scope:

This standard applies to work which disturbs, or may disturb the physical construction or the adjustment to the working of signalling and control systems on the railway.

Attachment 1 records the status of various Departmental and Group Quality Notices (DQNs and GQNs) and their superseding standards or documents, where relevant.

Purpose

The purpose of this Standard is to bring together various key safety critical processes which shall be followed when work is undertaken which disturbs, or may disturb the physical construction or the adjustment to the working of signalling and control systems on the railway.

This standard defines processes directly impacting on the operation of signalling or control systems, which shall be applied in a consistent way in order to facilitate the management or monitoring of safety.