Brake Shoes

Brake shoes are metal parts positioned next to the wheels on rail vehicles . They are the main means of stopping, relied on by a few braking systems , such as the train brakes , independent brakes and handbrakes . Braking with brake shoes is achieved using friction to convert rotational energy of the wheels into heat. Brake shoes are pushed against the turning wheel surface, heating up in the process and slowing the vehicle down.

With excessive use, for example when taking too heavy trains downhill at a high enough speed, the brake shoes may overheat. While in this state, they glow and make a metallic chime noise. Their braking ability is weakened and restored only once the shoes cool down again. Depending on the grade and other factors, if brake shoes overheat, a train may start gaining speed uncontrollably, resulting in a runaway disaster.

To avoid overheating the shoes, alternative methods of reducing speed may be used, such as dynamic brakes . By braking dynamically, vehicles offload some of the work from their brake shoes to their powertrains . Another way of reducing the use of brake shoes is to use any available uphill grades as a way to slow down .

For situations where brake shoes overheating is likely to occur, having a caboose coupled to the train may help. The caboose is equipped with brake shoes that are so much more resilient to overheating, that its handbrake can be kept permanently applied to help slow down a train where doing so with other braking methods is inadequate.

Brake shoes can be applied to the wheels in two ways. Handbrakes do it by being cranked up with a human hand, whereas train and independent brakes do it with compressed air .

The only way to monitor brake shoe temperature on a gauge is with a infrared thermometer gadget installed.