Accident investigation branch to study Network Rail maintenance practice

A Network Rail maintenance project will be investigated as part of an independent inquiry launched by the Rail Accidents Investigation Branch, which is looking into the causes of the derailment of a passenger train and the consequent collision with another oncoming train near Watford earlier this month.

A southbound train was derailed at 06.55 on 16 September, when it hit material from a landslip following heavy overnight rain just before entering the northern portal of the Watford Tunnel on the West Coast Main line (WCML). The train was then hit a glancing blow from a northbound train, which did not derail. Two passengers suffered minor injuries and major disruption was caused as the WCML was closed for the duration of Friday 16 September and the following weekend as Network Rail worked to retrieve the damaged trains and repair the line.

The WCML is in a deep steep sided cutting as it approaches the Watford Tunnel from the north. A Network Rail project to strengthen the cutting slopes was being carried out at the time. Photographs taken of the incident show that trees and vegetation were being cleared and a system of geotextile netting laid over the cutting, but while the clearing of trees had reached the tunnel portal, fixing of the bank stabilisation had not been completed.

According to the RAIB, its investigation will study why the landslip occurred; issues affecting the stability of the cutting slope, knowledge of, and response to, the heavy rainfall; the actions of staff and performance of safety systems between the derailment and subsequent collision; and any relevant underlying management factors.