Baltimore and Ohio No. 9624 TR4 cow-calf set at Riverside Yard, Baltimore, in 1969.

(Roger Puta, courtesy Marty Bernard, Public domain, via Wikimedia Commons)

 

Electro-Motive logo

EMD SW7 DIESEL-ELECTRIC LOCOMOTIVE

The EMD SW7 was a diesel switcher locomotive built by General Motors Electro-Motive Division between October 1949 and January 1951. It was powered by a 1,200 horsepower (895 kW)12-567A engine. The SW7 replaced the earlier 1,000 horsepower NW2 switcher in EMD's catalog. A total of 489 SW7 locomotives were produced. The majority of the SW7s were built by EMD Plant No. 3 in Cleveland, Ohio. In addition, 15 TR4 cow-calf paired sets were produced.

SW7 production was discontinued in 1951 in favor of the new SW9.

 

Southern 8202 at the Southeastern Railway Museum, Duluth, GA.

(Josh Hallett from Winter Haven, FL, USA, CC BY-SA 2.0 <https://creativecommons.org/licenses/by-sa/2.0>, via Wikimedia Commons)

 

Original buyers

Railroad Quantity Road numbers
Arkansas and Louisiana Missouri Railway 1 11
Atlantic Coast Line Railroad 9 643–651
Central Railroad of New Jersey 4 1080–1083
Charleston and Western Carolina Railway 2 800–801
Chesapeake and Ohio Railway 26 5214–5239
Chicago and Eastern Illinois Railroad 6 126–131
Chicago and Eastern Illinois (Chicago Heights Terminal and Transfer Railroad) 2 132–133
Chicago and Illinois Western Railroad 3 101–103
Chicago, Burlington and Quincy Railroad 20 9249–9268
Chicago, Milwaukee, St. Paul and Pacific Railroad 1 1646
Clinchfield Railroad 6 350–355
Colorado and Southern Railway 1 154
Conemaugh and Black Lick Railroad 15 103–117
Cornwall Railroad 3 120–122
Detroit and Toledo Shore Line Railroad 3 116–118
Detroit Terminal Railroad 1 116
Detroit, Toledo and Ironton Railroad 5 920–924
Erie Railroad 6 428–433
Great Northern Railway 11 163–170, 11–13
Illinois Central Railroad 50 9300–9319, 9400–9429
Kansas City Southern Railway 10 1300–1309
Kansas City Southern Railway (Louisiana and Arkansas Railway) 6 1310–1315
Lakeside and Marblehead Railroad 1 12
Lehigh Valley Railroad 5 220–224
Louisiana Midland Railway 1 10
Louisville and Nashville Railroad 22 2245–2266
Maine Central Railroad 3 331–333
Missouri Pacific Railroad 5 9142–9146
Monessen Southwestern Railway 1 21
Montour Railroad 1 72
Nashville, Chattanooga and St. Louis Railway 10 24–33
New York Central Railroad 34 8851–8855, 8880–8897, 8911–8921
New York Central (Indiana Harbor Belt Railroad) 40 8835–8850, 8856–8879
New York Central (Chicago River and Indiana Railroad) 6 8898–8903
New York Central (Peoria and Eastern Railway) 7 8904–8910
New York, Chicago and St. Louis Railroad (“Nickel Plate Road”) 3 230–232
Northern Pacific Railway 8 107–114
Pennsylvania Railroad 48 8861–8868, 8871–8872, 9358–9395
Peoria and Pekin Union Railway 5 406–410
Phelps Dodge Corporation (New Cornelia Branch Mine) 1 6
Philadelphia, Bethlehem and New England Railroad 4 31–34
River Terminal Railway 2 61–62
Southern Railway (Alabama Great Southern Railroad) 5 6505–6509
Southern Railway (Cincinnati, New Orleans and Texas Pacific Railway) 14 6060–6073
Southern Railway (Georgia Southern and Florida Railway) 4 8200–8203
Southern Railway (New Orleans and North Eastern Railway) 12 6852–6863
St. Louis Southwestern Railway (“Cotton Belt”) 4 1054–1057
St. Louis-San Francisco Railway (“Frisco”) 5 300–304
Texas and Pacific Railway 4 1020–1023
Union Pacific Railroad 25 1800–1824
Union Railroad 4 571–574
Wabash Railroad 8 355–362
Weyerhaueser Timber Company 2 300–301
Woodward Iron Company 2 50–51
Youngstown and Southern Railway 2 70–71
Total 489

Belt Railway of Chicago 504 and 512 in Clearing Yard, Chicago, IL in January 1985.

(Roger Puta, courtesy Marty Bernard, railfan 44, Public domain, via Wikimedia Commons)

 

TR4

Railroad Quantity Road numbers
Atchison, Topeka and Santa Fe Railway 2 sets 2418,A–2419,A
Belt Railway of Chicago 5 sets 502AB–506AB
Chesapeake and Ohio Railway 2 sets 6001AB–6002AB
Chicago, Milwaukee, St. Paul and Pacific Railroad 6 sets 2001AB–2006AB

Maine Central EMD SW7 331 at Bangor, Maine, November 14, 1980. Photographer: J R Quinn.

(Craig Garver, Public domain, https://www.flickr.com/photos/digitalrailartist/51003915222/)

 

Overview

Type and origin
Power type: Diesel-electric
Builder: General Motors Electro-Motive Division (EMD)
Model: SW7, TR4
Build date: October 1949 – January 1951
Total produced SW7: 489
Total produced TR4: 15 sets
Specifications
Configuration:
​• AAR B-B
• UIC Bo′Bo′
Gauge: 4 ft 8+1⁄2 in (1,435 mm) standard gauge
Prime mover EMD 12-567BA
Engine type: V12 diesel
Aspiration: Roots-type supercharger
Cylinders: 12
Performance figures
Power output: 1,200 hp (895 kW)