THREE teenagers are starting prison sentences for an act of stupidity which endangered the lives of rail passengers.

Benjamin Sheppard, Saul Jacobs and Kevin Reese, all aged 19, placed concrete posts on a Hampshire railway line and waited for trains to hit them.

They also set fire to several barns and commercial warehouses in the Eastleigh area, Winchester Crown Court was told.

The gang was caught when Sheppard bragged to his now former girlfriend about the exploits of the gang he dubbed the "Hampshire Hit Squad" and she went to the police.

Sentencing each to four and a half years in prison, Judge Patrick Hooton said: "What you three did was extremely dangerous. It is difficult to imagine what would have happened if that train had gone off the rails, full of people, rolled down the embankment and killed the passengers.

"What would have happened if a barn, a roaring inferno, had hit someone's house and someone had died in the flames? That is the reality of what you three put at risk.

"You have come from respectable families and are effectively of good character. There was nothing to suggest in your history, family background, school that you would behave in the way you did."

Beverley Watkins, prosecuting, said the first incident on the railway took place on April 10 when Sheppard and Jacobs placed a 6ft concrete post on the track. The train, carrying 20 passengers struck the object, causing damage estimated at £3,234. "The driver felt the train would be derailed. The train lost power to the front. It retained power to the rear and was able to carry on."

Two days later, Reese and another person who has been cautioned, joined the other two to return to the same spot and placed a similar post.

"The four then drove to Shawford station and stood on the platform waiting to see what would happen," said Mrs Watkins.

"The train was approaching at 75mph. The driver saw the post and applied the brakes, but there wasn't enough time and the train collided with the post."

Five days later the trio torched barns at Fir Tree Farm, Fir Tree Lane, Horton Heath, and Big Muddy Farm, Alma Lane, Lower Upham. The Fir Tree fire destroyed the barn and caused damage estimated at £65,000.

Overnight on April 23-24, Mrs Watkins said Sheppard and Reese set fire to a warehouse on Barton Park industrial estate, Eastleigh. Unknown to them it contained 9,000 tonnes of plastic bags.

On April 24 the same two set fire to a catering unit at B&Q in Woodside Avenue, Eastleigh. Damage was estimated at £2,000.

Reese asked for eight offences, three thefts and five arsons - to be taken into consideration; Sheppard asked for six and Jacobs, for five.

James Newton-Price, mitigating for Sheppard, said his client, a shopworker, came from a respectable family who were "shocked, angry and upset" at the offences. In a letter, the family said: "We feel he needs punishing and we don't feel sorry for him being in prison, because he deserves to be there."

For Reese, formerly in the Royal Navy, Gary Venturi said; "He's appalled and ashamed by what he has done."

Keely Harvey for Jacobs said he was a former Scout leader and had offered to rebuild the barn at Fir Tree Farm.

Sheppard and Jacobs admitted two charges of endangering the safety of railway passengers; Reese admitted one. Sheppard and Reese admitted four arsons; Jacobs admitted two.

The judge imposed sentences of 18 months for the rail offences and three years for the arsons.