What are the differences between a slug, calf, and a B unit?
Slug : a unit that has no engine in it. Basically a weighted frame with trucks. It gets its power from an adjacent unit. There are both road slugs and yard slugs. The difference is usually what type of truck the unit has. Many slugs are recycled regular units.
Calf : A cabless switcher. A “B unit” switcher.
B Unit : A unit without full controls, that is designed primarily as additional power. It has all the same machinery as the A or controlling unit, but no place for an engineer to operate. Most had basic controls that could be used to hostled the engine by itself, but not full controls.
Dave H.