Published : 17/11/2025
On China's high-speed rail lines, the first train to run every morning is very special. It neither offers ticket sales nor carries passengers, and it cannot even be found on the timetable.
Why does this train run "empty"?
"Minesweeper train" verifies the results of maintenance work
Equipment such as high-speed rail trains and lines is usually scheduled for inspection and maintenance during the "skylight period" in the middle of the night. But how effective is the maintenance, and could any issues have been missed?
To ensure that nothing is overlooked, the authorities arrange for the earliest train on the high-speed rail line each day to run "empty" for verification purposes. Its official name is dynamic inspection confirmation train (動檢確認車), and it is also vividly nicknamed the "minesweeper train" by railway enthusiasts.
Although the "minesweeper train" also has a service number, it does not appear on regular timetables.
Read more: Why are there so few overnight high-speed trains in China?
Mechanics monitor the technical condition of the facilities
While it is running, there would be only three or four staff members on board, such as the driver and mechanics.
They each have their own duties. For example, the mechanics are responsible for monitoring the train's operation and the technical condition of the contact network, verifying the compatibility between the line and the vehicle.
They need to focus on observing whether any facilities have failed to be restored after the line's "skylight period" maintenance. If any problems are found, they must be dealt with immediately.
If everything is normal, the dynamic inspection confirmation train will immediately change its service number upon arrival at the station, reverting to a passenger train to begin a new day of operation.
Part-time express delivery to ease logistics pressure
In addition, although the dynamic inspection confirmation train does not carry passengers, it may take on "part-time" delivery tasks, for instance, transporting fresh food, medicines, and electronic products.
It also carries general courier items during the "Double 11" period to help ease logistics pressure.
According to media reports, a dynamic inspection confirmation train can carry a cargo weight of up to 15 tonnes, with a delivery time comparable to air transport.
Speaking of the dynamic inspection confirmation train, there is actually another type of "dynamic inspection train" on the high-speed rail lines — the "comprehensive high-speed inspection train" (高速綜合檢測列車).
Read more: Why don't high-speed trains provide seat belts?
"Doctor Yellow" specialises in testing new railway lines
This type of train similarly does not sell tickets nor carry passengers, and it will not appear on the timetable either.
Its carriages do not have rows of seats, but are instead loaded with various high-tech inspection and control equipment. Because its body is painted yellow, it is also known as "Doctor Yellow".
Whenever a new high-speed rail line opens, "Doctor Yellow" will be the first to conduct tests on the line, and collect data for analysis, to ensure the line meets operational requirements.
"Doctor Yellow" in China is extremely rare. According to 2023 figures, there are only 17 sets of "High-speed Comprehensive Inspection Trains" of all models in the entire country.
For railway enthusiasts to catch a glimpse of it, it can be described as a rare opportunity that one might encounter but cannot seek.