Scenario dependency of safety targets for platform doors.

ABSTRACT: Platform barriers for railways shall protect passengers from different events like being crushed
by a train or falling off the platform onto the track. Passenger can access a train through automatically operating
platform doors that are integrated into the platform barriers. From a safety perspective, platform doors are an
electronically controlled system, whose risks need to be analysed and reduced to an acceptable level. One of
the most discussed points, in that relation, is the allocation of safety (design) targets for different functions of
platform doors.

This paper proposes the application of SIRF for the determination of safety targets for functions of platform
doors. Beside a theoretical reasoning for using SIRF the paper gives examples for its application to platform
doors. Especially, the hazard ’vehicle starts moving and doorways are open’ is analysed for its criticality and the
related functions are assigned with safety targets. It is shown, that this process highly depends on the scenario
even if the starting conditions are equal. This leads to the conclusion that all scenarios for the same situation
have to be analysed.
The conclusion is that SIRF can be applied to platform doors easily, and delivers reasonable results.