The M-K TE70-4S was a four-axle B-B

diesel-electric locomotive A diesel locomotive is a type of railway locomotive in which the prime mover (locomotive), prime mover is a diesel engine. Several types of diesel locomotives have been developed, differing mainly in the means by which mechanical power is conv ...

built by Morrison-Knudsen. The locomotive was a rebuild of the

GE U25B The GE U25B was General Electric's first independent entry into the United States domestic road switcher diesel-electric locomotive railroad market for heavy production road locomotives since 1936. From 1940 through 1953, GE participated in a de ...

with a Sulzer V-12

prime mover Prime mover may refer to: Philosophy *Unmoved mover, a concept in Aristotle's writings Engineering * Prime mover (engine), motor, a machine that converts various other forms of energy (chemical, electrical, fluid pressure/flow, etc) into energy o ...

installed. Morrison-Knudsen rebuilt four for the

Southern Pacific Railroad The Southern Pacific (or Espee from the railroad initials- SP) was an American Class I railroad network that existed from 1865 to 1996 and operated largely in the Western United States. The system was operated by various companies under the ...

in 1978. The experiment proved unsuccessful and no additional units were rebuilt.

Design

The

for the M-K TE70-4S was a Sulzer 12ASV 25/30. Normally found in

marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military * ...

or stationary uses, the 12ASV 25/30 had been in production since 1969. The

four-stroke A four-stroke (also four-cycle) engine is an internal combustion (IC) engine in which the piston completes four separate strokes while turning the crankshaft. A stroke refers to the full travel of the piston along the cylinder, in either directio ...

turbocharged In an internal combustion engine, a turbocharger (often called a turbo) is a forced induction device that is powered by the flow of exhaust gases. It uses this energy to compress the intake gas, forcing more air into the engine in order to pro ...

engine was rated for a maximum of at 1000

RPM Revolutions per minute (abbreviated rpm, RPM, rev/min, r/min, or with the notation min−1) is a unit of rotational speed or rotational frequency for rotating machines. Standards ISO 80000-3:2019 defines a unit of rotation as the dimensionl ...

. The locomotives retained the GE GT598 D3A

generator Generator may refer to: * Signal generator, electronic devices that generate repeating or non-repeating electronic signals * Electric generator, a device that converts mechanical energy to electrical energy. * Generator (circuit theory), an eleme ...

s and GE 752

traction motor A traction motor is an electric motor used for propulsion of a vehicle, such as locomotives, electric vehicle, electric or hydrogen vehicles, elevators or electric multiple unit. Traction motors are used in electrically powered rail vehicles (ele ...

s from the U25B. The capability of the prime mover notwithstanding, the locomotive was rated at . The new prime mover required substantial alterations to the cab, carbody, and

underframe An underframe is a framework of wood or metal carrying the main body structure of a railway vehicle, such as a locomotive, carriage or wagon. See also * Chassis * Headstock * Locomotive bed * Locomotive frame * Undercarriage Undercarriage is t ...

. The locomotive measured long by wide, and stood high. It weighed .

History

Southern Pacific sent four GE U25Bs ( 7030–7033), then at the end of their service life, to Morrison-Knudsen for rebuilding. Morrison-Knudsen rebuilt the four locomotives in its

Boise, Idaho Boise (, , ) is the capital and most populous city of the U.S. state of Idaho and is the county seat of Ada County. On the Boise River in southwestern Idaho, it is east of the Oregon border and north of the Nevada border. The downtown are ...

, shops in 1977–1978. The first revenue run occurred beginning March 1, 1978, when the four locomotives handled a

Seattle Seattle ( ) is a seaport city on the West Coast of the United States. It is the seat of King County, Washington. With a 2020 population of 737,015, it is the largest city in both the state of Washington and the Pacific Northwest regio ...

–

Los Angeles Los Angeles ( ; es, Los Ángeles, link=no , ), often referred to by its initials L.A., is the largest city in the state of California and the second most populous city in the United States after New York City, as well as one of the world' ...

trailer-on-flatcar Trailer on flatcar, also known as TOFC or piggyback, is the practice of carrying semi-trailers on railroad flatcars. TOFC allows for shippers to move truckloads long distances more cheaply than can be done by having each trailer towed by a truck, s ...

(TOFC) train between Portland and Los Angeles. Inauspiciously, one of the four locomotives broke down during the trip. The locomotives carried a unique paint scheme featuring the red-and-orange of the SP's famed "Daylight" passenger trains, albeit in a different style. The color scheme led to the nickname " Popsicle". Due to their consistent unreliability, all four were retired in 1987 after less than ten years; none were preserved.

Notes

References

* * * * * *

External links

Southern Pacific TE70-4S on My Espee Modelers Archive
{{MPI Locomotives TE70-4S B-B locomotives Diesel-electric locomotives of the United States Railway locomotives introduced in 1978 Freight locomotives Standard gauge locomotives of the United States

Design

History

Notes

References

Further reading

External links