EMD "SW1" Locomotives: Data, Specs, Roster

Last revised: December 20, 2024

The SW1 was the second switcher Electro-Motive produced that featured a welded frame and respectable 600 horsepower.

It was the first to feature a General Motors prime mover, the 567 and 567A, and began EMD's modern line of switchers that continued through the MP15 series.

The SW1 proved quite popular, witnessing 660 sales before production ended. While it did not sell as well as the NW2, the SW1 and it successors became EMD's primary switcher line.

Today, examples can still be found in all types of applications, from regular freight service to industrial settings.

In addition, you can find them hosting excursions and tourist trains. Even one of the first SW1's built, Southern Pacific #1000, is preserved at the California State Railroad Museum in Sacramento.

Lehigh Valley SW1 #112 was photographed here at the road's terminal in Sayre, Pennsylvania on September 9, 1972. Bob Wilt photo. Warren Calloway collection.

Overview

While Electro-Motive produced a wide range of highly successful switchers such as the NW2, SW1200, SW1500, and SW9 the series can be traced back to a group of early six and nine hundred horsepower variants built during the latter 1930s.

This included the SC, SW, NC, and NW manufactured with either cast or welded frames. For example, SC referred to Six hundred horsepower, Cast frame while SW denoted Six hundred horsepower, Welded frame.

Identification

These switchers were built during an era that predated the modern road diesels and some railroads still preferred locomotives with cast frames, harkening back to the steam era.

As the years passed, EMD's method of identifying models seemingly changed every few years; in some cases the number simply denoted its number in the series while later the horsepower rating was included.

In addition, the NW2 was the last in the short-lived "NW" line. Following its production run, Electro-Motive dropped the first letter in identifying the horsepower rating. It also eliminated the cast or welded designation as the latter became the preferred production method.

In their place, the builder retained the "SW" lettering, which now meant simply Switcher. The SW1 featured a 600 horsepower prime mover and retained Electro-Motive's signature short carbody of just 44-feet with tapering near the cab for improved visibility.

The SW1's most recognizable feature is the large sandbox just under the grill. Its location is unique to this particular model.

Reading SW1 #20 sits in the dead line at the company's shops in Reading, Pennsylvania on April 22, 1973. By this date the locomotive was being parted out to rebuild other SW1's. Author's collection.

As Jerry Pinkepank notes in his book, "Diesel Spotter's Guide," another of the switcher's noteworthy trademarks is a single, centered, conical stack.

After World War II the SW1 was reequipped with EMD's updated 567A prime mover, which still produced 600 horsepower. During this time the model also featured a slight update to its carbody. The original was designed with a double-taper near the cab while the updated version included a single taper.

Data Sheet and Specifications

Entered Production	12/1938 (Electro-Motive #755)
Years Produced	12/1938 - 11/1953
EMD Class	SW1
Engine	567/567A (6 Cylinder)
Engine Builder	EMD/GM
Horsepower	600
RPM	800
Length	44' 5"
Height (Top Of Rail To Top Of Cab)	14' 5" (Built prior to January, 1945.)
Height (Top Of Rail To Top Of Cab)	14' 4 5/8" (Built after January, 1945.)
Width	10' 2" (Built prior to January, 1945.)
Width	10' 0" (Built after January, 1945.)
Weight	198,000 Lbs
Fuel Capacity	600 Gallons
Air Compressor	3C2C (Westinghouse)
Air Brake Schedule	6-BL (Westinghouse)
Trucks	B-B
Truck Type	GRS Rigid Bolster, Drop-Side Equalizer (AAR Type-A)
Truck Wheelbase	8' 0"
Wheel Size	40"
Traction Motors	D7* (4), EMD/GM
Traction Generator	D4A/D4/D4D*, EMD/GM
MU (Multiple-Unit)	No
Dynamic Brakes	No
Gear Ratio	62:15 (Before January, 1945) or 65:12 (After January, 1945)
Tractive Effort/Starting	49,500 Lbs (at 25% adhesion)
Top Speed	65 mph (62:15); 55 mph (65:12)

* Only the model D4D generator was used in SW1's built between January, 1945 and December, 1949. Electro-Motive's "Operating Manual #2303" states the D27 traction motor and D15A main generator were used in SW1 models built after December, 1949.

