Hey,
This may be a silly question but at our local yard (former BNSF branch through Sidney Montana, now owned by WACO (i think) on a lease) they have a couple of geeps, i never thought to look at what they actually were taking for granted they were just straight 38’s (assuming -2), i was waiting at the crossing to go back to work today and noticed that one was a GP38-3, so i guess the question is what is the difference between -2 and -3?
Ken
first of all, -3 is not an official name from EMD. It’s an aftermarket term.
Generally speaking it means the loco has been upgraded to include either a Qtron or EM2000 computer system similar to what the Superseries (50/60) introduced.
The ‘-3’ is an aftermarket term. It can mean just about anything. The DM&E has a group of GP38-3 engines. They were rebuilt out of old GP40’s that were de-turboed, but still have the GP fans and longer radiator grills. Only the twin non-turbo exhast stacks are the real external spotting features
Jim
Well, I somewhat disagree, while -3 does not have a single explicit and specific meaning, it does generally mean upgrade to computerized excitation/control via EM2000 or Q-tron computers. NS is the only railroad I’m aware of that does not use -3 to mean this.
-2 means solid state electricals, relays and modules.
…and just to further complicate the issue, I recall reading a few years back in EXTRA 2200 SOUTH of a rebuilding program to remanufacture GP38s into GP38-4s…these retained their as-built generators (rather than being upgraded with alternators) but had modular electronics and a microprocessor control system installed…
How would the upgade of an engine, e.g: an SD40 rated at 3000 HP to an SD40-3 rated at 3300 HP and upgraed to -3 electronics affect their tractive effort?.
The better wheelslip controls might make it pull a little better at low speeds, but most 6-axle engines of similar weight will pull about the same. Higher horsepower enables running at faster speeds with the same load.
The tractive effort/horsepower line is usually around 12-15 mph.
The higher horsepower from the SD40 probably wouldn’t be worth it. More wear and tear on the prime mover to get that extra 300 hp, not to mention all the extra fuel. Radiator and other systems built for 3000 hp may not handle the extra power. An overhaul to get back to the rated 3000 hp would be good enough, and with the new emissions regs, who knows what exactly is allowed.
I haven’t read of too may instances in the “modern” era of rebuilding 645 powered EMDs where the engines are uprated, more often they are derated to improve reliability…
And that derating is generally for 20 Cylinder SD45 and 645F3 SD50s.
According to information lthe Minnisorta Commercial Railroad, the RS20’s which are rebuilt RS3’s upgraded to 2000 HP with 251 engines instead of the original 244’s.and have weight added. The additional weight results in a starting tractive effort of 61575 pounds vs 60000 for an RS3. So the additional HP does not do anything fo enhance a locomotioves TE. It would allow you to run at higher speeds without stressing the power plant.
Was that misspelling intentional? Appropriate for a road that has a lot of switching!
Ironically, the Oct Trains has a short article on Dash-3s adding the computer.
I wonder if this thread had anything to do with it.