The Pakistani Navy has commissioned its first Chinese-built Hangor-class submarine at Sanya on China’s Hainan Island, a major naval facility. The submarine, PNS Hangor, is the first of eight vessels that China is set to deliver to Pakistan by 2028.
According to reports, four submarines are being constructed in Karachi, while the remaining four have been built and launched by China Shipbuilding & Offshore International Co. Ltd (CSOC), as reported by Naval News.
Air Independent Propulsion enhances underwater endurance
The Hangor-class is derived from the Chinese Type-039A attack submarine design and is equipped with an Air Independent Propulsion (AIP) system, significantly improving underwater endurance.
The system enables conventional diesel-electric submarines to remain submerged for extended periods without surfacing to run diesel engines for battery charging. Such submarines can stay underwater for around two to three weeks. In comparison, non-AIP submarines must surface or snorkel more frequently, increasing vulnerability to detection by aircraft and surface ships.
India’s modernisation plans and P-75I delay
The Kalvari-class submarines are expected to receive indigenously developed AIP systems in the coming years. India is also planning to induct six Type-214 submarines, which will feature AIP capability.
The Indian Navy had earlier aimed to field 24 conventional submarines by 2030. However, four Sindhughosh-class submarines—Sindhughosh, Sindhudhvaj, Sindhuvir and Sindhurakshak, have been retired.
The Shishumar-class submarines have recently undergone mid-life upgrades and are expected to remain in service for another decade, according to Naval Technology reports.
India’s P-75I programme, aimed at acquiring six advanced conventional diesel-electric submarines with AIP systems, has been under consideration for nearly two decades. The project is now expected to progress, with the government likely to clear Germany’s ThyssenKrupp Marine Systems by July for a deal valued at approximately $10 billion.
Expansion of Pakistan’s AIP submarine fleet
With the commissioning of PNS Hangor, Pakistan’s number of AIP-equipped submarines has risen to four and is expected to reach eleven by 2028 as additional Hangor-class submarines are inducted.
Pakistan’s current submarine fleet also includes three Agosta-90B submarines, all fitted with AIP systems supplied by Turkish firm STM, according to The Diplomat.
Indian Navy submarine strength and composition
In comparison, the Indian Navy operates approximately 18–19 submarines as of May 2026. This includes around 16 conventional diesel-electric (SSK) submarines and 2–3 nuclear-powered ballistic missile submarines (SSBNs).
The conventional fleet comprises six Kalvari-class (Scorpene) submarines, while older Sindhughosh and Shishumar-class vessels continue to make up the remaining strength, though several Sindhughosh boats have already been decommissioned in recent years.
How big is the Chinese Navy's underwater fleet
China maintains the world’s largest and fastest-expanding navy, with its submarine fleet projected to reach 65 units this year and further increase to around 80 by 2035, according to estimates of its ongoing naval buildup.
