Railway Application - Command, Control and Signalling - Signalling Relays

Relay based installations represent today the backbone of most railway signalling assets. Many experts believe that relay-based signalling installations will be in operation in most countries for much longer than 2030.

The use of relays in circuits with requirements regarding 'functional safety' demands an analysis of the associated risks. This includes faults or incidents to be considered using relays, possible consequences and potential hazards. A proven measure, that eliminates hazards or reduces them significantly, is the use of relays which comply with the functional requirements of IRS 70736. Another aspect to be considered is life cycle related recommendations provided by IRS 70736.

UIC Signalling Expert Group (SEG), a permanent expert group of the UIC RSF Telecom & Signalling sector, oversees IRS 70736. However, IRS 70736 was written in a close collaboration with signalling experts of several railways & infrastructure managers.

Note: The UIC Technical Report "Use of Signalling relays" [2] provides information about hazards to be considered using relays which are effectively mitigated by the requirements defined and recommendations made in IRS 70736.