A joyriding teenager caused a £25,000 trail of destruction after rampaging through a building site in a stolen forklift truck and smashing through gates to a level-crossing.

Police and Network Rail said the incident could have resulted in a railway disaster if the forklift had been abandoned on the railway, or damaged the tracks.

Elton Bulley and his friend Laurence Griffith, both 18, stole a set of keys to the Manitou BT420 forklift from a building site in Marlborough Road, south Oxford, at about 6.30pm on September 1.

Bulley got behind the wheel and caused £15,000 worth of damage to the site by crashing into scaffolding, building work, two chemical toilets, and pallets of bricks, magistrates in Oxford heard on September 3.

He then drove the forklift along a track off Whitehouse Road, and crashed through a white single-bar gate.

Sarah Shears, prosecuting, said Bulley then tried to "display" the £20,000 forklift, performing dangerous driving manoeuvres in front of his friend.

Bulley then lost control and crashed into a railway access gate and security fencing.

Griffith then took over and drove the vehicle for about 50 metres along the track, parallel to the railway line, before losing control.

Bulley took the wheel for a second time and smashed through padlocked gates to a level crossing, which allows emergency vehicles access to the rail network. But instead of continuing across the tracks, Bulley reversed into a wall.

He then drove back along the track and abandoned the vehicle in undergrowth, after causing damage totalling more than £25,000.

Callum Collins, Network Rail spokesman, said: "This incident could have led to a catastrophic accident and that is why we take a zero-tolerance approach to all crime along the railways. We fully support the police in this prosecution."

Det Sgt John Clayton, of Oxford police's autocrime team, said: "It could have resulted in a full-blown train disaster, and that does not bear thinking about -- it's horrendous."

The duo were arrested after a short pursuit on foot by officers. Griffith gave himself up and Bulley was found by the police helicopter's heat-sensitive camera.

Bulley, of Riverside Court, Oxford, admitted aggravated vehicle-taking; endangering the safety of railway passengers and staff; causing £8,000 of criminal damage to emergency access gates and security fencing; causing criminal damage worth £4,000 to a metal security gate and retaining wall and causing £15,000 of criminal damage to a building site. Bulley and Griffith both admitted stealing the forklift keys in a burglary, and driving without insurance. Griffith, of Lansdown Close, Sandwell, Bristol, further admitted driving the forklift without consent.

Lee Reed, defending Bulley, said his father had lost both his legs to gangrene several years ago and depended on his son to help with cooking, cleaning and shopping.

She said her client only had one previous conviction, for stealing items worth £90, which he had admitted.

Karen Sidhu, defending Griffith, said her client, who had no previous convictions, was staying with Bulley in Oxford for a week when the offences occurred. Both had been friends growing up in Bristol.

The case was adjourned until Monday, October 6, when Bulley and Griffith will be sentenced before a judge at Oxford Crown Court.

They were bailed on condition they live and sleep at their home addresses and report to their local police stations three times a week.