SD45-2

SD45-2
Name	SD45-2
Powertype	Diesel-electric
Builder	Electro-Motive Division
Builddate	1972–1974
Totalproduction	1,200 (example)
Aarwheels	C-C
Primemover	EMD 645E3
Poweroutput	3,600 hp
Gauge	4 ft 8+1⁄2 in (1,435 mm)

SD45-2

The SD45-2 was a six-axle diesel-electric freight locomotive produced by Electro-Motive Division for North American railroads during the early 1970s. It served mainline freight duties for companies such as Union Pacific Railroad, Southern Pacific Railroad, Santa Fe Railway, Canadian National Railway, and Conrail, becoming a common sight on heavy coal, intermodal, and manifest trains. The model combined the high-horsepower EMD 645-series prime mover with the rugged road locomotive features seen in contemporary EMD SD40-2 and EMD SD45 designs.

Introduction

Designed as part of EMD's 645 engine family lineage, the SD45-2 aimed to provide 3,600 horsepower for heavy-haul applications for carriers such as Atchison, Topeka and Santa Fe Railway, Penn Central, and Illinois Central Railroad. It emerged amid competition from General Electric models like the GE U30C and market shifts involving Amtrak era regulatory changes and the freight consolidations that created CSX Transportation and Norfolk Southern Railway. The locomotive's development reflected influences from locomotive engineering trends led by figures at EMD and corporate strategies following mergers involving General Motors.

Design and Technical Specifications

The SD45-2 employed an EMD 20-cylinder EMD 645E3 prime mover delivering approximately 3,600 hp, paired with an EMD main generator and six EMD traction motors arranged in a C-C wheel configuration. Its carbody shared the long hood, low short hood, and dynamic braking systems similar to the SD40-2 while incorporating a longer crankshaft line typical of high-displacement engines used earlier by EMD SD45 predecessors. Running gear and suspension used standard EMD bolster and truck designs derived from collaborations with suppliers that also served Northern Pacific Railway and Great Northern Railway. Cooling packages, radiator assemblies, and turbocharging technologies reflected engineering advances contemporaneous with Alco and Fairbanks-Morse developments. Brake systems followed standards used by Association of American Railroads members and integrated compatibility with Positive Train Control precursor signaling and multiple-unit control systems shared with locomotives operated by Conrail and Chessie System.

Production and Service History

Electro-Motive Division manufactured units for delivery between 1972 and 1974 to a range of major freight carriers including Southern Pacific Transportation Company, Seaboard Coast Line Railroad, and Canadian Pacific Railway. The SD45-2 entered revenue service on heavy freight corridors such as routes formerly belonging to Pennsylvania Railroad, New York Central Railroad, and routes across the Transcontinental Railroad network serving Chicago, Los Angeles, and Houston. As railroad mergers reshaped North American railroading—exemplified by the formation of Conrail and the mergers leading to CSX—many units were re-rostered, repainted, and reassigned to duties including unit coal trains, general freight, and intermodal lanes pioneered by carriers such as Norfolk Southern and Union Pacific. Reliability and maintenance records influenced later EMD designs and freight procurement decisions alongside competitor offerings like the GE Dash 7 series.

Operators and Liveries

Major original operators included Chicago and North Western Transportation Company, Santa Fe, Southern Pacific, Union Pacific Railroad, Seaboard Coast Line, Missouri Pacific Railroad, and Illinois Central Gulf. Liveries ranged from the high-visibility heralds of Southern Pacific and the warbonnet of Santa Fe to the yellow-and-gray schemes of Union Pacific and the blue-and-white of Conrail. Units transferred among owners carried repaints under the identities of successor companies such as CSX Transportation, Canadian National, Canadian Pacific, and regionals like Burlington Northern prior to its merger with Santa Fe to form BNSF Railway. Special service or leased examples briefly bore markings for operators including Amtrak subcontracted maintenance or Providence and Worcester Railroad shortline use.

Modifications and Variants

Several SD45-2 units were rebuilt or modified by shops at EMD La Grange, National Railway Equipment Company, and railroad-owned facilities such as Union Pacific's Omaha Shops and Conrail's Juniata Shops. Common modifications included engine derating to improve reliability, upgrades to microprocessor-based controls from vendors including GE Transportation Systems and Wabtec, replacement of 20-cylinder prime movers with 16-cylinder EMD 645F blocks in rebuild programs, and installation of updated braking and signaling gear compatible with Positive Train Control rollouts. Some units were converted into cabless slug units to match electric or higher-traction lead units on heavy drag services for carriers such as CSX and Norfolk Southern.

Preservation and Surviving Units

A number of SD45-2s survive in railroad museums, tourist operations, and private preservation, maintained by organizations like National Railroad Museum (Green Bay), Illinois Railway Museum, California State Railroad Museum, and regional preservation groups such as Pacific Locomotive Association and RailGiants Train Museum. Preserved examples occasionally operate on excursions across historic routes connecting cities like Chicago, San Francisco, and Denver, and are subjects for study by railway historians associated with institutions including the Smithsonian Institution and societies like the Railway and Locomotive Historical Society. Some units remain in storage or active shortline service with roads such as Genesee & Wyoming subsidiaries or industrial operators near former mainline corridors.

Category:Electro-Motive Division locomotives Category:Diesel-electric locomotives of the United States