EMD SD7
{{Short description|Model of 1500 hp Co′Co′ American diesel locomotive}}{{More citations needed|date=May 2024}}{{Infobox locomotive
| name = EMD SD7
| powertype = Diesel-electric
| image = 2023-05-27 Southern Pacific 1518.jpg
| caption = SP #1518 inside Barn 9 at the Illinois Railway Museum in Union, Illinois on May 27, 2023.
| builder = General Motors Electro-Motive Division (EMD)
| buildmodel = SD7
| builddate = May 1951 – November 1953
| totalproduction = 188
| aarwheels = C-C
| gauge = {{track gauge|ussg|allk=on}}
| trucks = EMD Flexicoil C
| wheeldiameter = {{convert|40|in|mm|0|abbr=on}}
| minimumcurve = 23° ({{convert|250|ft|m|2|abbr=on}} radius)
| wheelbase = {{convert|48|ft|7|in|m|2|abbr=on}}
| length = {{convert|61|ft|2+3/4|in|m|2|abbr=on}}
| width = {{convert|10|ft|8|in|m|2|abbr=on}}
| height = {{convert|15|ft|4+1/2|in|m|2|abbr=on}}
| locoweight = {{convert|309000|lb|abbr=on}}
| fuelcap = {{convert|1200|usgal|L impgal|abbr=on}}
| rpmrange = 800
| enginetype = V16 diesel engine
| aspiration = Roots-type blower
| displacement = {{convert|9072|cuin|L|abbr=on}}
| generator = D-12-C
| tractionmotors = (6) D-27-B
| headendpower =
| cylindercount = 16
| poweroutput = {{convert|1500|hp|MW|2|abbr=on}}
| maxspeed = {{convert|65|mph|kph|0|abbr=on}}
| tractiveeffort = {{convert|77250|lbf|abbr=on}}
| locale = United States
| disposition = Some still in service, others preserved
}}
The EMD SD7 is a model of 6-axle diesel locomotive built by General Motors Electro-Motive Division between May 1951 and November 1953. It had an EMD 567B 16-cylinder engine producing {{convert|1500|hp|MW|2}} for its six traction motors. United States railroads bought 188 units.{{cite book|last=Pinkepank|first=Jerry A|title=The Second Diesel Spotter's Guide|year=1973|publisher=Kalmbach Books|lccn=66-22894|pages=71}}
This was the first model in EMD's SD (Special Duty) series of locomotives, a lengthened B-B GP7 with a C-C truck arrangement. The two extra axles and traction motors are useful in heavy, low-speed freight service. EMD continues to produce SD series locomotives to this day. Some SD7s both high and short-hood can still be found in service today on shortline railroads and industrial operators, although most Class I roads stopped using these locomotives by the 1970s and 1980s.{{cite web|last=Guss|first=Chris|title=EMD's pioneering SD7 and SD9 locomotives |url=https://www.trains.com/trn/railroads/locomotives/emds-pioneering-sd7-and-sd9-locomotives/|date=May 16, 2023|publisher=Kalmbach Media|work=Trains Newsletter|access-date=May 16, 2023}}{{Cite book |last=Solomon |first=Brian |url=https://books.google.com/books?id=JubUBAAAQBAJ&dq=Union+Pacific+SD7+-wikipedia&pg=PA249 |title=GE and EMD Locomotives: The Illustrated History |publisher=Voyageur Press |isbn=978-0-7603-4612-9 |publication-date=2014 |pages=249 |language=en}}
Design and production
The SD7 was conceived as a modification of the existing EMD GP7 with two additional powered axles, one for each truck. Providing two more axles served two purposes: it gave the locomotive more tractive effort compared to the four-axle GP7, and it distributed the locomotive's weight more evenly.{{Cite book|last=Schafer|first=Mike|url=https://www.worldcat.org/oclc/38738930|title=Vintage diesel locomotives|date=1998|publisher=Motorbooks International|isbn=0-7603-0507-2|location=Osceola, WI|pages=36–37|oclc=38738930}}
EMD produced its first examples of the SD7 in May 1951, using the 567B engine. Starting in August 1953 a total of 26 SD7s were produced which used either the 567BC engine or the 567C engine.
SD7s were originally set up to run long hood forward, usually noted by the letter "F" painted adjacent to the top step of the long hood boarding steps. Many were later changed or upgraded to run short hood forward as is today's Association of American Railroads standard.
EMD ended production in November 1953 and began producing the SD7's successor, the SD9, in January 1954.
