NR TPWS/TGN/009 ISSUE 1 PDF

This document covers power supplies to TPWS equipment at all qualifying signals controlled from mechanical signal boxes.

This document does not cover power supplies to TPWS equipment at buffer stops and Permanent Speed Restrictions (PSRs) in areas controlled by mechanical signal boxes.

This document relates solely to design and installation: operation and maintenance issues will be addressed separately.

Purpose

The standard TPWS design solution assumes that suitable secure 110V AC power supplies are already available at signals qualifying for fitment. For signals controlled from a mechanical signal box, this is not necessarily the case and new supply arrangements will need to be considered in the majority of cases.

It has been established that where existing supplies are not suitable for use, power distributed to signals from a centrally located Uninterruptible Power Supply (UPS) is the preferred solution for signals close to the controlling signal box. For signals located at significant distances from the controlling signal box, an alternative solution in the form of a DC Signalling Interface Module (SIM) supplied by local batteries is available.

The purpose of this Guidance Note is to explain how the TPWS UPS and DC SIM solutions should be applied in order to ensure compliance with the overall requirements for TPWS.

This Guidance Note should be read in conjunction with Railtrack Line Specifications RT/E/S/10133 and RT/E/PS/00011.