Chicago & North Western SW1 #1270 at the Prairie Street crossing in Elgin, Illinois in November, 1975. Rick Burn photo.

Production Roster

(Total Built = 660)

Owner	Road Number	Serial Number	Order Number	Completion Date	Quantity
Electro-Motive (Demonstrator)	755*	755	E292	12/1938	1
Seaboard Air Line	1200	802	E236	3/1939	1
Fort Worth Belt Railway	1	803	E232	1/1939	1
Electro-Motive (Demonstrator)	804**	804	E257	2/1939	1
Central Railroad Of New Jersey	1009-1010	805-806	E229	1/1939	2
New York Central	600-613	808-821	E217	2/1939-4/1939	14
New York Central	574-579	853-858	E217	1/1939	6
Great Northern	5101-5102	859-860	E218	1/1939	2
Reading	16-18	871-873	E230	1/1939	3
Lehigh Valley	112	874	E237	4/1939	1
New York Central	614-616	875-877	E239	5/1939	3
Milwaukee Road	1610-1611	878-879	E240	6/1939	2
Wabash Railroad	101-103	880-882	E247	6/1939	3
Missouri Pacific	9004-9005	895-896	E249	9/1939	2
Chicago, Burlington & Quincy	9136-9140	897-901	E259	6/1939	5
Pere Marquette	10	902	E262	7/1939	1
Phelps Dodge Corporation	A	903	E265	7/1939	1
Milwaukee Road	1612	904	E268	8/1939	1
Electro-Motive (Demonstrator)	905***	905	E287	8/1939	1
Electro-Motive (Demonstrator)	906****	906	E283	8/1939	1
Soo Line	320	907	E273	9/1939	1
Louisville & Nashville	11	908	E275	9/1939	1
Richmond Terminal*****	1	909	E307	9/1939	1
Republic Steel Corporation (Buffalo)	370	910	E277	10/1939	1
Electro-Motive (Demonstrator)	911******	911	E349	10/1939	1
Boston & Maine	1109-1111	912-914	E288	11/1939	3
Southern Pacific	1004-1009	975-980	E281	11/1939	6
Illinois Central	9014-9020	981-987	E284	12/1939-1/1940	7
Western Pacific	502-503	988-989	E283	12/1939	2
International-Great Northern (Missouri Pacific)	9200-9203	990-993	E289	12/1939	4
Fort Worth & Denver City (Burlington)	602	994	E290	12/1939	1
New York Central	617-621	1010-1014	E282	12/1939-1/1940	5
Elgin, Joliet & Eastern	220-224	1015-1019	E291	1/1940-2/1940	5
Lehigh Valley	113-115	1020-1022	E295	2/1940	3
Great Lakes Steel	12	1023	E349	9/1940	1
Wabash Railroad	104	1024	E297	2/1940	1
Houston Belt & Terminal	10	1025	E300	3/1940	1
Buffalo Creek Railroad	42	1026	E303	3/1940	1
Delaware, Lackawanna & Western	427-429	1027-1029	E304	3/1940	3
Milwaukee Road	1613-1624	1039-1050	E298	3/1940-4/1940	12
Delaware, Lackawanna & Western	430-437	1051-1058	E304	4/1940-5/1940	8
Chicago, Burlington & Quincy	9141-9147	1068-1074	E310	5/1940-6/1940	7
Wabash Railroad	105	1075	E311	5/1940	1
Terminal Railroad Association Of St. Louis	501-504	1076-1079	E313	6/1940	4
Missouri Pacific	9006	1083	E316	8/1940	1
St. Johns River Terminal (Southern Railway)	8565	1085	E319	7/1940	1
Philadelphia, Bethlehem & New England	212	1088	E321	6/1940	1
Baltimore & Ohio	200-215	1098-1113	E324	8/1940-9/1940	16
Reading	19-22	1128-1131	E329	8/1940	4
Philadelphia, Bethlehem & New England	213-214	1160-1161	E337	8/1940	2
Elgin, Joliet & Eastern	225-230	1162-1167	E338	9/1940	6
Milwaukee Road	1625-1633	1178-1186	E343	10/1940-11/1940	9
Chicago, St. Paul, Minneapolis & Omaha (Chicago & North Western)	55	1194	E346	10/1940	1
