Chinese media mocks Arihant-class SSBN design of India; An analysis to remind them what they forgot

IgMp Bulletin

When Chinese defence commentary questions the acoustic stealth of India’s Arihant-class nuclear-powered ballistic missile submarines, the debate deserves more than a nationalistic rebuttal. It requires a closer look at underwater acoustics, submarine design and the challenges every nuclear navy faces. China’s early nuclear submarines also encountered major engineering constraints. India, meanwhile, has used the Arihant programme to develop the foundations of a sea-based nuclear deterrent.

The central issue is not whether one submarine is universally quieter than another. Acoustic performance depends on machinery isolation, propeller design, operating speed, ocean conditions and crew procedures. India’s progression from INS Arihant to the planned S5 class reflects a long-term effort to improve these capabilities. However, precise acoustic figures and several claimed design details remain unverified in the supplied information.

The NetEase Narrative: Deconstructing Chinese Claims on Arihant’s Acoustic Signature

Chinese media NetEase criticises India Arihant class submarine acoustic stealth is a useful starting point for examining how online commentary can blur technical assessment and speculation. The supplied brief says NetEase, hosted at 163.com, ranked Arihant sixth in a submarine comparison. It also describes allegations about reactor-pump noise, foreign sonar technology and India’s ability to manufacture large pressure hulls.

Such claims require evidence. A ranking does not establish a submarine’s actual radiated-noise level unless the publisher explains its methodology and supporting data. Likewise, claims about reactor noise need details about the propulsion plant, machinery isolation and operating conditions. Public sources rarely reveal the complete acoustic signature of a modern nuclear submarine.

🇮🇳 China is questioning the design of India’s Arihant-class nuclear submarines. Chinese commentators have raised concerns about their acoustic stealth, sonar capabilities and India’s ability to build larger next-generation submarines. But here’s the bigger picture: India has already commissioned multiple nuclear-powered ballistic missile submarines, strengthening its ability to launch a nuclear response even after an enemy attack. The next big challenge is the S5-class submarine, which is expected to be larger and carry more missiles. China can question India’s capabilities, but India’s progress in nuclear submarine technology is real. The key question now is how quietly and effectively India can operate these submarines.

— Ashutosh (@thegeo_sync) October 14, 2026

Forum commentary about a future 12-metre pressure hull raises a separate engineering question. A large pressure hull demands advanced steel, precision forming, welding and rigorous inspection. Yet hull diameter alone cannot prove whether a country can build a submarine. Material properties, fabrication quality, structural design and testing all matter.

India should acknowledge Arihant’s limitations as an early technology demonstrator. Its compact design and initial missile capacity represented a first step, not the final form of India’s sea-based deterrent. That distinction makes the subsequent development programme more meaningful than an unsupported argument about which navy has the quieter submarine.

The Acoustic Irony: China’s Type 091, 093 and Type 094 Submarine Legacy

The Type 094 Jin-class noise level versus Arihant-class submarine comparison needs historical context. China’s People’s Liberation Army Navy (PLAN) developed its nuclear submarine fleet over several generations. Early Type 091 attack submarines and Type 092 ballistic-missile submarines faced significant design and operational challenges. Later Type 093 and Type 094 boats reflected efforts to improve performance, endurance and acoustic discretion.

The US Office of Naval Intelligence has assessed Chinese naval capabilities in its public reporting. Western analysts have also discussed the acoustic challenges associated with China’s early nuclear submarines. However, exact decibel comparisons require caution. Published estimates may use different measurement conditions, and current submarine signatures remain classified. The claim that the Type 094 is noisier than a specific Soviet submarine should therefore not be treated as a definitive, independently verified measurement. [Source: US Office of Naval Intelligence]

China’s Type 094 also illustrates the compromises involved in ballistic-missile submarine design. Its prominent missile compartment, often called a turtleback, accommodates vertical-launch ballistic missiles behind the sail. This configuration changes the hull’s external shape and can affect water flow. At certain speeds and conditions, turbulence and flow separation may contribute to hydrodynamic noise. Yet the shape alone does not establish a submarine’s complete acoustic signature.

