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China science

How China’s military weapons inspired invention of a laser cannon to clean power lines

Experts warn, however, that the device trialled in Guangdong province could pose a danger to people and even passing aircraft

PUBLISHED : Friday, 28 July, 2017, 4:23pm
UPDATED : Friday, 28 July, 2017, 10:35pm

Workers are using a “laser cannon” to remove objects tangled in overhead power lines in southern China, according to Chinese media reports.

The device saves staff from the highly dangerous task of climbing among high-voltage cables to remove objects blown into the lines.

Experts, however, have warned that the technology could pose a danger to people in the area if poorly aimed – and even to passing aircraft.

The Chinese-developed laser cannon was based on similar devices used by the military, according to a report on a website run by the government’s National Energy Administration.

The device uses carbon dioxide to create a laser beam, which can burn and destroy objects tangled high in power lines such as plastic and fabric.

The laser cannon was designed at China Southern Power Grid.

The lead developer Cai Xiaofeng was quoted as saying that he was reading a military magazine when he realised the potential of the technology to deal with junk on power lines. “If a laser can shot down a satellite or missile, why not debris on a power line?” he said.

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Workers in Dongguan in Guangdong used the device to remove nearly 70 per cent of the debris caught in power lines in the area last year, according to the report.

Rubbish blown on to cables can create sparks and even cause power outages.

Debris previously had to be removed by hand, with staff required to wear special safety suits.

Any holes in the suits’ insulation layer could cause fatal injuries, according to the report.

The power company is now considering using the cannon in other areas of southern China, including Yunnan and Guizhou provinces.

However, Li Rukang, a researcher at the Chinese Academy of Sciences in Beijing, said there could be safety risks using the devices in public areas.

Li said one Chinese civilian laser manufacturer had produced a device that could generate a beam strong enough to penetrate a thick layer of steel from across a room.

A powerful laser device on the ground might be able to reach an aircraft flying at relatively low altitude, such as during take-off or landing, putting passengers at risk, he said.

“The sky is where they aim and sky is where planes fly,” said Li, a lead scientist in several national laser research projects. “You definitely don’t want to be on the plane when this happens, Heaven knows what damage can be done.”

There are no government regulations on the use of high power lasers in public areas in China, according to a gas laser scientist at Huazhong University of Science and Technology in Wuhan, Hubei, where some of China’s largest civilian laser equipment manufacturers are based.

Most non-military devices were used indoors for welding or cutting in manufacturing industry, said the researcher, who asked not to be named.

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The energy level of Cai’s cannon was not revealed in the report, but judging by the size of the device it could reach one kilowatt, according to the researcher.

“Such a power output may not be able to shoot down a plane, but if aimed mistakenly at a building or human, it could cause serious damage,” he said.

The device is unlikely to be used as a weapon by civilians as it requires a huge generator and bulky cooling system to prevent overheating, he said.

Power cable maintenance workers in Xiangyang in Hubei province found another way earlier this year to remove a net stuck in power lines – using a flame-throwing drone.