Many people will come across orange high-speed train sets instead of our common blue and white Harmony by chance, and there is not a single passenger on these orange high-speed train sets. This is because these high-speed trainsets are used to comprehensively inspect other high-speed trains to ensure the safety of the trains as well as the passengers.
This kind of train is specially designed to check the safety performance of trains, so it is not used to carry passengers. It usually appears at night, because in the daytime there are too many high-speed routes will start running, daytime testing will only hinder the normal travel of passengers. In order to distinguish it from other trains, it was changed to yellow, so it is called "yellow doctor". The scope of its detection is more comprehensive and more, mainly focusing on the detection of three major aspects.
The first one is to detect the railroad track on which the high-speed train runs. So in fact, this high-speed train is different from other trains, it will run on the high-speed railroad track once can check the car to the bottom of the railroad track has not been damaged, there is no other security risks. If there is any problem with the rail, then the train staff will go down to repair the rail in time to ensure the normal operation of the rail.
Second test track contact network. We all know that the high-speed train running speed is very fast, and can bring the speed so high is because of the high-speed train track has a contact network. So the contact network is also very critical for high-speed train, if the contact network is not flexible, it will affect the normal operation of the train.
The third detection communication system. High-speed train running length is very long, and in a short period of time as quickly as possible, so this is very high for the requirements of the communication system, the different status of the network signal is different, in order to ensure that the communication system is smooth this is also to be checked frequently.