In December 2025, China ran seven 5,000-ton coal trains across Inner Mongolia as a formation heavier than three Eiffel Towers combined, without physically connecting them; engineers believe it could boost rail capacity by over 50% without new tracks

China successfully tested seven freight trains operating as one unit. These trains were virtually coupled using advanced wireless control systems. This innovative technology allows trains to move in close formation without physical connections. The experiment demonstrated increased freight line capacity without building new tracks. This development offers a significant advancement for heavy-haul railway operations.