ALCO RSD-1

ALCO RSD-1

Former US Army ALCO RSD-1, now owned by the Tennessee Valley Railroad Museum. Donated from the Eglin Air Force Base Railroad when that operation was abandoned.

Type and origin Power type Diesel-electric Model RSD-1 Build date November 1942 – May 1946 Total produced 150

Specifications AAR wheel arr. C-C UIC class Co'Co' Gauge 4 ft 8 1⁄2 in (1,435 mm) standard gauge 1,520 mm (4 ft 11 27⁄32 in) – Russia Length 55 ft 5 3⁄4 in (16.91 m) Width 10 ft 0 in (3.05 m) Height 14 ft 5 in (4.39 m) Loco weight 247,500 lb (112,300 kg) Fuel capacity 1,000 US gal (830 imp gal; 3,800 L) Prime mover ALCO 539T Engine type Straight-6 Four-stroke diesel Aspiration Turbocharger Displacement 9,572 cu in (157 L) Generator DC generator Traction motors DC traction motors Cylinders 6 Cylinder size 12 1⁄2 in × 13 in (318 mm × 330 mm) Transmission Electric Loco brake Straight air Train brakes Air

Performance figures Maximum speed 65 mph (105 km/h) Power output 1,000 hp (750 kW) Tractive effort 40,425 lbf (179,820 N)

Career Locale North America, Soviet Union, Iran

The ALCO RSD-1 was a diesel-electric locomotive built by American Locomotive Company (ALCO). This model was a road switcher type rated at 1,000 horsepower (750 kW) and rode on three-axle trucks, having a C-C wheel arrangement. It was often used in much the same manner as its four-axle counterpart, the ALCO RS-1, though the six-motor design allowed better tractive effort at lower speeds, as well as a lower weight-per-axle. It was developed to meet the need to supply the Soviet Union over the Trans-Iranian Railway starting in mid 1943. On the other hand, due to the traction generator and appurtenant control apparatus being sized for four axles and yet having two additional powered axles, it had poorer performance at higher speeds.

There were three different specifications issued that covered the RSD-1 model; E1645 and E1646 were for wartime production for the US Army, while E1647 was a post-war order for the Mexican National Railways (Ferrocarriles Nacionales de México).

Seventy of the RSD-1s were shipped overseas to the Soviet Union in early 1945 during World War II, as part of the Allied war effort. They were classed there as the Soviet Railways Д^A20 (D^A20) class, also known just as Д^А after 1947 (D for Diesel, A for Alco and 20 for axle load in tons). They were used in ordinary line service rather than shunting, especially in southern parts of the Soviet Union (Turkmenistan), where water for steam locomotives was scarce. These locomotives were also used on the Trans-Iranian Railway. The Soviets subsequently kept of the RSD-1s after the war, adopting the design to form the basis of their own line of diesel locomotives TE1, TEM1 and TEM2. Two RSD-1s were sunk en route to the Soviet Union when the ship they were on was torpedoed by a German U-boat (Д^A20-41 and Д^A20-50) and 68 were received. They entered service from March 1945, and some were still in service in the 1980s. The D^A20-27 hauled Stalin's train to Potsdam Conference, and its positive evaluation was among reasons to copy the design (the Soviet Union built only 51 diesel locomotives before the war, so it had not enough experience with designing).