scope:

This standard covers the processes and governance for the design of OCS for Network Rail and the relationship to sub-systems.

This standard is applicable to all OCS Designers.

It covers the design of the OCS for new electrification projects, renewals, and enhancements for the following system types:

• 25kV AC

• 750V DC

• 1500V DC

This standard does not include requirements for the following:

• Structural loading of OCS structures;

• Foundation design for OCS structures;

• Traction power equipment mounted on OCS structures, e.g. Structure Mounted Outdoor Switchgear;

• Rail systems on shared highway corridors;

• Fencing and security requirements for electrified routes;

• OCS designed for line speeds above 140mph (225km/h);

• Dual electrified overhead interface between a.c. and d.c. systems;

• Maintenance of existing clearances.

Purpose

The purpose of this standard is to specify the Network Rail requirements to achieve safety, economy and performance when developing Overhead Contact System (OCS) design for an electrified railway.

This document suite:

• Identifies electrical safety principles to allow the Principal Designer (CDM) to work with other railway sub system designers to allow the railway system safety to be optimised;

• Documents system level hazards and operating conditions deemed reasonably foreseeable which should be addressed by the Designer in a Common Safety Method (CSM) Risk Assessment;

• Contains guidance (in the modules) on the application of design to the National Technical Rules (NTRs), TSIs, euronorms, and external standards for the Designer.

• This document suite provides a common strategy to demonstrate compliance with key legislative requirements and optimise the design of railway subsystems, but is not intended to reiterate legislation and governing standards.