A helicopter will patrol Chiltern Railways' route equipped with a 360 degree zoom camera with thermal imaging.

The initiative, called Operation Skyhawk, aims to catch trespassers as well as deter youngsters from straying near the tracks during the school holidays.

Vandalism and trespassing on the railway kills more than 120 people every year in the UK and costs the rail industry �26m in delays and damage.

School holidays

Richard Fearn, Railtrack midlands director said: "Using the helicopter will enable us to react quicker to any incident that is reported and the video camera on board means we will have evidence to support any prosecution."

A spokesman for Chiltern Railways said: "Railway crime costs the industry millions of pounds each year and tragically results in injury and lost lives.

"The use of helicopters to patrol the railways has been proven elsewhere and we're very pleased to be taking part."

A spokeswoman for Railtrack said teenagers caused most of the damage to tracks and the number of incidents often increased during the school holidays.