 m) Locomotive: 40 ft 0 in (12.19 m) Loco & tender: 75 ft 8 ^1⁄2 in (23.08 m) Axle load 55,000 lb (24,900 kg) Adhesive weight 220,000 lb (99,800 kg) Loco weight 320,000 lb (145,100 kg) Tender weight 172,000 lb (78,000 kg) Total weight 492,000 lb (223,200 kg) Fuel type Coal Fuel capacity 32,000 lb (14,500 kg) Water cap 10,000 US gal (37,900 l; 8,300 imp gal) Firebox:  • Firegrate area 70.8 sq ft (6.58 m^2) Boiler pressure 200 psi (1.38 MPa) Heating surface 4,130 sq ft (384 m^2)  • Tubes 2,598 sq ft (241.4 m^2)  • Flues 1,176 sq ft (109.3 m^2)  • Firebox 329 sq ft (30.6 m^2) Superheater: ​  • Heating area 957 sq ft (88.9 m^2) Cylinders Two Cylinder size 27 in × 30 in (686 mm × 762 mm) Valve gear Walschaerts Valve type 14-inch (356 mm) piston valvles
Performance figures Tractive effort 53,900 lbf (239.76 kN) Factor of adh. 4.1
Career Preserved None

A total of 47 locomotives were built under the auspices of the USRA.

Original owners

URSA originals

Railroad	Quantity	Class	Road numbers	Notes
Missouri Pacific Railroad	7	MT-69	5301–5307
Nashville, Chattanooga and St. Louis Railway	5	J1-54	550–554
New York, New Haven and Hartford Railroad	10	R-1	3300–3309
Southern Railway	25	Ts-1	1475–1499	3 to AGS 6692–6694, 5 to CNOTP 6495–6499
Total	47

Copies

Railroad	Quantity	Class	Road numbers	Notes
Louisville and Nashville Railroad	22	L-1	400–421
Nashville, Chattanooga and St. Louis Railway	8	J1-54	555–562
New York, New Haven and Hartford Railroad	30	R-1-a	3310–3339
New York, New Haven and Hartford Railroad	9	R-1-b	3304–3348
New York, Ontario and Western Railway
Minneapolis, St. Paul and Sault Ste. Marie Railroad (Soo Line)	21	N-20	4000–4020
Total	90

None of the originals built under USRA auspices or any of the subsequent copies were preserved.

References

• Drury, George H. (1993), Guide to North American Steam Locomotives, Waukesha, Wisconsin: Kalmbach Publishing Company, ISBN 0-89024-206-2, LCCN 93041472
• Edson, William D.; Corley, Raymond F. (Autumn 1982). "Locomotives of the Grand Trunk Railway". Railroad History. Boston, Mass.: Railway and Locomotive Historical Society. 147. JSTOR 43520915.
• Huddleston, Eugene L. (2002). Uncle Sam's Locomotives: The USRA and the Nation's Railroads. Bloomington, Ind.: Indiana University Press. ISBN 0-253-34086-1.
• Westcott, Linn H. (1960). Model Railroader Cyclopedia, Volume 1: Steam Locomotives. Milwaukee, Wis.: Kalmbach Publishing Co. ISBN 0-89024-001-9.