Pakistan Hangor-class submarines under Indian Navy radar from the word go

China recently handed over the third of eight new Hangor-class submarines to Pakistan, bolstering Islamabad’s naval strength as Beijing expands its footprint in the Indian Ocean, a region India considers its strategic backyard. The submarine was launched in Wuhan. The second vessel was delivered in March. Pakistan has also received four modern Chinese frigates in recent years, alongside Beijing’s development of the Gwadar port on the Arabian Sea.

Chinese experts describe the Hangor-class as a stealthy platform with long endurance, high mobility, and powerful underwater combat capabilities. The Hangor-class submarines, an export variant of the People’s Liberation Army-Navy’s (PLA-N) Type 039B Yuan-class submarines, are a product of the agreement signed during President Xi Jinping’s visit to Islamabad in April 2015.

Under this agreement, Pakistan contracted with China for eight submarines, four of which were to be built in China, and the remaining four were to be constructed by Karachi Shipyard & Engineering Works Ltd (KS&EW) under the Transfer of Technology (ToT) arrangement.

However, the Hangor-class submarines, built by China for Pakistan, face potential weaknesses against Indian anti-submarine warfare capabilities, particularly in areas such as underwater endurance and stealth, due to their reliance on older technology compared to some Indian submarine platforms.

India's anti-submarine warfare (ASW) capabilities are designed to detect and track Hangor-class submarines from their departure points in Pakistan. India has developed a multi-layered ASW network, including aircraft, surface ships, and underwater systems, to monitor and counter potential submarine threats.

The importance of shallow-water ASW capability is further amplified by the shifting geopolitics of the Indian Ocean Region, where Chinese influence and technology transfers to Pakistan are altering the balance of power at sea.

As Chinese shipyards continue to construct Hangor-class boats for the Pakistan Navy under Project Hangor-II, India is arming itself with advanced anti-submarine warfare (ASW) weapon platforms backed by indigenized sonar systems, acoustic barriers, and shallow-water crafts (SWCs), such as INS Arnala, which was recently commissioned into the Indian Navy.

With maritime conflicts in the 21st century increasingly defined by stealth, sensors, and sonar shadows rather than surface firepower, the SWCs will ensure that Pakistan’s submarines will have no escape route once they come near India’s coastal waters. This platform represents a quantum leap in our ability to detect, track, and if required, engage enemy submarines operating close to our shores. Its role will be vital in deterring Pakistan’s asymmetric undersea threat.

The Indian Navy also has Kamorta-class corvettes in service, with an ASW system. Built at Garden Reach Shipbuilders & Engineers (GRSE), Kolkata, they are the first anti-submarine warfare stealth corvettes to be built in India.

Apart from the anti-submarine vessels, we have airborne assets, such as the Indian Navy’s P-8I Poseidon aircraft, which provide wide-area surveillance across the Arabian Sea, utilising sonobuoys and magnetic anomaly detectors. The MH-60R Seahawk helicopters are equipped with dipping sonar and torpedoes, enabling them to rapidly detect and engage submarines. India is also focusing on Unmanned Underwater Vehicle (UUV) technology to enhance its ability to monitor and track submarines.

While Pakistan's submarine fleet, particularly the Agosta 90B class/Hangor with Air Independent Propulsion (AIP), poses a challenge, the Indian Navy has demonstrated the capability to detect and track Pakistani submarines, including locating them in their own waters, which potentially deters Pakistan’s undersea threat.