Want to walk from Car 8 to Car 9? Unless you stop the train...

Audit expert: Zhou Hongzhi

Senior Experimentalist, School of Physics and Optoelectronic Engineering, Beijing University of Technology

Master Supervisor

The 2025 Spring Festival travel season will begin on January 14 (the 15th day of the twelfth lunar month). Whether traveling or visiting relatives, high-speed rail has become an important means of travel. When riding the high-speed rail, have you noticed that carriages 8 and 9 are not connected? If you want to go to other carriages through this section, you must wait for the high-speed train to stop and walk from the outside.

If you pay close attention to each train, you will find that sometimes a high-speed train is composed of two EMUs connected end to end. In fact, this is a common mode of operation, called reconnection.

Image source: China Railway

0 1What is a high-speed train?

D-Series High-Speed ​​Train, also known as "EMU train", is a type of modern train. EMU consists of several powered vehicles (EMU) and non-powered vehicles (trailers). The train runs in a fixed marshaling mode during its normal service life.

In the ticketing system, the "(ordinary) EMU train" starts with a capital letter "D" as the prefix (derived from the Chinese pinyin letter for "动"), and is referred to as a "D-prefix train". The maximum operating speed is 160~250 km/h. As the lowest level of passenger transport, the EMU passenger train mainly undertakes medium and long-distance passenger transport tasks, and some of them also travel between short-distance cities.

Intercity EMU trains, referred to as "C-prefix trains", are specially used for medium and short-distance trains between cities or suburbs; high-speed EMU trains, referred to as "G-prefix" trains, are specially used for trains operating at speeds of 300-350 kilometers per hour.

0 2Why do EMUs need to run in multiple units?

The EMU carriages have characteristics such as integrity, sealing, aerodynamic characteristics and high speed, which are very different from ordinary green-skinned train sets, so they cannot be disassembled in actual operation.

For this reason, when the EMU needs to increase its carrying capacity, two train sets can be directly connected head to tail. In actual operation, two EMU sets of the same model with 8 carriages can be connected together through components such as couplers, and one of the sets can be divided into 9 to 16 carriages.

It is worth mentioning that when running in multiple units, the running speed of the two EMUs remains the same as before the multiple units are run in multiple units.

The purpose of coupling EMUs is to increase capacity when the number of passengers increases, and to remove coupling during the off-season to reduce operating costs. After coupling, the train's transportation capacity is significantly improved. For example, during the peak passenger flow period of the Spring Festival travel rush, the railway department will increase capacity by coupling EMUs to meet the travel needs of passengers returning home, traveling, etc.

0 3 connected together, how many drivers are needed to operate?

The first EMU in the forward direction needs to be operated by a driver.

The second EMU can complete acceleration, deceleration, starting and stopping actions synchronously without the need for a driver.

0 4You need to confirm the carriage number before boarding

It should be noted that when the EMUs are running in multiple units, carriages 8 and 9 cannot pass through each other.

Therefore, please confirm the car number before boarding.

If you get on the wrong car, you can contact the conductor for help. When the train arrives at the intermediate stop, move from the platform to another train. Never force the door open!