RAIB issues urgent advice to FirstGroup after Croydon tram derailment

16th Nov 2016 14:16

(ShareCast News) - The Rail Accident Investigation Branch released its interim report into the deadly Croydon tram crash on Wednesday, issuing urgent safety advice to the tram and infrastructure operators while it continued its investigation.Seven people died in the incident just after 0600 GMT on 9 November, when a single articulated tram derailed and overturned at a junction close to Sandilands station, on Transport for London's Tramlink network.In the report, the RAIB said that based on its initial findings from the tram's on-tram data recorder (OTDR) - similar to an aircraft black box - the tram was travelling around 70 km/h (44mph) as it entered the curve on the junction between the Lloyd Park tunnels and Sandilands station.The curve has a speed restriction of 20 km/h, however.It did find evidence that some braking had been applied on the approach to the junction, but only enough to reduce the tram's speed from 80 km/h - the maximum permitted on the straight section through the tunnels - to 70 km/h."A tram approaching the Sandilands Junction area from Lloyd Park at 80 km/h would need to brake at its full service rate of 1.3 metres per second approximately 180 metres before the speed restriction board in order to be travelling at 20 km/h when the board was reached."The RAIB pointed out that the Tramlink system operates on a line-of-sight basis, meaning tram drivers rely on speed restriction boards and other trackside signage with no other advance warnings.In this case, the speed restriction board was placed just 20 metres before the curve, with the investigators also noting the fact it was dark and raining heavily at the time of the incident."'The factors that led to the over-speeding are still under investigation," the RAIB said in its urgent safety advice to the tram operators."Until these factors are better understood, and before the junction re-opens to passenger operation, the RAIB advises London Trams and Tram Operations Ltd to jointly take measures to reduce the risk of trams approaching Sandilands Junction from the direction of New Addington at an excessive speed."Options for consideration should include the imposition of a further speed restriction before the start of the existing 20 km/h speed restriction around the curve and/or additional operational signs."London's Tramlink network is owned and managed by Transport for London through its London Trams division, with the trams themselves operated under contract by FirstGroup, through its subsidiary Tram Operations Ltd.