Wheel flats are formed on the wheel tread due to unintentional sliding of the wheel on rails. Additionally, metal deposits in lump form caused due to brake binding result in out-of-round wheels and have the same effect as wheel flat. Isolated wheel-flats, molten metal deposition on wheel tread, out of roundness of a wheel etc. cause repeated impact loads. Heavier trains and higher speeds accentuate the influence of imperfections causing distress to both track and vehicle. A fresh wheel-flat has the shape of a geometric chord at the wheel circumference. However, when the brake unlocks, the corners of the flat profile soon become rounded due to running.

A prototype automated system for On-Line estimation of Wheel Impact Loads and detection of Wheel Flats of running trains has been developed.

The Instrumentation System consisting of both Hardware and Software components has then been rigorously field tested at Ajgain Railway Station, near Lucknow for more than two years.

Strain-Guage Technology has been employed and data is collected over 24-channels along a rail length of five meters. Intelligent software algorithms and codes have been developed and embedded into the hardware processors.