scope:

This standard does not cover the maintenance requirements for disc signals with moving parts, and passenger information video display units. Dot matrix indicators are the subject of engineering standard E7010.

The primary user of this standard is the Asset Steward.

Workshop overhaul is not covered by this standard.

This standard supersedes E7153 A4, which is withdrawn.

Purpose 

This standard defines the minimum maintenance requirements for the signals, signs and indicators which control or are controlled by train movements used on London Underground.