Layers upon Layers

PLA Navy submarines in the Indian Ocean Region has far-reaching implications

Adm. Arun Prakash (retd)

Recent reports that ‘Chinese submarines’ had been detected in the Indian Ocean caused a transient flutter in the Indian media but, typically, there was lack of clarity about the source as well as veracity of the reports. One TV channel claimed to have ‘exclusive access’ to a report received by the ministry of defence (MoD) drawing attention to ‘22 unknown submarine contacts’ that were, apparently, detected by Indian Navy (IN) and US Navy (USN) units in the Indian Ocean.

Sources were quoted to provide a geographical breakdown, indicating that six of these submarine contacts were picked up north-west of the Straits of Malacca (i.e. in the vicinity of the Andaman and Nicobar Islands), 13 of them off Dondra Head (south of Sri Lanka) and two as far away as the Arabian Sea. Indian and US intelligence sources were reported, by the media, to have confirmed the origin of these putative submarines as Chinese since it was the only ‘other navy’ that could operate in these areas. While discussing these reports, there is need to remind the reader of two important facts, at the outset.

Firstly, the UN Convention for Law of the Seas (UNCLOS) permits unfettered freedom of navigation on the high seas, and a foreign warship or submarine has as much right to be in the Bay of Bengal as a similar Indian vessel would in the South China Sea. Even in territorial seas, i.e. waters regarded as sovereign territory of a State, there exists the right of ‘innocent passage’ for all vessels. Passage is ‘innocent’ so long as it is not prejudicial to the peace, good order or security of the coastal State. Acts that may vitiate innocent passage include the use of weapons, operation of aircraft, undertaking research or survey activities, and causing pollution. In the case of submarines, while passing through territorial waters they are required to navigate on the surface and to show their national flag; otherwise, they are free to remain submerged.

A Chinese Navy nuclear-powered submarine sails during an international fleet review to celebrate the 60th anniversary of the founding of People’s Liberation Army Navy off Qingdao

Secondly, there are currently, four ‘other navies’ in our very close neighbourhood which operate submarines; those of Indonesia, Malaysia, Singapore and Pakistan. The submarines belonging to these navies can, and perhaps do, undertake exercises in waters around India.

Reports of this nature, especially when delivered in the form of ‘breaking news’, are likely to cause concern and create misperceptions amongst, not just the general public but also, India’s politico-bureaucratic establishment, whose grasp of national security issues remains somewhat fuzzy. It would, therefore, be useful to examine a few aspects of China’s maritime power in a larger frame of reference. Such an examination may help evaluate the accuracy of reports regarding PLA Navy (PLAN) submarines lurking in waters around the Indian peninsula, and how much excitement such an event warrants.

PLAN Missions
The PLAN task-groups that have been operating on anti-piracy duties in the Gulf of Aden since 2008 have provided adequate proof that this navy has made rapid strides towards attaining a ‘blue-water’ status. This implies that the PLAN now possesses reliable, multi-role, modern warships, has accumulated adequate professional expertise and possesses the ability to sustain forces at long distances from home for protracted periods. The establishment of logistic arrangements with countries in the vicinity and the use of space-based command and control have obviously helped in the success of these operations. A major spin-off from this deployment, for the PLAN, has been a measurable enhancement in its self-confidence. Already a force of substance, the PLAN is one of the major beneficiaries of China’s defence budget which has been seeing double-digit growth over the past decade, and reached USD 200 billion in 2012. Consequently, new classes of warships, diesel and nuclear submarines and aircraft-carriers — all indigenously designed and built — are steadily joining the PLAN. The utility of the PLAN as an instrument of state power and policy-implementation has, obviously, been well understood by China’s political leadership. This is manifest in increasingly frequent naval deployments, for crisis management, in the South and East China Seas as well as the Gulf of Aden. Within the larger ambit of a maritime strategy, frequent mention is made, in Chinese discourse, of ‘offshore defence’, an elastic phrase, which can be stretched to encompass an array of activities.

The scope of ‘offshore defence’ appears to extend from territorial defence to pre-emptive offensive action, and its range, depending on circumstances and capabilities, is likely to extend from China’s coast to the first island chain (which includes Japan, Taiwan and the Philippines) to the South China Sea and well beyond. The objectives assigned to the PLAN can, thus, be broadly translated into the following missions:

• Maintaining an undersea strategic deterrent against the US, Russia and India.

