GP20 pusher duty

Was in Bingo today saw SU100 I think the eastbound what ever it is any how she had Three big Alc's and Two T's for power and half way through the cars comes GP20 2062 no crew but she was on line. STRANGE never seen that on the "Q" before.

There is a difference, between idling, and being on line. I seriously doubt the Suzy has invested in DP technology, then installed it on a GP-20. If there was no one on board, operating the loco, I would believe it to be idling, only. Just my thoughts, though......

Golden Arm... a question about idling. I understand that there's no DP functionality there. But an idling locomotive in line... does the idling engine still run an air compressor, or is the air line just a straight pass through in this situation?

If the engine is running the compressor is running, at least on a GP20. The brake pipe would be connected and cut in (anglecocks open) with the train, but the automatic brake valve on that unit would be cut out. This means the idling trailing unit would not be supplying air to the brake pipe.

Thanks! That's what I assumed, just looking for a professional confirmation.

Rich

Where in Binghamton? It may have been a BH- train setting it off somewhere along the line. OR they had to clear a switch, and were gonig to shove it back. They may have jsut put 2 trains together and not bothered to take it off.

She the GP20 was siting in the the back of the yard tucked in between some cars thought maybe off line mechanically.But the SU train started getting put together and the GP want along left the chase near KIRKWOOD.And I know she wasn't a pusher it just seemed odd that she would be idiling in mid consist.

Some roads also have restrictions, regarding hauling locos in a train, and the placement of those locos. The idling loco certainly does produce air, as stated by LCJ. With a driveshaft connecting the air compressor to the diesel engine, it pumps as long as the loco is running. (of course, if it hasn't been "unloaded", as to NOT pump air into the reservoirs.) The loco will store the air it pumps, locally, and will stop compressing the air, once it reaches the pre-set, cut-off pressure. Most roads have in train restrictions to the head-end, or sometimes up to 35 cars deep. That's the furthest back I have ever witnessed, personally, in a TT or SI. That loco is essentially a "boxcar", when placed back in the train, without a crew onboard. It's just there for the ride. Also remember, that the term "on line" means the unit is set up to be controlled, either from it's cab, or from another loco in the consist, or remotely. A unit simply idling, is "isolated" is not set up to produce power, and is isolated from a consist and will not respond to the commands of the controlling loco. (except for applications of the brakes. Regards