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EMD MP15DC
UP 1363 (ex-MP 1363) in Silvis, Illinois (2020)
Type and origin Power type Diesel-electric Builder Electro-Motive Division (EMD) Model MP15DC Build date 1974–1980 Total produced 351
Specifications Configuration: ​  • AAR B-B Gauge 4 ft 8+1⁄2 in (1,435 mm) standard gauge Trucks Blomberg B Wheel diameter 40 in (1,016 mm) Minimum curve 55° (107 ft (32.614 m) Wheelbase 24 ft 2 in (7.366 m) between bolsters; 9 ft 0 in (2.743 m) between axles in each truck Length 47 ft 8 in (14.53 m) or 48 ft 8 in (14.83 m) depending on build date Width 10 ft 0+3⁄4 in (3.067 m) Height 15 ft 0 in (4.57 m) Loco weight 248,000 lb (112,493 kg) Fuel capacity 1,100 or 1,400 US gal (4,200 or 5,300 L; 920 or 1,170 imp gal) Lubricant cap. 197 or 284 US gal (746 or 1,075 L; 164 or 236 imp gal) Coolant cap. 230 US gal (871 L; 192 imp gal) Sandbox cap. 0.849 or 1.133 m (30.0 or 40.0 cu ft) Prime mover EMD 12-645E RPM: ​  • RPM low idle 235 RPM  • RPM idle 318±4 RPM (normal) 517±15 RPM (switching 2 mode)  • Maximum RPM 904±4 RPM Engine type V12 diesel Aspiration Mechanical using a Roots blower 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+1⁄16 in × 10 in (230 mm × 254 mm) Gear ratio 62:15
Performance figures Maximum speed 65 mph (104.6 km/h) Power output 1,500 hp (1,119 kW) Tractive effort 62,000 lbf (275.79 kN)

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

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.

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

See also

• List of GM-EMD locomotives
• EMD_MP15AC

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. ^ EMD MP15DC Locomotive Service Manual (2nd ed.). Electro-Motive Division. November 1980. 32S980.
3. ^ Pinkepank, Jerry A. (1973). The Second Diesel Spotter's Guide. Kalmbach Books. pp. 10, 12–13, 48–50. LCCN 66-22894.
4. ^ Pinkepank, Jerry A.; Marre, Louis A. (1979). Diesel Spotters Guide Update. Kalmbach Books. pp. 4–9. ISBN 0-89024-029-9.
5. Johnston, Howard; Harris, Ken (2005). Jane's Train Recognition Guide. HarperCollins Publishing. pp. 414, 425. ISBN 978-0-06-081895-1.
6. ^ "Union Pacific Railroad: Roster of Diesel and Turbine Locomotives, 1934-2009". UtahRails.net. March 14, 2023. Retrieved December 20, 2024.
7. EMD MP15 Specifications for Order A-74741. Electro-Motive Division. September 1973. 8097-5.

References

• Combs, John (2006). "Alaska Railroad Locomotive Roster". John's Alaska Railroad Web Page. Retrieved May 14, 2006.
• "MP15DC specification page". 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). "Union Pacific Railroad Locomotive Model Quantities – All-Time (1934–2002)". Utah-Rails. Archived from the original on April 24, 2005. Retrieved April 6, 2005.

• B-B locomotives
• Electro-Motive Division locomotives
• Diesel–electric locomotives of the United States
• Standard gauge locomotives of the United States
• Standard gauge locomotives of Canada
• Shunting locomotives