September 11, 2018

Japan-US-Indian IUSS cable link completed across Bay of Bengal

With the completion of the Port Blair to Chennai undersea IUSS sensor cable link 
(see Map A below) India and the US have concluded political/technical agreements to most fully exploit it. USNS Zeus (T-ARC-7) is the most likely ship to have laid the sensor cable link. Alternatively as Japan has been involved in Pacific IUSS cable laying the Bay of Bengal, Indian Ocean layer might be KDDI PACIFIC LINK?

India is reliant on the US Navy (backed by the acoustic signature "dictionary" records of US Naval Intelligence and the NSA) to most thoroughly identify Chinese submarines and surface ships physically crossing the link or Chinese sonar signals being triangulated by nodes.

The agreements include a Communications Compatibility and Security Agreement (COMCASA) within the US Combined Enterprise Regional Information Exchange System (CENTRIXS). This agreement part was reported early September 2018 in the Indian media.  

The sensor link could be described as a major Integrated Undersea Surveillance System (IUSS) (old name "SOSUS") infrastructure project with the link being an extension to the Indo-Pacific undersea "fishhook" sensor link. (see Map B)

The Port Blair to Chennai link can be patrolled by the Sea Guardian Predator B/Reaper UAV variants (see Indian website) sold to India by the US in 2017. 

In time of conflict if the link sensors and/or Sea Guardians detect hostile Chinese (or Bangladesh Navy Ming) submarines or ships then Indian P-8I "Neptune" maritime patrol aircraft, sold by the US, can use their sensors or weapons. Indian submarines, surface ships and land based cruise missiles can also "weaponise" the link.

Map A - Port Blair is a base on India's Andaman & Nicobar Islands territory while Chennai is a major city with an average size naval base on India's south eastern coast. (Map originally in this SubMatters article )

Map B - May depict past or current IUSS (was SOSUS) undersea Indo-Pacific sensor positions. Note the Indian Ocean point of the "hook" terminated near Port Blair, Andaman Islands, This is from page 54 “Map 4. The US ‘Fish Hook’ Undersea Defense Line” of Desmond Ball and Richard Tanter, The Tools of Owatatsumi Japan’s Ocean Surveillance and Coastal Defence Capabilities (2015, ANU Press) (Originally published at this 2015 SubMatters article and at

Map C - India's coastal defence intelligence network, with the Command Centre at Gurgaon in central India. It is likely that the network of India's NSA (the NTRO) may coincide to a degree. (Map originally in this 2016 SubMatters article )

IUSS links are likely to be in many more strategically important places - some of importance to India.



GhalibKabir said...

The IUSS completion, signing of COMCASA, arming of the predator/guardian drones are like parts of a puzzle coming together.

The IUSS makes it easier to detect even quieter Chinese subs (will it deter them altogether, I guess no) and might help with sub hunting if things do go south.

The Indian Navy P-8s have already proven their worth (2016 or 2017, not sure) when they were able to track a Type 093 PLAN sub as it emerged from the Sunda Straits and the 93 was forced to make evasive maneuvers. (Apparently, the export version P-8I in some respects is only 50-60% as capable as the USN P-8A. Speaks volumes about the tech edge the US has)

Pete said...

Hi GhalibKabir

Yes I agree Chinese subs will continue to patrol the Indian Ocean (in part to monitor and defend its oil/gas SLOCs).

This is no matter if US-Japan-Indian IUSS and Western and Indian patrol aircraft, ships, satellites and subs manage to detect Chinese subs.

Detection happens but it is a cost for doing military business rather than an automatic precursor to a sub's destruction in peacetime.

India's deep, decades old, relations with Russia on sensitive strategic and weapons levels are probably reasons why the US is withholding some sensitive ASW, anti-ship and ground recce technolology for India's P-8Is (oddly called "Neptunes").



GhalibKabir said...

Agree on the SLOC patrol and the general 'flex my muscle/ego'presence of PLAN SSNs (and Carrier Groups in the very near future) in the Indian Ocean.

Admittedly the P-8Is supplied in 2016 were pre-COMCASA implying India was not eligible for sensitive ASW equipment (for instance search depth limited to half of the P-8A, sensors also degraded by software to 60-70% of their US versions etc.)

While some restrictions will still remain, thanks to 2018 signing of the COMCASA, some stuff should get upgraded incl. ability to interlink armed guardian drones and facilitating better interaction with surface assets of the IN.

However littoral attack abilities, deeper depth sub track abilities should still remain out of bounds.. COMCASA or No COMCASA

US vs Russia Balance:

To an extent I think India has been able to satisfy the US by generally keeping US assets separate incl. agreeing to annual inspections under a modified EUMA.

As far as Russia goes, occasional blighters they might have been, however, nothing compares close to the consistent solid support the ex-USSR and Russia have given to India. (it might have been very costly in dollar terms, but still better than the untrustworthy US)

Any knowledgeable foreign office mandarin in Delhi will attest to the fact that the US is never to be 'trusted' to the point of being appointed as the sole source of sensitive weaponry (the capricious bullying behavior of the US congress has affected India once too often since 1947). 'Triple Verify' and then 'Minimally "Trust"' is the only thing a nation with a lesser leverage can realistically hope for in any dealing with the US.

Pete said...

Hi GhalibKabir [at 10/10/18 3:31 PM]

The strategic environment is even getting more complex with:

- increasing Japanese plans to send warships to the Indian Ocean to defend Japan's oil/gas SLOCs


- India sending warships to the Western Pacific
= to Vietnam to promote encirclement of China,
= probably scope patrols of Indian future SSBNs to operate closer to China's coastal cities
= and to defend SLOCs protecting Indian imports to East Asia.

India's non-aligned and nuclear armed posture certainly allows it to be more discerning than Australia in relations with the US. Australia is heavily reliant on the US - though Australia's purchase of French submarines and UK Frigates are attempts at Weapons Buy Alliance Diplomacy.

US diplomacy and power projection will be even more erratic under Trump's tutalege.

I can see that Russian technology and military development from a high historical base works in sympathy with India higher financial funding position.