Rail Runner MP36PH-3C in New Mexico
|Builder||Motive Power, Inc. (Wabtec)|
|AAR wheel arr.||B-B|
|Gauge||4 ft 8 1⁄2 in (1,435 mm)|
|Wheel diameter||3 ft 4 in (1,020 mm)|
|Minimum curve||248 ft (76 m)|
|Wheelbase||9 ft 0 in (2.74 m) (original)
9 ft 4 in (2.84 m) (new)
|Length||68 ft (21 m)|
|Width||10 ft 7.5 in (3.239 m)|
|Height||15 ft 6 in (4.72 m)|
|Locomotive weight||285,000 to 295,000 lb (129,000 to 134,000 kg)|
|Prime mover||EMD 16-645F3B (MP36PH-3S,3C)
EMD 16-710G3B-T2 (MP40PH-3C)
|Top speed||108 mph (174 km/h)|
|Power output||3,600 hp (2,700 kW) (MP36PH-3S,3C)
4,000 hp (3,000 kW) (MP40PH-3C)
|Tractive effort||88,500 lbf (394 kN) (starting)
78,000 lbf (350 kN) (continuous)
MPXpress is a series of diesel-electric passenger train locomotives designed for commuter rail service. The manufacturer, Motive Power (Wabtec), offers the locomotives with a number of customizable options such as different prime movers and traction motors, head end power (HEP) generated by a separate engine or by the prime mover, and new or refurbished trucks. To date, MPI has offered four main variants: MP36PH-3S, MP36PH-3C, MP40PH-3C, and MP32PH-Q
The MPXpress line of locomotives were the first production passenger locomotives to meet EPA Tier 1 and Tier 2 emissions regulations, as well as FRA safety regulations regarding crashworthiness and fire safety. The line also meets APTA crashworthiness standards.
The MP36PH-3S uses a 16-cylinder EMD 645F3B diesel engine as its prime mover. Its HEP is generated from a static inverter that receives its power through connections to the prime mover — hence the "S" (static) designation. When providing full electrical power to the passenger cars connected to it, the prime mover must maintain a higher RPM in order to supply power to the passenger cars. The traction power when providing full HEP load of 500 kW is 2930 HP, since HEP generation diverts some power from the prime mover.
Chicago's Metra ordered 27 of these locomotives, which were built and delivered in 2003–2004. Fourteen were to replace Metra's aged F40C fleet, while the rest were for expansion. When the locomotives were first delivered, they exhibited software and computer problems, to the point that Metra had to put two F40Cs back into service for a short time in 2004. One of the unique features of the MP36s in Metra's fleet compared to other operators is that they are equipped with a Gyralite (which is standard equipment on all of Metra's passenger locomotives), which are mounted in the spot on the front of the locomotive where the locomotive number board would otherwise be located. Metra is currently the only operator of the MP36PH-3S version.
In November 2012, Metra announced plans to convert 17 of their MP36PH-3S locomotives to the MP36PH-3C standard in an effort to reduce noise pollution and boost fuel efficiency.
The MP36PH-3C has the same prime mover as the "-3S" model, the EMD 645F3B diesel engine, but with its HEP generated by a separate Caterpillar C-27  diesel engine, thus the "C" in its model name. In this arrangement, when providing HEP, the full 3600 HP from the prime mover is available for traction, and the prime mover is allowed to idle at a lower RPM. The Wabtec Q-Tron control system is used in all models built prior to 2008/9, while newer units use the same EM2000 system like GO Transit's MP40PH-3C.  Caltrain was the first to purchase the MP36PH-3C in 2003.
The MP40PH-3C is similar to the MP36PH-3C, but with several differences:
- the MP40PH-3C uses a 16-cylinder EMD 710GB series diesel engine instead of the EMD 645F3B, generating 4000HP instead of 3600.
- the use of EMD's EM2000 computer and associated control system instead of Wabtec/MPI's own system in the MP36.
- the use of an EMD alternator and traction motors.
GO Transit ordered 27 locomotives of this model to replace their aging EMD F59PH fleet, which were delivered throughout 2007 and 2008. An order for 20 additional units was signed in July 2008. In February 2010, yet another order was signed for 10 additional units. It was announced on November 1st, 2011 that GO Transit would be swapping out the EMD prime movers of 11 MP40s for the new Cummins QSK95. It is currently unknown if the engine swap program will be expanded to include the rest of the GO fleet which is still relatively young.  More recently, it was decided that two QSK60s would be installed in lieu of the QSK95. This would provide a power increase to 5400 horsepower and improve emissions to EPA Tier IV standards.
While GO Transit at this time is the only operator of this locomotive, Sound Transit has placed an order for 3 of these models to be used on their Sounder commuter rail service. They are to meet EPA Tier III emissions regulations.
The MP32PH-Q was built for SunRail to the similar specifications as new MPXpress but are refurbished units that had previously operated on MARC as GP40WH-2 locomotives. Inside the locomotive, the engines have been rebuilt and electronics have been upgraded using the same equipment as other MPXpress locomotives, but on the outside the MP32PH-Q retains the hood unit layout of the GP40WH-2 (but with a new MPXpress cab.) 
|MP36PH-3C||Caltrain||San Francisco, California||6|
|FrontRunner||Salt Lake City, Utah||11|
|Metrolink||Los Angeles, California||15|
|Northstar Line||Minneapolis, Minnesota||6|
|New Mexico Rail Runner Express||Albuquerque, New Mexico||9|
|Virginia Railway Express||Washington, D.C./Virginia||20|
|West Coast Express||Vancouver, British Columbia||1|
|MP40PH-3C||GO Transit||Toronto, Ontario||57 + (10)|
|Sounder Commuter Rail||Seattle, Washington||3|
|MP32PH-Q||SunRail||Greater Orlando, Florida||(7)|
- Lex, Robert (29). "Northstar Commuter Rail MP36PH-3C Parts". Parts List for MPXpress locomotives.
- Cummins to produce Tier 4 compliant diesel engine - Railway Gazette
- "SunRail, Sound Transit order MotivePower locomotives". Trains Magazine. September 12, 2011. Retrieved September 13, 2011.
- "A very Colorful Line-up at Motive Power today". Retrieved 24 October 2013.
- http://discuss.amtraktrains.com/index.php?/topic/57022-sunrail-locomotive-delivered/ First SunRail locomotive delivered
|Wikimedia Commons has media related to MPI MP36PH-3S locomotives.|
|Wikimedia Commons has media related to MPI MP36PH-3C locomotives.|
|Wikimedia Commons has media related to MPI MP40PH-3C locomotives.|