I never expected to use Rail Technology magazine as a source for writing stories about Lewisham. But it’s the first publication with the lowdown on why that freight train that caused so much havoc for commuters derailed in the first place.
Cast your mind back to a little more than a year ago when conditions were quite similar to now: wintry days with a few flurries of snow .
The incident below happened in the early hours of January 24, 2017 and commuting from Lewisham practically ground to a halt for several days.
Many of you will recall seeing images of spilled aggregate littering the Courthill Loop South junction – as it is known to those in the know – just outside of Lewisham Station.
Now investigators have concluded their analysis, stating that the accident was apparently due to the track that had been laid 10 days previously as well an unevenly balanced load on board.
Here’s the technical explanation courtesy of Rail Technology Magazine: “Investigators found the first of the two derailed wagons, which was probably carrying an uneven payload, encountered a significant track twist, which resulted in insufficient wheel load at the leading left-hand wheel to prevent its flange climbing over the rail head.
“The track twist had developed quickly following the hand-back [from maintenance] because the support offered by the track bed to the concrete bearers was poor and the inherent flexibility of the bearer ties between the two running rails made one side more susceptible to the poor track bed than the other.”
The track had undergone maintenance the previous evening, but was not in the right condition for the freight train to pass, investigators said.
“The track was poorly supported when it was handed back for traffic on the day before the derailment, because there had not been time for the machines to finish tamping the ballast, and manual consolidation work was ineffective,” said Simon French, the chief inspector of rail accidents.
“If there had been another train nearby when the accident happened, the subsequent collision could have been disastrous,” he said.
He also sounded a warning about the same thing happening again, noting the following in his full report: “RAIB [Rail Accident Investigation Branch] has investigated this interaction between poor track geometry and unevenly loaded trains several times before.
“In reports on investigations published in 2009 and 2014 we have recommended action to deal with the problem. It is of concern to me that, although the railway industry has established a working group to examine these issues, it remains unclear how its findings will be translated into actions to mitigate the risk of freight train derailment.”
See more information from Rail Technology Magazine here.
You can also read the full report from the Rail Accident Investigation Branch here.