Were the policemen always on the train?

The police are not always on the train.

According to the regulations of the China Railway Public Security Department, train police are part of the railway public security system and are responsible for maintaining public order and passenger safety on trains. They will be stationed according to the route and frequency of the train, but not every train will have police officers on board. The working hours and shift arrangements of train police are determined based on needs to ensure safety and order on the train.