China plans X-prefix trains for 400 km/h services on new Chongqing–Chengdu line

Why it matters: China already runs the world's largest high-speed rail network, and train prefixes are how passengers tell services apart when booking: G for the fastest, D for slower, and K and T for conventional trains. A new top tier signals that tickets and timetables will be reorganised again, and faster trains could pull travellers away from short-haul flights.

China Railway Group recently announced a new X-prefix category for high-speed trains, reserved for future services running above 350 km/h, according to the WeChat account Jieju Caijing. The X prefix would rank above G, which currently marks the fastest trains.

Under the same adjustment, the letter prefixes are being reordered by speed: G for 350 km/h, T for 300 km/h, K for 200 to 250 km/h and D for 200 km/h. T and K will no longer mean conventional rail only.

The first X-prefix service is expected on the Chongqing–Chengdu middle line, part of the Yangtze River corridor, which is due to open in 2027 and is designed for speeds above 400 km/h. The operator says the trip between Chongqing and Chengdu will then take about 50 minutes.

The CR450 test train has reached 453 km/h, and a rail science and technology plan calls for putting 400 km/h trains into commercial use. Main lines such as Beijing–Shanghai and Beijing–Guangzhou may adopt them first.

The number of train prefixes for electric multiple units rises from four to seven, increasing the number of available train numbers by nearly 40 percent, the report said. During the National Day holiday peak, G-prefix numbers were almost exhausted, it added.