Shrouded deep-sea threats: China's cutting-edge technology unveiled

Underwater cables are easy targets. They can be severed by dragging a multi-tonne anchor along the seabed, or – in the case of more sensitive objects, such as a gas pipeline lying on the seabed – even just the anchor chain.

Such actions are relatively simple to carry out, and proving intentional action on the part of the perpetrators is difficult, as it could be attributed to negligence or crew error. For this reason, underwater infrastructure has become the target of many attacks in recent years. Some of these have been carried out by ships belonging to Chinese shipping companies.

However, such attacks are limited to relatively shallow waters, where the depth does not exceed several dozen metres or at most about 100 metres. Infrastructure at such a depth is easy to destroy, but in most cases, repairs are also relatively straightforward.

In this context, the equipment revealed by China rises to the level of a very dangerous weapon. Developed by the State Laboratory of Deep-Sea Manned Vehicles, it is a cutter designed to operate in deep-sea conditions, intended to be integrated with various types of underwater units.

According to official statements, the new device is intended to support the exploration of marine resources and was designed under a civil programme related to maritime rescue and mining, but its capabilities have caused global concern.

Made of titanium and protected against the pressure present at great depths, the equipment is equipped with a kilowatt electric motor and a 150 mm diamond blade running at 1600 revolutions per minute.

It is designed to minimise the water turbulence generated by the operation of the blade, which could stir up a cloud of sediment on the seabed and impair visibility.

Although the blade sizes might seem modest (popular, home angle grinders have blades with a diameter of around 100 to 125 mm), the Chinese equipment can operate at depths of up to 3,650 metres, cutting through rubber or polymer-coated cables, as well as those protected by a steel braid.

China also possesses underwater vehicles capable of utilising the new equipment. In 2020, Beijing revealed the capabilities of the manned submersible Striver (Chinese: Fendouzhe). During a 12-hour mission, the three-person unit descended to the bottom of the Mariana Trench, reaching a depth of 10,900 metres.

For the construction, which must withstand pressure of around 1100 bar, a special titanium alloy was developed, as well as a new type of battery that minimises the risk of fire during long-duration submerged missions. Among the devices that make up the Striver's equipment, the two manipulators capable of lifting objects weighing up to about 60 kg are particularly noteworthy.

Alongside manned vehicles, in recent years, China has also developed deep-sea drones, such as the Haidou, capable of autonomous operation at very great depths.

The information released by the Chinese has met with great interest – although the new equipment is presented as a research tool, there is no doubt about its potential use as an underwater weapon. Moreover, this is not the first equipment designed for such a purpose developed by China.

As early as 2020, a team from Lishui University published information about a device for cutting undersea cables "in crisis situations," intended for use in case of illegal laying of submarine cables near the Chinese coast.

The device takes the form of an anchor with blades equipped with a copper detector – metal found not only in the cables themselves but also, for example, in the sheathing that protects fibre optic bundles. The detector's task is to confirm that a cable cut has indeed occurred, as evidenced by copper particles found on the blades.

How might China use such devices? Scenarios including one drawn by the Hong Kong newspaper "South China Morning Post" consider the potential. In addition to generating losses caused during peacetime by data transmission disruptions, Beijing could use the underwater equipment during wartime operations.

Apart from the infrastructure connecting Taiwan with the world, Chinese actions could target the underwater cables in the region of Guam, where the United States military base is located – one of the key installations from the standpoint of the balance of power in the Pacific.

Although cutting cables currently does not guarantee an information blockade, it must be remembered that undersea cables account for about 95% of global data circulation. Wireless communication not only offers lower bandwidth but is also more susceptible to disruption.