The Buzz

How the Falklands War (Thanks to a Stealthy Submarine) Could Have Gone Very Differently

The following day, the British submarine Conqueror torpedoed the Argentine cruiser General Belgrano, which sank along with 323 members of its crew. The entire Argentine surface fleet subsequently withdrew to coastal waters, leaving the San Luis the only Argentine vessel opposing the British invasion force. British ships and helicopters began reporting sonar contacts and periscope sightings everywhere, and launched nine torpedoes in waters the San Luis never even ended up approaching.

The San Luis’s crew, for its part, thought they had been fired upon by a British submarine on May 8, and after taking evasive maneuvers, launched a Mark 37 torpedo against an undersea contact. The torpedo was heard to explode and the contact was lost. This, too, was likely a whale.

Two days later, San Luis detected the Type 21 antisubmarine frigates HMS Arrow and Alacrity on the northern passage of the Falkland Sound. Masked by the noise produced by the fast-moving frigates, the San Luis crept within five kilometers of the Alacrity, fired another SST-4 torpedo and readied a second for launch.

Yet again, the wires of the SST-4 cut out shortly after launch. However, some accounts state the torpedo actually struck a decoy being towed by HMS Arrow, but failed to detonate. Azcueta gave up on firing the second torpedo and ordered the San Luis to disengage to avoid a counterattack.

However, the British ships cruised on, unaware of the attack. The captain of the Alacrity did not even learn of the close call until after the war!

Demoralized, Azcueta radioed home that the torpedoes were useless, and he received permission to return to base, which he accomplished on May 19. The Argentine garrison surrendered on June 14 before the San Luis could be put back to sea. Fifteen years later, the San Luis became one of only three Type 209 submarines to be decommissioned after an incomplete overhaul. Another fifty-nine serve on in various navies.

What went wrong with the San Luis’s torpedoes? There are a half-dozen explanations, variously holding crew error and technical flaws culpable. Manufacturer AEG first claimed the torpedoes had been launched from too far away, and without active sonar contact. Another claim is that the Argentine crews mistakenly reversed the magnetic polarity of the gyros in the torpedoes, causing them to run astray. However, there is also evidence that the torpedoes failed to arm their warheads and could not maintain depth. Suggestively, AEG implemented numerous upgrades to the torpedo after the Falklands conflict.

The San Luis was no super-submarine, nor did it have a super-crew. Yet, benefiting from a competent commander using ordinary tactics, it still managed to run circles around a dozen antisubmarine frigates from one of the most capable navies in the world, and might easily have sunk several warships had its torpedoes functioned as intended.

The Royal Navy, for its part, expended hundreds of expensive antisubmarine munitions and dispatched 2,253 helicopter sorties chasing false contacts—without detecting the San Luis on either occasion it closed within firing range.

Real submarine warfare has been, thankfully, extremely rare since World War II. The Falkland experience suggests that cheap diesel submarines could be very difficult to counter even when facing well-trained and well-equipped adversaries.

Sébastien Roblin holds a Master’s Degree in Conflict Resolution from Georgetown University and served as a university instructor for the Peace Corps in China. He has also worked in education, editing, and refugee resettlement in France and the United States. He currently writes on security and military history for War Is Boring.

Image: South African Type 209 naval submarine SAS Charlotte Maxeke. Wikimedia Commons/LA(Phot) Caroline Davies/MOD