EMD SW1
The EMD SW1 is a 600-horsepower (450 kW) diesel-electric switcher locomotive built by General Motors' Electro-Motive Corporation (later Division) between December 1938 and November 1953. Final assembly was at EMD's plant at LaGrange (McCook) Illinois. The SW1 was the second generation of 3,402 cu in (55.75 L) switcher from EMD, succeeding the SC (cast frame) and SW (welded frame). The most significant change from those earlier models was the use of an engine of EMD's own design, the then-new 567 engine, here in 600 hp (450 kW) V6 form. 661 locomotives of this design were built, not withstanding diesel switcher production having been suspended between 1942 and 1945 by the War Production Board, as the 567 engines were needed elsewhere, mainly for U.S. Navy LST vessels.
Engine and powertrain
The SW1 introduced a 6-cylinder version of the 567 (later 567A) series engine to EMC/EMD switchers. Developing 600-horsepower (450 kW) at 800 rpm., this engine remained in production until 1966. Designed specifically for railroad locomotives, this was a supercharged 2 stroke 45 degree V type, with an 8 1⁄2 by 10 in (216 by 254 mm), bore by stroke, giving 567 cubic inches (9.29 L) displacement per cylinder. A D.C. generator provides power to four motors, two on each truck, in a B-B arrangement. The SW1, like most EMD switchers, use the AAR Type A switcher truck. EMC/ EMD has built all its own components since 1939.
EMC Winton-engined switchers
Early Electro-Motive Corporation switchers were built with Winton 201-A engines. A total of 175 were built between February 1935 and January 1939. Two main series of locomotives were built, distinguished by engine size and output: the straight-8, 600 hp (450 kW) 'S' series, and the V12, 900 hp (670 kW) 'N' series. Both were offered with either one-piece cast underframes from General Steel Castings of Granite City, Illinois, denoted by 'C' after the power identifier, and fabricated, welded underframes built by EMC themselves, denoted by 'W'. This gave four model series: SC, SW, NC and NW. Further developments of the 900 hp (670 kW) models gave model numbers NC1, NC2, NW1, and NW1A, all of which were practically indistinguishable externally from the others, as well as a pair of unique NW4 models for the Missouri Pacific Railroad and a solitary, twin-engined T transfer locomotive model built for the Illinois Central Railroad.
600 hp (450 kW) S series
The production S series locomotives are identical except for cast or welded underframes, which are identical to those used under the N-series 900 hp (670 kW) locomotives. The hood on the S series is shorter, and the locomotives have a characteristic, rounded-edged "satchel" in front of the radiator. The straight-8 600 hp (450 kW) Winton 201-A engine moved the exhaust stacks off-center to the engineer's left, while the N series' were central. The Winton-engined switchers can be distinguished from later EMD 567-engined units by small louvres at the top front sides of their hoods, as well as top-of-hood ventilation through several lifting vents rather than the large top grille of those later units.
Podcasts:
