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Risk management and assessment for rolling stock safety cases

Abstract Since the introduction of the Railway (Safety Case) Regulations in 1994 the railway industry has gone through a steep learning curve as the new safety culture has become established. A key question for any safety case is ‘how safe is safe enough’ since it is never possible to eliminate all risk. To answer this question it is necessary to establish risk or safety targets and then demonstrate compliance with them. Based on his experience preparing the Heathrow Express rolling stock safety case for Siemens, the author describes the stages of establishing the safety targets and demonstrating compliance with them. The criteria by which individual risks, rather than the train's overall safety performance, are judged is also considered. Finally, the merits of this approach compared to the risk matrix adopted by Railtrack, and currently being reviewed, is discussed.