scope:

This Business Process Document applies to Automatic Track Warning Systems (ATWS) and Lookout Operated Warning Systems (LOWS) when used to provide warning on fixed and mobile sites of work, including situations in which the warning equipment is:

• Deployed at the lineside

• Attached to rail vehicles

• Worn by track workers

All requirements and statements in this document apply to both ATWS and LOWS unless indicated otherwise.

This Business Process Document does not apply to:

• Fixed ATWS with train detection provided through interface with the signalling system interlocking.

• Other systems, such as TOWS and Pee Wee, which share some of the characteristics of TWS.

TWS shall be installed and operated in accordance with the relevant requirements of legislation, Railway Group Standards, Network Rail Company Standards, accepted product safety cases and product acceptance certificates. In the event of any conflict, these requirements shall take precedence over the requirements of this Business Process Document.

Purpose

The purpose of this Business Process Document is to mandate the requirements for the safe use of Track Warning Systems (TWS) on Network Rail controlled infrastructure.