The EMD GP9R was a rebuild from

EMD GP9 The EMD GP9 is a four-axle diesel-electric locomotive built by Electro-Motive Diesel, General Motors' Electro-Motive Division between 1954 and 1963. The GP9 succeeded the EMD GP7, GP7 as the second model of EMD's General Purpose (GP) line, inco ...

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

that were rebuilt by the

Chicago and North Western Transportation Company The Chicago and North Western was a Class I railroad in the Midwestern United States. It was also known as the "North Western". The railroad operated more than of track at the turn of the 20th century, and over of track in seven states befor ...

Grand Trunk Western Railroad The Grand Trunk Western Railroad Company was an American subsidiary of the Grand Trunk Railway, later of the Canadian National Railway operating in Michigan, Illinois, Indiana, and Ohio. Since a corporate restructuring in 1971, the railroad ha ...

Southern Pacific Transportation Company The Southern Pacific (or Espee from the railroad initials) 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 names ...

History

Chicago and North Western

The

was willing to rebuild the majority of their older GP9 locomotives and thus had rebuilt a total of 71 units. Each being rebuilt in nine batches. The first batch was rebuilt between November 1971 and October 1972, with the second batch being rebuilt between June 1972 and October 1973, the third batch being rebuilt between September 1972 and August 1978, the fourth batch being rebuilt in December 1973, the fifth batch being rebuilt between April 1977 and September 1977, the sixth batch being rebuilt between August 1977 and October 1977, the seventh batch being rebuilt between July 1978 and November 1980, and the ninth batch being rebuilt between July 1981 and August 1981.

Grand Trunk Western

The

(GTW) was studying options for a low-horsepower switcher locomotive that would replace their fleet of GP9 units. Following the ending of EMD’s GP15-1 program, and the lowest horsepower locomotive in EMD’s catalogue had concluded the 3,000hp GP59, which used a 710

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

. The GTW decided to fully rebuild the GP9 units into their own GP9R units, specifically by upgrading the electrical systems, engine components, and cabs. The units were rebuilt by the Grand Trunk Western at their own Battle Creek Shops between 1989 and 1993. The rebuilds had also included solid-state electrical systems, wheel slip control modules, AC generator systems, air and braking system updates, and structural improvements. The original EMD 567 power assembly was replaced by 645 components for higher reliability and easier part access and the GP9Rs retained their 1,750 horsepower rating. These units were numbered by the GTW as 4600 – 4611.

Southern Pacific

Beginning in 1970 with SP GP9 #3424, all of the pre-existing EMD GP9 diesel locomotives that were on the

St. Louis Southwestern Railway The St. Louis Southwestern Railway Company , known by its nickname of "The Cotton Belt Route" or simply "Cotton Belt", was a Class I railroad that operated between St. Louis, Missouri, and various points in the U.S. states of Arkansas, Tennessee ...

(also known as the "Cotton Belt Route") and Southern Pacific's roster were rebuilt into GP9E's and GP9R's with the number series beginning at #3100. The Southern Pacific Transportation Company began rebuilding their units in 1970, while the St. Louis Southwestern Railway (also known as the "Cotton Belt Route") began rebuilding their units in 1974. Some of their units would be downgraded to switching duties and would do so until the Southern Pacific's merger into

Union Pacific Railroad The Union Pacific Railroad is a Railroad classes, Class I freight-hauling railroad that operates 8,300 locomotives over routes in 23 U.S. states west of Chicago and New Orleans. Union Pacific is the second largest railroad in the United Stat ...

References

Bibliography

* {{Cite book , last=Strapac , first=Joseph A. , url=https://www.abebooks.co.uk/servlet/BookDetailsPL?bi=31398362326&searchurl=sortby%3D17%26tn%3Dsouthern%2Bpacific%2Bmotive%2Bpower%2Bannual&cm_sp=snippet-_-srp1-_-title1 , title=Southern Pacific Motive Power Annual 1973 , publisher= Chatham Publishing , year=1974 Rebuilt diesel locomotives Rebuilt locomotives B-B locomotives