NR SSIDIS145 ISSUE 4 PDF

INTRODUCTION

This document has been produced for the approval of MCB level crossing interfaces to be used on the Colchester – Clacton and other projects. The methods are derived from those originally used on Leeds North West, and subsequently used on other projects such as Woking-Surbiton and Nottingham. Details have been updated to the latest MCB typical circuits X70000-series drawings, dated 07/04/2007.

This paper details the interfaces required for an MCB crossing with CCTV-monitoring, auto-lower, auto-raise, absent control, and bi-directional working. The appropriate interfaces should be omitted where a particular feature is not required. An annotated extract of the MCB typical circuits, showing the interfaces required, is given in appendix B for reference. This should also be referred to for the applicable layouts.

The level-crossing circuits need to be interfaced to the SSI for interlocking purposes. It is strongly recommended that the interface TFMs should be housed inside the crossing REB, for reliability and to avoid having to repeat the TFM output relays into the crossing REB.

In addition, the SSI may, optionally, also be used as the transmission medium between the signalbox and the level-crossing for the crossing controls and indications, saving the provision of a separate TDM system and telecom channel.

Exactly what interfaces are required will depend on the method of control, method of train detection, and crossing features to be implemented. However, a typical TFM analysis is given in appendix A.

Where (X) appears in the data, this should be replaced by the two or three letter abbreviation for the crossing name. Note that the typical circuits do not include the level-crossing name in the relay titles, and this convention is followed for t he SSI TFM outputs. However, as an SSI may interface to two or more MCBs, the SSI latches must include the appropriate level-crossing name, and this convention is followed for the TFM input names.