2014 – July – Aitken – In all normal and reasonably foreseeable abnormal situations

John Aitken BE MIRSE SMIEEE Aitken & Partners “New rolling stock or electrical/electronic equipment to be used in rolling stock modifications must be designed, built and maintained with regard to EMC in order that they operate safely throughout their operational life. This applies to all normal and reasonably foreseeable abnormal situations, including failures.” Such a statement is easily made but compliance is not readily demonstrated, particularly when there is little or no definition of what might make something electromagnetically compatible (EMC). Signalling systems are generally poorly defined from an EMC viewpoint, so foreseeing abnormal situations can require considerable insight into the design and failure modes of the signalling systems.This paper discusses what is normal and then considers some of the failure modes and vulnerable areas in train detection systems; the threats posed by traction systems