Starting this month, the machine with a crude head and coke-bottle eyes mounted on a truck -- which can drive on rails -- will be put to use for maintenance work on the firm's network.

Its operator sits in a cockpit on the truck, "seeing" through the robot's eyes via cameras and operating its powerful limbs and hands remotely.

With a vertical reach of 12 metres (40 feet), the machine can use various attachments for its arms to carry objects as heavy as 40 kilograms (88 pounds), hold a brush to paint or use a chainsaw.

For now, the robot's primary task will focus on trimming tree branches along rails and painting metal frames that hold cables above trains, the company said.

The technology will help fill worker shortages in ageing Japan as well as reduce accidents such as workers falling from high places or suffering electric shocks, the company says.

"In the future, we hope to use machines for all kinds of maintenance operations of our infrastructure," and this should provide a case study for how to deal with the labour shortage, company president Kazuaki Hasegawa told a recent press conference.