2013 Torfield derailment

The 2013 Torfield derailment was a derailment at Torfield which occurred on 2 May 2013. Although not a major derailment as such, it was thrust into the limelight as it brought into question the safety of British freight wagons.

Accident
At 1636 on 2 May, while heading the 6M84 freight between West Thurrock and Torfield depot, the driver of the locomotive heading the train, 66412, applied the emergency brakes just south of Torfield station after feeling a large shudder and hearing a loud cracking sound. During the deceleration period, the driver reported feeling the train vibrate violently. After the train came to a halt, he found that one of the wagons had derailed.

Investigation
The derailment was caused by the collapse of the entire undercarriage of one wagon, which caused the trailing axle to deform in shape very quickly, bending at first and then snapping totally roughly fifteen seconds after the original undercarriage collapse. The snap of the axle flung the wagon off the track. As the rear axle trailed along the floor while the train was decelerating, one of the two wheels on the axle shattered into many pieces.

After the derailment, RAIB found that several bolts and latches that held the undercarriage of the wagon together had rusted severely and failed, causing the structural failure. It is likely that the rear axle would have snapped anyway after this, although it potentially sped up by the fact it was rusty too. However, the wagon would have derailed anyway, even if the rear axle did not snap. The wheel shattering in the aftermath of the accident was also found to be caused by rust.

RAIB ordered an immediate thorough investigation into all of the UK's freight wagons, to prevent another similar accident due to poor maintenance. No other lackluster wagons were found in the Torfield area, but several were found across the country and immediately taken out of service for repairs or withdrawal.

Disruption
Both lines on the double-track mainline out of Torfield station were closed around Torfield from 1640, following the accident. The unaffected wagons were driven away by 66412, while the affected wagon was taken away by road crane. Investigators took time to investigate the accident, and debris was cleaned up.

Due to minor track damage, overnight repairs will be needed, with the affected line due to reopen on 3 May at 0800 BST. The unaffected line adjacent reopened at 1830 BST, and until then services, albeit disrupted heavily, will run out of Torfield, using this line only, effectively turning the line into a single-track line until the next morning.