The Indian Railways is now adopting a unique modern technology for maintenance of its passenger coaches, wagons and locomotives. The new maintenance technique which uses acoustic method of diagnostics is known as Acoustic Bearing Detectors (ABD) & Wheel Impact Load Detectors (WILD). When used in combination together they are known as Online Monitoring of Rolling Stock (OMRS) systems.
This technique involves placing arrays of microphones and sensors that record the audible noise and forces generated by the running coaches, wagons and locomotives. Conventional method to maintain passenger coaches, wagons and locomotives is to physically examine when these are in stationary condition at the maintenance depots. Under the new technique, the faults in the Rolling stock can be detected while on run which is a big advantage as it will make maintenance faster reducing turn around time for Rolling stocks thereby ensuring availability of high number of wagons/coaches etc. for operation.
The OMRS equipment is so sensitive and accurate that it is often able to indicate the specific sub-component that is not behaving the way it should and therefore causing abnormal noise. Moreover, this can be monitored remotely using mobile communication facilities. In the conventional method, it is nearly impossible to detect this problem unless major assemblies are completely dismantled and checked in the maintenance depot.
One such system, which is a combination of ABD, OMRS & WILD systems, is installed near Bakkas in Lucknow division of Northern Railway as a pilot project. It has successfully detected a number of wheel bearing faults avoiding the problem of wheel bearing becoming hot which results in the stoppage of the train at the station or worse still-in between two stations. WILD have been installed in 15 locations across the country in the initial phase and these have also detected faulty vehicles that have caused higher than normal impact force on the rails. These 15 locations are; Ajni, Asansol, Mughal Sarai-I, Mughal Sarai – II, Barwadih, Vishakhapatnam, Arakkonam, Gunakal, Mahalimarup, Dongargarh, Bilai, Hospet, Bina, Itarsi and New Katni.