Salisbury train crash: Clearance of leaves delayed by engineering work

The trains collided at Fisherton Tunnel, located immediately east of Salisbury Station

Crushed leaves suspected of causing a crash between two passenger trains were not cleared due to planned engineering work, an investigation has found.

Fourteen people required hospital treatment when the trains collided near Salisbury, Wiltshire in October.

The South Western Railway (SWR) train slipped on the tracks and smashed into a Great Western Railway (GWR) service.

A special train was due to clear leaves from the track less than two hours before the collision but was delayed.

An interim report by the Rail Accident Investigation Branch (RAIB) revealed that a railhead treatment train (RHTT) was due to pass over the track, but planned engineering work between Southampton and Brockenhurst meant its deployment was delayed.

The last time an RHTT treated the junction was about 32 hours before the crash, which happened at 18:43 GMT on Sunday 31 October.

Analysis of the tracks after the collision found that "many areas had a medium or heavy level of contamination" by crushed leaves, the report said.

The impact of the collision was likened to a bomb going off

RHTTs, operated by Network Rail, are fitted with high-pressure water pumps to remove crushed leaf film that causes train wheels to slip.

They can also apply a sand-based gel to help break up any remaining leaf film and assist with braking.

The last RHTT to pass through the crash site used water jets but did not apply gel, the RAIB said.

The inquiry found the SWR train was travelling at 86mph -(138kmh) which was within the speed limit - as it approached a stop signal near Fisherton Tunnel.

When the driver applied the brakes, the train's wheels "began to slide almost immediately".

The collision happened on 31 October at 18:43 GMT as many families were out trick or treating nearby

The train slid 191 metres (626ft) past the signal until it hit the side of the GWR service at a junction.

The interim report found the signalling system was "operating as designed".

As well as the 13 passengers and one driver who were taken to hospital, the crash also caused major damage to the trains and the railway infrastructure.

Rail services through Salisbury did not fully resume for 16 days while repairs took place.

A full investigation will consider a number of factors, including Network Rail's policies relating to the prevention of wheels slipping on rails, and the regulation of trains at high-risk locations.