EMD GP7

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EMD GP7
Illinois Terminal 1605, July 16, 2005, Illinois Railway Museum.jpg
Type and origin
Power type Diesel-electric
Builder General Motors Electro-Motive Division (EMD)
General Motors Diesel (GMD/GMDD)
Build date October 1949 – May 1954
Total produced 2,729 (plus 5 B units)
Specifications
Configuration:
 • AAR B-B
Gauge 4 ft 8 12 in (1,435 mm) standard gauge
Wheel diameter 40 in (1.016 m)[1]
Minimum curve 19° (301 ft (91.74 m) radius)
Wheelbase 40 ft (12.19 m)
Length 55 ft 11 in (17.04 m)
Width 10 ft 3 in (3.12 m)
Height 15 ft 0 in (4.57 m)
Loco weight 246,000 lb (112,000 kg)
Fuel capacity 1,600 US gal (6,100 l; 1,300 imp gal)[1]
Lubricant cap. 200 US gal (760 l; 170 imp gal)[1]
Coolant cap. 230 US gal (870 l; 190 imp gal)[1]
Sandbox cap. 18 cu ft (510 dm3)[1]
Prime mover EMD 567B[2]
RPM range 275–800[1]
Engine type V16 Two-stroke diesel
Aspiration Roots-type supercharger
Displacement 9,072 cu in (148.66 L)
Generator EMD D-12-B[1]
Traction motors (4) EMD D-27-B[1]
Cylinders 16
Cylinder size 8 12 in × 10 in (216 mm × 254 mm)
Loco brake Independent air; optional: dynamic brakes
Train brakes Air, schedule 6-BL[3] or 6-BLC[4]
Performance figures
Power output 1,500 hp (1,119 kW)
Tractive effort 61,500 lbf (274 kN)
Career
Operators See list
BBRR 1, a GP7, with the ODC special, Dillwyn, Virginia.
Chesapeake and Albemarle 2158 (an ex-ATSF GP7U) in Chesapeake, VA.
OmniTrack 4433 (a GP7 rebuilt by the Chicago and North Western Railway) spotted on CSX in Augusta, Georgia.

The EMD GP7 is a four-axle road switcher diesel-electric locomotive built by General Motors Electro-Motive Division and General Motors Diesel between October 1949 and May 1954.[2] Power was provided by an EMD 567B 16-cylinder engine which generated 1,500 horsepower (1,119 kW).[5] The GP7 was offered both with and without control cabs, and those built without control cabs were called a GP7B. Five GP7B's were built between March and April 1953.[2] The GP7 was the first EMD road locomotive to use a hood unit design instead of a car-body design. This proved to be more efficient than the car body design as the hood unit cost less to build, was cheaper and easier to maintain, and had much better front and rear visibility for switching.

Of the 2,734 GP7's built, 2,620 were for American railroads (including 5 GP7B units built for the Atchison, Topeka and Santa Fe Railway), 112 were built for Canadian railroads, and 2 were built for Mexican railroads.

This was the first model in EMD's GP (General Purpose) series of locomotives. Concurrently, EMD offered a six-axle (C-C) SD (Special Duty) locomotive, the SD7.

History[edit]

ALCO, Fairbanks-Morse, and Baldwin had all introduced road switchers before EMD, whose first attempt at the road-switcher, the BL2 was unsuccessful in the market, selling only 58 units in the 14 months it was in production.[6] Its replacement, the GP7, swapped the truss-framed stressed car body for an un-stressed body on a frame made from flat, formed and rolled structural steel members and steel forgings welded into a single structure (a "weldment"), a basic design which is still being employed today. Unfortunately, in heavy service, the GP7’s frame would bow and sag over time.[7] This defect was corrected in later models. The GP7 proved very popular, and EMD was barely able to meet demand, even after opening a second assembly plant at Cleveland, Ohio. Later, locomotives in EMD's GP-series came to be nicknamed ‘Geeps’. Many GP7s can still be found in service today, although most Class 1 roads stopped using these locomotives by the early 1980s.[citation needed] The "GP" designation stood for "general purpose", while the "7" had no meaning other than matching the EMD F7 cab unit then in production.[8]

