Tramlink gains over-speed protection certification
system installed on the London Tramlink network to prevent the over-speeding of trams has received Safety Integrity Level 2 certification – a UK first for a light rail over-speed protection system. In January 2019, DB ESG was selected by Transport for London to develop, design, install and commission a device to physically prevent the over-speeding (known as PPOS) of trams operated by London Trams in Croydon.
DB ESG collaborated with Sella Controls, which provided the hardware and software.
This system has been operational for more than a year, during which time it has achieved 100% availability, with no system failures experienced. In February 2023, the Independent Safety Assessor certified the system.
The managing director of DB ESG, Nick Goodhand, 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.”
Sella Controls business development director Chris Elliott said: “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.”
The fitting of over-speed protection equipment to the trams followed the derailment of London Tramlink Bombardier CR4000 Tram 2551 on November 9, 2016, which derailed and overturned on a sharp curve at Sandilands Junction in Croydon, killing seven passengers and injuring a further 62, 19 of whom suffered serious injuries.
The subsequent investigation into the incident found that the tram was travelling at more than three times the line speed for the section as it entered the curve, with the most likely reason being the driver losing attention after going into a microsleep.