A robotic lifting arm and remote-controlled bulldozers are some of the innovations being rolled out on Japanese construction sites as the country’s workforce shrinks and gets older.

The move to automation comes as trade body the Japan Federation of Construction Contractors estimates that there will be 1.28 million fewer construction workers by 2025 compared with 2014.

It shows that a government push to integrate high technology into the construction sector, called “i-Construct”, may be bearing fruit after its launch in 2015. Ministers are concerned that productivity in Japanese construction has lagged far behind other sectors.

In 2015, some 30% of all construction workers were aged 55 or over, while those below 29 accounted for only about 10%, according to official figures, according to a Kyodo New agency report carried in Japan Times.

Construction giant Kajima has started using unmanned, automated dump trucks, bulldozers and vibrating rollers with GPS systems at its building sites. A single worker can direct the preprogrammed machinery using a tablet computer.

A Kajima spokesman told the Kyodo that a looming shortage of 300,000 workers in the industry meant it was crucial to find ways of boosting productivity.

“That’s why we are all scrambling for a solution,” said the spokesman, Atsushi Fujino.

Another major construction firm, Shimizu Corp., has developed an arm-shaped robot that lifts heavy reinforcing rods (pictured).

While it normally takes up to seven people to manoeuvre one 200-kg rod, this machine needs only three workers to direct the robot and place the rod.

The robot is now being leased out to construction sites.

“This is a realisation of human-robot collaboration,” Tomoaki Ogi, a manager at a technology division of Shimizu, told Kyodo.

Construction can never be fully automated, however, said Kajima’s Fujino: “There are things that only people can do, for example, getting small corners done or interiors that require artisan skills.”

But Shimizu’s Ogi said there is still much room for robotics to lend strength and speed in construction. “Let the robot do the heavy work under people’s (guidance),” he said.

Another company, Shojigumi Inc. in Shizuoka Prefecture, uses robots and other automated machines, and launched a nation-wide network of companies in 2015 that lets them try new technologies and share information, Kyodo reports.

Yohei Oya, a 38-year-old construction supervisor Shojigumi told Kyodo that productivity at the company had been boosted by up to 10 times through automation. “We’re not at the site all night like we used to be,” he said. “You don’t even have to be highly skilled anymore to get the work done.”

He added: “The burden has been reduced on our workers and on management. Work is completed in half the time it used to take.”

The government’s infrastructure ministry said it will support with funding public works projects that plan to use drones and other technology for advancing productivity.

“When we think about the shortage of workers 10 years from now, this is the last chance for the government to invest and conduct radical reform (in the construction industry),” Yasushi Nitta, senior deputy director of the ministry’s public works project policy planning, told Kyodo.

Image: An arm-shaped robot developed by Shimizu Corp. helps construction workers lift 200-kg steel rods in Chiba Prefecture last August (Shimizu Corp/Kyodo)