645 posted:Lehigh Valley Railroad posted:Exactly. Get to track speed as quick as possible.
I rode an off-peak Long Island Rail Road train from Jamaica to Montauk and back some years ago in the cab with permission . . . Normally such a consist would have a single GP38-2 for power but we had a pair. Made for much faster acceleration from stops / speed restrictions. Do the math - that train had eight traction motors so was two more than what a single U34CH has so the two GP38-2's probably would be pulling away bit by bit if you could have them side by side from a stop if the consists being pulled were identical.
You are correct about the results of the race, but I believe you are giving too much weight to tractive effort and not enough to horsepower.
Tractive Effort is necessary to move tonnage without slipping or stalling. Horsepower is necessary for speed. I'll agree that the pair of GP38-2's would probably accelerate faster than the single U34CH, but it's because they have 4,000 horsepower and the GE only has 3,400 available for traction. Now, as to tractive effort, the GP38-2's had EMD's then-current wheel slip control, based on individual traction motor current, whereas the U34CH had GE axle alternator wheel slip which reacted if the speed of one axle increased significantly over the other axles. The EMD wheel slip system of that era was definitely superior to GE's, as it reacted much more quickly. And the GP38-2's would have had full field loading within seconds of advancing the throttle to Run-8 (maximum), whereas the GE's would have been regulating amperage to avoid black exhaust due to turbo lag (even though the diesel engine did not go to idle RPM's when the throttle was placed in Idle). In commuter service, the Engineer gets the train moving and then goes either straight to Run-8 or goes to Run 4 or 5 and then to Run-8. In any case the engine is fully wound up by the time the train is going 10 MPH (or 15 MPH with a single unit and a long train).
So. the pair of GP38-2's would have accelerated like a muscle car, while the GE would have mimicked a 1950 Dyna-Flow Buick. Race goes to EMD. Case closed.
