Freezing rain caused the catenary to freeze, and the train was blocked from receiving power and current flow. Professor Cai Guoqiang of the National Key Laboratory of Advanced Rail Transit Autonomous Operation: "Unlike the low temperatures, heavy snowfalls, strong winds and other climates, the real problems faced by high-speed rail operations in many places this year are from freezing rain surprise attack" The overall trend is to It has weakened, but we still need to pay attention to weather risks in some periods and areas, Zhang Hengde said.