Train-mounted track monitoring devices are to replace manual inspection of UK railways, saving thousands of man hours each year and eventually reducing disruption to services.
At present wear and tear develops in the track beds, due to vibration in the track and wildlife such as rabbits digging holes, eventually causing subsidence or leaving a gap between the rail and ballast.
The weight of the train on the unsupported rail can lead to cracks and fractures, as can fatigue, which was instrumental in the Hatfield derailment in October 2000.Following Hatfield, Railtrack was given a multimillion-pound budget to spend on technologies to improve track monitoring.
Current maintenance procedures rely on time-consuming manual inspections of track with rail engineers covering around seven miles per day, hitting the track with hammers and listening to the resulting sound.
Railtrack is now working with US company Edwin Reeves Associates to install train-mounted units that measure the track’s geometry and stiffness using a combination of laser and camera technologies. Data is downloaded at the end of each journey, allowing engineers to monitor tracks on a daily basis, correcting faults at an early stage before expensive repairs are necessary.
US firm Sperry is also helping the company to develop train- mounted ultrasonic equipment, providing an accurate picture of the rails’ internal structure to find cracking, while engineering consultancy Scott Wilson has been brought in to provide handheld ground-probing radar testing of the ballast and rail bed.
A Railtrack spokesman said: ‘We have scoured the world looking for new technologies that will help to improve rail services. These systems were chosen because we needed technologies that will come on line as soon as possible.’
But the Worcestershire-based Tricorn Group, which provides ground-probing radar technologies for construction projects, says its train-mounted Track Inspection Vehicle is a single unit that could perform all the above tasks and identify problems with ballast before this affects the track. It approached Railtrack in 1999, proposing that the company took a stake in the £250,000 cost of developing their technology, but were turned down.
As well as monitoring the track using a ground-probing radar unit mounted on a commuter train, Tricorn says it could include satellite geopositioning to provide location data accurate to the nearest 0.5m, while an alert system could be activated if signs of serious rail deterioration were detected.
‘The system is based on existing working technology and could have been up and running by now if we had received the necessary assistance,’ said Tricorn managing director Andrew Cowan.
‘However, if Railtrack is putting money into new technologies this looks like an ideal time to approach them again.’