Wabash Railroad	106	1197	E350	11/1940	1
Southern Railway	2002-2004	1206-1208	E354	11/1940	3
Inland Steel Company	54	1223	E361	11/1940	1
Philadelphia, Bethlehem & New England	215-216	1228-1229	E364	11/1940-12/1940	2
Central of Georgia Railway	2-3	1230-1231	E365	1/1941	2
Elgin, Joliet & Eastern	231-237	1233-1239	E367	12/1940-1/1941	7
New York Central	622-641	1254-1273	E372	3/1941-9/1941	20
New York Central	642-644	1274-1276	E373	4/1941	3
New York Central	645-647	1277-1279	E374	7/1941	3
Chicago, Burlington & Quincy	9148-9153	1280-1285	E375	2/1941	6
Donner-Hanna Coke Corporation	1	1305	E378	1/1941	1
Great Lakes Steel	30-31	1306-1307	E379	2/1941	2
Missouri Pacific	9011	1314	E383	8/1941	1
Southern Pacific	1010-1016	1316-1322	E385	4/1941-7/1941	7
Texas & New Orleans (Southern Pacific)	11	1323	E385	7/1941	1
Detroit, Toledo & Ironton	900-901	1324-1325	E386	5/1941-8/1941	2
Great Lakes Steel	14-15	1326-1327	E387	3/1941	2
International-Great Northern (Missouri Pacific)	9204-9205	1338-1339	E392	6/1941	2
Milwaukee Road	1634	1369	E399	9/1941	1
Chicago & Eastern Illinois	97-98	1378-1379	E457	1/1942	2
Great Northern	5103-5105	1380-1382	E436	9/1941	3
Wabash Railroad	107	1388	E403	11/1945	1
Elgin, Joliet & Eastern	238-246	1396-1404	E407	9/1941-11/1941	9
Canton Railroad	21	1448	E425	10/1941	1
Philadelphia, Bethlehem & New England	217-218	1449-1450	E426	10/1941	2
Reading	23-24	1451-1452	E427	11/1941	2
Commonwealth Edison	10	1453	E429	11/1941	1
Boston & Maine	1112-1113	1457-1458	E430	11/1941	2
Central of Georgia Railway	7	1459	E441	12/1941	1
Chicago & Eastern Illinois	99	1474	E457	1/1942	1
Memphis Union Station	10	1475	E435	1/1942	1
Nashville, Chattanooga & St. Louis	15	1537	E443	12/1941	1
Louisville & Nashville	12-15	1563-1566	E448	12/1941	4
New York Central	648-650	1582-1584	E456	12/1941	3
Inland Steel Company	57	1588	E455	12/1941	1
New York Central	651-654	1589-1592	E456	1/1942-2/1942	4
Chicago, Indianapolis & Louisville (Monon)	50	1597	E460	2/1942	1
Baltimore & Ohio Chicago Terminal	217, 216, 218-221	1601-1606	E462	5/1942-8/1942	6
Central Railroad of New Jersey	1011-1012	1610-1611	E465	2/1942	2
Commonwealth Edison	11	1632	E469	2/1942	1
Chicago Short Line	200	1677	E474	2/1942	1
Rock Island	529-536	1678-1685	E475	2/1942-4/1942	8
Pere Marquette	11	1714	E478	4/1942	1
Chicago & North Western	1207-1212, 1214-1215	1738-1745	E489	9/1942-12/1942	8
Canton Railroad	22-23	1750-1751	E493	6/1942	2
Republic Steel Corporation	371	1778	E500	1/1942	1
Pennsylvania	5910	1852	E512	8/1942	1
Philadelphia, Bethlehem & New England	220-221	1853-1854	E513	3/1942	2
Chicago & Eastern Illinois	95-96	1855-1856	E514	6/1942	2
Fort Worth & Denver City (Burlington)	604	1864	E517	8/1942	1
New York Central	580-584	1878-1882	E521	12/1942-3/1943	5
Republic Steel Corporation (Gadsden, Alabama)	890-891	1936-1937	E528	3/1942	2
U.S. Army	7001	1990	E533	3/1942	1
U.S. Army	7003-7004	2000-2001	E543	6/1942	2
U.S. Army	7002	2012	E548	5/1942	1
Broward County Port Authority (Fort Lauderdale, Florida)	400	2384	E595	2/1943	1
