scope:

This specification applies to all signalling schemes and detailed design where signals are altered or new signals introduced, or where signalling control panels, signal boxes and Visual Display Units are altered or new ones introduced.

The plating of signals is specified in Section D110, and the control of signals is specified in Section D310. 'Signals On' controls are covered in NR/SP/SIG/10131.

This specification applies where the control of the signal is automatic irrespective of whether the signal is plated as passable or non-passable.

Purpose

This section forms part of the Signalling Principles Handbook (NR/L2/SIG/30009) and is to be read in conjunction with the other modules of the handbook.

This Section details Network Rail's policy on Signal Replacement Facilities and comprises mandatory sections, statements of best practice (which shall be followed unless an alternative can be demonstrated to be beneficial to the company and no less safe), and guidance on historical practices (which are not to be applied to new works but provide information on previous standards or their interpretation.