How do trains brake? The wear and tear seems to be huge, doesn't it?

Currently, the most common type of braking used in railroad rolling stock is the brake tile brake. With cast iron or other materials made of tile brake block, when braking clutch wheel tread, through friction to make the wheel stop rotating. In this process, the braking device to the huge kinetic energy into heat dissipated in the atmosphere. The braking effect of this good or bad, but mainly depends on the friction heat dissipation ability. When using this type of braking, the brake tile friction area is small, most of the heat load by the wheel to bear. The higher the speed of the train, the greater the heat load of the wheels during braking. If the cast iron brake tile, the temperature can make the brake tile melting; even with the more advanced synthetic brake tile, the temperature will be as high as 400 ~ 450 ℃. When the wheel tread temperature increases to a certain extent, it will make the tread wear, cracks or peeling, both affecting the service life and safety. It can be seen that the traditional tread brake can not be adapted to the needs of high-speed trains. So a new type of braking device - disk brake came into being.

Disc brake, it is in the axle or in the wheel spoke plate side mounted brake disc, with brake clamps to make the synthetic material made of two brake pads tight pressure brake disc side, through the friction generated braking force, so that the train stops moving forward. Because the force is not on the wheel tread, disk brake can greatly reduce the thermal load and mechanical wear of the wheel tread. In addition, the braking is smooth and almost no noise. Disc brake friction area is large, and can be installed according to the need for a number of sets of braking effect is significantly higher than the cast iron brake tile, especially for high-speed trains at speeds of more than 120 kilometers per hour, which is the reason why countries generally use disc brake. But the shortcomings of the wheel tread without brake tile scraping, will make the wheel-rail adhesion deterioration; brake disk so that the weight of the spring and shock vibration increases, the operation of the consumption of traction power.