Weather report

Rail Research UK is developing a train-mounted sensor to measure the temperature of track throughout the UK’s rail network, to prevent points systems freezing in winter and to reduce the number of speed restrictions during hot weather.

Rail Research UK is developing a train-mounted sensor to measure the temperature of track throughout the country’s rail network, to prevent points systems freezing in winter and to reduce the number of speed restrictions during hot weather.

The research body, which is funded by the EPSRC and is made up of a consortium of seven universities, is investigating the use of an infrared sensor to measure the temperature of the rail from a moving train.

Such a device would allow better management systems to be implemented when there is a likelihood of ice forming in the cold or rails buckling in high temperatures, said Alan Stirling, centre manager for Rail Research UK at its Birmingham University headquarters. ‘We are looking for low temperatures so we can do any necessary de-icing, and high temperatures for the prediction and prevention of buckling.’

On straight stretches of track ice is not normally a particular problem, as the heat and pressure generated by the trains tends to melt any ice formed overnight. But the first train to travel over a stretch of track in the morning would benefit from a warning that its braking distance is likely to be longer, and the device would also alert staff to the need to turn on heaters at moving parts such as points and crossings, to prevent them freezing, said Stirling.

‘The device would be used to tell us what the entire network temperature profile is, which could be utilised against future weather predictions to identify the hot and cold spots on the network. We would get this information from a number of trips through the area, which would tell us the spots that will be worse than neighbouring sections [in cold or hot weather].’

By improving the prediction of stretches of track likely to be more vulnerable to buckling in high temperatures, the device would allow maintenance managers to ensure these areas are monitored more closely, while reducing the number of speed restrictions introduced on the rest of the network, said Stirling.

The sensor is likely to be fitted under the carriage of the train, and the researchers are investigating how far above the rail the device can be installed, to balance the safety issues involved in placing it too close to the track with the reduced accuracy of placing it further away.

The device will be tested on a spinning wheel of railway track recently installed at the university. The wheel, which can spin at up to 50mph, is also testing the use of powerful train-mounted lasers for removing leaves from the line.

The lasers, developed by Southampton-based LaserThor, are already being tested byNetwork Rail on special engineering trains. But the wheel will allow the devices to be tested extensively without the costs and safety issues of installing them on moving trains, said Stirling.

The researchers will also use the wheel to test ultra-sound sensors to detect where rails have become misshapen and worn.

Note: Researchers at Newcastle University’s Stephenson Centre have developed a tiny electronic device capable of detecting rail faults such as buckling. The device, which is fitted to a train’s wheel axles, logs any problem and uses GPS to detect its exact location, before sending a warning message via the GSM network.