December 5, 2017

Chinese's SOSUS in South China Sea On Dual-Use Cables


Since February 18, 2016Submarine Implications of Woody andthe 3 Reef basesSubmarine Matters has been concerned about China laying Sound Surveillance System (SOSUS) arrays on the seafloor: At that time I wrote:

“-  For ASW and anti-shipping China can also string its undersea SeaWeb (SOSUS just part of it)
     networks between the island/reefs and the Chinese mainland.”


This concern about Chinese SOSUS has become more widespread. 

On the Australian Strategic Policy Institute’s (ASPI’s) The Strategist website Eli Huang from Taiwan has written a most interesting article which describes mainland China’s campaign to string SOSUS capable high speed undersea fibre optic cables between its recently militarised islands in the South China Sea.

The article “China’s cable strategy: exploring global undersea dominance” is dated
December 4, 2017. The following is just a small part of Ms Huang's article:

“...China sees cable networks as an essential element of its One Belt, One Road initiative. Undersea cables will ensure that Beijing is well placed to influence media and psychological operations as part of its ‘three warfares’ strategy. In the military arena, such a cable network creates a strategic advantage in anti-submarine warfare for the Chinese navy. It will form an irreplaceable part of China’s underwater observation system in the South China Sea. This ‘underwater great wall’ includes a number of subsurface sensors connected through optical cables to a central processing and monitoring facility in Shanghai. The system will function much like America’s SOSUS network, which employs fixed sensor arrays to detect Soviet submarines. A Chinese system could erode American undersea warfare advantages in the South China Sea.
Undersea cables have been described as Taiwan’s Achilles’ heel. In the event of a conflict across the Taiwan Strait, the cables will be prime Chinese targets: cutting them will cripple Taiwan’s international communications. And the damage wouldn’t be confined to Taiwan. There are at least 10 international submarine cables between Taiwan and Asia–Pacific countries. Damaging Taiwan’s cables would disrupt international business and financial markets, leading to severe economic effects on regional countries, including Japan, Singapore, Indonesia and Australia...”
Eli Huang is an assistant research fellow of the Prospect Foundation in Taiwan. She is also special assistant to Dr Chong-Pin Lin, former deputy minister of national defense in Taiwan. The views expressed in this post are her own and do not necessarily represent the views of the Prospect Foundation.



Separately from the Article. China's claimed islands are in red above, most are being militarised with 100,000s tons of sand and concrete for sea ports and airports on which weapons are placed. Dual civilian-military use undersea cables can carry SOSUS arrays, For example, from Mischief Reef-Woody Island-Hainan Island-mainland China. (Map courtesy amti.csis, janes and lawfareblog). 

Scroll across to the South China Sea on this TeleGeography-Huawei Marine Networks interactive submarine cable map to see how intense cable laying across the South China Sea is becoming.



Anonymous said...

Besides undersea sensors, modern warfare is essentially a networked battlespace. It is expected China would link up Woody, Fiery Cross, Subi and Mischief via DWDM undersea fibers. The undersea sensors are likely on different fibers in my view because they are laid at 900-1000 meters depth for best acoustic performance while communications undersea fibers are probably on the seabed floor. Parts of SCS or ASEAN sea are very deep.
Once China builds up Scarborough (which is expected regardless of what Duterte thinks he got from Xi), then an undersea sensor linking it with Hainan and/or Woody would control the northern entrance to SCS.
In addition, past September and November, China launched 6 spy satellites YG30 designed to capture electronic transmissions from carrier groups, naval fleets and probably submarines. The chosen inclination and orbits appear to point to focused surveillance of the SCS and Indian Ocean for the latter 3 micro satellites. There will be more YG30 to be launched I am sure.
As we know, China recently confirmed they deploy fighters to Woody, contrary to an earlier promise made by Xi. There are aircraft hangars on all the 3 other reefs (as well as on Woody) so there are likely fighters parked inside. The mobile SAM TELs are also parked inside buildings. China just simulated a logistic air drop from Sichuan to Fiery Cross (not from Hainan or Guangzhou), a scenario when these outpost may become isolated (as in a conflict). There are probably 1000 Chinese living on Fiery Cross, they may be right in the middle of a lot of water but they are going to need the right kind of un-salted water just to survive.

Peter Coates said...

Thanks KQN

Your info and assessment is so interesting I'll make it an article this week.



Josh said...


My understanding is that the sensors of a SOSUS like system generally are floated at the optimal depth (or placed on convenient sea mounts) but that the cables connecting them to land are still on the seabed. But I do agree that communication cables and SOSUS cables probably are different systems, in that they wouldn't use the same routes and also this would increase vulnerability. It would be interesting to know what US sensors are deployed in the same area; it seems unlikely that the USN just left the SCS empty of any detection system. Minimally the first island chain is ringed with a system to contain the PLAN to that domain in the event of war.

China also as a robust network of oceanic recon satellites the dwarf US efforts - while the US does have a very robust and cable NOSS for recieving signals, China additionally has a couple of different sets of SAR satellites as well as dedicated wide field EO satellites (presumably as a backup SAR being jammed), as well as any number of standard EO satellites that can be used to ID targets acquired by other means.


Anonymous said...

If we just look at the orbits of the constellation of YG-30 micro satellites (6 launched with at least 3 more planned), it will provide near (with a pass every 1/3 hour) real time coverage over the Middle east (Suez canal and strait of Hormuz), Indian ocean (including Diego Garcia) and the Pacific (SCS, Taiwan, Okinawa, Guam, Northern Australia).