EMD GP38

EMD GP38
terry cantrell · CC BY-SA 2.0 · source
Name	EMD GP38
Powertype	Diesel-electric
Builder	General Motors Electro-Motive Division
Builddate	1966–1971
Totalproduction	2,213
Aarwheels	B-B
Primemover	EMD 645 naturally aspirated V16
Poweroutput	2,000 hp
Tractiveeffort	starting 61,000 lbf
Disposition	Various in service, rebuilt, preserved

EMD GP38 is a four-axle diesel-electric road switcher built by General Motors's Electro-Motive Division between 1966 and 1971. The model became a workhorse for numerous North American railroads, influencing freight operations for companies such as Union Pacific Railroad, Atchison, Topeka and Santa Fe Railway, Penn Central Transportation Company, Conrail, and Canadian National Railway. Its simple, reliable EMD 645 engine and B-B wheel arrangement made it popular for yard switching, branchline freight, and short-haul duties across the United States, Canada, and Mexico.

Design and development

The GP38 emerged from EMD's lineage that included the EMD GP30, EMD GP35, and the earlier EMD GP9, incorporating lessons from World War II-era dieselization and postwar freight demands. Designed under leadership at General Motors and EMD engineering teams, the locomotive used the non-turbocharged EMD 645 V16 to prioritize reliability over peak horsepower, catering to railroads like Southern Pacific Transportation Company, Baltimore and Ohio Railroad, Chicago and North Western Transportation Company, and Milwaukee Road. The electrical systems leveraged technology shared with contemporaries such as the EMD SD35 and EMD GP40 while simplifying maintenance for shops at facilities owned by Norfolk and Western Railway and Seaboard System Railroad. Regulatory and market influences from agencies like the Interstate Commerce Commission and trends in freight traffic density shaped its specification and modular components used across fleets.

Production and variants

EMD produced 2,213 GP38s between 1966 and 1971, with units delivered to major operators including Atchison, Topeka and Santa Fe Railway, Southern Railway (U.S.), New York Central Railroad, Erie Lackawanna Railway, and Canadian Pacific Railway. Variants and related models included the high-hood and low-hood GP38 versions and the later GP38-2 produced by EMD, which incorporated Electro-Motive Division's modular electronics and upgraded systems favored by Conrail and Amtrak for light-duty roles. International licensees and export customers such as Mitsui, MALAYSIAN RAIL, and Mexican carriers adapted the GP38 platform for regional needs. Leasing companies and shortline operators also acquired units, with organizations like Genesee & Wyoming Inc. and Progressive Rail operating rebuilt examples.

Technical specifications

The GP38 used an EMD 645E 16-cylinder, two-stroke diesel engine rated at 2,000 horsepower, coupled to a DC generator and four EMD D77B traction motors arranged in a B-B configuration comparable to equipment on EMD GP7 and EMD SD7. Cooling, air intake, and exhaust systems mirrored those found in EMD's family of 645-engined locomotives employed by Pennsylvania Railroad and Burlington Northern Railroad. Fuel capacity, weight distribution, and braking systems were specified to meet interchange standards used by Association of American Railroads members and to operate on mainlines owned by carriers such as Union Pacific Railroad and Canadian National Railway. Control stands and cab ergonomics reflected contemporary practices at shops like Alco and Baldwin Locomotive Works that competed in the diesel market.

Operational history

Railroads deployed GP38s for mixed freight, transfer runs, and switching across networks operated by Conrail, Southern Pacific Transportation Company, Illinois Central Railroad, St. Louis Southwestern Railway (Cotton Belt), and many regional carriers. Their reliability led to widespread use in hump yards, local freights, and secondary mainlines by companies such as Chessie System, CSX Transportation, Norfolk Southern Railway, and Amtrak for non-passenger duties. Over decades GP38s have been renumbered, repainted, and rostered by shortlines including Iowa Interstate Railroad and Missouri Pacific Railroad spinoffs, reflecting mergers like the Conrail consolidation and the Staggers Rail Act-era restructuring of North American freight rail.

Modifications and rebuilds

Numerous railroad shops and independent companies rebuilt GP38s with upgrades such as microprocessor controls, alternator conversions similar to the GP38-2 electrical package, and emissions-focused repowering with engines from manufacturers like Cummins and Caterpillar. Major rebuild programs were undertaken by entities including National Railway Equipment Company, GE Transportation remanufacturers, and railroad shops at Kansas City Southern and BNSF Railway to extend service life, add dynamic braking, or modify gearing for switching work. Leasing firms and preservation groups sometimes installed updated cab amenities or crashworthiness features to comply with newer safety frameworks influenced by Federal Railroad Administration guidelines.

Preservation and surviving examples

Several GP38s survive in operation on tourist, heritage, and shortline railroads operated by organizations like Durango and Silverton Narrow Gauge Railroad affiliates, Gettysburg Railroad successors, and museums associated with Illinois Railway Museum, California State Railroad Museum, and National Railroad Museum. Preservation efforts are led by historical societies, museum volunteers, and private collectors who maintain units for excursion service, static display, and educational programs highlighting dieselization milestones represented alongside exhibits on figures such as E. H. Harriman and events like the Pennsylvania Railroad transitions. Some units are listed in rosters of preserved equipment maintained by state historical agencies and railroad heritage groups.

Category:Diesel-electric locomotives Category:Electro-Motive Division locomotives