The January 2018 East China Sea incident offers another lesson in operational caution. Reports described Japanese maritime forces tracking a Chinese submarine, which later surfaced and displayed the Chinese flag. Some accounts identified the vessel as a Type 093. However, the precise circumstances, tracking duration and reason for surfacing require careful verification before drawing firm conclusions about its acoustic performance. Detection can result from several factors, including intelligence gathering, aircraft surveillance and tactical circumstances. [Source: Japan Ministry of Defense]

The Evolutionary Curve: How INS Arighaat and Aridhaman Advance India’s SSBN Programme

The Stealth Leap (INS Arighaat & INS Aridhaman): global experts today focuses on India's steep learning curve. Newer vessels in the class—such as INS Arighaat (commissioned in 2024) and INS Aridhaman (undergoing induction in 2026)—incorporate massive upgrades specifically designed to mitigate noise. Experts have praised how quickly India have learnt through its evolution of building more sophisticated and quieter nuclear submarines.

INS Arihant, commonly described as India’s first indigenous nuclear-powered ballistic-missile submarine, helped validate reactor integration, underwater operations and submarine-launched ballistic missiles. Its compact size and limited missile capacity reflected the challenges of establishing a new national capability. India subsequently commissioned INS Arighaat in 2024, marking another step in its SSBN programme. [Source: Press Information Bureau, Government of India]

Improving acoustic performance involves many engineering disciplines. Natural circulation in reactor cooling systems can reduce dependence on certain mechanical pumps under suitable operating conditions. Resilient mounts can isolate machinery vibration from the hull, while anechoic coatings can reduce some forms of sonar reflection. Propeller geometry also influences cavitation, which can generate noise when local water pressure falls enough to form vapour bubbles.

The supplied brief attributes specific upgrades to India’s newer submarines, including an 83 MW cooling configuration, titanium acoustic mounts and custom seven-blade, high-skew propellers. These details should not be presented as confirmed specifications without authoritative documentation. The same caution applies to claims about the exact equipment fitted to INS Aridhaman. The broader engineering principle remains sound: reducing vibration, flow noise and cavitation can improve acoustic discretion, but the outcome depends on the entire vessel and its operating profile.

Because of these stealth advancements, international observers recognize that the newer Arihant-class variants can effectively maintain continuous at-sea deterrence. Operating inside the safe bastion of the Bay of Bengal, their refined noise signatures make them highly resilient against anti-submarine warfare networks, solidifying India's position in an elite global club of nuclear triad powers.

The S5 and Project-77 Frontier: Reactor Power, Pressure-Hull Engineering and Bastion Deterrence

India’s S5-class SSBN plans point towards a larger platform designed to carry more capable long-range missiles. The supplied brief gives a projected submerged displacement of roughly 13,500 tonnes and discusses a reactor rated at 190 MW. It also mentions pump-jet propulsion and integrated electric-drive concepts. These figures and arrangements require official confirmation; they should be treated as programme assumptions rather than established specifications.

Can India manufacture a 12-metre pressure hull for S5? India has a substantial heavy-engineering base, including defence and industrial work by Larsen & Toubro. Its facilities support complex fabrication, welding and large structural assemblies. But manufacturing a large submarine pressure hull requires more than possessing heavy presses. Engineers must demonstrate material consistency, weld integrity, dimensional accuracy and resistance to repeated pressure cycles. Public evidence of industrial capacity does not, by itself, confirm the precise diameter or manufacturing method selected for S5. [Source: Larsen & Toubro]

Pressure-hull steel must combine high strength with toughness and resistance to defects. India’s naval materials development has advanced through collaboration among defence laboratories and industrial partners. However, claims that specific HY-80, HY-100 or HY-130 grades will form the S5 pressure hull need confirmation from programme authorities. The same applies to claims about a dive depth of 450–500 metres.

The strategic rationale for a larger SSBN is clearer. The K-15 missile’s relatively short range constrained the patrol areas from which early boats could threaten distant targets. Longer-range missiles such as K-4, and the reported future K-5 and K-6 programmes, could expand the area from which India maintains a credible deterrent. Public sources do not confirm every projected range or the final S5 missile fit. [Source: Federation of American Scientists — Nuclear Weapons]

A protected patrol area in the Bay of Bengal could help India sustain a second-strike capability closer to its own support network. Maritime patrol aircraft, surface ships and anti-submarine helicopters can contribute to surveillance and protection. They cannot guarantee that hostile forces will never detect a submarine. The purpose of a bastion strategy is to reduce operational risk, not eliminate it.

