scope:

This guidance applies to the interlocking machines used by London Underground (LU) that ensure signals cannot be cleared unless points are laying in the correct position and also prevents the clearing of other signals such as might lead to the collision of two trains.

This guidance should be followed by Asset Stewards when preparing maintenance regimes for interlocking machine as used by London Underground.

Purpose

The purpose of this document is to provide guidance on the minimum annual maintenance requirements for hand and air operated miniature lever frames. It is not intended to define the methods of test, but where it does so the Maintainer should adhere to those tests.