Can anyone explain the differences between a GP-40 and the GP39H-2 that MARC Rail transit used?
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If I recall correctly, the GP39H2 was a locomotive rebuilt from GP40's by Morrison Knudsen for MARC. An additional generator was added to provide HEP power to the coaches for passenger service. This HEP generator required about 1000 HP (or one third of the total horsepower available) thus leaving them with about 2000 horsepower available to power the traction motors.
This is all from memory so......any corrections are welcome.
GP 40 , great info, thanks! I see they added an exhaust pipe out the back of the right side must be for the HEP addition.
My memory of these units is slowly returning .......The GP39H2's were rebuilt GP40s. Morrison-Knudsen rebuilt them from used GP40's by replaceing the 3000HP turbo charged 16 cylinder prime mover (standard GP40) with a turbo charged 12-cylinder prime mover (as the standard EMD GP39's had) for MARC. They were downgraded from 3,000 horsepower to 2,300 horsepower, and re-equipped with 4-stroke Cummins engines for the HEP generator, hence the additional exhaust pipe and muffler protruding from the air compressor compartment on the rear right side .
Hope I haven't confused you too much.
GP40, all great info! So as far as outside appearance its basically a GP40 with the added vent stack on the rear right side?
VistaDomeScott posted:GP40, all great info! So as far as outside appearance its basically a GP40 with the added vent stack on the rear right side?
Yes, for the most part. The original GP40's (wherever they came from) most likely would not have had the ditch lights or the anti climber ends when built by EMD ......and red marker lights were installed on both ends, in place of the original locomotive classification lights on the MARC GP39H2 rebuilds, for use when the locomotive is/was positioned on the rear of the movement in "push-pull" commuter service into and out of DC's Union Station.
There are many external differences between the a GP40 and the GP39H-2. Anticlimbers were mentioned, the rear step wells were completely replaced with vertical steps (similar to how tunnel motors looked), the long hood was extended on the back end to accommodate the needed space for the HEP, which also caused the rearmost radiator fan to be shifted back...the HEP exhaust muffler, round vent on the rear nose.
It also depends on what era they were seen in...a/c was added over time, as were ditchlights, a slightly different paint scheme, and now large metal buffer plates on the anticlimbers.
GP 40 posted:VistaDomeScott posted:GP40, all great info! So as far as outside appearance its basically a GP40 with the added vent stack on the rear right side?
Yes, for the most part. The original GP40's (wherever they came from) most likely would not have had the ditch lights or the anti climber ends when built by EMD ......and red marker lights were installed on both ends, in place of the original locomotive classification lights on the MARC GP39H2 rebuilds, for use when the locomotive is/was positioned on the rear of the movement in "push-pull" commuter service into and out of DC's Union Station.
Initially, they retained both the class lights and had red marker light housing installed. I believe the class lights disappeared after the first (post MARC) rebuild.
