Pakistan’s naval establishment has been quick to celebrate the launches of its new Hangor-class submarines, framing them as “game-changers” that will upend the balance of power in the Arabian Sea. The narrative from Islamabad is clear: with eight air-independent propulsion (AIP) equipped boats on order from China, the Pakistan Navy will be able to extend deterrence well beyond its littorals, creating a new anti-access and area-denial (A2/AD) envelope that will complicate India’s operations.
But the gap between projection and reality is stark. Defence and security officials familiar with the programme point out that the Hangor-class is plagued by delays, powered by unproven engines, delivered in export-standard configurations, and hemmed in by geography and logistics. The economic costs of sustaining them may prove just as challenging as their technical limitations. Above all, India’s steady investment in anti-submarine warfare (ASW) capabilities ensures that Pakistan’s narrative of undersea dominance will remain more aspiration than achievement.
From 2015 Deal To Likely 2030s Delivery
The Hangor deal was signed in 2015, with an aggressive timeline: four submarines were to be delivered from China by 2023, and another four built in Karachi Shipyard by 2028. If that schedule had held, Pakistan’s submarine fleet would already be undergoing a transformation.
Instead, the first boat, PNS Hangor, was launched only in April 2024, two years late. A second, PNS Shushuk, followed in March 2025, and a third, PNS Mangro, in August 2025. None has yet been inducted into operational service. Induction of the first boat is unlikely before late 2025 or early 2026, and Karachi’s first build is still years away.
Officials in India’s defence establishment note that Karachi Shipyard has never constructed AIP-equipped submarines before, and even routine refits of older Agosta-90B boats had to be outsourced to Turkey. “The idea that Karachi will roll out four sophisticated submarines on time is fantasy,” one senior officer observed. “Delays of two to three years per hull are far more realistic, which means full delivery could easily stretch into the 2030s.”
The Engine Gamble
At the heart of the Hangor-class lies a strategic compromise that Islamabad prefers not to discuss. The design is derived from China’s Yuan-class submarines, originally powered by German MTU diesel engines. When Berlin blocked military exports of MTUs to China, Beijing turned to its own CHD620 engines.
These engines are untested outside China. Thailand, which also ordered a Chinese S26 submarine, resisted the CHD620 for two years, demanding proof of reliability. Only after 6,000 hours of bench testing and extended warranties did Bangkok reluctantly agree — and its own delivery slipped nearly a decade.
Pakistan has no such leverage. Its Hangors will sail with CHD620 engines from day one. “Pakistan is the proving ground for China’s new diesel engines,” a defence analyst said bluntly. “That means higher risk of breakdowns, dockyard bottlenecks, and lower availability. Engines are the heart of submarine reliability — and here, Islamabad has taken a gamble.”
Stealth: Export Standard, Not Superweapon
Islamabad’s messaging has leaned heavily on the Hangor’s stealth features — Stirling AIP for silent running, double-hull construction, and non-magnetic steel to reduce acoustic and magnetic signatures. The narrative paints a picture of near-undetectable boats capable of slipping past Indian defences.
But this is misleading on several counts.
Firstly, Stirling AIP gives endurance at very low speeds (4–5 knots). At anything faster, the submarine must revert to conventional diesel-electric mode and snorkel, exposing itself to detection. Fuel-cell AIP, being developed for India’s Scorpenes, is quieter than Stirling because it has no moving pistons. Secondly, while a double hull increases survivability, it also enlarges displacement and can increase noise from hydrodynamic flow. Thirdly, the Hangor is not the same Yuan-class boat that the PLA Navy operates. Beijing downgrades sonar suites and weapons integration in export versions.
“Features like non-magnetic steel and double-hulls are not unique to Pakistan,” one naval source pointed out. “India’s Scorpenes already use similar technology, and India is moving to more advanced AIP systems. The idea that Hangor’s stealth makes it a superweapon is misplaced.”
Weapons Load And Strike Ambitions
Another part of the narrative is that Hangor will provide Pakistan with a credible sea-based strike platform, carrying heavyweight torpedoes and even Babur-3 nuclear-capable cruise missiles.
In reality, integration of Babur-3 onto a submarine is still unproven. The missile was tested from a submerged barge in 2017, but there has been no public evidence of successful submarine launch capability since. “Weapons integration is the most complex part of submarine induction,” an Indian defence official explained. “It requires fire-control software, safety validation, and live tests. Pakistan is far from fielding a reliable sea-based deterrent.”
