Rail Gauge

Rail Gauge

Track gauge is a technical term used in rail transport to define the spacing of the rails in an individual railway track.

All the vehicles operating over a network must have running gear that is compatible with the track gauge, and in the earliest days of railways, selection of a proposed railway's track gauge was a key issue.

As the dominant parameter determining interoperability, it is still frequently used as a descriptor of a route or network.

There is a distinction between the nominal track gauge of a network and the actual current track gauge at some locality, due to divergence of the track components from the nominal. Railway engineers use a device to measure the actual track gauge, and this device is also referred to (in another sense of the words) as a track gauge.