EMD 645

EMD 645
Karsini · Public domain · source
Name	EMD 645
Powertype	Diesel-electric
Builder	Electro-Motive Division of General Motors
Builddate	1965–1992
Primemover	EMD 645 series
Cylindercount	12, 16, 20
Aspiration	Roots/blower, turbocharged
Poweroutput	1,500–3,600 hp
Disposition	In service, preserved, scrapped

EMD 645 The EMD 645 is a family of two-stroke diesel engines produced by Electro-Motive Division of General Motors for railroad, marine, and stationary applications. Introduced in the mid-1960s as a successor to the EMD 567 series, the 645 series powered major locomotive models and influenced designs used by Atchison, Topeka and Santa Fe Railway, Union Pacific Railroad, Canadian National Railway, and numerous international operators. The series supported a wide range of power ratings and configurations, becoming a backbone of North American locomotive motive power during the late 20th century.

Development and Design

Development began at General Motors Research Laboratory and Electro-Motive Division facilities seeking increased displacement per cylinder and improved thermal efficiency compared to the EMD 567 series. Engineers led by teams at La Grange, Illinois optimized the 645's cylinder liner, crankcase, and fuel delivery to support higher horsepower in locomotives like the SD40 and SD45. Design choices reflected lessons from contemporary projects at Baldwin Locomotive Works, Fairbanks-Morse, and international builders such as Alco and Sulzer. The block and crankshaft layout permitted modular installation across adoptive platforms used by General Electric competitors and shipyards servicing Mitsubishi Heavy Industries and Hyundai Heavy Industries. Accessory systems—governors, turbochargers, and blowers—were developed in coordination with suppliers including Holset, BorgWarner, and Roots-type manufacturers.

Technical Specifications

The 645 series used 645 cubic inches (10.5 L) per cylinder with 45-degree V configurations offered in 12-, 16-, and 20-cylinder arrangements, producing nominal outputs from 1,500 hp to 3,600 hp. Core features included two-stroke scavenging via roots blowers or turbochargers, unit fuel injectors derived from designs tested at Caterpillar and Rolls-Royce research programs, and modular cylinder assemblies facilitating overhaul at facilities like Beardmore and EMD La Grange Shops. Compression ratios, bore and stroke, and cam-driven injector timing were standardized to ease maintenance across fleets operated by Conrail, Southern Pacific Railroad, Chessie System, and British Rail for exported units. Cooling, lubrication, and electrical generation interfaces matched traction alternators and generators supplied by Westinghouse Electric Company, General Electric Company, and Traction Control Corporation.

Variants and Upgrades

Variants included the turbocharged 645E and blower-scavenged 645F families, with subvariants tuned for low-speed freight, high-speed passenger, and heavy-haul export markets. Upgrades over time incorporated electronic fuel injection and microprocessor controls influenced by projects at Siemens, Bendix, and ABB, yielding retrofits on classes operated by Amtrak, Deutsche Bahn, and SNCF. Rebuild programs by National Railway Equipment Company, Progress Rail Services, and GATX Corporation replaced 645 blocks with emissions-compliant modules inspired by collaborations with EPA-driven standards and California Air Resources Board guidelines. Marine adaptations served fleets of Maersk, Mitsui O.S.K. Lines, and NYK Line with auxiliary drives and gensets modified for stability by naval architects from New York Shipbuilding Corporation and Vancouver Shipyards.

Production and Service History

Mass production at EMD La Grange and license-building arrangements with General Motors Diesel Division in Canada and overseas yards led to thousands of installations between 1965 and 1992. The 645 powered iconic locomotive models such as the SD40-2, GP40, and SD45-2, shaping freight operations of Norfolk Southern Railway, Kansas City Southern Railway, and Illinois Central Railroad. Export orders supplied operators in Australia (including Commonwealth Railways), South Africa (including Spoornet), and India for industrial and mainline service. Lifecycle support from EMD parts depots, third-party rebuilders, and railroad shops extended service lives into the 21st century, while market shifts toward diesel-electric hybrid and emission-reduction programs influenced late-generation retirements.

Applications and Operators

The 645 family saw broad application: mainline freight by Union Pacific Railroad and BNSF Railway; passenger service on Amtrak routes such as the Silver Meteor and Auto Train; industrial switching for Consolidated Rail Corporation and Providence and Worcester Railroad; and marine power for vessels operated by Crowley Maritime. International operators included Australian National, Transnet Freight Rail, Ferrocarriles Argentinos, and Kenya Railways. Leasing companies like GATX and Morrison-Knudsen circulated 645-powered units across private contractors, mining firms such as Rio Tinto and BHP, and energy sector clients including ExxonMobil and Chevron for stationary generation.

Preservation and Legacy

Numerous preserved examples appear in museums and heritage railways, including collections at the National Railway Museum (York), Illinois Railway Museum, and California State Railroad Museum. Enthusiasts and preservation groups restore units originally built for Atchison, Topeka and Santa Fe Railway, Southern Pacific Railroad, and Chicago and North Western Transportation Company. The 645’s engineering influenced successor families and sparked scholarship at institutions like MIT, University of Illinois, and University of Michigan on diesel efficiency and emissions control. Its longevity in revenue service and adaptability for rebuilds underscore its legacy in late 20th-century locomotive development.

Category:Diesel locomotives