Four Axle Units On Mainline Trains

Gee, that train probably accelerates faster than my old Jeep…I wonder what the 0-60 time on those is.

I would maybe use both to accelerate, but when at speed I’d take the head-end engine off-line.

The P42s have 38,000# TE continuous with a minimum continuous full HP speed of 38mph, and a max speed of 110 mph. That implies some really “tall” gearing. Implied adhesions is about 24%. They have standard GE DC traction motors (752AH)

The HEP can siphon off up to 800KW.

Taking the Pennsylvanian as an example, 6 Amfleet cars going up HSC need about 15,000# TE (6 cas x 60 tons per car x 20 #/ton/% x 2% grade) so a single P42 is more than enough and can easily climb the hill at the 30-35 mph track speed.

There’s a neat video by “delayed in block” on YouTube that shows a couple of Wolverines. One with a P42 and one with an Siemens loco. The Siemens loco accelerated the train rather swiftly from the stop. The P42 is really slow. The difference is the loading rate of the GE. Takes it 80 seconds to get from idle to full load, and the first minute of that it doesn’t even get half way there.

You are comparing apples with oranges, or perhaps more apt you are attributing bug behavior to something GE knows and considers an explicit feature.

I think it’s well established that GEs in general load slow because the ‘computer is programmed that way’. For a large part of recent history this involved an attempt to limit sooting and other exhaust pollution. Perhaps a better idea of what a 7FDL can do is the acceleration of a U34CH when its engine is already at high nominal RPM and all that’s needed is to add more fuel into the traction load, bypassing the artificial map of rotational speed increase by notch.

Now I’d expect a GE accelerated at what would be ‘natural’ full acceleration would smoke at least as bad as a 251 until the turbo caught up, but it would sure accelerate much more quickly than you seem to imply GEs are power-limited to do.

A unicorn on CP train 253…

https://www.railpictures.net/photo/703315/

Up until a few years ago, UP in Roseville used GP60s and GP40-2s in regular service on Locals and occasionally on Haulers. However, between the SD59MXs and the SD70Ms getting supplanted by ACes, the 4 axles almost never make it on to a hauler any more and even the locals often have a 59MX or SD70M or SD40-2 mixed in with the 60s and 40-2s.