EMD SD7R

The EMD SD7R was a rebuild from EMD SD7 diesel locomotives that were built by General-Motors Electro-Motive Division for the Southern Pacific Transportation Company.[1][2]

EMD SD7R
Two of SP's then forty-year-old SD7R's still at work switching the East End of the Roseville Yard.
Type and origin
Power typeDiesel-electric
BuilderGeneral Motors Electro-Motive Division (EMD)
ModelSD7
SD7R
Build dateMay 1951 – November 1953
Total produced42
Rebuild dateJanuary 1979 – June 1980
Specifications
Configuration:
  AARC-C
Gauge4 ft 8+12 in (1,435 mm) standard gauge
TrucksEMD Flexicoil C
Wheel diameter40 in (1,016 mm)
Minimum curve23° (250 ft (76.20 m) radius)
Wheelbase48 ft 7 in (14.81 m)
Length61 ft 2+34 in (18.66 m)
Width10 ft 8 in (3.25 m)
Height15 ft 4+12 in (4.69 m)
Loco weight309,000 lb (140,000 kg)
Fuel capacity1,200 US gal (4,500 L; 1,000 imp gal)
Prime moverEMD 567B (SD7)
EMD 16-645E3 (SD7R)
RPM range800
Engine typeV16 diesel engine
AspirationRoots-type supercharger
Displacement9,072 cu in (148.66 L)
GeneratorD-12-C
Traction motors(6) D-27-B
Cylinders16
Performance figures
Power outputSD7: 1,500 hp (1.12 MW)
SD7R: 2,000 hp (1.49 MW)
Tractive effort77,250 lbf (343,600 N)
Career
Numbers5279–5293, 5309–5335
2700–2742
1400–1442
1500–1542
LocaleUnited States
PreservedSee here
DispositionFour preserved (Three SD7Rs and one SD9M), one rebuilt into an SD9M, remainder scrapped

They were all originally built in May 1951 and November 1953 and rebuilt between January 1979 and June 1980.[2]

History

Between May 1951 and November 1953, the Electro-Motive Division had built and delivered a total of 42 EMD SD7 diesel locomotives for the Southern Pacific Transportation Company as the Southern Pacific needed more locomotives for their freight trains.[1][2]

When they delivered to the Southern Pacific Railroad, they were originally numbered in a 52 and 53 sequence, the first 15 locomotives as 5279–5293, and the remaining 27 locomotives as 5309–5335, with 5321, 5322, 5323, 5334 and 5335 being built with an EMD 567C prime mover, and the rest of them being built with an EMD 567B prime mover.[1][2]

Then, in 1965, they were renumbered in a 2700 sequence as 2700–2742 until in 1974, when they were all renumbered as 1400–1442.[1] Due to the age of the EMD SD7 locomotives and their 567B prime movers, this resulted in the Southern Pacific Transportation Company rebuilding all 42 of their EMD SD7 diesel locomotives of what had become the EMD SD7R between January 1979 and June of 1980 under the General Rehabilitation and Improvement Program (G.R.I.P).[1][3][2]

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 645E3 prime movers, this resulted in the power output being updated from 1,500 hp (1.12 MW) to 2,000 hp (1.49 MW).[3][2]

After all 42 of the Southern Pacific's EMD SD7 units were rebuilt under the Southern Pacific's General Rehabilitation and Improvement Program (G.R.I.P), the Southern Pacific Railroad renumbered them to 1500–1542.[4][2]

All of the SD7R locomotives were painted in Southern Pacific's "Bloody Nose" paint scheme, but surprisingly, no SD7R diesel locomotives were painted into Southern Pacific's SPSF "Kodachrome" livery, and all of them had their steam generators removed upon being rebuilt.[2]

A new electrical cabinet was fitted, which resulted in an 'umbrella' or 'hump' behind the locomotive's cab. Southern Pacific unit #1507 received a 'normal' 36" cap top dynamic fan and a flat top or high shroud type DA-2001 and also kept its non-standard fuel tank.[2]

A full SP 5 light show was fitted both at the front end and the rear end similar to a DW103 or made from DA1001, 1002, 1003.[2]

41 of the SD7R locomotives had their dual tanks removed while the other three units #1506, #1528 and #1533 had kept their dual tanks.[2] #1541 had the roadname stacked at the rear of the unit in a Roman script.[2]

All 42 units were retired from active service on the Southern Pacific Transportation Company.[5][2] Four units (#1502, #1504, #1511 and #1537) were given to Progress Rail of Fresno, California, six units (#1500, #1510, #1525, #1529, #1531 and #1535) were sold to San Joaquin Valley Railroad at Fresno, California on November 3rd, 1995, and two units #1530 and #1532 were delivered to the Willamette and Pacific Railroad.[5] While the rest stayed with the Southern Pacific either to be scrapped or be part of the Union Pacific's roster.[2]

Preservation

Out of all 42 of the EMD SD7R locomotives used on the Southern Pacific Transportation Company, four EMD SD7R diesel locomotives have been preserved:

See also

References

  1. Withers (1995), p. 5
  2. Shine (1991), p. 9-56, 186
  3. Signor (2005), p. 13
  4. "SP Rebuild Programs". utahrails.net. Retrieved 2023-09-30.
  5. "SP Retirements, 1995–1997". utahrails.net. Retrieved 2023-10-23.
  6. "IRM Roster – Southern Pacific 1518". Illinois Railway Museum. Retrieved 2008-06-27.
  7. Alberston, Bob. (1996). "EMD SD7-SP 1518, A precursor to all engines on rails today". Railfan & Railroad. Vol. 15. p. 50.
  8. Hering, Hasso. "Court decree affects two local locomotives". www.hh-today.com. Retrieved 2023-10-14.
  9. Hering, Hasso. "Locomotives: Old, not so old, and really new". www.hh-today.com. Retrieved 2023-10-14.
  10. "Diesel Motive Company". www.thedieselshop.us. Retrieved 2023-10-13.
  11. "Portland & Western". www.thedieselshop.us. Retrieved 2023-10-23.

Further reading

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