Japan’s railway workers are about to get two giant mechanical coworkers, and one of them comes armed with a chainsaw. West Japan Railway Company, known as JR West, is adding two new maintenance robots, led by the dual-arm ZX-3, a semi-humanoid machine with a large gripper on one arm and a saw on the other. Mounted on the boom of a maintenance vehicle, it can reach up to 15 meters (49 feet) above the ground, with one arm holding a branch steady while the other cuts it. An operator stays safely on the ground and steers the machine while watching the live feed from cameras in its head. The ZX-3 is smaller and lighter than the ZX-1, which JR West has used since July 2024, yet it has a longer boom and is scheduled to start work in November.

Its partner, the single-arm ZX-2, is scheduled to start work this month and can hold loads of up to 120 kilograms (265 pounds), which should make it a big help when crews replace heavy overhead-line components. Both machines belong to the ZIZAI railway robot series, developed by JR West together with Nippon Signal, robotics firm Jinki-Ittai and rail vehicle maker Toyo Sharyo. The reason is simple: Japan is short of workers, and climbing poles or working beside live wires is dangerous, so keeping people on the ground cuts the risk of falls and electric shocks. JR West aims to reduce the number of workers needed for these maintenance jobs by about 30%, the same target it set when it first rolled out its robot in 2024. What remains to be seen is how well the new machines perform on real tracks, and whether the robots will free up crews for other work or simply shrink the teams.