41032 Missing AWS cancelling indicators (Colchester-Chelmsford)

September 2010 in Network Rail and Suppliers

Equipment Infrastructure East Anglia

A reporter is concerned that Automatic Warning System (AWS) cancelling indicators are not being set up correctly as per Rule Book requirements on the stretch of line between Colchester and Chelmsford.

AWS cancelling indicators are used where temporary and emergency speed restrictions are in force on single or bi-directional lines, as shown in the diagram below taken from the Rule Book module SP (permissible speeds and speed restrictions).

The reporter's main concern is that a cancelling indicator is being used in one direction only. This leaves Drivers unprepared to cancel the warning as the board is not there to forewarn them. It is unclear whether Network Rail, or a contractor, is responsible for the indicators in this area. The reporter also notes that the cancelling indicators are not being securely mounted at Colchester, despite a previous Network Rail response that said this would be rectified:

"The continued use of ballast buckets for mounting boards has
been stopped and replaced by rail-foot-clamped speed board brackets."

The situation improved for a while after the initial CIRAS report, but has now deteriorated.

The reporter suggests Network Rail:

• investigate why the cancelling indicators are missing;
• ensure the use of a second cancelling indicator as per Rule Book requirements; and
• ensure the secure mounting of all boards in the area.

Response from Network Rail

Network Rail would like to thank the reporter for bringing their concerns to our attention.

The reporter is correct in their observation that cancelling indicators should be set up in this manner on either single lines or bi-directional lines.

The Up and Down Main London to Norwich (LTN) lines between Chelmsford and Colchester are bi-directional so should have cancelling indicators as shown in the diagram.

The route between Chelmsford and Colchester is now Emergency Speed Restriction (ESR) and Temporary Speed Restrictions (TSR) free so there are no speed restrictions currently in force related to this problem.

All staff involved with the design and implementation of TSRs have been reminded of this section of the Rule Book. Should any further speed restrictions need to be imposed on any bi-directional or single lines on the Colchester area, an additional check of the design will be carried out by an independent engineer.

The reporter is also correct that for a short period of time, 'ballast bucket' type speed board mountings were used on this section of line. This was due to a problem with the rail foot clamped mountings which has now been adressed.