Abstract: The HOT AXLE AUTOMATIC BRAKE APPLICATOR is a successor to Present solutions for rail coach axle protection against high temperatures as these methods are costly and they require replenishable parts and costly electronics maintenance. The invention incorporates a heat sensing Thermal actuator namely Heat capacitance motor which pushes a closed valve with its piston as soon as it detects dangerous temperature. The moment the valve opens it applies air brake to the Railway coaches Thus avoiding derailment or accident by dangerously melted bearings and broken axle of the Railways coach.