six foot

The six foot is the space between the running rails of two adjacent standard gauge railway lines. Despite its name, the actual measurement varies by railway authority and country. On British railways, it typically measures between 1.83 metres (6 feet) and 2.13 metres (7 feet) from the outer edge of one rail to the outer edge of the adjacent rail. The term persists as a piece of railway vocabulary even when the physical distance differs from six imperial feet.

This gap exists to allow safe passage for workers, equipment, and maintenance vehicles between tracks without fouling the running lines themselves. In marshalling yards and sidings with multiple parallel tracks, the six foot becomes crucial for movements along the line during shunting operations. Track workers, fitters, and inspectors move through the six foot regularly during maintenance windows. The space must remain clear of permanent obstructions, though temporary equipment like lamps, tools, and cable runs are often positioned there during work.

Variations and practical constraints

The six foot shrinks noticeably where permanent structures encroach on it. Platforms, signal posts, bridge supports, and lineside buildings can reduce the working space significantly. Some older lines have six foots as tight as 1.5 metres, creating genuine hazard for personnel working between running lines. Modern signalling and electrification equipment installed in the six foot can further obstruct movement and visibility, particularly when two overhead line systems run parallel to one another.

The term itself originated in the early railway era when this measurement was standardised across British rail networks. It remains embedded in railway language and construction standards even on modern lines where actual spacing may be specified more precisely in millimetres. Different railways set different minimum distances, and heritage lines may follow historical spacing. The six foot is distinct from the platform road, which is the space between a platform and an adjacent track, usually wider and designed for passenger and goods handling rather than personnel access.

Working in the six foot during line operations requires strict safety protocols. Track workers must be protected by lookouts, speed restrictions, or line closures depending on traffic density. The confined nature of the space and proximity to moving trains makes it one of the more hazardous work environments in railway maintenance. Understanding what the six foot is, and recognising where it is too narrow or obstructed, is fundamental safety knowledge for anyone working on or around railway lines.