SSP048 Iss 1
Requirements for Simplified Bi-directional Signalling
The purpose of this document is to provide a simplified and more economical method of bi-directional signalling suitable for use on track circuit block lines where wrong direction movements are normally made only during possessions or emergencies. This system is not to be used on bi-directional lines which are regularly used for the passage of booked trains in the wrong direction.
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- In Force: