I have always wondered if it is possible to jump start a modern diesel electric locomotive. is it possible?

What kind of jump start are you talking about? A rolling push and the 'pop the clutch' per say? Something like that is not possible because Diesel Electric trains have multiple motors. To give a very simple explanation, a Diesel engine(s) which turns a generator to create electricity to power electric motors to move the train. There is no transmission in a modern Diesel locomotive.

But I guess if you are talking about jumper cables, I don't see why you couldn't jump your diesel battery to get the diesel engine started..

Miner Greg

I know that the locomotives have traction-motors. I love trains, so I know quite a bit. I was talking about if the starting battery was dead is it possible to jump it if you have another loco on a track next to it that you could run leads to.

Sure can, been there and done that a few time in years past. Cables in through the cab window from a running unit on an adjacent track, clip onto the knife switch. We had one GE unit that would not start one night, ran the batteries flat, got another alongside and still no start. Turned out some clown used the Emergency Stop switch and hadn't fully turned it back to the run position. I was out on the running board pulling open the injectors to help, got myself covered in GE soot. Two fitters, four enginedrivers and two firemen and we still missed positioning of the ES switch. Duh.

Chris
in New Zealand

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LOL! that sucks. What would you do if you didn't have a loco on an adjacent track? or no adjacent track for that matter?

so they actually make jumper-cables for locomotives? Wow, those things must be really long and very thick!

"so they actually make jumper-cables for locomotives? Wow, those things must be really long and very thick!"

Dave,
the battery voltage is 64v and auxilary generator output voltage is 74v so not really that heavy a lead. You're thinking about the 600v traction voltage. I doubt the cables were any longer than 12 ft.

Chris
in New Zealand

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Alive and Well....for now

ok.

Whoops missed seeing this bit, well any thinking crew wouldn't shut the unit down if they knew the batteries were sus, but that said....(!) it probably did happen. We on the old NZR didn't leave locos running like the Americans did. The GE U-26C's were bad at running cold when idling for a period of time so mods were made to run up the primemover every so often. Nowadays they have all sorts of gismos to save fuel.
Now if you didn't have another unit around for a jumpstart then another unit would have to be scrounged off the first train passing or another unit sent out to rescue. And if there were no side tracks, unless the cables were long enough to get units nose to nose then the dead unit would be towed to the first siding I guess. Loco's were more likely to be towed in because of traction motor flashovers than ever any had flat batteries and the only time I had a Diesel fail on the road was the fan speed increaser clutch coupling failed( the G-12's had EMD switchengine radiator drives). We just got cancelled and sent home on the Passenger.

Chris
in New Zealand

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Alive and Well....for now

Ok, cool. I've recently heard that you can also use an arc welder to jump them. Is this true?

what are flashovers like you mentioned? Also, I was recently train-spotting (yes, as well as being a modeler, I'm a "foamer" and proud of it!) at the local yard of the Canadian National in North Fondy, and saw a road locomotive on a RIP track with a pair of cables stretched between it and a pair of yard goats. I had my trusty scanner, so I was able to hear what was happening. I also was able to talk to a guy from the maintenance department who was going on break when this was happening, and he told me it was the result of a faulty grounding, so it shorted out the battery and completely drained it.

Flashovers or ground relays on Diesel-Electrics are caused by the traction motor brush arcing when seperated from the commutator. Rough track and grade crossings can do it, we called it brush bounce. Can get them in the Main Gen too I recall.
I never remember the big GE's ever having a G.R. though. Our GMD/EMDs had D-19 and D-29 traction motors.
As for jumping with an arcwelder, dunno!

Chris
in New Zealand

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Alive and Well....for now

I'm sorry, but I'm not much of an electrician,so you will have to walk me through what you mean. sorry.

I think a lot of the confusion has to do with each industry and/or shop uses terms that are unique to them. I'm pretty good at electronics but have some problems with loco. electrical since I have no experience with it.

In the example you gave: "and he told me it was the result of a faulty grounding, so it shorted out the battery and completely drained it." I don't fully understand what he means by faulty grounding, in my mind a faulty ground would indicate a poor or intermittently open connection on the return side of the circuit. Ground is commonly connected to the chassis, which is often connected to earth ground ( which reduces the chance of electrical shock).

But none of that would explain how that would drain a battery. To drain a battery both terminals would have to get connected together or the power side insulation would have to break down.

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I don't even know all the questions!

the traction motors got a good dousing of water when we had a large rain, and the loco was sitting in a (large) puddle up to it's walkways, and when they tried to move it atfer the puddle dried up, the traction-motors shorted out, over loading the circuit breakers, and killing the prime mover. then they had to tow it out of the water, and when tehy tried to restart it, it wouldn't. they completely drained the battery trying to get it started. (This was an old Wisconsin Central Geep) Tehy had it hooked up to a slug, so that didn't help any, either.