What is "top and tail"

n. The top and bottom of something vb. 1 To add to the beginning and end of something, such as the salutation and valediction added to a letter 2 To remove something from the top and bottom of an item, such as in preparing carrots for the pot 3 (sense: colloquial) To bathe a small child in a minimal way by wiping its face and bottom

A top-and-tail railway train has locomotives at both ends, for ease of changing direction. This is a British term. It is normal for only the leading locomotive to power the train when in top-and-tail mode, cf push pull operation with both locomotives powering.

It is properly distinct from a push-pull train, which has a locomotive at one end and a control cab at the other end.

Trains going up zig zags of the Khyber Pass are top-and-tailed, although Pakistan Railways calls this by a different term.

In Japan, the term " push-pull" is confusingly used to describe trains top-and-tailed with a locomotive at either end. (True push-pull operation with a locomotive at one end is not seen on Japanese mainline railways.)