scope:

This Specification details the requirements for the design of the interface between the Redifon MEL solution for the track sub-system of TPWS and conventional signalling systems and their associated power supplies. It applies only to retro-fitting of TPWS to existing signalling. It does not apply to the trainborne equipment. Later versions of this document will consider the application of TPWS to searchlight signals, d.c. fed signals, direct fed signals, and the requirements for fitment of TPWS during resignalling.

Purpose

This Specification details the requirements for the design of the signalling interface associated with retro-fitment of the Train Protection and Warning System (TPWS) to existing Railtrack infrastructure.