A gang of graffiti vandals caused damage worth £60,000 by spray-painting massive signatures on train carriages.

William Setzdempsey, an unemployed 19-year-old from Sussex, was one of four men jailed after a long police investigation into vandalism on the railways in the South East.

A court was told he belonged to gangs called JKS (Just Kant Stop) and FDC (Forever Doing Crime).

Members risked their lives on the tracks, even carrying on their criminal pastime after being electrocuted on live rails.

Setzdempsey, from Hillmead, Uckfield, is beginning a 15-month jail sentence after admitting spraying signature 'tags' on train carriages in organised graffiti sessions on the railways.

Police found a bag full of spray-paint cans and photos of himself carrying out the vandalism when they searched his car.

From 2005 to their arrest in Hertfordshire in April 2007, tags belonging to the group were linked back to vandalism at East Grinstead, Redhill, Woking, Tonbridge, Epsom, Bletchley, Horsham, Hastings, Tunbridge Wells and Ramsgate.

Detective Sergeant Pete Thrush of the British Transport Police said: "Numerous bits of graffiti paraphernalia were seized during various house searches.

"Many had tags linking back to each of them on everything from railway timetables to shoe boxes, with even a pair of slippers being seized with their tags on it."

Police found text messages between the defendants, which said: "Safe M8 U up 4 doin a live tube plot 2nite" and "I'm doin sum track sides by myself anyway I've got 6 cans of stella an paint."

DS Thrush said: "These people are persistent dedicated vandals. The court has recognised the seriousness of the offences, the risk these young men take with their lives and the cost to the train companies and public of south London.

"I would rather see people go to court than go to the morgue."

At Southwark Crown Court on Friday Judge Stephen Robbins handed down combined sentences of six and a quarter years to the gang, saying prison should be a deterrent to other vandals.

He said: "The fact is that this type of offending sickens members of the public who have their travelling lives blighted by this sort of criminal damage."

Setzdempsey admitted conspiracy to cause criminal damage along with three other men.

Tom Collister, a 22-year-old glazier from West Wickham, Kent, was sentenced to 30 months in prison.

Darren Austin, a 21-year-old plumber of Beckenham, Kent, was given 18 months and Joshua Piehl, a 19-year-old apprentice locksmith from Tunbridge Wells, was handed a 12-month sentence.