scope:

This Guidance Note applies to all those undertaking engineering activities of any sort on the railway in the vicinity of TASS installations. It is limited to work directly affecting TASS balises which does not affect their configuration.

Any work likely to alter the configuration of the infrastructure particularly those affecting track position and clearances, areas where trains are permitted to tilt, published speeds, S&C configurations, locations of cant deficiencies over 150mm and new signalling should consider the need to change the current TASS installation.

Purpose

The Tilt Authorisation and Speed Supervision (TASS) system is installed on Network Rail infrastructure.

As with any signalling equipment its operation may be disrupted by inappropriate actions by those engaged in other activities on the railway including design, installation, maintenance and renewal of track, power supplies and civil structures.

This Guidance Note gives advice to those engaged in various engineering activities on the treatment of the TASS system and the precautions they should take in respect of it. Detailed requirements are given in the three documents.