The MRT 912 system is designed, comprising of an axle mounted Speed Sensor to give the speed signal, a micro controller based measuring and control system to compute the speed and distance, DC Step Motors to drive the Recording styluses for speed and time graph, as well as Hour printing wheel, and a computer controlled DC Step Motor driven pointer for speed indications. The number of components is very much reduced by using micro controller for processing. Hence the reliability of the system is proven to be very high. Further the DC Step Motors selected are very small in size and highly reliable. A switch mode power supply has been designed which can cater for wide fluctuations in the loco battery voltage.

The medium used for recording i.e., Wax impregnated paper is tamper proof, low cost and indigenously available. Further in this system, the data can be retained even after physical damage to the unit during accidents.