• Deterring a Taiwanese declaration of independence while preparing for re-unification.

• Protecting Chinese interests and claims in the South/East China Sea.

• Safeguarding vital sea-lanes which carry China’s seaborne trade and energy supplies.

PLAN Submarine Force
The PLAN submarine arm started life with gifted Soviet diesel submarines of the ‘Whiskey’ and ‘Romeo’ classes received in the mid-1950s. After the Sino-Soviet split, both classes were built in China; the latter being reverse-engineered as the Type 033, of which about 100 were built over 20 years. The first Chinese designed boat was an improved version of the Type 033, designated the ‘Ming’ class, and 18 of these had been inducted by 1995. At this juncture, China ordered the Russian missile-armed ‘Kilo’ class, of which, 12 were delivered by 2006 (the IN has 10 of them). The next Chinese design to emerge was the ‘Song’ class, which has been followed by the latest ‘Yuan’ Class, equipped with air-independent propulsion (AIP), which extends the underwater endurance of a diesel boat from a few hours to two weeks or more.

The PLAN’s first nuclear propelled boat was an attack submarine (or SSN) the ‘Han’, which went to sea in 1974. Although it experienced persistent reactor problems, a total of five boats of the ‘Han’ class were built. A more successful SSN design designated the ‘Shang’ Class has followed. China ventured to commission its first ballistic missile submarine (or SSBN) only in 1983, when the ‘Xia’ entered service with the JL-1 short-range missile. Only one boat of this class was built and it has, recently, been superseded by the new ‘Jin’ class, first sighted in 2009. Armed with a battery of twelve 8,000-km range JL-2 ballistic-missiles, the ‘Jin’ can target both San Francisco and New Delhi from the South China Sea. Currently, the PLAN’s submarine fleet of more than 60, includes diesel boats of the ‘Yuan’, ‘Kilo’, ‘Song’, and the obsolete ‘Ming’ classes, while the nuclear force includes five SSNs; three of the ‘Han’ class plus two ‘Shang’-class boats, and five SSBNs; one of the ‘Xia’ class and four of the ‘Jin’ class.

Submarine Deployment
What are the likely deployment patterns of the world’s second largest submarine force? A far as its SSBNs are concerned, China has two options for positioning its crucial underwater nuclear deterrent. It could follow the Soviet model of deploying them in ‘bastions’ or sanctuaries, close to home, where they would be afforded the protection of own forces. Or it could follow the US Navy paradigm and deploy these boats in safe areas of the South China Sea or Pacific, which would require extensive protective measures to ensure safe transits to and from the patrol areas. In either case, SSBNs are unlikely to be in the vicinity of the Indian Ocean and we need to examine the possibility that the ‘Chinese intruders’ lurking in the Bay of Bengal were either the PLAN diesel boats or their SSNs.


A critical factor in planning submarine deployments is the distance and endurance involved. In this context, it is necessary to take note of China’s recently inaugurated, Yulin naval base on Hainan Island. Off the south-west coast of China, close to Vietnam, this base will not only facilitate projection of maritime power in the South China Sea; an area of ‘core interest’, but also enable the PLAN to dominate shipping lanes that traverse three crucial links between the Pacific with the Indian Ocean, namely the Straits of Malacca, Lombok and Sunda. Satellite imagery of the Yulin base (located near the holiday destination of Sanya), reveals the entrances to several rock caverns, which can accommodate SSBNs and SSNs in safety and secrecy. In addition, the base is reported to have adequate facilities to support one or more aircraft-carriers as well as amphibious shipping for expeditionary operations. In view of its optimal location, it would be logical to assume that any PLAN submarine probes or forays into the IOR would originate from the Yulin naval base. Since a transit via the Malacca Strait would require the submarine to remain on surface and compromise secrecy, use of this entry into the IOR is precluded. The boat would, therefore, have to pass through either the Sunda or the Lombok Strait. Parts of the Sunda Strait are very shallow, with sandbanks, strong tidal flows and oil platforms rendering it notoriously difficult to navigate. The Lombok Strait, between the Indonesian islands of Bali and Lombok is much deeper and would be the preferred option for a sub entering the Indian Ocean from the Java Sea.

