EMD GP7 / GP9 / GP18 / GP20 locomotives

Even as EMD's F-units were replacing steam locomotives, the company was already pressing ahead with a family of locomotives that would in turn replace the classic "covered wagons". The GP7 roadswitcher design was aimed at correcting one of the biggest disadvantages of carbody units; namely their poor crew visibility in yard conditions. The GP7 (the GP standing for "General Purpose") had a full-width crew cab, but the front and rear hoods were narrower, permitting a much better view to the rear. Additionally, whereas the F-unit's carbody was the central structural feature of the locomotive, the "Geep's" hoods are only shells covering the engine and other components, making heavy maintenance much easier. The GP7 would go on to set the standard for the increasingly popular hood unit, and many will still be in service past the turn of the century.

Photo: Alaska Railroad GP7L #1826 at Anchorage. This ex-US Army unit was fitted with spark arresters.Railroad August 1973 p.43
Photo: C&NW HE15 (rebuilt GP7) #4200 Railfan & Railroad September 1980 p.21
Photo: Chop-nosed L&NW GP7 #50 Railfan & Railroad July 1982 p.2
Photo: Pittsburgh & Shawmut GP7s still in Conrail paint. Railfan & Railroad January 1982 p.29
Photo: North Central Texas GP7 #612 Railfan & Railroad May 1982 inside front cover
Photo: Cadillac & Lake City GP7 #105 Railfan & Railroad May 1982 p.51
"Seaboard Air Line GP7s" Prototype Modeler Aug-Sept 1985 p.34-35
Photo: TP&W GP7 #103 Prototype Modeler September 1986 p.30
Photo: WT&J GP7 #4370, ex C&NW Railfan & Railroad April 1993, p.74
Photo:Cape Cod Central GP7 #1501 Railpace September 2006 p.38
Art Danz "Modeling five Midwestern Geeps" Railroad Model Craftsman November 1993 p.89-94 Modeling CB&Q ("Way of the Zephyrs") CGW, Rock Island ("Route of the Rockets") C&NW, and Illinois Central GP7s in HO scale using Front Range shells and Athearn GP9 drives.

An uprated GP9, the GP18 differred from its predecessors in being powered by the 567D1, rated at 1,800hp. Although some units were built with the high short hood, a lowered hood configuration was offerred for the first time.

Photo: Lehigh Valley GP18s and GP38 near Victor, New York. Railroad, June 1974 p.2

Photo: TP&W GP18 #600 Prototype Modeler September 1986 p.32

Photo: Vermont Railway GP18 during snow removal operations Railfan & Railroad April 1996 p.39

The last direct derivative of the original Geep to be built, the GP20 was introduced in 1959 as the first turbocharged member of the family, being powered by a 567D2 rated at 2,000hp. GP20 production had been spurred by Union Pacific's experiments with turbocharging GP9s - the "Omaha GP20s" evaluated AiResearch and Elliot units, while later rebuilds tested EMD's own design.

A total of 260 GP20s were turned out, fewer than any other first generation Geep, with the Santa FE being the largest customer. Most were built with low short hoods, but Great Northern and Western Pacific units retained the old style high hood configuration.

A total of ten GP20s were rebuilt as GP20Cs with Cat engines for the Burlington Northern by Generation II, with these units subsequently being acquired by the Soo and later the TC&W.

The Life-Like Proto 2000 GP20 in HO scale was produced in Burlington Northern, Norfolk & Western, Burlington, Conrail, Frisco, and New York Central colors. The Mantua GP20 has been available in BN, erie Lackwanna, Conrail, PRR, and Reading raodnames.

John J. Ryczkowski "Western Pacific GP20s" Prototype Modeler November 1985 p.27-31. Photos includes units #2001, #2004, #2007, #2008

Photo: TP&W GP20u #2001 Railfan & Railroad January 1990 p.4

"Review: Mantua HO-scale GP20" Model Railroader April 1992 p.42-45 Includes a prototype photo of Union Pacific #714.

Photo: LTV STeel Mining GP20ms, ex BN GP20s Railfan & Railroad April 1993 p.4