铁道车辆的空气制动装置是利用摩擦力来制动的 ,若有水及冰雪介于磨擦面之间则摩擦系数低下从而降低制动效果。尤其是有冰雪时 ,制动力下降更为明显。另外 ,近年来 ,由于在既有线的车辆编组中 ,拖挂车的数量增多 ,因此 ,在拖挂车中承担主要制动作用的轴装式盘形制动器性能下降 The air brake of railway vehicles is to use the friction to brake, if the water and ice between the friction surface friction coefficient is low to reduce the braking effect. Especially when there is snow and ice, the braking force drops more obviously. In addition, in recent years, the number of towed vehicles has increased in existing train sets, and therefore, the performance of shaft-mounted disk brakes, which take the major role of braking in trailers, has been degraded