A teenager who almost caused a “catastrophic” train crash after concrete and other debris was piled on a railway line has been locked up for six months.

Train driver Russell Mead had to slam on the emergency brakes of his high speed train to London as he approached Higham station just before Christmas last year.

Almost £8,000 worth of damage was caused to the train and Railtrack assessed the resulting delays at over £23,000.

Troy Willis, of Dombey Close, Higham, was sentenced to youth custody after admitting endangering the safety of rail passengers.

A boy, aged 17, from Chatham, also admitted the offence and was given a 12-month referral order at Medway Magistrates' youth court.

A 15-year-old boy also from Higham, denied the charge and was acquitted at Maidstone Crown Court.

Prosecutor Trevor Wright said the three teenagers were shown on CCTV footage at the station just before 5pm on December 23.

“They are seen to be hanging around both platforms and being a nuisance,” he said. “They leave the station and return later.”

Shortly after 8pm station manager Jane Powell told two transport police officers a train had struck something.

It was due to pass through the station at about 70mph without stopping on its way to St Pancras.

“On this occasion Mr Mead was running at caution speed because of a previous report of another train striking something on the line,” said Mr Wright. “At caution, the speed was 25-30mph.

“Confident there was no obstruction he started to increase speed and as he exited the tunnel into Higham station he could see objects on the line about 70 metres from the exit.

“He immediately slammed on the emergency brakes, but the train hit the mass on the line. The speed on impact was later assessed at 38 mph.

“The train finally came to a stop with the first three carriages in the platform. Mr Mead reported the impact to the signaller and all trains were stopped.”

Workmen cleared the line of two Acrow props - tubular steel supports - one of which was touching the live rail and arcing, a large amount of concrete, a mangled wheelbarrow and a large piece of plastic.

The train had to be taken out of service for repairs.

Willis, 18, and his two friends were found hiding behind a tree in nearby woods.

Judge Jeremy Carey said had the train been travelling at its usual speed of 70mph the consequences could have been catastrophic with a probable loss of life.

Only a custodial sentence could mark the seriousness of the criminality involved, he added.