The EMD MP15, sometimes referenced as MP15DC, is a 1,500 hp (1,119 kW) diesel–electric road switcher locomotive model produced by General Motors' Electro-Motive Division between 1974 and 1980. It was equipped with a V12 12-645E engine sporting a Roots blower. The length was either 47 ft 8 in (14.53 m) or 48 ft 8 in (14.83 m) depending on the build date.

The early MP15 and the SW1500 were similar in appearance and applications. They were fitted with the same engine in a similar appearance. The primary difference is the MP15's standard Blomberg B trucks.

Development

Mosaic 212, an EMD MP15DC Fort Meade, Florida

Switchers up to the SW1500 had been restricted to AAR type A switcher or Flexicoil lightweight trucks, both with a 96 in (2,438 mm) wheelbase. In 1973 60 special order Mexico-only SW1504s were built on a slightly longer frame, allowing EMD's standard Blomberg B trucks, with a 108 in (2,743 mm) wheelbase, to be used. In EMD's eyes (among others) this made the new locomotive a road switcher rather than a pure switcher, since it was capable of road speeds up to 60 mph (97 km/h) or so. The new model MP15DC designation thus meant Multi-Purpose locomotive, 1500 hp, DC generator. Originally the locomotive was simply designated the MP15; the arrival of the alternator/rectifier MP15AC in 1975 changed the name.

With the success of the MP15, there was a demand for a model with an advanced AC drive system. The MP15AC replaced the MP15DC's DC generator with an alternator producing AC power which is converted to DC for the traction motors with a silicon rectifier. The MP15AC is 1.5 ft (457 mm) longer than an MP15DC, the extra space being needed for the rectifier equipment. The alternator-rectifier combination was more reliable than a generator, and this equipment became the standard for new diesel-electric locomotive designs.

The MP15AC was easily distinguished from the DC models. Instead of the front-mounted radiator intake and belt-driven fan used on all previous EMD switchers, these had intakes on the lower forward nose sides and electric fans. Side intakes allowed the unit to take in cooler air, and the electric fans improved a serious reliability issue found in its earlier DC sisters.

Engine

The MP15 used a 12-cylinder version of the 645E series engine developing 1,500 hp at 904±4 rpm. Introduced in the SW1500, this was a 2-stroke, 45-degree V type, with a 9 1⁄16-inch bore by 10-inch stroke, giving 645 cubic inches displacement per cylinder. The 645 series, introduced in 1966, was EMD's standard engine through the 1980s.

Original buyers

RailroadQuantityRoad numbersNotes
Alcoa17
Alton and Southern Railway11522
Altos Hornos de México5146–148, 159, 166
American Cyanamid218, 19
Arizona Public Service12
Bauxite and Northern Railway215, 16
BC Hydro3151–153
Belt Railway of Chicago4533–536
Birmingham Southern Railroad2260, 261
Cambria and Indiana Railroad219, 20
Chicago and Northwestern151302–1316C&NW 1313 retired prior to UP merger. Remaining 14 units renumbered to UP 1315–1328 in 2000–2001.
Cities Service1109
Conn. Davison Chemical Division4121, 122, 131, 132
Genesee and Wyoming Railroad245, 46
Georgetown Railroad21011, 1012
Graysonia, Nashville & Ashdown Railroad180
Gulf Oil1101
Houston Belt & Terminal Railroad560–64
Industrial Minera México22, 10
Kansas City Southern Railway44363–4366
Kelly's Creek and Northwestern Railroad21, 2
Lake Erie, Franklin and Clarion Railroad425–28
Louisville and Nashville Railroad105030–5039
Manufacturers Railway3251, 252, 254
Metropolitan Sanitary District of Greater Chicago14
Missouri Pacific Railroad621530–1554, 1356–1392#1530 was the first MP15 built; renumbered by UP as 1330–1392 between 1986 and 1993.
North Louisiana and Gulf Railroad442–45
Pittsburgh and Lake Erie Railroad251574–159815 units sold to Union Pacific in 1985 (1574-1583 and 1584, 1587, 1588, 1596 and 1598). Repainted and numbered 1300-1314 by UP in 1987.
Point Comfort and Northern Railway511–15
Quebec Iron and Titanium29, 10
Reading Company102771–2780Equipped with remanufactured and renewed ALCO RS-3 truck assemblies, including the General Electric 752 traction motors. To Conrail as #9621–9630
Rockdale, Sandow and Southern Railroad313–15
Southern Pacific Railroad122690–27012691 and 2692 retired in 1994 and sold to Progress Rail, then OmniTRAX, and then Helm Financial, which leased them to Union Pacific as 1289 and 1290; these retired from UP in 2002 and sold to Caltrain in 2003 as 503 and 504. 2690 rebuilt by Union Pacific in 2005 and renumbered to 2005 as a GS14B Truck Engine Switcher, which was the first Genset locomotive. 2697 retired prior to merger with UP; remaining eight (2693-2696;2698-2701) renumbered consecutively as UP 1292-1299 after merger.
Southern Railway882348–2435
St. Louis–San Francisco Railway5361–365To Burlington Northern Railroad as #4000–4004, later renumbered to #1000–1004
St. Mary's Railroad2504, 505
Swift Chemical Company11976
Tennessee Eastman12
Terminal Railway Alabama State Docks7761, 771, 772, 801, 802, 821, 822
Texas and Northern Railway2998, 999
Texas City Terminal Railway335–37Split from the last Missouri Pacific order of MP15DCs. Painted and lettered for Missouri Pacific
Union Railroad2410–33
U.S. Steel15170, 955–968
Total351

See also

Notes

  • Combs, John (2006). . John's Alaska Railroad Web Page.
  • . GATX Rail Locomotive Group. Archived from on April 8, 2005.
  • Hayden, Bob, ed. (1980). Model Railroader Cyclopedia-Volume 2: Diesel Locomotives. Kalmbach Books. ISBN 0-89024-547-9.
  • Strack, Don (2004). . Utah-Rails. Archived from on April 24, 2005.