Rebuilds
= SD7R =
The Southern Pacific Transportation Company had rebuilt a total of 42 of their SD7 locomotives into the EMD SD7R. They were numbered 1500–1542. The rebuilds had also included upgrades to the electrical systems, traction motors, as well as a changeout of the prime movers swapping the 16-cylinder 567B prime movers with 16-cylinder 645CE prime movers.{{Harvp|Withers|1995|p=5}}{{Harvp|Shine|1991|p=9-56, 186}}
Original buyers
| class="wikitable"
!Image ! Owner !! Quantity !! Numbers !! Notes !Ref. | |||
| rowspan="2" |
| rowspan="2" |Electro-Motive Division | rowspan=2 style="text-align:center;" |2
|style="text-align:center;" |990 | to Southern Pacific 5308 then to 2715 to 1415 and finally 1518. Preserved at the Illinois Railway Museum. | |
| style="text-align:center;" |991 | to Baltimore and Ohio 760
| | ||
| |Baltimore and Ohio Railroad | style="text-align:center;" |4 | style="text-align:center;" |761–764 | These units were built with the 567BC engine.
| |
| |Bessemer and Lake Erie Railroad | style="text-align:center;" |8 | style="text-align:center;" |451–455, 801–803 | | |
| |Chicago and North Western Railway | style="text-align:center;" |5 | style="text-align:center;" |1660–1664 | | |
| 150x150px | style="text-align:center;" |37 | style="text-align:center;" |300–324, 400–411 | 322-324 were built with the 567BC engine. To Burlington Northern 6023-6059
| |
| |Chicago, Burlington and Quincy Railroad (Colorado and Southern Railway) | style="text-align:center;" |10 | style="text-align:center;" |810–819 | To Burlington Northern 6070-6079
| |
| 150x150px
|Chicago, Burlington and Quincy Railroad (Fort Worth and Denver Railway) | style="text-align:center;" |11 | style="text-align:center;" |850–860 | 858-860 were built with the 567BC engine. To Burlington Northern 6080-6090
| |
| 150x150px | style="text-align:center;" |24 | style="text-align:center;" |2200–2223 | Renumbered 500–523, 2215-2223 were built with the 567BC engine.
| |
| |Central of Georgia Railway | style="text-align:center;" |1 | style="text-align:center;" |201 | | |
| |Denver and Rio Grande Western Railroad | style="text-align:center;" |5 | style="text-align:center;" |5300–5304 | | |
| |Great Northern Railway | style="text-align:center;" |23 | style="text-align:center;" |550–572 | To Burlington Northern 6000-6022 |
| |Kennecott Copper Corporation | style="text-align:center;" |1 | style="text-align:center;" |903 | | |
| |Minneapolis and St. Louis Railway | style="text-align:center;" |2 | style="text-align:center;" |852, 952 | Renumbered 300–301. To Chicago and North Western Railway.
| |
| |Nevada Northern Railway | style="text-align:center;" |1 | style="text-align:center;" |401 | Sold to LADWP in the 1980s; reacquired by Nevada Northern in 2021, along with RSD-4 #201.
|{{Cite web |title=Bring 401 and 201 Home |url=https://nnry.com/pages/bringHome.php}} |
| |Pennsylvania Railroad | style="text-align:center;" |2 | style="text-align:center;" |8588–8589 | These units were built with the 567BC engine. Later renumbered to 6950-6951, to Penn Central 6998-6999, and to Conrail 6998-6999
| |
| 150x150px | style="text-align:center;" |42 | style="text-align:center;" |5279–5293, 5309–5335 | 5321-5323, 5334-5335 were built with the 567C engine
| |
| |Union Pacific Railroad | style="text-align:center;" |10 | style="text-align:center;" |775–784 | | |
| !Total | 188 | ! |
|---|
Preservation
= Currently preserved =
- Burlington Northern #6008 (ex-Great Northern #558) is preserved at the Minnesota Transportation Museum in Saint Paul, Minnesota. #6008 was one of the first 20 SD7s to be built in 1952; it's currently under restoration to its original appearance as Great Northern #558.{{Cite web |date=2018-03-14 |title=Minnesota museum acquires Great Northern SD7 {{!}} Trains Magazine |url=https://www.trains.com/trn/news-reviews/news-wire/07-minnesota-museum-acquires-great-northern-sd7/ |access-date=2024-05-16 |website=Trains |language=en-US}}
- Southern #197 is preserved at the Virginia Museum of Transportation. It was originally built as Central of Georgia #201.
