An interior view of the subway train set to run on Beijing's new airport subway line, Jan 29, 2019.[Photo/IC]

The trains each have a business class carriage, a first in the country. The eight-carriage train, which is about 22.8 meters long and 3.3 meters wide, will be able to carry a maximum of 1,500 passengers.

There are wheelchair spaces and USB charging ports by the passenger seats on the train.

The new subway trains are expected to start trial operation in September, when the Beijing Daxing International Airport is due to open.