Identification[edit]

The GP7, GP9 and GP18 locomotives share a similar car-body that evolved over time. Most GP7s had three sets of ventilation grills under the cab (where the GP9 only had one), and two pair of grills at the end of the long hood (where only the pair nearest the end was retained on the GP9).[2] However, some late GP7s were built with car-bodies that were identical to early GP9s. Early GP7s had a solid skirt above the fuel tank, while late GP7s and early GP9s had access holes in the skirt (see photo of Illinois Terminal 1605, top left). Many railroads later removed most of the skirt to improve access and inspection.

Locomotives could be built with the engineer’s control stand installed for either the long hood, or the short hood designated as the front. Two control stands for either direction running was also an option, but one end would still be designated as the front for maintenance purposes. The GP7 was also available with or without dynamic brakes, and a steam generator installed in the short hood was also an option. In the latter case the 1,600 US gallons (6,100 l; 1,300 imp gal) fuel tank was divided, with half for diesel fuel, and half for boiler water. One option available for locomotives without dynamic brakes, was to remove the two 22.5 in × 102 in (571.5 mm × 2,590.8 mm)[9] air reservoir tanks from under the frame, and replace them with four 12 in × 150.25 in (304.80 mm × 3,816.35 mm)[4] tanks that were installed on the roof of the locomotive, above the prime mover. These "torpedo tubes" as they were nicknamed, enabled the fuel and water tanks to be increased to 1,100 US gallons (4,200 l; 920 imp gal) each, although some railroads opted for roof-mounted air tanks and 2,200 US gallons (8,300 l; 1,800 imp gal)[10] fuel tanks on their freight ‘Geeps’.

Original buyers[edit]

Locomotives built by Electro-Motive Division, USA[edit]

