LOCOMOTIVES which move wagons containing 20 tonnes of coke at 1320íC between the 132 ovens and two quenching towers at the Redcar plant of steelmaker Corus are subjected to extremely harsh conditions as the plant runs continuously every day of the year.

’Each cooling operation produces 2 tonnes of steam, so often the drivers can’t see each other’, said Dave Aston, Manufacturing Engineer at the plant. The increases the risk of collisions between the locos, which weight up to 110 tonnes when fully loaded. ’Even though they are in radio contact, they could not always see where they were clearly, so there was a potential risk of collision. This would then lead to possible injury and loss of production.’ Plans to use shaft encoders, laser or sonar positioning and satellite tracking to monitor the location of the locos proved impractical, so Corus turned to RFID tags.

A total of 309 LRP250 passive read-write RF tags are spread along 370m of track at intervals of 1·2m, matching the spacing of the coke oven doors. Each of the three locos has been fitted with a sealed, bi-directional LRP820-02 long range reader-writer antenna, and an in-cab monitor which shows the position of the loco to within 0·30m.

An automated control system provides audible warnings in the two locos in service at any one time if they are within 90m of each other. Closer than 80m the speed is automatically cut from 125m/min to 25m/min, and the locos are brought to a halt if they get 15m apart.

DataScan Systems, UK