China updates railway numbering system for high-speed trains

China State Railway Group Co., Ltd. has announced a major update to the national train numbering system to accommodate increasing speeds and service types. The restructuring will occur in two phases, scheduled for late November and late December. A new “X” series prefix will be introduced specifically for future high-speed trains with maximum operating speeds exceeding 350 km/h.

Central to this technological advancement is the Fuxing CR450 electric multiple unit (EMU). This train has achieved a test speed of 450 km/h and an operational speed of 400 km/h, with all homologation tests expected to be completed by March 2026. According to the China Academy of Railway Sciences Corporation Limited (CARS), the CR450 is currently the fastest high-speed train in the world by operating speed. Notably, the CR450 maintains energy efficiency comparable to existing models, consuming less than 22 kWh per kilometer at 400 km/h.

The new numbering system will categorize trains by speed: the X series for over 350 km/h, G series for 350 km/h, T series for 300 km/h, and K series for 200-250 km/h. This reform follows a massive expansion of China's high-speed network, which saw the number of 300-350 km/h trains grow by 209% between 2014 and 2025.

In a broader regional context, China's high-speed technology is also utilized in international projects, such as the Laos-China railway. While the Laos-China line operates at lower passenger speeds of approximately 160 km/h to accommodate both freight and passenger needs, it utilizes Chinese standards and infrastructure.