Railway applications — Safety related electronic systems for signalling (IEC twin of EN 50129)

Scope

Specifies requirements for the demonstration and acceptance of the functional safety of safety-related electronic systems, subsystems and equipment for railway signalling, covering both generic products and specific applications through a structured safety case. As the international (IEC) twin of EN 50129, it is used by signalling suppliers, safety assessors and authorities to demonstrate and cross-accept the safety of signalling systems worldwide. Edition 2.0 (2025) cancels and replaces the 2007 first edition.

IEC 62425 specifies requirements for demonstrating and accepting the functional safety of safety-related electronic systems, subsystems and equipment used in railway signalling, structured around a safety case that can be built up from a generic product level through to a generic application and finally a specific application deployed on a particular railway. As the international IEC twin of the CENELEC standard EN 50129, it provides substantially equivalent technical requirements, allowing signalling suppliers and safety authorities in markets outside the CENELEC area to apply an internationally recognised equivalent when demonstrating and cross-accepting the safety of signalling systems. Signalling suppliers, safety assessors and railway authorities worldwide use it as the basis for building and reviewing safety cases for interlockings, train control systems and other safety-related signalling equipment. Edition 2.0, published in 2025, cancels and replaces the original 2007 first edition, bringing the standard's technical content up to date after nearly two decades. It is commonly referenced alongside its CENELEC counterpart's successor, EN 50129, in international signalling tenders and safety case submissions.