- Southern Pacific #1518 (ex-EMD demonstrator #990), is preserved in operational condition at the Illinois Railway Museum. #1518 was the first SD7 (later converted into an SD7R) built by EMD.
- Portland and Western formerly rostered SD7 #1501 (Ex-SP #5280), which was retired in 2023 as part of a fine resolution agreement with the EPA.{{cite web |title=G&W locomotives to scrap or upgrade per EPA decree in 2023 |url=https://www.trains.com/trn/news-reviews/news-wire/gw-locomotives-to-scrap-or-upgrade-per-epa-decree-in-2023/ |access-date=27 January 2023 |website=Trains.com}}
- The Dakota Southern Railway rosters one SD7, #512 (ex-MILW #2212)
- ILSX #1751 (ex-Pennsylvania Railroad #8589) is in operation at Red Trail Energy in Richardton, ND.
- Nevada Northern Railway 401 is in service at the Intermountain Power Plant in Delta, Utah. When retired, it will be donated to the Nevada Northern Railway Museum, as part of an agreement with the museum.{{Cite web |last=Franz |first=Justin |date=2021-09-29 |title=Nevada Northern Raising Money to Bring Two Historic Diesels Home |url=https://railfan.com/nevada-northern-raising-money-to-bring-two-historic-diesels-home/ |access-date=2024-03-09 |website=Railfan & Railroad Magazine |language=en-CA}}
References
{{reflist}}
Further reading
- {{Cite book |last=Solomon |first=Brian |url=https://books.google.com/books?id=bVEhihy7tKEC&dq=%22EMD+SD7%22+-wikipedia&pg=PA69 |title=American Diesel Locomotives |publisher=Voyageur Press |isbn=978-1-61060-605-9 |language=en |pages=69}}
- {{Cite book |last=Strapac |first=Joseph A. |url=https://openlibrary.org/books/OL8360777M/Southern_Pacific_Historic_Diesels_Volume_4_SD7_and_SD9_Locomotives |title=Southern Pacific Historic Diesels Volume 4, SD7 and SD9 Locomotives |publisher=Shade Tree Books, Bellflower, California |year=1997 |isbn=9780930742171 |edition=1st |ol=8360777M}}
- {{Cite book |last=Withers |first=Paul K. |title=Diesel Era, November/December 1995, Volume 6 Number 6 |publisher=Withers Publishing |year=1995}}
- {{Cite book |last=Shine |first=Joseph |title=SP into the '90's |publisher=Four Ways West Publications |year=1991 |isbn=9780685752104}}
- {{Cite book |last=Shine |first=Joseph |title=SP 1987/88 Motive Power Pictorial |publisher=Four-Ways West Publications |year=1988 |isbn=9780961687434 |edition=1st}}
- {{Cite book |last=Signor |first=John R. |url=https://books.google.com/books?id=JbG3AAAAIAAJ&q=EMD+SD7R+-wikipedia |title=SP Trainline - Issues 83-93 |publisher=Southern Pacific Historical & Technical Society |year=2005 |edition=1st}}
- {{Dorin-North Western|page=114}}
- {{cite book|last=Pinkepank|first=Jerry A|title=The Second Diesel Spotter's Guide|year=1973|publisher=Kalmbach Books|lccn=66-22894|isbn=0-89024-026-4|pages=17, 26, 71–72}}
- {{Cite web |last=Sarberenyi |first=Robert |title=EMD SD7 Original Owners |url=http://www.trainweb.org/jaydeet/sd7.htm |access-date=2006-08-27 |website=www.trainweb.org}}
- Diesel Era Volume 6 Number 6 November/December 1995, "EMD's SD7" by Paul K. Withers pp 5–20; 47–50.
External links
{{Commons}}
- [https://web.archive.org/web/20191028010245/https://vignette.wikia.nocookie.net/obts/images/8/8c/Bogi.xCxx_1952.EMCo_1m435~1m016~4m140~29t82~152k9.PDF#page=1 Locomotive Truck EMD FlexiCoil C]
{{EMD SDs}}
Category:Diesel–electric locomotives of the United States
Category:Railway locomotives introduced in 1952
Category:Standard-gauge locomotives of the United States
Category:Baltimore and Ohio locomotives
Category:Chicago and North Western Railway locomotives
Category:Chicago, Burlington and Quincy locomotives
Category:Denver and Rio Grande Western Railroad locomotives
Category:Great Northern Railway (United States) locomotives
Category:Milwaukee Road locomotives
Category:Pennsylvania Railroad locomotives