When attempting to start a heavy load on level grade and dry rail, at what throttle setting would the wheels start slipping (w/o turning sanders on), if at all, with something like an EMD GP7 or GP38-2? What about the SD40-2?
I once heard of a CNW engineer on a scrap train, running on a line that was currently being torn up did this before pulling out of town- he put the old GP7 in N8 (most likely w/ train brakes still set) and “burned 'em off” to make nice ruts in the rails, then he’d have a piece of rail to remember the CNW by(sort of a souviner)
I remember on a SP Magma local several years back, they were at McQueen siding switching out the newspaper plant, and with a pair of GP40-2s as power, the engineer slipped the wheels at about notch 5 on a cut of 30 cars, some of which had handbrakes set and the air line not hooked (and the car reservoirs not bled off).
Sounded and felt like an earthquake when the wheels started slipping.
It might be, depending on how much weight is behind the power, but also know that the traction motors will exceed their operating amp draw at stopped to low speeds and this may result in damage to the traction motors. Most engineers will thereby notch the throttle as needed to prevent this from happening, you’re generally not going to see an engineer throw it to run 8 on a stopped train.
define “start” you can put it from idle to run 8 as fast as you want but theres lag between that and “full power” at the rail…exciter load traction motor load generator load prime mover govenor…might only be a sec or two but its not like hitting the gas in your Hemi Cuda…plus all the othe rfactors im sure people have discussed…weather carload etc etc
Are you trying to kick cars, or pull them? When pulling, you would usually try to start in the lowest notch possible to get things moving. That way it is less likely to get a knuckle or drawbar.
Most diesels have automatic sanding, if needed. SD40-2s don’t like going from idle to Run8. [#oops]
The yard I’ve worked in is messed up. You have to kick at 10 mph to get the car to roll into the track instead of stalling out, or rolling back at you.[|(] I’ve had a pair of GP38s to switch out ~50 loads without air. You stop when you stop. Go to run8, loads up around 1100 amps. As you get moving, the amps drop. Shortly later, they say “That’ll do” and you go to idle and slap on the jammer. It was less than optimal to do it with 1 GP7.[censored] It loaded up slow, but went up to 1000-1100 amps. I had 5-6 cars with air to help stop within 1000 feet of where the cndr wanted me to.
They didn’t slip. When I was pulling the track out I had the sanders on. It is down hill pulling the track out, and kicking is uphill. By the first switch is the peak, and then the track goes downhill into the tracks. It isn’t quite right, have to kick them hard. If the yard is proper, just a little pin will get the cars to roll into the tracks, with out rolling back out at you. There is very little flat track anywhere. It goes up and down all over the place.
They still having problems with cars coming back out on the west end of that new yard??? There’s only about 6 feet or so of new rock under those switches because the grading crew screwed up.
you can pull with a wheel slip. wheel slip isnt bad if you are just spinning then you need to stop. and the only way you get things done around here with high tonage under powered train is to forget about the short time rating and keep on pulling.