The whole UK rail network could be checked for cracks in just 20 days with a new set of train-borne devices on test with Railtrack, it claimed this week.
Four trains fitted with US-designed ultrasonic monitoring equipment will be in operation by next summer. Meanwhile, maintenance staff will be issued with more powerful hand-held devices to confirm the presence of defects in the rail.
The Hatfield rail crash in October 2000 prompted the HSE to call on the rail industry to improve its methods for monitoring rail conditions.
David Cooper, a Railtrack senior asset engineer, said this week that the ultrasonic trains would not be attached to normal services. ‘Due to the laws of physics for ultrasound the trains can only travel at 40mph. So most of the work will be night inspection, especially for the East Coast, West Coast and Great Northern main lines.’
The first two trains currently on test use rubber wheels with in-built ultrasonic probes, which fire ultrasound into the rails as they pass over the track. The results of the inspections will be held on a central database, which will be used to direct staff to carry out inspections with the hand-held ultrasonic sticks to confirm the presence of cracks in the rails.
‘The sticks will be utilised until the integrity of the train-mounted technology has been established and then we may remove the sticks from service,’ said Cooper.
The sticks use ultrasound waves operating at 4MHz, much faster than the ultrasonic hand units used previously. The drawback with the old pedestrian method was its speed. Because only seven miles of the 26,000-mile rail network could be scanned per day, it took over 3,000 days to inspect every inch of rail. But the four trains can do it in just 20.