scope:

This Network Rail standard specifies the requirements for the design and construction of track with line speeds up to 125 mph. This includes:

a. the construction of new sections of track, and routes;

b. the replacement of contiguous lengths of track components or switch and crossing layouts, either singly or in combination, as part of project or renewal activities;

c. the replacement or new construction of trackbed layers, drainage, level crossings, direct fastening systems, buffer stops or other track fixtures;

d. the replacement of components of the track system, carried out during maintenance, that significantly changes its design or configuration (for instance the installation or removal of check rails or the installation of cast crossings with welded extension legs in place of semi-fabricated crossings);

e. the requirements to be met whenever existing tracks are upgraded to carry higher speeds or tonnages of rail traffic; and

f. the requirements for the design of track geometry for both newly installed and existing track.

This standard applies to those who specify, design or supervise the installation of new track and those who design alignments on existing track.

Design and Construction requirements for track exceeding 125mph are subject to agreement with the Network Technical Head Track.

Purpose

This standard is intended to control the risk of incorrect materials and components being specified and to control the required quality of installation of track. It specifies the design principles and minimum standards for the construction of new or relayed track, including the materials to be used. It also specifies acceptance criteria for new or relayed track in terms of workmanship and the track geometry requirements for both newly installed and existing track.