NR NR/L3/TRK/3406 ISSUE 4 PDF

This document provides a framework for the design, installation and maintenance of modular switch and crossings bearer joints. The standard is split into modules for each aspect.

This document applies to:

a) all staff who work with modular Switch and Crossing System (S&C). This includes designers, installers, manufacturers, maintainers both within Network Rail and external suppliers; and

b) all existing and new modular S&C installations (to the RE/PW standard design) on Network Rail infrastructure.

Purpose

This standard gives requirements for the design, installation and maintenance of modular Switch and Crossing systems. The standard is split into modules for each aspect. The purpose of the document is to control the risk of the following failure modes occurring in modular S&C layouts:

a) wide gauge;

b) damaged and ineffective thread on dowels at the bearer joint;

c) bearers cracking;

d) screws breaking (in shear at end of thread or head breaking off);

e) loose screws; and

f) twist faults around joints.