Commonwealth Edison	14	2864	E638	6/1946	1
Great Lakes Steel	16-18	3182-3184	E656	9/1945-10/1945	3
Republic Steel (Canton, Ohio)	50-54	3219-3223	E661	10/1945	5
Republic Steel (Youngstown, Ohio)	300-301	3224-3225	E661	10/1945	2
Illinois Central	9021-9030	3289-3298	E668	6/1946	10
Pennsylvania	5944-5946	3414-3416	E679	6/1946	3
Pennsylvania	5947-5951	3580-3584	E694	6/1946-7/1946	5
Wheeling Steel	1001-1002	3769-3770	E720	10/1946	2
Boston & Maine	1114-1116	3884-3886	E727	10/1946	3
Boston & Maine	1117	3895	E727	10/1946	1
Electro-Motive (Demonstrator)	700*******	3896	E730	10/1946	1
Maryland & Pennsylvania	70	4162	E771	12/1946	1
Mathieson Chemical Corporation	1	4479	E804	1/1947	1
Chicago District Electric Generating Company	3	4492	E806	1/1947	1
Manufacturers Junction Railway	6	4498	E810	1/1947	1
Atlantic & East Carolina Railroad	9	4582	E812	4/1947	1
Wabash	108	4730	E823	4/1947	1
Southern Railway	2007-2011	4743-4747	E827	4/1947-8/1947	5
St. Joseph Belt Railway (Missouri)	12	4793	E831	4/1947	1
Republic Steel (Buffalo, New York)	372	4804	E835	4/1947	1
Chattanooga Traction Company	4	4840	E837	4/1947	1
Pennsylvania	5952-5953	4957-4958	E850	9/1947	2
Commonwealth Edison	12	4995	E856	9/1947	1
Terminal Railroad Association of St. Louis	505-508	5022-5025	E859	9/1947-10/1947	4
Pennsylvania	9138, 9137, 9139-9151	5370-5384	E898	4/1948-7/1948	15
Angelina & Neches River Railroad	10	5656	E931	9/1947	1
Georgia Marble Company	1	5663	E933	9/1947	1
Pennsylvania	5987-5999	5664-5676	E934	3/1948-4/1948	13
Tennessee Coal, Iron & Railroad	1000-1003	5753-5756	E945	3/1948	4
Wheeling Steel	1003-1004	5764-5765	E947	8/1948	2
Commonwealth Edison	13	5767	E949	3/1948	1
Pennsylvania	9152-9154	5814-5816	E898	8/1948	3
Allis-Chalmers Manufacturing Company (West Allis, Wisconsin)	8	5920	E959	9/1947	1
Erie Railroad	360	6148	E977	7/1948	1
Inland Steel	70-73	6169-6172	E980	3/1948-4/1948	4
Hanna Furnace Company	14-15	6258-6259	E990	4/1948, 4/1949	2
New York Central	585-609	6391-6415	E999	4/1949-6/1949	25
Mathieson Chemical Corporation	2	6466	E1003	4/1949	1
Great Lakes Steel	33-34	6753-6754	E1023	7/1948, 4/1949	2
Pennsylvania	9200-9209	6759-6768	E1049	4/1949	10
Chicago District Electric Generating Company	4	6769	E1025	8/1948	1
Great Lakes Steel	22	7402	E1023	4/1949	1
Roscoe, Snyder & Pacific Railway	100	7458	E1061	8/1949	1
Rock Island	537-546	7473-7482	E1064	7/1949	10
Union Railroad	455-468	7502-7515	E1070	6/1949-8/1949	14
Wabash	109	7533	E1094	6/1949	1
Wabash	110-111	7741-7742	E1094	6/1949	2
Canton Railroad	24-25	7744-7745	E1067	8/1949	2
Detroit Edison	210-211	8152-8153	E1139	4/1949	2
Chicago Short Line	201	8154	E1140	4/1949	1
Boston & Maine	1118	8321	E1154	4/1949	1
Chicago, Indianapolis & Louisville (Monon)	5-6	8423-8424	E1254	8/1949	2
Union Railroad	469-470	8531-8532	E1185	1/1950-2/1950	2
Galveston Wharves	201-202	8613-8614	E1194	4/1949	2
Galveston Wharves	203-204	10083-10084	6041	12/1949	2
Central Indiana Railway	1	10111	6005	7/1949	1
Great Northern	80-82	10118-10120	4027	1/1950	3
