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Wednesday 31 Oct 2012

The future of continuously-welded track inspection is here

Region & Route:

National

What if you could survey long stretches of plain line using technology, so railway staff could spend more time fixing faults than finding them?

The answer to that question is Plain Line Pattern Recognition (PLPR), a new service ready to be offered to Network Rail’s routes in the coming year.

Currently fitted to the New Measurement Train, the system uses seven linescan cameras (two on the railhead, one on the four-foot, and one on the outside and one on the inside of each rail), four 3D cameras and two thermal imaging cameras to scan the track as it passes beneath the train.

The cameras record raw images at up to 76kHz – a significant technical achievement in itself – allowing it to capture images at up to 125mph.

Each camera stores the information on its own terabyte hard drive, which are then downloaded to an on-board computer. The data are then decoded using machine vision software developed by MVTec, synchronised with real time positioning system and geometry data, and then analysed by an on-train inspector. Reports are then dispatched to the teams on the ground helping them accurately locate any faults found.

■ Information captured includes geometry, condition of track and fixings. The system does NOT analyse switches and crossings.

■ PLPR has been three years in development and testing on trial stretches of the WCML. Further development continues.

■ Four more PLPR rigs are being developed to fit to Network Rail’s measurement trains. These will be rolled out across Network Rail’s continuously-welded rail network.

■ Staff no longer have to walk miles along a 125mph railway and can focus on fixing problems. Targeted maintenance also means only assets that need replacing are dealt with, rather than blanket renewals.

■ PLPR will be delivered by Asset Information at Network Rail, and offered as part of its infrastructure condition monitoring services to the devolved routes.

Further innovations in the coming years will see greater flexibility on how data is disseminated and analysed by trackside engineers.