EMD MP15DC

The EMD MP15, sometimes referenced as MP15DC, is a 1,500 hp (1,100 kW) switcher-type diesel locomotive model produced by General Motors' Electro-Motive Division between 1974-1980. It was equipped with an 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.^[1]

EMD MP15DC
Mosaic 212, an EMD MP15DC Fort Meade, Florida.
Type and origin Power type Diesel-electric Builder Electro-Motive Division (EMD) Build date 1974–1980^[1] Total produced 351
Specifications Configuration: ​  • AAR B-B Gauge 4 ft 8+1⁄2 in (1,435 mm) standard gauge Trucks 9 ft 0 in (2.743 m) Wheel diameter 40 in (1,016 mm) Length 47 ft 8 in (14.53 m) or 48 ft 8 in (14.83 m) depending on build date^[1] Width 10 ft 0+3⁄4 in (3.067 m) Height 15 ft 0 in (4.57 m) Loco weight 258,000 lb (117,000 kg)^[1] Fuel capacity 1,100–1,400 US gal (4,200–5,300 l; 920–1,170 imp gal) Prime mover EMD 12-645E Engine type V12 diesel Aspiration Mechanical Displacement 645 cu in (10.57 L) / cyl 7,740 cu in (126.8 L) Generator D32 Traction motors 4 × D77/78 DC Cylinders 12 Cylinder size 9 in × 10 in (229 mm × 254 mm)
Performance figures Power output 1,500 hp (1,100 kW) Tractive effort 62,000 lbf (275.79 kN)

The early MP15 and the SW1500 were similar in appearance and applications. They were fitted with the same engine (a V12 EMD 12-645E) in a similar appearance. The primary difference is the MP15's standard Blomberg B trucks.^[1]

Development

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 is more reliable than a generator, and this equipment became the standard for new diesel-electric locomotive designs.

The MP15AC is easily distinguished from the DC models. Instead of the front-mounted radiator intake and belt-driven fan used on all previous EMD switchers, these have 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.^[2][3][4]

Engine

The MP15 used a 12-cylinder version of the 645E series engine developing 1500 hp at 900 r.p.m. Introduced in the SW1500, this was a 2-stroke, 45-degree V type, with a 9-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.^{[2]: 26 [3]}

See also

• List of GM-EMD locomotives

Notes

1. Solomon, Brian (June 15, 2016). Field Guide to Trains: Locomotives and Rolling Stock. Voyageur Press. p. 44. ISBN 978-0-7603-4997-7 – via Google Books.
2. Pinkpank, Jerry A. (1973). The Second Diesel Spotter's Guide. Kalmbach Books. pp. 10, 12–13, 48–50. LCCN 66-22894.
3. Pinkepank, Jerry A.; Marre, Louis A. (1979). Diesel Spotters Guide Update. Kalmbach Books. pp. 4–9. ISBN 0-89024-029-9.
4. Johnston, Howard; Harris, Ken (2005). Jane's Train Recognition Guide. HarperCollins Publishing. pp. 414, 425. ISBN 978-0-06-081895-1.

References

 

Wikimedia Commons has media related to EMD MP15DC locomotives.

• Combs, John (2006). "Alaska Railroad Locomotive Roster". John's Alaska Railroad Web Page. Retrieved May 14, 2006.
• . GATX Rail Locomotive Group. Archived from the original on April 8, 2005. Retrieved April 5, 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 the original on April 24, 2005. Retrieved April 6, 2005.