The approximate sea distances from the Yulin naval base to Dondra Head (Sri Lanka), Kochi, Chennai, and Indira Point (southernmost point of the Nicobar group) via the Lombok Strait are 8,100 km, 9,000 km, 8,500 km and 7,500 km respectively. This means that a round trip to any of these locations (without patrolling or loitering), by a sub would entail a voyage of between 15,000 and 18,000 km lasting between 30-40 days. These figures are at the limit of a diesel-sub’s endurance and such a deployment could not be undertaken without a support ship or a friendly port available for replenishment. Moreover, a lot of a diesel boat’s time would have to be spent on the surface, charging batteries, which would render it susceptible to detection. On the other hand, an SSN could undertake a long-range patrol of such duration without any problem.

The Black Art
At this point it would be worthwhile digressing briefly to take a look at the means by which navies conduct anti-submarine warfare (ASW) operations. Unlike the atmosphere, which permits unimpeded passage of electro-magnetic (EM) radiations, such as radar, for detection of objects, the hydrosphere (or sea) is not conducive for EM wave-propagation. Acoustic energy, or sound, is therefore the preferred means of underwater detection. Currently, there are two acoustic methods — active and passive — by which ASW forces (ships, aircraft and helicopters as well as hunter-killer submarines) locate prowling submarines.

The active mode is by use of sonar (an acronym for ‘sound navigation and ranging’); a device which pumps out sound energy in pulses and then waits for an echo to bounce off the target indicating its bearing and range. The drawback here is that sonar transmissions can be heard at long ranges, and are a dead give-away of the hunter’s presence. The more stealthy or ‘passive’ method of submarine detection is called low frequency analysis and recording (or LOFAR). It involves deploying a set of microphones (hydrophones) underwater, and listening for discrete frequencies generated by propellers and machinery, which indicate the presence of a sub. While LOFAR can provide indications of target bearing, its range has to be computed.

Both methods have inherent ambiguities and rely heavily on signal-processing as well operator expertise. Conditions of high temperature and salinity that prevail in our tropical waters add complexity to ASW, and the presence of fish, rocks, air bubbles or thermal layers are some of the factors that often trigger frequent false-alarms of a ‘submarine’. For all these reasons ASW has come to be seen as a ‘black art’ and reports of submarine ‘contacts’ need to be treated with a degree of scepticism until confirmed by other technical means, or by intelligence.

From the earlier analysis it becomes obvious that the submarine intruder was either a diesel boat which managed to find sustenance from a friendly port and cleverly avoided being sighted while charging batteries, during an extended patrol. Or it was one of the PLAN’s nuclear powered ‘Han’ or ‘Shang’ class SSNs. In comparison with the slow and short-legged diesel submarine, the SSN has far superior reach, endurance and speed. It can remain submerged for months, as compared to hours or days for the diesel engine-cum-battery propelled conventional boats; even one with AIP. Once it dives into deep waters, the SSN is not only difficult to detect, but has (unlike the diesel sub) enough speed to overtake or outrun most other submarines or warships if required. The classic roles of a SSN are to protect carrier battle groups and to hunt enemy SSBNs, but it is also an ideal platform for the anti-ship, land-attack, and surveillance roles.

In a related context, there is great significance in the reported statement that ‘22 unknown submarine contacts were detected’ by IN and USN units. Diesel boats are known to be very quiet and difficult to detect. In October 2006, a Chinese ‘Song’ class diesel submarine surfaced, undetected, within a few miles of the carrier USS Kitty Hawk, causing considerable embarrassment to the US Navy. SSNs, on the other hand, are relatively much ‘noisier’ and therefore easier to detect if they allow themselves to be tactically out-manoeuvred by ASW forces.

The report of ‘22 detections’, therefore, leads one to the conclusion that whether it was a diesel boat or an SSN, it was a case of poor tactical handling, especially in the vicinity of known ASW forces. When pressed hard, an astute submarine Captain would, typically, dive deep and go into a ‘silent regime’ till the hunters had spent their patience and endurance. If it was, indeed, a Chinese SSN this could be an indicator that it is a poorly designed and noisy boat which was handled indiscreetly by its Captain. Both are bad news for the PLAN.

