GAUGE corner cracking and other forms of rolling contact fatigue can be detected using a field gradient rail inspection camera developed by Newt International. The Lizard camera presents television-like pictures of flaws in the rail (or other engineering structures) and uses an odometer to record defect locations. It can see through corrosion and grime up to 10mm thick, meaning there is no need for surface cleaning. Crack size or surface geometry does not limit the Electro Magnetic Array technology, unlike ultrasonic inspection.

The camera has an LCD screen with rolling colour imaging of rail defect position and severity. The battery operated equipment is based on PC architecture There is a data port for file transfer to desk or laptop computers for data analysis and archiving. Data from many kilometres of inspection can be stored on DVD for asset management purposes, and there is an optional modem for direct intranet transfer.

Heathrow Express is currently using the camera as a manually operated Pedestrian Unit. Guided by double flanged wheels, the £42000 camera is pushed along the rail at walking speed.

Railtrack has agreed to invest £400 000 of R&D funding over two years to help develop a camera able to identify defects in switch blades. Funding may also be obtained to accelerate the development of a train-mounted version.

Newt International, Great Britain

Reader Enquiry Number 144