Owner Quantity Numbers Notes
Electro-Motive Division (demonstrator)
1
525
1350 hp GP7m; to Atchison, Topeka and Santa Fe 99, renumbered 2899[11] This unit was built with a 567BC engine.
3
100 (ex 922), 200, 300
to Chicago & North Western 1518–1520
Aberdeen and Rockfish Railroad
1
205
Atchison, Topeka and Santa Fe
244
2650–2893
2855-2858 were built with 567C engines
5
2788A–2792A
GP7B; 2788A-2789A, 2791A-2792A were built with 567C engines
Atlanta and St. Andrews Bay
2
501–502
Atlanta and West Point Rail Road
5
571–575
Atlantic and East Carolina Railway
1
501
Atlantic Coast Line Railroad
154
100–253
Baltimore and Ohio Railroad
33
720–731, 740–746, 910–922, 6405
728-729; 740-746 were built with 567BC engines
Bangor and Aroostook Railroad
16
560–575
Belt Railway of Chicago
8
470–477
Boston and Maine Railroad
23
1555–1577
Butte, Anaconda and Pacific Railway
3
101–103
Central of Georgia Railway
15
106–107, 120–132
Central Railroad of New Jersey
13
1520–1532
Charleston and Western Carolina Railway
21
200–220
Chesapeake and Ohio Railway
180
5700–5719, 5739–5797, 5800–5900
5720–5738 built by GMD
Chicago and Eastern Illinois Railroad
30
203–232
Chicago and North Western Railway
110
1521–1550, 1556–1559, 1562–1599, 1601–1603, 1625–1659
Chicago and North Western (Chicago, St. Paul, Minneapolis and Omaha Railway—"Omaha Road")
11
151–161
Chicago, Burlington and Quincy Railroad
68
200–267
253-267 were built with 567BC engines
Chicago Great Western Railway
2
120–121
Chicago, Rock Island and Pacific Railroad
113
430–441, 1200–1237, 1250–1311, 1308 (2nd)
1294-1299 were built with 567BC engines
Clinchfield Railroad
17
900–916
Colorado and Wyoming Railway
2
103–104
Colorado Fuel and Iron
2
101–102
Columbia, Newberry and Laurens Railroad
5
100–104
Delaware, Lackawanna and Western Railroad
20
951–970
To Erie Lackawanna
Denver and Rio Grande Western Railroad
14
5100–5113
Detroit and Toledo Shore Line Railroad
10
41–50
Detroit, Toledo and Ironton Railroad
24
950–973
964-973 were built with 567BC engines
Erie Railroad
52
1200–1246, 1400–1404
To Erie Lackawanna
Florida East Coast Railway
15
607–621
Georgia and Florida Railroad
6
701–706
Georgia Railroad
16
1021–1036
1035-1036 were built with 567BC engines
Great Northern Railway
56
600–655
Illinois Central Railroad
48
8800–8801, 8850–8851, 8900–8911, 8950–8981
8800–8801, 8900–8911 had steam generators
Illinois Terminal Railroad
6
1600–1605
Kansas City Southern Railway
8
155–162
Kansas City Southern (Louisiana and Arkansas Railway)
5
150–154
Kansas, Oklahoma and Gulf Railway
9
801–809
Louisville and Nashville Railroad
61
400–440, 500–514, 501–502 (2nd), 550–552
Maine Central Railroad
19
561–569, 571–580
566-569 were built with 567BC engines
Meridian and Bigbee Railroad
1
1
Midland Valley Railroad
4
151–154
Minneapolis, St. Paul and Sault Ste. Marie Railroad ("Soo Line")
7
375–378, 381–383
Missouri Pacific Railroad
208
4116–4194, 4197–4325
29 units owned by International-Great Northern Railroad, 28 by St. Louis, Brownsville and Mexico Railway; 4290-4291, 4316-4320, 4325 were built with 567BC engines; 4292-4315, 4321-4324 were built with 567C engines.
Missouri-Kansas-Texas Railroad
33
1501–1529, 1761–1764
1700s had steam generators. Renumbered 91–123
Nashville, Chattanooga and St. Louis Railway
37
700–731, 750–754
700-705 built with AAR Type A Switcher Trucks
Ferrocarriles Nacionales de México
2
6600–6601
New York Central Railroad
218
5600–5817
35 units owned by Pittsburgh and Lake Erie Railroad (5676–5685, 5713–5737); 14 by Peoria and Eastern Railway (5612–5625)
New York, Chicago and St. Louis Railroad ("Nickel Plate Road")
48
400–447
Northern Pacific Railway
20
550–569
to Burlington Northern Railroad 1624–1643;[7] 560-569 were built with 567BC engines
Pennsylvania Railroad
66
8500–8512, 8545–8587, 8797–8806
Phelps Dodge Corporation
7
1–2, 7–8, 27–29
Portland Terminal Company [Maine]
1
1081
Reading Company
44
600–636, 660–666
625-636 were built with 567BC engines
Richmond, Fredericksburg and Potomac Railroad
4
101–104
Seaboard Air Line Railroad
123
1700–1822
Southern Railway
57
2063–2077, 2156–2197
Southern Railway (Cincinnati, New Orleans and Texas Pacific Railway)
11
6200–6205, 6240–6244
Southern Railway (Alabama Great Southern Railroad)
5
6540–6544
Southern Railway (Georgia Southern and Florida Railway)
4
8210–8213
St. Louis Southwestern Railway
1
320
Renumbered to 304
St. Louis-San Francisco Railway
129
500–549, 555–632, 615 (2nd)
Tennessee, Alabama and Georgia Railway
3
707–709
Texas and Pacific Railway
21
1110–1130
Texas Mexican Railway
3
850–852
Toledo, Peoria and Western Railway
2
102–103
Union Pacific Railroad
30
700–729
720-729 were built with 567BC engines
United States Army
20
1821–1840
Built with AAR Type A Switcher Trucks; 12 later served on Alaska RR
Wabash Railroad
33
450–452, 454–483
453 built by GMD
Western Maryland Railway
4
20–23
Western Pacific Railroad
13
701–713
Western Railway of Alabama
6
521–526
Totals 2617
5
GP7
GP7B

