Slug cars

[Anonymous]

What is/was the purpose of "slug" cars in a hump yard? What equipment does the car carry, and what are the large wire or wires strung over the top?

[wabash1]

a slug is nothing more than extra traction motors for heping in movements in the yard. i have not had the pleasure of using one. and i dont remeber if they have dynamic capability or not.

[Anonymous]

A slug is a locomotive without a engine, it gets its power from the locomotive that it is coupled to, the large wires you saw. The purpose is to give the powered locomtive more slow speed power, if the diesel engine is run to full power with only 4 traction motors the locomotive will have wheel slip or be to fast for hump service, running less than full power waste fuel and will under be powered for hump service, the slug allows the locomotive to put full power across 8 traction motors at low speed and pull a long string of cars across the yard.

gwl
http://photosbygreg.20m.com

[Anonymous]

There are also some roads which have slugs built for service on road trains,generally local freights or heavy,bulk trains. CSX has a fleet of these rebuilt from old GP30/35/40 units. These retain the cab and carbody of the locomotive and also have dynamic brakes. The slug/mother set may be run from either cab.