Classic Streamliners - TRAINCYCLOPEDIA
The EMD DD35A was a 5,000 hp (3,730 kW) diesel-electric locomotive of D-D wheel arrangement built by General Motors Electro-Motive Division exclusively for the Union Pacific Railroad. They were a cab-equipped variant of the previous, cabless booster (B unit) EMD DD35 (sometimes erroneously called the 'DD35B'). Fifteen DD35A locomotives were built between May and July 1965; they were assigned road numbers 70 through 84. A further development of the 8 axle, twin-engined locomotive produced the final, best known type, the DDA-40X "Centennial".
Like its cabless predecessor, the DD35A was essentially two EMD GP35 locomotives on a common frame, riding on a pair of 4-axle Flexicoil trucks. The cab of a GP35 was fitted to the front end, requiring a longer frame than the DD35; the fuel tank beneath was lengthened, and the center pass-through walkway was offset a little to the rear because of the single cab. Another difference was that the DD35A was fitted with the new flared radiator section EMD was testing on its EMD 645-engined demonstrators (the prototype SD40 demonstrators).
The DD35s were initially quite unreliable; some of this was blamed on sand from the internal sandboxes getting in electrical gear, so new sandboxes were fitted on the walkways in 1969. The DD35s were among the last EMD road units to be built with DC generators and old-fashioned switchgear, which were more maintenance intensive than the later AC/DC equipment.
Once teething troubles had been overcome, the DD35s were reasonably successful, but they were less flexible than smaller units and thus with the economic downturn of the early 1980s they were withdrawn from service. All were retired by 1981, and scrapped by July 1982. In their final months of service they operated around Salt Lake City, Utah. No examples of this type remain.
Owner: Union Pacific Railroad
EMD DD35A Overview
Type and origin
Power type: Diesel-electric
Builder: General Motors Electro-Motive Division (EMD)
Build date: 1965
AAR wheel arrangement: D-D
Gauge: 4 ft 8 1⁄2 in (1,435 mm)
Wheelbase Between truck centers: 65 ft 0 in (19.81 m)
Truck wheelbase: 17 ft 1 1⁄2 in (5.22 m)
Length: 88 ft 2 in (26.87 m)
Width: 10 ft 4 in (3.15 m)
Height cab roof: 14 ft 11 3⁄8 in (4.56 m)
Height overall: 16 ft 4 in (4.98 m)
Locomotive weight: 519,353 lb (235,575 kg)
Fuel capacity: 8,230 gal (31,200 l; 6,850 imp gal)
Prime movers: Dual EMD 16-567D3A
Engine type: V16 diesel
Safety systems: Leslie Supertyfon model S5TRRO or S3LR horns
Power output: 5,000 hp (3,730 kW)
Operator: Union Pacific
Numbers: 70 – 84
Disposition: All scrapped
A pair of 5,000 hp brutes pose for the camera at the Union Pacific facilities in North Platte, Nebraska. On the left, No. 53, a GE U50D, and on the right, No. 82, a General Motors EMD DD35A. Photo: Union Pacific Railroad.
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Text: wikipedia.org. Images: Public Domain; http://www.commons.wikimedia.org (unless otherwise specified) and 17 U.S. Code § 107 fair use. References: Lewis, Robert G. The Handbook of American Railroads. New York: Simmons-Boardman Publishing Corporation, 1951, 2nd Edition 1956. Site Map Contact webmaster HERE.