Tew Plus is fitting detectors at level crossings from Scotland to the south coast. After nearly two years of testing, the installer gained full Network Rail Product Approval for its Level Crossing Obstacle Detector (LIDAR) using the Redscan detector from OPTEX as the core element. The complete MCB-OD level crossings products includes the LIDAR as the Complementary Obstacle Detector (COD) alongside radar and CCTV equipment. While the radar is used to detect vehicles or large objects that can damage a train and endanger its passengers, the LIDAR is designed to protect passers-by or cyclists who could be trapped between the barriers. The system is sensitive enough to detect a nine-year-old standing, laying upon or crossing the track. The signalling tells the LIDAR when the level crossing is active, and the detection system scans the crossing area within the barriers accordingly. If the crossing is clear, the signal turns green and the train can go through safely. If an object is detected, then the barriers are raised to enable that object (a vehicle or pedestrian) to leave the area before allowing the train to pass. The system is fully automated: if the object is static and the system has gone through three cycles, a message can be sent to the train driver to proceed with caution at no more than 5mph to determine what it is obstructing the track.
So far more than 60 of the Tew Plus-designed LIDAR systems have been installed and a further 80 have been sold to Network Rail. The products are to be rolled out to more than 400 level crossings over the next five years.
Dave Farman, Product Development Director at Tew Plus, says that the new system has been working to specification: “Since the first system was designed in 2012, a number of modifications have been made: trains passing through kick up mud, dust and spray water; the first laser sensors weren’t protected from it and after a while dust covered the sensor lens affecting its performance. We have therefore added motorised shutters that only open when the barriers are down; the system scans and then shuts just before the train passes. Specific algorithms have also been developed to analyse particular environmental obstacles such as snow building up on the track or weeds growing up in front of the scanner.”
Safety integrity level (SIL) 3 trials are underway in mainland Europe that will enable the LIDAR to become the primary obstacle detector approved to SIL 3 rating. The outcome of the trials should be known in about 18 months.
Ricky Miwa, Managing Director of OPTEX Europe says the level crossing detector is another example of how precise and versatile the Redscan is: “It is extremely satisfying to see this award-winning laser detector as part of a solution to make level crossings safer.”
