China Unveils Deep-Sea Cable-Cutting Device

Chinese researchers have detailed a deep-sea cable-cutting device that could threaten critical communications networks during times of crisis, amidst intensifying international tensions.

While the device was developed for civilian us in salvage or seabed mining, it is also capable of cutting armored cables at depths of up to 4,000 metres, twice the maximum operational depth of existing subsea communications infrastructure, the South China Morning Post reported.

It is designed for integration with China’s crewed and uncrewed submersibles, the largest fleet of its kind in the world.

Diamond-coated cutting wheel

Developed by the China Ship Scientific Research Centre (CSSRC) and the affiliated State Key Laboratory of Deep-sea Manned Vehicles, the device can cut cables armoured with steel, rubber and polymer sheaths, such as those that underpin most of the world’s data transmissions.

It uses a titanium alloy shell and oil-compensated seals to prevent implosion at 4,000 metres, where water pressure exceeds 400 atmospheres, according to a paper in the Chinese-language journal Mechanical Engineer published on 24 February.

In order to cut steel-reinforced cables while minimising marine sediment disturbance, the device uses a 150mm diamond-coated grinding wheel spinning at 1,600rpm, wrote the team led by engineer Hu Haolong.

It is powered by a one-kilowatt motor with an 8:1 gear reducer to provide a torque of six Newton-metres while using a minimum of power for submersibles with constrained power budgets.

The device is designed to work with advanced positioning technology to avoid misalignment, as it is operated by robotic arms in near-zero visibility.

In Guam, the United States hosts more than a dozen fibre-optic cables with both military and civilian clients, including Google, that could be stealthily targeted by such a deep-sea cable-cutting tool.

Hu wrote that the cable-cutter would help build up China “into a maritime powerhouse”.

Sabotage fears

The paper comes at a time when tensions have been rising over China’s claim to govern Taiwan and the possibility that it could take control of the island by force, putting at risk a territory that produces most of the world’s semiconductors.

In January Swedish authorities opened an investigation into suspected aggravated sabotage and seized a ship following damage to an underwater fibre-optic cable in the Baltic Sea from Latvia to the Swedish island of Gotland.

That incident came less than a month after NATO launched a new mission in the Baltic in response to repeated attacks on underwater power and telecoms cables, some of which have been blamed on Russia.