Report by James Cracknell
Network Rail has apologised to passengers after admitting its culpability for a train derailment that closed a London Overground line for almost a month.
The freight wagon derailment in January this year occurred near Wanstead Park and damaged a two-mile section of track through Leytonstone, Leyton and Walthamstow, on the route between Barking and Gospel Oak.
In a report on the incident published last month, Rail Accident Investigation Branch (RAIB) concluded that Network Rail had been at fault for not realising that rail sleepers used on a particular bridge had “severely deteriorated”.
The RAIB report stated: “A wagon in the rear half of a heavily-loaded freight train derailed on a small radius curve as it crossed a bridge.
“The forces from the train caused the rails on the bridge, which were attached to large longitudinal timbers, to spread apart. Two adjacent wheelsets from different wagons derailed, but one wheelset re-railed itself after travelling a short distance. The other wheelset remained derailed as the train continued for 2.5 miles before stopping, and this caused significant track damage. Wagons positioned behind the derailed wagons remained on the track.
“Track where the rails are supported on longitudinal timbers is subject to special inspections by staff who have received additional training to undertake this role. RAIB found that the condition of the timbers at the point of derailment had severely deteriorated because of rot, but this was concealed by their superficially good exterior condition.
“The inspection method and tools used by Network Rail staff were not sufficient to detect the poor internal condition of the timber.”
Network Rail has apologised. Ellie Burrows, route director for Network Rail Anglia, said: “We accept we relied too heavily on the GPS data for our track inspections, which wasn’t accurate enough, and as such we missed the opportunities to adjust the gauge of the track before the derailment at Wanstead Park.
“We’re grateful that no-one was hurt and very sorry that the resulting damage caused weeks of disruption to passengers and our freight customers. Since the incident, we have reviewed and improved our maintenance inspection and reporting processes to prevent any future incident.
“In addition, all softwood longitudinal timbers that were damaged during the derailment have been replaced with hardwood – except for Ramsay Road bridge which has deadload restrictions.
“We now use a new testing technique that enables us to inspect the inside of timbers and identify if it is rotting, even if from the outside it looks fine. In addition, all of our wheel timber inspectors have undergone specialist training to help them identify hidden problems and we have appointed a senior asset engineer to coordinate our wheel timber programme.”
RAIB also placed some blame for the accident on the owners of the freight train, after it found the first wagon to derail “had experienced unusually rapid wheel wear over several years” which meant that it could have “imposed higher than normal lateral forces on the track”.