>>1084437Another thing N&S likes to do with old locomotives is to remake them as "slugs." A slug is usually a loco whose prime mover is worn out, but its traction motors are still good. The diesel engine is pulled and concrete weights are put its place. The concept is that a diesel electric can generate move power than it can use at slow speeds, so the slug is electrically connected to a standard locomotive to use its excess electrical power to add tractive effort. Yard slugs are generally cut down, like this one, for visibility.