scope:

This specification is MANDATORY for all new schemes or alterations to existing schemes.

Purpose of Document

The purpose of this document is to provide a reader with sufficient information to design an SSI scheme. It is assumed that the reader is already familiar with those areas of signalling scheme design which are not specific to SSI. Other documents cover data preparation, checking, testing and commissioning, and use of the SSI Design Workstation in detail. It will be necessary to refer to these during the design process (See Section 5). This document provides sufficient information to order the equipment for the SSI portion of the Scheme.