Global defense analysts view India’s upcoming Project-77 SSN and S5-class SSBN programs as a monumental technological leap from the incremental, technology-demonstrator baseline of the early Arihant class to true peer-level naval stealth.

Rather than viewing them as retrofitted platforms, international maritime experts regard Project-77 and the S5-class as clean-sheet designs intended to rival modern Western and Russian platforms like the French Suffren (Barracuda), the American Virginia class, and the Russian Borei class.

Core Stealth Advancements Highlighted by Experts

• ·        Transition to Pump-Jet Propulsion: While the Arihant class relied on conventional multi-blade skewed propellers, both Project-77 and the S5-class will utilize indigenously engineered pump-jet propulsors. Experts note this virtually eliminates cavitation at high tactical transit speeds, significantly flattening acoustic spikes.
• ·        Next-Generation 190–200 MW CLWR Reactor: The small 83 MW compact light-water reactor in the early Arihant required active mechanical pumping systems that generated distinct acoustic signatures. The larger 190–200 MW reactor developed by the Bhabha Atomic Research Centre operates with higher natural circulation margins at low-to-moderate speeds, allowing the submarines to cruise silently without heavy cooling pump noise.
• ·        Turbo-Electric / Nuclear-Electric Drive (TED/NEP): For the Project-77 attack submarines, naval architects are incorporating electric drive propulsion. By eliminating physical reduction gears—historically the loudest mechanical noise source on nuclear boats—acoustic isolation reaches contemporary Western standards.
• ·        Advanced Hydrodynamics and Hull Metallurgy: Built using high-yield HY-130 steel and hydrodynamic teardrop hulls with X-rudder configurations, these submarines can dive deeper (exceeding 500 meters). Operating below oceanic thermocline layers dramatically shields them from surface-ship sonar sweeps. 
• ·        Full-Coverage Active/Passive Anechoic Coating: Supported by India's Large Cavitation Tunnel testing facilities, the boats will incorporate conformal sonar arrays integrated flush with advanced sound-damping rubber tiles across the hull.

Strategic Implications Assessed Globally

• ·        Project-77 as "Chokepoint Predators": Experts from platforms like The Diplomat and regional maritime institutes assess that quiet SSNs give the Indian Navy the ability to tail Chinese People's Liberation Army Navy (PLAN) submarines entering the Indian Ocean through narrow choke points (e.g., Malacca, Sunda, and Lombok straits) without being detected.
• ·        True Stand-off Bastion Deterrence (S5-class): With a displacement of 13,500+ tonnes carrying 12 to 16 K-5 and K-6 intercontinental SLBMs (with ranges exceeding 5,000–8,000 km), the S5 class will not need to leave the protected, quiet bastions of the Bay of Bengal to target adversaries. This renders enemy Anti-Submarine Warfare (ASW) tracking far less viable.

As India’s nuclear-submarine capabilities continue to evolve, Chinese media and commentators may seek to downplay their strategic significance, as they have often done with other elements of India’s defence programme. The evolution of Chinese commentary on India’s Agni-V missile offers a useful example. When the missile was first tested in 2012, some Chinese commentators questioned its practical significance. Over time, however, the discussion shifted towards its potential strategic reach. Some Chinese analysts have since speculated that India may be understating the missile’s actual range, suggesting that it could potentially reach as far as 8,000 km rather than the officially cited figure of around 5,000 km. Such claims remain unverified, but they illustrate how perceptions of India’s growing strategic capabilities can change over time.

A similar shift in Chinese commentary could occur as India strengthens its nuclear-submarine fleet and improves its ability to operate discreetly across the wider Indo-Pacific. If tensions persist over freedom of navigation in the South China Sea and East China Sea, Beijing should recognise that other countries also have legitimate interests in maintaining access to international waters. China frequently emphasises its own maritime interests in the Indian Ocean Region; it should therefore acknowledge that the same principle of freedom of navigation applies elsewhere. Rather than attempting to undermine other nations’ strategic interests or alter territorial realities through coercion, Beijing would be better served by respecting international norms and exercising restraint. Strategic pressure invites strategic responses—and no country should assume that its actions will remain without consequences.