scope:

This Module applies to all technologies of on-track equipment used for the operation and proving of:

a) facing and trailing points (combining to form crossovers, tandem points, single and double slips, etc.);

b) swing nose crossings;

c) switch diamond crossings (effectively two point ends);

d) trap points and catch points;

e) train operated points (including spring points);

f) hand points;

g) derailers; and

h) scotch blocks.

The Design Principles in Section 2 give the minimum requirements that need to be addressed, even when a risk-based approach is used.

The following guidelines satisfy the essential principles encompassed within the standard:

a) guidelines on rail clamp point locks (clamp locks) in NR/GN/SIG/11774;

b) guidelines on the use of track circuits in point layouts in NR/L2/SIG/11752;

c) the standard drawings for point layouts, fittings and detectors listed in NR/LS/CAT003;

d) supplementary mechanical information on points and fittings in NR/L2/SIG/11201, Module B14;

e) the typical circuits for point operation and detection listed in NR/GN/SIG/CAT005, which are described in NR/L2/SIG/11201, Module B15; and

f) guidelines for SSI installations in NR/L2/SIG/11201, Module B16.

PURPOSE AND INTRODUCTION

This module forms part of the Signalling Design handbook (SDH: NR/L2/SIG/11201) and is to be read in conjunction with the other modules of the handbook and reference documentation.

This Network Rail standard contains requirements and guidance on signalling engineering applications. The content supports the specific and general requirements described in Railway Group Standards and the Network Rail Signalling Principles Handbook [NR/L2/SIG/30009].

NOTE Where there is a conflict between this standard and a Railway Group Standard or the Network Rail Signalling Principles Handbook [NR/L2/SIG/30009] then this standard does not take precedence.

Decisions made by a competent person should be supported by appropriate evidence or documentation.

NOTE Use of designer notes on drawings (see HSE CDM guidance) will generally suffice as may Design Log entries.

Any adoption of alternative solutions requires an assessment commensurate with the significance of the proposed change and which follows the guidance provided by the Common Safety Method for Risk Evaluation and Assessment [CSM-RA]; Network Rail's adopted method for the control of safety risks.