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, Hubei province, state-run Global Times reported. 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.
Pakistan’s Deputy Chief of Naval Staff Vice Admiral Abdul Samad said the Hangor-class submarines, equipped with advanced sensors and weaponry, would help maintain “regional power equilibrium” and ensure maritime security.
Heavy Reliance on Chinese Arms
China supplied more than 81% of Pakistan’s arms in the past five years, according to the Stockholm International Peace Research Institute (SIPRI). Key purchases include the Rizwan spy ship, over 600 VT-4 battle tanks, and 36 J-10CE fighter jets, which Pakistan has already used in conflicts with India.
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.
Transfer of Technology and Local Construction
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.
Weaknesses Against India’s ASW Capabilities
However, the Hangor-class submarines, built by China for Pakistan, face potential weaknesses against Indian anti-submarine warfare (ASW) capabilities, particularly in areas such as underwater endurance and stealth, due to their reliance on older technology compared to some Indian submarine platforms.
Delays and Combat Management System Issues
Pakistan’s reliance on China for technology and construction makes the program susceptible to shifts in China’s strategic priorities. The Hangor-class submarines have experienced delays in delivery due to issues with the combat management system (CMS). While the initial plan was to deliver the first four submarines between 2022 and 2023, only one has been launched for sea trials, and none have been commissioned to date. The CMS, crucial for coordinating sensors and weapons, has encountered integration challenges and potential incompatibilities with Pakistan’s existing systems.
Engine Troubles: German Withdrawal and Chinese Alternatives
Germany’s refusal to provide Rolls-Royce MTU396 diesel engines initially delayed the project, forcing Pakistan to use Chinese-made CHD620 engines. The construction of the eight submarines was significantly impacted by these issues, leading to a revised schedule. Thailand also had to abandon the purchase of these submarines due to the unavailability of German engines.
Thailand’s Submarine Dilemma
In 2017, the initial contract to buy the S26T Yuan-class submarine with German-origin MTU-396 diesel engines was framed between China and Thailand. However, Germany’s withdrawal from the agreement, citing policy restrictions on using its engines, triggered complications.
Beijing suggested a domestically manufactured replacement, providing reverse-engineered CHD620 engines from China’s state-owned submarine manufacturer. The CHD620 engine is a Chinese-produced version of the German MTU396 engine, manufactured under license. However, Thailand rejected the Chinese-made engine, allegedly due to concerns about its quality.
However, new reports suggest that the Thai Defence Ministry has decided to reverse its earlier decision and “agree in principle” to proceed with the S26T purchase. The submarine will now be delivered with an “unproven” Chinese-made engine despite the Thai government’s previous reservations about it. Adding to Bangkok’s woes, the first of the submarines is not expected to be delivered by 2027.
Regional Challenges with Chinese Submarines
Across the region, navies that have acquired Chinese submarines — such as Bangladesh’s refurbished Ming-class and Myanmar’s older designs — have faced maintenance and performance challenges. The engine is not just a piece of machinery — it is the lifeline of a submarine. If this is compromised, then a sword of uncertainty hangs over its performance in a combat scenario, always threatening its effectiveness.
Risks for Pakistan
Pakistan is risking its maritime security by augmenting its submarine fleet with unproven technology from a vendor whose weapon systems failed completely against Indian missiles and air defence systems, as seen during Operation Sindoor.
