London Trams’ new system to prevent overspeeding has received official certification. The Safety Integrity Level (SIL) 2 accreditation is a UK first for a light rail overspeed protection system and provides independent safety assurance.

In January 2019, following a competitive tendering process, DB ESG – part of DeutscheBahn – was selected by Transport for London to develop, design, install and commission a device to prevent overspeeding of light rail vehicles operated by London Trams in the Croydon area. DB ESG collaborated with engineering solutions company Sella Controls, which provided the hardware and software, including a Physical Prevention of OverSpeeding (PPOS) controller and Tracklink III system.

This work follows the Croydon tram crash in 2016, which killed seven people when a tram travelling at three times the speed limit came off the rails. The Office of Rail and Road prosecuted Transport for London, Tram Operations Ltd and the tram’s driver over the disaster, although the driver was cleared.

This system has been fully operational for over a year, during which time it has demonstrated, 100 per cent availability and zero system failures. In February 2023, the Independent Safety Assessor certified the overspeeding protection system as being safety assured at Level 2 (SIL2). The certification covers both hardware and software.

Nick Goodhand, Managing Director, DB ESG said: “We are absolutely delighted that this system has received this mark of safety quality. Protecting a tram network with the highest possible level of safety gives operators the
peace of mind that they are doing their uttermost to keep their passengers safe. “

Chris Elliott, Business Development Director for Sella Controls, added: “The successful delivery of the PPOS solution to London Trams is a fantastic achievement for us and our partners in this project, DB ESG and Transport for London. Knowing that we have implemented a solution that will provide our client with the highest level of safety for its tram network is of the upmost importance. As a passenger it is good to know that safety is at the forefront of London Trams’ operation”.