scope:

This instruction applies to all staff engaged in the maintenance and testing of all lineside telephones (such as Signal Post Telephones, Crossing Telephones etc) and operational building telephones.

For the purposes of this instruction an operational building includes: -

•    Operational Control Offices

•    Electrical Control Offices

•    Signalling/Operating Centres (including Signal Boxes, Gate Boxes, Crossing Keepers Huts, token huts, Ground Frame (GF) huts and shunters cabins etc)

•    Equipment Rooms (such as relay rooms, Re-locatable Equipment Buildings (REB) etc)

•    Electrical installations (such as Track Section Cabins, Feeder Stations, Principal Supply Points (PSPs) etc)

It excludes: -

•    Non-operational rooms situated in operational buildings (such as messrooms, offices etc),

•    Public Emergency Telephone System (PETS) units in Signalling/Operating Centres as defined above (this is covered under maintenance standard NR/L3/TEL/30181/013)

•    Lineside plug points and telephones connected to Tunnel Emergency Communication Systems (this is covered under maintenance standard NR/L2/TEL/30097)

•    GSM/GSM-R Crossing telephones (covered under standard NR/L3/TEL/30181/006)

•    GSM-R Human Machine Interfaces (HMI's) (covered under NR/L3/TEL/30181/012)

•    Concentrator HMI's

Purpose

This telecoms maintenance instruction defines the maintenance and functional testing that Network Rail require for telephones used lineside and in operational buildings, which are provided to facilitate safety critical communications for the safe operation of the railway.

The purpose of maintaining and testing these telephones is to decrease the incidence of failures through deterioration and to identify potential failures before they become service affecting.