The India-Pakistan War of 1971 was triggered by the armed struggle by erstwhile East Pakistan (now Bangladesh) to liberate itself from Pakistan. Pakistan Army launched Operation Searchlight to brutally suppress the Bengali Nationalist movement. The Indian Navy launched naval interdiction, air defence, ground support, and logistics missions to choke Pakistan from the Indian Ocean. The Indian Army & Indian Air Force applied pressure on the Pakistan Army operating in East Pakistan & it also destroyed a number of Pakistani boats & ships in the East Pakistani ports. After the success of the Indian Navy’s operations in the East, it launched major operations in the West namely Operation Trident and Operation Python.

Submarine Operations

Pakistan had two Submarines: PNS Hangor, a Daphn class submarine which was deployed on the west coast and PNS Ghazi, Tench class long range submarine which was deployed on the east coast.’

East Coast: PNS Ghazi was the flag ship of the Pakistani Navy & was conducting operations on the east coast & Bay of Bengal. It was in search of aircraft carrier INS Vikrant which was deployed on the east coast. According to military historian Srinath Raghavan, US President Richard Nixon and Henry Kissinger “believed that there was an outside chance for a ceasefire before the Pakistan army caved in on the eastern front”. Nixon instructed his Chief of Navy “to assemble an impressive naval task force and move it off the coast of South Vietnam, into the Malacca Straits, and onward to the Bay of Bengal”. Task Group 74 included the largest aircraft carrier in the US navy, the USS Enterprise. India did not cave in & rest is history. On December 1, 1971, Commander in Chief of the Eastern Naval Command, Vice Admiral N. Krishnan briefed the commanding officer of INS Rajput, that a Pakistani submarine had been sighted off the Sri Lankan coast and was absolutely certain that the submarine would be somewhere around Madras or Visakhapatnam. As a result PNS Ghazi was sunk on December 4, 1971 in the proximity of Visakhapatnam with 11 officers & 82 sailors.

West Coast: PNS Hangor had detected a large number of Indian Navy’s ships near Karachi harbour & passed this information to its naval HQs which was intercepted by Indian intelligence & two Indian Anti submarine warfare frigates INS Khukri & INS Kirpan were despatched. On December 9, 1971, PNS Hangor sunk Khukri with two homing torpedoes. Along with the ship, 178 sailors and 18 officers made the supreme sacrifice. Captain Mahendra Nath Mulla, captain of the Khukri, chose to go down with his ship. Afterwards Hangor also attacked INS Kirpan twice but missed & INS Kirpan successfully got away.

Operation Trident -Attack on Karachi

Karachi was the HQs of the Pakistan Navy, hub of Pakistan’s maritime trade & economy thus a lucrative strategic target. Destruction or blockade of Karachi port would have disastrous results for Pakistan’s naval operations as well as its economy thus it was heavily defended against any naval or air strikes. The Indian Fleet based itself 400 km away from the Karachi Port, well away from the range of Pakistani Air Force & could easily creep closer at night as Pakistani Air Force had no night vision capability. The intelligence gathered by the Pakistani submarine was faulty or not adhered too. The Indian Navy launched Operation ‘Trident’ on December 4, 1971 against the Karachi Port.

The Indian Navy’s pre-emptive strike with Indian Navy’s “Killer Squadron” resulted in great success. The Indian missile ships successfully sunk the minesweeper PNS Muhafiz, the destroyer PNS Khaibar and the MV Venus Challenger which, according to Indian sources, was carrying ammunition for Pakistan from the US. The destroyer PNS Shah Jahan was damaged beyond repair. The missile ships also bombed the Kemari oil storage tanks of the port which were burnt and destroyed causing massive loss to the Karachi Harbour. Operation Trident was an enormous success with no physical damage to any of the ships in the Indian task group, which returned safely to their garrison. December 4 is thus celebrated as ‘Navy Day’.

The Indian Navy launched a follow up operation to Trident, code named ‘Operation Python’ on the midnight of December 8-9, 1971. INS Vinash, a missile boat, and two multipurpose frigates, INS Talwar & Trishul took part in the operation. They closed on Karachi and fired four missiles. During the raid, the Panamanian vessel Gulf Star and the British ship SS Harmattan were sunk and Pakistan Navy’s Fleet Tanker PNS Dacca was heavily damaged. More than 50 per cent of Karachi’s total fuel reserves were destroyed. The warehouses & naval workshops were also destroyed. Because of the gallant & audacious operations by the Indian Navy by literally going into the enemy’s naval port & attacking it, resulted in stupendous success & complete control of oil routes from the Persian Gulf to Pakistani ports. In a short time the Indian Navy had established control of Pakistan’s east & west coast.

The damage inflicted on the Pakistani Navy stood at seven gunboats, one minesweeper, one submarine, two destroyers, three patrol craft belonging to the coast guard, 18 cargo, supply and communication vessels, and large scale damage inflicted on the naval base and docks of Karachi. Three merchant navy ships – Anwar Baksh, Pasni and Madhumathi and ten smaller vessels were captured. Around 1,900 personnel were lost, while 1,413 servicemen were captured by Indian forces in Dhaka. According to one Pakistan scholar, Tariq Ali, the Pakistan Navy lost a third of its force in the war.