scope:

This specification applies to all signalling schemes and detailed design where trap points, points leading to a sand drag or other arresting device and where sliding or friction buffer stops are to be altered or provided.

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 providing derailment detectors at trap points and friction buffer stops and comprises mandatory sections, statements of good 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.