Leaves on the line caused Salisbury train crash: 10 recommendations from report

14 people were injured in the accident in October 2021

Author: Aaron HarperPublished 24th Oct 2023
Last updated 24th Oct 2023

The Fisherton Tunnel rail crash in 2021 in Salisbury was caused by leaves on the line according to a full investigation into the crash by the Rail Accident Investigation Board (RAIB).

The accident saw two trains collide, injuring 14 people, damaging both trains and the rail infrastructure.

The investigation found that the tracks at the junction had become slippery through a combination of crushed leaves contaminating the lines and a drizzle shortly before the collision around 18:43pm on 31st October 2021.

The full report, released by the RAIB, makes ten recommendations to prevent future accidents.

RAIB Chief Inspector, Andrew Hall, says it’s vital to learn the lessons from accidents, despite their rarity.

“The phrase 'leaves on the line’ may cause some to smile. But the risks associated with leaves being crushed onto the top of rails by the pressure of trains’ wheels, resulting in a slippery layer, is very real and long known.

“As with many accidents, this one resulted from a combination of many different circumstances coming together, both in the time before the accident and on the day. As a result, the barriers put in place to avoid this type of event did not work effectively.”

Report Findings

According to the RAIB’s report, the train reporting number 1L53 was travelling at approximately 52mph when it impacted with the side of train 1F30, which was travelling at around 20mph.

The report states that, as well as the slippery tracks, the driver of train 1L53 did not apply the brakes ‘sufficiently early’ on approach to the signal protecting the junction and that the brakes were unable to mitigate for the low level of grip on the tracks.

RAIB’s report says the ‘probable’ underlying factor was Network Rail’s Wessex route failed to effectively manage the risk of tracks becoming slippery in association with leaf fall season.

It also found South Western Railway had not effectively prepared it’s drivers for assessing and reporting ‘low adhesion’ conditions was a possible factor in the accident.

Two safety observations were made by the RAIB, relating to the design of the Train Protection and Warning System and the assessment of the overrun risk and how it accounts for slippery lines.

They also found two issues which contributed to the severity of the accident, which were the loss of survival space in the drivers cab of train 1L53 and the jamming of internal sliding doors, which obstructed evacuation routes for passengers.

Report Recommendations

As a result of the investigation, and accounting for the work done by the industry since the accident, RAIB has made ten recommendations.

Seven of these recommendations are made to Network Rail. These relate to: a review of the processes, standards and guidance documents relating to the management of leaf fall low adhesion risk; the training and competence of staff dealing with vegetation management and seasonal delivery; responses to emerging and potential railhead low adhesion conditions; management of railhead treatment regimes; assessment of the risk of overrun at signals which have a site at high risk of low adhesion on their approach; and a review of the retrospective application of design criteria for the Train Protection and Warning System.

One recommendation is made to South Western Railway to review and improve its arrangements for training and briefing drivers to ensure that they are able to effectively identify areas of low adhesion and report them as appropriate.

One recommendation is made to the Rail Delivery Group in consultation with train operators and the Rail Safety and Standards Board regarding the review of technologies other than sanding systems and wheel slide protection to improve braking in low adhesion conditions.

One recommendation is made to Porterbrook, Eversholt and Angel Trains regarding the design of the internal sliding doors on class 158 and 159 carriages.

South Western Railway response

Managing Director of SWR, Claire Mann, said:

“SWR thanks RAIB for its report, which highlights the importance to the industry of the management of low adhesion during the leaf fall season and SWR welcomes the actions that Network Rail has taken in response to the recommendations made by RAIB. SWR has already reviewed its arrangements for training and briefing drivers and additional enhancements were implemented soon after the incident in 2021.

“SWR’s commitment to the safety of our customers and colleagues is our number one priority. The incident at Salisbury Tunnel Junction was a stark reminder of the challenges autumn poses to the railway and we continue to work closely with Network Rail and the wider industry to learn the lessons, continuously improve and reduce the risk of it happening again.”

Network Rail response

Mark Killick, Network Rail Wessex route director, said:

“The incident at Salisbury nearly two years ago will live long in our memory and our thoughts remain with those customers and colleagues involved in this accident.

“We welcome the RAIB report and accept its recommendations. We have been working closely with RAIB over the past two years to implement a number of responses following the initial findings and our own internal investigation, to make improvements in the way we manage the risk of poor rail adhesion during Autumn.

“Autumn is the railway’s most challenging season and we work closely with our industry partners to keep trains running safely and reliably. Ahead of last Autumn, we utilised train mounted high-definition cameras to complement the efforts of our fleet of specialist autumn leaf busting trains, and this year are also testing the use of drones to enhance our rail head leaf fall inspections.”

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