WWI and WW2 cemented the submarine’s place in military arsenals all around the world. German submarine activity in WWI was one of the major reasons the US entered the war. Just over two decades later, German U-boats claimed 3,000 Allied vessels during WW2 alone. However, since WW2 ended, only two submarines have sunk enemy ships in combat.
After the war, submarines remained an integral component of navies all around the world and received massive technological boosts. The post-war period saw submarines gain the ability to launch nuclear weapons. Nuclear powerplants also found their way into submarines, which, along with equipment that could extract oxygen from the surrounding water, allowed submarines to stay submerged for months on end.
Despite these improvements and extended capabilities, no submarines sank any enemy ships in this period. This would be the case until the 1971 Indo-Pakistani War.
PNS Hangor would be the first submarine to sink an enemy ship since 1945. In late November 1971, the Pakistani submarine was dispatched into the Arabian Sea, where she discovered a large group of ships from the Indian Navy. She maintained her distance from the vessels and investigated their communications. Over the next few days, the Indian Navy would learn of PNS Hangor’s presence and sent two British-made frigates to find her.
PNS Hangor was a French-made Daphne-class submarine. She was 200 ft long and armed with twelve 550 mm torpedo tubes.
On December 9, PNS Hangor detected the two frigates approaching her and dived deep until they came into torpedo range. Once they were in range, Hangor fired a homing torpedo at one of the frigates, INS Kirpan, which missed. Kirpan hightailed it away from Hangor as soon as they realized they were being targeted. Meanwhile, the second frigate, INS Khukri, barrelled towards the submarine in an attempt to sink it, however, Hangor fired a second torpedo at Khukri, which hit.
This torpedo dealt a fatal blow to the Khukri, which sank in mere minutes, claiming the lives of 18 officers and 176 sailors. Kirpan returned for another attack, which Hangor responded to with a third torpedo. This failed to stop Kirpan but caused the Indian frigate to flee.
After the engagement, the Indian Navy launched a huge search and destroy mission to find and sink Hangor, but the submarine reached safe waters after remaining submerged for almost a week.
Today, PNS Hangor is on display at the Pakistan Maritime Museum, Karachi, Pakistan.
HMS Conqueror was the second submarine to sink an enemy vessel after WWII and is currently the only nuclear submarine to have ever sunk an enemy vessel. Its actions during the Falklands War in 1982 are some of the most famous of all naval encounters in recent decades.
HMS Conqueror was a British Churchill-class nuclear-powered submarine that launched in 1969. She was 285 ft long and displaced 5400 tons while submerged. Powered by a Rolls-Royce nuclear reactor, Conqueror could operate for as long as the crew had supplies. She began the long journey down to the Falkland Islands in the South Atlantic the day after Argentina invaded the islands.
Once there, she was tasked with guarding the British exclusion zone and monitoring Argentine naval activity in the area. Near the end of April 1982, Conqueror spotted the Argentinean cruiser ARA General Belgrano, a WWII-era cruiser that was originally a US ship.
During WWII she was known as USS Phoenix and was present when the Japanese attacked Pearl Harbor in 1941. By the 1980s, General Belgrano had little chance against a modern nuclear submarine such as the HMS Conqueror.
On May 2, Conqueror received permission from the British government to attack General Belgrano, firing three Mark 8 torpedoes, two of which hit the Argentine ship. Similar to PNS Hangor, after sinking the enemy ship, Conqueror had to evade efforts to find and sink her.
After the Falklands War ended, Conqueror returned to the UK flying the Jolly Roger flag, a Royal Navy tradition for submarines that achieved a kill.
Conqueror was retired in the 1990s and is still waiting to be scrapped.