开行组合列车、重载列车是我国当前提高铁路运能的一项重大技术措施。很多铁路局已将单机牵引定数提高到3000～3700t,双机、三机牵引定数提高到6000～7500t。这样,可缓和运能与运量之间的矛盾。但是,发展组合列车、重载列车在我国只是刚刚起步,虽然取得了一些成功的经验,然而也暴露出不少问题,其中最突出的是制动平稳性极差。如锦州铁路分局组织的两次组合 The combination of train operation and heavy-haul trains is a major technical measure to increase railway transport capacity in our country. Many railways have increased the number of single traction to 3000 ~ 3700t, double, triple traction number increased to 6000 ~ 7500t. In this way, can ease the contradiction between capacity and capacity. However, the development of combined train and heavy-haul train has just started in our country. Although some successful experiences have been made, many problems have also been exposed. The most prominent one is the poor braking stability. Such as Jinzhou Railway Branch organized two combinations