NR TI 022 ISSUE 2 PDF

These rules apply to the placement of TPWS loops where works require TPWS to be provided or amended.

This instruction applies to signals requiring TPWS in accordance with NR/L2/SIG/10137 (or other signals equipped with TPWS on the basis of risk) which can be approached from another running signal.

Signals not approached from a running signal or where trains start from rest (with no locking beyond the signal) are excluded.

Purpose

To replace the rules in NR/L2/SIG/10138 for the positioning of TPWS loops on the approach to a signal to achieve improved effectiveness for all trains.

This instruction supports the achievement of the safety objectives agreed by the cross industry TPWS strategy group. It also allows loops to be placed up to 900m from the signal with greater flexibility in the arrangement of the loops utilising a risk based approach.

This instruction should be read in conjunction withNR/GN/SIG/00028.