MP15 Series

From RailroadfanWiki

MP15DC

The MP15DC is a 4 axle, 1,500 HP diesel-electric locomotive built by EMD between 1974 and 1980. Like the SW1500 before it, the MP15DC uses a 12 cylinder 645 prime mover rated at 1,500 HP. The locomotive was marketed as a direct replacement of the SW1500, and the two locomotives are very similar mechanically and physically.

Unlike the SW1500 which could be ordered with Flexi-coil or AAR switcher trucks, the MP15DC came only equipped with Blomberg trucks, the same type used on EMD Geeps like the GP38-2. In addition to it's road switcher trucks, the MP15DC was also geared for speeds of up to 60 mph. EMD thus marketed it as a Multi-Purpose (hence the "MP") locomotive, being more than just a yard switcher. 351 MP15DC's were built, with the majority still in service for Class 1's, shortlines and leasers today.

Originally called the "MP15", the name was changed to "MP15DC" after the introduction of the MP15AC.

MP15AC

The MP15AC is a variation of the MP15 built by EMD and GMD between 1975 and 1984. MP15AC's use an alternator that produces AC power which is converted to DC power before it reaches the traction motors by a silicon rectifier. Visually, the MP15AC is somewhat different from the standard MP15DC. The MP15AC is 1 and 1/2 feet longer than the MP15DC, the extra space being taken up by the AC equipment. The MP15AC also has small air intakes located directly behind the nose on the sides of the locomotives, instead of the large single air intake on the nose of the MP15DC.

246 MP15AC's were built, 4 being built in Canada. Most remain in service today.

MP15T

The MP15T is another variant of the MP15 built by EMD from 1984 to 1987. Instead of the normally aspirated 12 cylinder 645 engine used in the MP15DC and AC, the MP15T uses a turbocharged 8 cylinder 645 to produce 1,500 HP. Because it used less cylinders and a smaller engine, the MP15T was more fuel efficient.

The only customers of the MP15T were Seaboard System (who ordered 42) and Dow Chemical (who ordered 1), making for a total production run of 43. The MP15T can be distinguished from the MP15DC and AC by the large bulge on the hood on the conductor's side of locomotive, which houses part of the turbocharger. The MP15T also has one short, fat exhaust stack, versus the 2 tall, skinny ones on the MP15DC and AC.

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