Evolving TPWSfour

Unipart Rail has achieved SIL1 compliance for its TPWSfour system - the first to receive this standard.

SIL1 (System Integrity Level 1) is a complex accreditation designed to assess technical products to a very exacting set of standards which demonstrates very low levels of risk.

With TPWSfour being a highly safety-critical system - stopping the train when the driver is not responding to the signalling, for example - it is very important that risk is minimised. Whilst TPWSfour has performed to extremely high levels since its introduction a decade ago, we recognised that as technology continued to develop, so our systems need to evolve.

Paul Blackburn, Product Design and Development Director at Unipart Rail said “We worked with AEGIS Certification Services as we needed a partner who could support and guide us to achieve this standard. I created a team that put together a thorough process which we worked through over 18 months. To now receive the SIL1 rating is very rewarding.”

Luigi D'Angelo, Head of Assessment Body Services at AEGIS said “AEGIS were appointed as Designated Body (DeBo) and Hardware & Software Independent Safety Assessor (ISA) for this project. We undertook very careful reviews of Unipart Rail’s already excellent documentation and conducted site audits in Leicester and Crewe where manufacturing is undertaken. We partnered with Unipart Rail throughout to support the innovation and manufacturing development, leading to the SIL1 accreditation for their new ‘Option 5’ Control Unit”.

To recognise and differentiate this new version of TPWSfour, we have named it TPWSfourEVO. It also has a range of new catalogue numbers to avoid confusion, and the previous version is now discontinued. For more technical and ordering information, please refer to the bulletin.

The new TPWSfourEVO equipment is starting to be fitted to new fleets from July 2020.

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