Railways to go shopping abroad for train wheel sensors

Railways plan to scout globally for advanced train wheel sensors at an estimated cost of Rs 113 crore to monitor maintenance needs of coaches, tracks and locos in advance for ensuring safer travels.
Billed as 'black box' for train operations, railways will introduce the long awaited sensor-based on board condition monitoring system for timely detection of defects related to passenger coaches, wagons, locomotives and tracks.
Railways will float the global tender soon to introduce sensor-based monitoring system that is attached to the train wheels, said a senior Railway Ministry official.
The system, operational in Western countries, would enable predictive maintenance and reduction in sudden catastrophic failures in coach suspension, roller bearings and track condition.

Railway Minister Suresh Prabhu had said in the Lok Sabha in 2015 that the on board rolling stock condition monitoring system is being planned to monitor the health and safety of key components of coaches, freight cars and locomotives that would finally result in improved safety, improved reliability, higher utilisation and reduced operation cost.
"The first phase trial of the on board condition monitoring system has got the approval in the budget now so we are working out to finalise the specifications for floating the tender," the official added.

Considered to be a paradigm shift in train maintenance, the most effective enabler for the system would be monitoring of critical components that have been identified as the major causes for derailment, delay and causes for infrastructure deterioration in railways.

The technology, operational in UK, Sweden and Ireland uses vibration analysis to predict changes in physical condition of the assets around the wheel rail interface.
Even after the derailment, the vibration analysis can be used to ascertain the cause of the accident whether it happened due to bearing failures, or defect in wheel or tracks.
According to the system, the on board sensors record vibrations and temperatures constantly. Vibration anomaly is the earliest indicator that something maybe wrong with the bearing. This allows for operators to mark those bearings out for careful observation, thus preventing any further damage.
Detection of bearing fault at this early stage will help prevent occurrences of incidents and maintenance schedules can be planned for bearings that show anomaly.

These unusual impacts reflect the deterioration of the
track and would enable operators to plan and prioritise maintenance in areas where these impact signatures are higher than normal. Causes of these unusual high impact can be many including surface cracks that eventually lead to rail fracture.
Besides, deterioration in wheel condition due to high impact load indicating excessive wear and tear in the wheels can also be detected by the system.
The wireless sensor nodes fitted on each wheel of the rolling stock would have inbuilt capability to record and identify embedded vibration, temperature and impact loads.
All of this data would be processed and the enabling software would allow for Indian Railways to direct alerts arising out of any early failure to the concerned department and officials that maintain rolling stock. These alerts will also be available to the loco pilot in the cabin on a tablet.