Network Rail have commented that the UK’s fifth heatwave of the summer has created challenges for the railway, following the derailment of two trains in less than 24 hours.
On Thursday 13 August, two passengers were seriously injured when several Southern train carriages left the track near Lewes in East Sussex and ended up on their side, trapping people onboard. The British Transport Police (BTP) declared a major incident that afternoon after the evacuation of around 150 passengers on board the service from London Victoria to Eastbourne. Two people were taken to major trauma centres with severe injuries.
On Friday 14 August, the BTP confirmed that the rear carriages of a Greater Anglia train derailed at Wickford railway station in Essex, adding that there were no reported injuries. The train was travelling from Southend to Liverpool Street with around 40 people onboard.
Martin Frobisher, the Group Safety and Engineering Director at Network Rail, said that an internal investigation into both derailments would be conducted to determine causes and factors. He revealed that hot and dry weather present challenges, but that Network Rail have taken proactive steps to manage and mitigate the impact - including closely monitoring the temperature of tracks, implementing speed restrictions where appropriate, and planning track renewals around high temperatures.
John Whitehurst, the Chief Executive of Greater Thameslink Railway, told BBC Radio 4’s Today programme that derailments were “incredibly rare” and a “full investigation” was under way with the Rail Accident Investigation Branch. Richard Bowker, a former chair of the Strategic Rail Authority, told the same programme that the inquiry would investigate the effects of heat on the damaged track, including whether the ground below the track had dried out.
The Guardian reported that railway engineer Gareth Dennis, author of ‘How the Railways Will Fix the Future’, said that despite there currently being no firm evidence to connect the two derailments, the “likelihood of two similar derailments in the hottest part of the country happening in quick succession without a common cause is extremely low”. He added that it was possible that the train derailments were caused by a track buckle, where steel rails that have expanded in the heat snap into a buckled shape under the wheels of a passing train. This idea is supported by the statement on Network Rail’s website, where they explain that the steel railway tracks absorb heat easily and can become 20°C hotter than the air temperature, causing the steel to expand.