As for torpedoes, Hangor’s loadout — six to eight tubes, 12–14 weapons — is standard for conventional submarines and matched by India’s Scorpenes. India also operates nuclear-powered boats with far heavier payloads.
Fleet Size Illusion
Islamabad emphasises that Hangor will quadruple its AIP-equipped submarines from three to eleven. This sounds impressive on paper, but operational availability tells a different story. Submarines operate on a three-cycle rotation: one deployed, one in training, and one in maintenance. At best, only a third of the fleet is at sea at any given time.
Even with eleven AIP boats, Pakistan could only deploy three or four simultaneously. India’s larger fleet — which includes nuclear submarines with far longer endurance — ensures a significant numerical and qualitative edge.
Geography, Logistics, And The A2/AD Mirage
Perhaps the boldest claim in Islamabad’s narrative is that Hangor will allow Pakistan to extend its A2/AD reach across the Arabian Sea into the wider Indian Ocean. In reality, geography and logistics make this highly improbable.
Pakistan has only two submarine bases, Karachi and Ormara. It has no overseas facilities, no replenishment submarines, and no nuclear boats for long-range patrols. Conventional AIP subs can lurk near home waters but cannot sustain operations far from port.
Extending deterrence into the central Indian Ocean requires long-endurance submarines, forward logistics, and ISR networks that Pakistan simply does not possess. India, by contrast, operates from the Andaman and Nicobar Islands, Lakshadweep, and maintains access to partner facilities across the Indo-Pacific.
“The Hangor subarimes are loud and operate at a geographic disadvantage. They are highly unlikely to evade our ASW web in Pakistan’s littorals,” a senior officer said. “The notion of them policing the Indian Ocean is a narrative, not reality.”
ASW Is Hard, But Not Impossible
Islamabad’s commentators argue that anti-submarine warfare is “exceptionally difficult” — a needle-in-a-haystack problem. While submarines are inherently stealthy, this argument ignores India’s sustained investment in ASW capabilities.
The Indian Navy now fields 12 Boeing P-8I Poseidon long-range patrol aircraft, 24 MH-60R Seahawk helicopters, four Kamorta-class ASW corvettes, and the new Arnala-class shallow-water craft designed specifically for littoral sub-hunting. Indigenous HUMSA-NG sonar arrays, the Maareech anti-torpedo system, and Varunastra heavyweight torpedoes add further layers.
This layered grid ensures that Pakistan’s submarines, while stealthy, are not undetectable. Recent crises prove the point. In 2019, after Balakot, Pakistan’s Agosta submarine was tracked and forced to retreat westwards. In 2025’s Operation Sindoor, Pakistan’s navy remained bottled up in harbour while India’s carrier group operated off Karachi. The “exceptionally difficult” ASW argument collapses when measured against these operational realities.
The Industrial And Economic Trap
Finally, there is the question of sustainment. The Hangor deal is worth an estimated $5–6 billion, Pakistan’s costliest naval acquisition ever. For a country reliant on IMF bailouts, with debt servicing consuming over half of its federal budget, the burden of operating and maintaining a fleet of eight advanced submarines will be immense.
Each submarine requires highly trained crews, imported spares, and periodic overhauls. Karachi’s limited industrial base means reliance on Chinese supply chains will continue for decades. Any disruption in political relations or logistics could cripple availability. “Buying the submarine is the easy part,” one analyst remarked. “Keeping it combat-ready every day is the real challenge — and that takes money Pakistan doesn’t have.”
The Strategic Balance
Taken together, these realities dismantle the narrative Islamabad is pushing. The Hangor-class will eventually enhance Pakistan’s coastal defence and complicate Indian operations in its immediate littoral waters. But the promises of reshaping A2/AD in the Indian Ocean are far removed from reality.
The programme is already years behind schedule, may slip into the 2030s, relies on unproven Chinese engines, and will be delivered in export-standard form. Pakistan’s economy is ill-suited to sustain such a force, and its industrial base will remain dependent on Beijing. India, meanwhile, retains clear superiority with nuclear submarines, aircraft carriers, and a fast-expanding ASW network.
For international observers, the lesson is clear. The Hangor-class represents ambition, not transformation. It reflects Pakistan’s growing reliance on China and its desire to signal deterrence. But the real balance of power in the Indian Ocean will continue to be shaped by India’s broader maritime posture, not by eight export-standard submarines struggling to enter service.