197307 – Graham – Computer Analysis of Signalling Failures

The reliability of signalling equipment is very important in the operation of an efficient railway service. Even a minor failure unless rectified quickly can have an adverse effect on train running with major disruptions and cumulative delays particularly to peak hour train services.

The purpose of this paper is as follows:-
– describe the procedure introduced for the computer analysis of signalling failures,
– review the annual statistics for 1972 to document the magnitude of the problem, and determine whether any specific item of equipment or geographic location is more prone to failure than any other, and,
– detail corrective action taken.

The maintenance organisation comprises two suburban districts and six country districts. Because the impact of signalling failures is greatest in the densely signalled suburban areas this paper will confine itself to review of failures for No.1 and No.2 districts only.

Whilst statistical analysis of failures is not new, the procedure was tedious and interpretation of results required additional cross referencing and research. The ability of the computer to research and print out failures for my given period, location or type of signalling equipment failure now provides the necessary data on which judgements may be made and appropriate action implemented.

The S.&C. Division compiles a detailed summary of all .signalling failures which occur in the system. These are the subject of review by the Assistant Signal & Communications Engineer at a weekly conference with the Suburban Maintenance Supervisors to ensure that temporary repairs are not left as such and to determine any corrective action which may be necessary to prevent a recurrence of any specific failure.