One method of reducing the number of cane train derailments caused by failed wheel bearings is to monitor the temperature of the axle boxes. When an axle box which is running hotter than normal is discovered it should be examined to determine whether it is likely to fail and cause a derailment. To enable axle box temperatures to be monitored in service the Sugar Research Institute has developed a hot axle box detection system using infra-red thermometers for temperature measurement. This paper describes the work carried out at Invicta mill during the 1984 season in determining the feasibility of an automatic hot axle box detector and the work carried out subsequently at Invicta, Marian and Farleigh mills during the 1985 and 1986 seasons to develop a reliable detection system.