Locomotives built by General Motors Diesel, Canada[edit]

Owner Quantity Numbers Notes
Algoma Central and Hudson Bay
21
150–170
Canadian National Railways
25
4824, 7555–7578
4824 rebuilt October 1958 with parts from wrecked F3A.
Canadian Pacific Railway
17
8409–8425
Chesapeake and Ohio Railway
19
5720–5738
Quebec North Shore and Labrador Railway
22
100–101, 104–123
Toronto, Hamilton and Buffalo Railway
7
71–77
Wabash Railroad
1
453
Total 112

Rebuilds, modifications and conversions[edit]

There are five GP7s on A J Kristopan's EMD Serial number page that reused previous serial numbers: B&O 6405, CRI&P 1308 (2nd), L&N 501 (2nd) and 502 (2nd), and SLSF 615 (2nd). These rebuilt units were rebuilt as new on new frames. Another rebuild by GMD is that CN 4824 was rebuilt as a GP7 with parts from an F3A in October 1958.

A few production GP7s and four of the GP7Bs were built with 567BC or 567C engines starting in March 1953 through May 1954. These are noted on the roster above.

Many railroads rebuilt their GP7s with low short hoods; some railroads went further in their rebuilding than others. Missouri Pacific Railroad upgraded their GP7s with 567BC engines and replaced the standard EMD 2-stack exhaust with a 4-stack "liberated" exhaust, raising their power output to 1,600 horsepower (1.19 MW).[12]

Illinois Central Railroad rebuilt most of its GP7s with 567BC engine blocks, liberated exhausts, paper air-intake filters, 26-L brakes (their original 6-BL brakes made them operationally incompatible with locomotives fitted with 24-RL or 26-L brakes).[13] All but the first locomotive rebuilt had their front (short) hood reduced in height for improved crew visibility. The IC designated these rebuilt locomotives GP8. The IC acquired many second-hand units through Precision National Corporation (PNC), and then started offering GP8 rebuilding services to other railroads.

In the 1960s the Alaska Railroad purchased several standard GP7s from the US Army and rebuilt them into GP7Ls by removing the high hood on the head end and replacing it with a low hood for better visual clearance

Preservation[edit]

Georgia Railroad 1026, an EMD GP7 -- on permanent display in Duluth, Georgia.

Numerous GP7s have been preserved on tourist lines and in museums. Holders include:

See also[edit]

Notes[edit]

  1. ^ a b c d e f g h Schrenk & Frey (1988) p.291
  2. ^ a b c d Pinkepank, Jerry A. (1973) pp. 53
  3. ^ IC Railroad 1969 diesel diagrams, pp.46–47
  4. ^ a b NP Railway diesel diagram, NP 557–558
  5. ^ The History of EMD Diesel Engines
  6. ^ Pinkepank, Jerry A. (1973) p. 51
  7. ^ a b Schren & Frey (1988). p.162
  8. ^ Ephraim 1995, pp. 45–46
  9. ^ NP Railway diesel diagram, NP 550–551
  10. ^ Schrenk & Frey (1988). p.159
  11. ^ Pinkepank, Jerry A. (1973) p.56
  12. ^ Marre & Pinkepank (1988). p.192
  13. ^ Marre & Pinkepank (1988). p.183

References[edit]

EMD Product Reference Data Card dated January 1, 1959 has the 567BC and 567C engine data used in the as-built roster.