Commonwealth Edison	15	10538	4034	9/1950	1
Union Railroad	471-476	10900-10905	4042	7/1950	6
Conemaugh & Black Lick Railroad	60-61	11009-11010	6060	12/1949	2
Great Northern	83	11025	4047	1/1950	1
Georgia & Florida Railroad	70-72	11097-11099	6070	7/1950	3
Pennsylvania	9396-9428	11190-11222	6081	7/1950-11/1950	33
Public Service Company Of Northern Illinois	9	11227	6083	1/1950	1
McLouth Steel	3	11316	6086	1/1950	1
St. Joseph Terminal	1-2	11378-11379	6089	2/1950	2
New York Central	610-614	11767-11771	6115	10/1950	5
New York Central (Chicago River & Indiana)	615-621	11782-11788	6116	6/1950-10/1950	7
Conemaugh & Black Lick Railroad	62-65	11938-11941	4060	10/1950	4
Detroit Edison	212	12087	6133	10/1950	1
Lehigh Valley	118-119	12212-12213	4067	12/1950	2
Republic Steel (Youngstown, Ohio)	302-303	12734, 13139	6167, 6183	10/1950-11/1950	2
Inland Steel (East Chicago, Indiana)	76-77	13547-13548	6215	11/1950-12/1950	2
Inland Steel (East Chicago, Indiana)	78-80	13575-13577	4094	3/1951	3
New York, Chicago & St. Louis (Nickel Plate Road)	105-106	13705-13706	6213	12/1950	2
Allegheny & South Side Railway	101	14058	4101	3/1951	1
Republic Steel	304	14098	6240	3/1951	1
Illinois Central	9031-9032	14388-14389	4119	8/1951	2
Republic Steel (Youngstown, Ohio)	305	14391	6262	3/1951	1
Public Service Company Of Northern Illinois	10	14478	6261	8/1951	1
McLouth Steel	4	14507	6267	3/1951	1
Republic Steel	306	14559	6266	8/1951	1
Republic Steel (Cleveland, Ohio)	340-341	14560-14561	6317	8/1951	2
Chihuahua Forests Company (Mexico)	500	14654	6296	8/1951	1
Granite City Steel	600-601	14721-14722	6292	8/1951	2
Inland Steel	81	14741	4094	3/1951	1
Republic Steel (Gadsden, Alabama)	893	14742	6316	8/1951	1
Galveston Wharves	205	14985	6324	8/1951	1
Electro-Motive (Demonstrator)	152********	15557	4152	6/1951	1
Republic Steel (Youngstown, Ohio)	352	16116	6379	2/1952	1
Republic Steel (Gadsden, Alabama)	894	16117	6394	2/1952	1
Great Western Railway of Colorado	61	16446	6391	2/1952	1
Public Service Company Of Northern Illinois	11	16704	6371	6/1952	1
Portland Traction Company	100	16889	6399	2/1952	1
Great Lakes Steel	36	17114	6435	3/1953	1
Great Lakes Steel	35	17137	6421	12/1952	1
Louisiana Midland Railway	11	17143	6437	6/1952	1
Metropolitan Sanitary District of Greater Chicago	1-3	17235-17237	6417	7/1952-12/1952	3
Garden City Western	201	17564	6472	10/1952	1
Portland Traction Company	200	17709	4210	3/1953	1
McLouth Steel	5	17895	6478	3/1953	1
Chicago & North Western	1268-1270, 1272-1273	18101-18105	4177	5/1953	5
Chicago & North Western	1271	18111	4227	5/1953	1
Chicago & North Western	1274-1279	18106-18110, 18112-18113	4228	5/1953	6
Boston & Maine	1119-1132	18186-18199	4214	7/1953-8/1953	14
Warner Sand & Gravel Company	15	18279	6508	5/1953	1
Hanna Furnace Company	16	18299	6510	5/1953	1
Lehigh Portland Cement Company	5	18441	6519	5/1953	1
Sahara Coal Company	No Number	18721	4237	9/1953	1
Great Lakes Steel	38	18783	4242	9/1953	1
Cleveland Quarries Company	2	19304	4254	11/1953	1

