Headshunt

A headshunt (US: escape track) is a short length of track, provided to release locomotives at terminal platforms, or to allow shunting to take place clear of main lines.

Terminal Headshunts

A terminal headshunt is a short length of track that allows a locomotive to uncouple from its train, move forward, and then run back past it on a parallel track. Such headshunts are typically installed at termini to allow the locomotive of an arriving train to move to the opposite end of (in railway parlance, 'run around') its train, so that it can then haul the same train out of the station in the other direction.

Shunting neck

The term headshunt may also refer to shunting neck or shunt spur: a short length of track laid parallel to the main line for the purpose of allowing a train to shunt back into a siding or rail yard without occupying the main running-line.

Run-round

To 'run round' is the practice of detaching a locomotive from its train, driving it to the other end of the train and re-attaching it, to allow the train to proceed in the direction it has just come from (e.g. when it reaches its destination and forms a service in the other direction). The cost (owing to the need to employ specialist staff to perform the dirty task at track level of detaching and attaching the loco, plus the dedicated track layout required) and complexity of this simple-sounding manoeuvre is one reason why loco-hauled trains are now scarce in the UK. Push-pull passenger service has also largely obviated this maneuver and the trackage required.