pilot engine

American  

noun

1. a locomotive sent on ahead of a railroad train to see that the way is clear and the track safe.

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pilot engine British  

noun

1. a locomotive that leads one or more other locomotives at the head of a train of coaches or wagons

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Etymology

Origin of pilot engine

First recorded in 1830–40

Example Sentences

A special pilot engine, tugging three cars full of Secret Service agents and railroad detectives, pulled out five minutes ahead of the presidential special to scout out possible sabotage along the 133-mile run.

From Time Magazine Archive

The pilot engine is fifteen minutes in advance of the Royal carriages at every station, and the space travelled over in that fifteen minutes is kept free and unobstructed. 

From Railway Adventures and Anecdotes extending over more than fifty years by Various

Order a pilot engine immediately to take me to Moscow.

From The International Spy Being the Secret History of the Russo-Japanese War by Upward, Allen

A pilot engine has gone before to keep the way clear. 

From Railway Adventures and Anecdotes extending over more than fifty years by Various

If word reached town that a bridge was down, The imperious summons rang — 'Come out with the pilot engine sharp, And away with the flying gang.'

From The Man from Snowy River by Paterson, A. B. (Andrew Barton)