So-called flexible trains, which can have carriages added or removed from a train on demand, will be on the market later this year. Photo: CRRC

(Beijing) — More flexibility is coming to China’s debt-laden high-speed rail network, as it chugs up a long and arduous hill to profits.

The operator of the world’s biggest bullet train system will soon be able to choose the number of coaches on each of its trains, in a major shift from the current system where all trains have only eight or 16 carriages.

The new flexible design is coming from CRRC Corp. Ltd., China’s main builder of high-speed rail and associated equipment, including actual trains, deputy chief engineer Huang Junhui told Caixin. He added that the first of the new flexible trains could be available for use by China’s rail operator within a year.

Photo: CRRC

The design will allow the rail operator to adjust train length based on demand, which varies widely between peak and slow seasons. The operator could also save money by only taking individual carriages out of service when they require maintenance, rather than sidelining an entire train for days when just a single carriage needs work.

“After we get a production permit and orders for these adaptable trains, it’s only a matter of time before they can enter the rail operator’s fleet,” Huang said.

Photo: CRRC

About 90% of the work has been done on development of the new flexible trains, and most remaining details involve interior design. Once that’s done the trains must undergo 600,000 kilometers of operational testing before commercial production can begin.

Huang estimated the new flexible designs could lower the number of carriages required by rail operators by up to half. The transport division of Germany’s Siemens AG has also developed high-speed trains with similar flexible capabilities.

China has spent trillions of yuan building a state-of-the-art 22,000-km high speed rail system that now links up most of the country. Much of the building cost has fallen to the network’s current operator, China Railway Corp. (CRC), whose debt now stands at 4.3 trillion yuan ($623 billion).

Photo: CRRC

That figure will only get higher as China rapidly expands the network. In December an official said the country planned to spend 3.5 trillion yuan on the railway sector as part of its 13th Five-Year Plan, which charts development goals for 2016-20. Under the plan, 30,000 km of new track will be built over the five years, which will expand the country’s railway network to a total of 150,000 km.

Contact reporter Yang Ge (geyang@caixin.com)