Spotting a defect on an overhead rail wire up to 25 ft above your head can be a difficult task even for an expert. But now, thanks to new cameras that have been rolled out to rail maintenance teams across Britain, the work can be carried out more efficiently and accurately than before, leading to fewer delays to passenger and freight services.

Following a successful trial, Network Rail (London, England) -- the authority responsible for the UK's railway network -- has supplied 30 cameras to maintenance delivery units on electrified routes across the UK. Engineers can operate the cameras without turning off the power and closing the line, saving a considerable amount of time.

When out on routine track patrols, engineers can attach the cameras to the overhead wires, which are held steady by two small stabilizing arms on insulated poles. The cameras can tilt so that images and video of the top and side of the wire can also be captured.

The images are then streamed to a portable laptop ,which can be more than 100 m away from the cameras. Engineers can view these to immediately review the condition of the wire or analyze the footage later. A schedule for repair of any defects can then be put in place.

Another benefit of the system is that it can measure the thickness of the contact wire so engineers can gauge wear rates, find thin spots, and then plan for renewals.

-- Posted by Vision Systems Design