scope:

The document is mandatory for all Network Rail routes from the 4th December 2010.

The document is a safety critical specification and defines the actions to be taken to manage the safety clearance between trains and structures and other trains. This is a relational distance (gap) and may be affected by changes to the position of the track, the structure or both.

The requirements shall be applied by any individual, group or supplier working on Network Rail infrastructure in a maintenance, renewal or new build project capacity whose worksite may affect the track adjacent to any bridge, platform, structure or tunnel

Or

Whose worksite on any bridge platform, structure or tunnel may affect the clearance to trains on an adjacent track.

Or Whose worksite on any track may affect the clearance between trains on that track and any adjacent track.

The requirements of this specification apply to all works whether temporary or permanent and calculation of clearance dimensions shall be undertaken at any location prior to the passage of trains.

Purpose

This document sets out the activities and control mechanisms which shall be applied across the network to define, monitor, assess, correct and advise gauge and clearances on routes to enable the safe passage of prescribed rolling stock.