Steps taken since the collision

Autumn leaves, crushed under the wheels of a train, form a hard Teflon-like coating on the surface of the rail.

The steel wheel-rail contact patch is the size of a 5p coin, where the coating reduces the limited grip, causing a train to slide across the top of the rail. In effect, it is the railway equivalent of black ice on the road.

The coating is tackled by a combination of water jets, with adhesive gel or sand to increase grip. Drivers adjust with gentler braking, which takes greater distance.

Network Rail is now running railhead treatment trains through Salisbury twice a day, seven days a week. Before the crash, trains ran daily, but with greater intervals at weekends.

The leaf-busting trains are running at reduced speed through 45 key sites, to increase the effectiveness of their water jets and gel applications.

These sites will be marked with new signs to alert drivers. The drivers are receiving what the train operator calls “an enhanced briefing”, and new drivers will be given additional training material.

The SWR Class 159 diesels are getting enhanced sand-laying equipment so that more sand can be dropped.

New technology is being trialled to monitor the wheel slip and slide protection system.

New high-definition cameras are also being trialled on the treatment trains and on some passenger trains, to collect images of the rail in order to help identify areas which require extra treatment. This data will be used to develop artificial intelligence software in the future, which could monitor and trigger treatment.

SWR Managing Director Claire

Mann visited Salisbury on the crash anniversary. She said: “People joke about leaves on the line. It’s no joke. This incident has made that very clear.

“We are trialling as much new technology as we can, to see if we can identify the issues before they arise. I can never say for certain that a thing like this could not

happen again. But what I can say is that we are working really closely across the industry to minimise that risk.”

Mark Killick, NR Wessex Route Director, said: “We have made some changes this year. We are running more leaf-busting trains at lower speed, so the water jetting is more effective. And we’ve worked hard to understand where our higher-risk sites are.

“The things we have done over the last year mean the railway is now safer than it was a year ago.”

COLOUR-RAIL/ NETWORK RAIL. Compare Tunnel Junction in 1954 (left) with the same view the day after the collision one year ago. Since the ending of steam-hauled trains, the cutting sides have become covered with self-seeded trees. Those trees are now mature, leaving the tracks with a daily carpet of autumn leaves. Network Rail says it has doubled the frequency of railhead treatment trains from once to twice each day.