* Became Inland Steel Company #51 in January, 1940.

** Became Southern Pacific #1000.

*** Became Central of Georgia #1.

**** Became Western Pacific #501.

***** This unit was built as Atlantic Coast Line #1901 but ultimately rejected and returned to EMD where it was resold to Richmond Terminal.

****** Became Great Lakes Steel #11.

******* Became Manufacturers Junction Railway #7.

******** Became Scullin Steel #6.

Pennsylvania SW1 #8590 (Class ES-6) was photographed here in Cincinnati, Ohio, circa 1967. The switcher was originally built as #5990 in March, 1948 and had been renumbered here in preparation for the upcoming Penn Central merger. Fred Byerly photo. American-Rails.com collection.

Sources

EMD. Operating Manual #2303: 600 & 1000 HP Switching Locomotives (Models SW1 & NW2; 567 & 567A Engines). La Grange: Electro-Motive Division (General Motors Corporation).

EMD. Operating Manual #2303: 600 & 1200 HP Switching Locomotives (Models SW1 & SW7; 567 Series Engines). La Grange: Electro-Motive Division (General Motors Corporation), January, 1950 (5th Edition).

Foster, Gerald. A Field Guide To Trains. New York: Houghton Mifflin, 1996.

Hayden, Bob. Diesel Locomotives: Cyclopedia, Volume 2 (Model Railroader). Milwaukee: Kalmbach Publishing Company, 1980.

Marre, Louis A. Diesel Locomotives: The First 50 Years, A Guide To Diesels Built Before 1972. Milwaukee: Kalmbach Publishing Company, 1995.

Pinkepank, Jerry A. Diesel Spotter's Guide. Milwaukee: Kalmbach Publishing Company, 1967.

Solomon, Brian. EMD Locomotives. Minneapolis: MBI Publishing Company, 2006.

A handsome Monon Railroad SW1 in a scene probably dating to the 1950's. Date, location, and photographer not listed. American-Rails.com collection.

Other new additions included a lower exhaust stack (which became standard on all future EMD switcher locomotives) for better crew visibility, rectangular instead of curved windshields above the hood (beginning in the mid-1950s), and twin sealed-beam headlights.

The SW1 enjoyed a long production run, from December, 1938 through November, 1953. Due to their flexibility, reliability and cheap price, numerous Class Is and short lines purchased switcher with some 660 manufactured over thirteen years.

It also found great interest in the private sector where companies like Wheeling Steel, Warner Sand & Gravel, Republic Steel, Cleveland Quarries, and even the U.S. Army bought the model.

Photos

Milwaukee Road SW1s #952 and #953 in freight service at Brownsdale, Minnesota in February, 1964. Today, this section of the Milwaukee across southern Minnesota is abandoned. Rick Burn photo.

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