Falklands War San Luis served in the Falklands War () of 1982. Only one other submarine, the
Second World War-era , was operational at this time. After
Santa Fe was damaged, captured and scuttled by the
British during the re-taking of
South Georgia on 28 April, and the nuclear submarine had sunk the cruiser on 2 May, the Argentine fleet retired to port for the duration of the war, with the exception of
San Luis, making her the only Argentine naval presence facing the British fleet.
San Luis was a major concern for the British as she presented a serious danger to all British warships in the area. Sea, depth and thermal conditions around the Falklands were favourable to diesel submarines, and difficult for anti-submarine ships. The
Royal Navy (RN)
aircraft carriers and were the priority targets for
San Luis. Sources conflict on whether
San Luis was capable of finding and attacking the RN carriers. Considerations include that the RN aircraft carriers were confined to operate east of the Falklands within sectors determined by the range of
Sea Harrier, the ability of the Argentines to intercept RN ships' satellite communications, and to a degree by
Soviet intelligence assistance.
San Luis reported two attacks on Royal Navy ships during the war. On 1 May, the
frigates and were sent to hunt down
San Luis, then operating north of
Stanley.
San Luis reported firing a German-made
SST-4 torpedo, on purely passive sonar detection of British gas turbine-powered warship(s) and
Sea King helicopters searching. The torpedo missed its target, presumably due to range, malfunctioning of the computer fire control system, gyro misalignment and the breakage of the wire guidance wire. Nevertheless, experts believe that a closer range attack or alternative use of the MK 37 in an anti-ship role might have been successful. Sonar operators aboard
Brilliant were certain they heard and confirmed the sound of an SST-4, and
Brilliant,
Yarmouth and three Sea Kings from
Hermess
826 Naval Air Squadron launched
depth charge, mortar and torpedo attacks for 20 hours until the short sub-Antarctic night on 1 May. Searching for the Type 209 submarine was hindered by the numerous wrecks of whaling boats and whales, indistinguishable from submarines.
San Luis had adopted the World War II tactics of German
U-boats and rested on the bottom some distance from the area of interest to the British frigates, where it shut down. During the short Falklands War, the United States supplied 200 Mk 46 torpedoes to the Royal Navy, which expended 50
Mk 46 torpedoes during the conflict against sonar detection of the possible sound of the single Type 209 submarine. The Royal Navy never detected or located the submarine, It seems that the torpedo hit
Arrow's towed decoy. In the subsequent counter-attack,
San Luis survived a 25-hour chase, which included the use of depth-charges. There were several problems with torpedoes and torpedo systems; in particular it appears that the torpedoes were not prepared properly, and did not arm themselves after firing, so would not explode even if they did hit a target. It has been suggested that previous apparent misses could have been due to torpedoes which struck home but did not explode. The mere presence of
San Luis was a severe nuisance to the Task Force. The threat posed by the Argentine submarine forced the Royal Navy to suspend the rescue efforts of two Sea King helicopters who ditched at sea on 12 May and 18 May 1982 respectively, while conducting anti-submarine operations. Both aircraft were eventually scuttled by naval gunfire.
San Luis returned to
Puerto Belgrano on 17 May for repairs to her weapons systems, and was not operational for the rest of the war.
Post-war After a failed overhaul,
San Luis was decommissioned in 1997. Its hull remains stored at
Tandanor shipyard, in
Buenos Aires. ==See also==