A Cat Amongst the Pigeons?
Whether true or not, these reports should give cause for reflection to IN planners in Delhi, as well as its war-fighters at sea. In its quest for securing strategic resources, China has cast its net world-wide; from Australia to the Russian Far East and from West Africa to the heart of South America. These far flung economic interests make China dependent on shipping for energy and trade, and the sea-lanes criss-crossing the IOR constitute an exposed jugular vein which could be exploited by the IN to redress the asymmetry on land.

Fully cognizant of this vulnerability, it makes sense for China to, not only deploy the PLAN in waters of the IOR, but also to seek convenient footholds around the Indian Ocean. Far from being ‘naval bases’ such footholds need to be merely ‘friendly places’ where a warship, submarine or aircraft can seek logistic sustenance or technical support in time of need. At the heart of this strategy is the Chinese-built Gwadar deep-water port on Pakistan’s Makaran coast, from where Singapore Port Authority has recently been ejected to make place for Chinese management. This port marks the beginning of an arc of maritime influence which has been created, through economic aid, arms transfers and presence of Chinese personnel. The arc runs from Pakistan, across Iran, Saudi Arabia, the Horn of Africa, Seychelles, Maldives and Sri Lanka to Myanmar and, possibly, Bangladesh.

While warships and aircraft carriers make versatile instruments for wielding maritime power, they are vulnerable to detection and attack from all three dimensions. The nuclear-powered SSN, on the other hand, operating in the opaque under-water environment has tremendous advantages, of endurance, stealth and long-range strike, that make it a true ‘game-changer’ in the maritime context. This makes it imperative for the IN to hone its submarine-hunting skills and provide a boost to ASW as a war-fighting speciality in all three dimensions.

It is indeed fortuitous that the state-of-the-art Boeing P-8 (I) Poseidon, long-range ASW and maritime recce aircraft is on the verge of being inducted into the IN. However, so vast are the ocean areas to be sanitised that half a dozen Poseidons are unlikely to make a major dent. The IN needs to, substantially, bolster its forces by the acquisition of many more fixed-wing and helicopter ASW platforms. It would also need to learn the advanced ASW skills developed by NATO and Japanese navies over many years of playing cat-and-mouse with Soviet SSBNs and SSNs. NATO had installed sound-surveillance systems (SOSUS) of seabed hydrophones in certain nodal points (like the Greenland-Iceland-UK gap), which would provide early warning of the approach of Soviet subs. Sets of such devices, installed in strategic locations, would be of great value to the IN.

Regardless of whether the media reports about PLAN submarines were authentic or not, they have drawn timely attention to an emergent security issue. Apart from the PLAN, there are many other navies which could have sent one of their subs into the Bay of Bengal or even the Arabian Sea with even greater ease. The proliferation of submarines in the region is rapidly gathering pace with Vietnam, Bangladesh, Thailand and Myanmar aspiring to own this weapon-platform; the first two navies being at an advanced stage of acquisition.

The media have also overlooked the possibility of a Pakistan Navy (PN) sub playing cat and mouse with the IN and USN. In this context, no one in India seems to have paid sufficient heed to the public inauguration of Pakistan Navy’s ‘Strategic Forces Command’, in 2011; nor has any attempt been made to analyse the intriguing announcement that the PN is the ‘custodian of Pakistan’s 2nd strike capability.’ Behind all these de-stabilising developments lies the, barely concealed, hand of China. Should the Chinese decide to emulate Russia and lease a nuclear sub to the PN, they could, at one stroke, change the balance of maritime power in the Arabian Sea!

Submarines are likely to be encountered with increasing frequency in the IOR. While bolstering its anti-submarine warfare capabilities, the IN must persuade the national security establishment that an SSN is the ultimate submarine hunter-killer and that there is an urgent need to dedicate resources to the creation of a small force of three-four SSNs to exercise sea-denial, counter a possible PLAN threat and, above all, to protect our own nascent SSBN force.

(The writer is a former chief of naval staff)

(May 2013)


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