The Falklands War - What you did not know

The modern German built submarine San Luis remained at sea and carried on a one-ship war on the British task force. Being very difficult to detect, the jumpy royal navy logged more than fifty attacks on targets they took for the San Luis without success. The San Luis itself attacked the fleet on May 1st and again on May 10th, each time firing torpedoes that missed.

In some ways the dog that had not barked had been the Argentine submarines. This was not for want of trying: San Luis, for example, fired a torpedo at a totally unaware Arrow but missed. The RN had, under the influence of comparatively narrow NATO scenarios, become a predominantly deep-ocean ASW force, focusing on the detection of SSNs by passive acoustic systems.

In the South Atlantic, the threat was from small, quiet SSKs, under conditions which were difficult and unfamiliar to the ASW teams, and the sonars in use had not all been reliable. As a result many false alarms were generated by marine life, bottom contact and the environment generally. This led to considerable nugatory weapon expenditure and postwar concerns that even when no contact was being made with submarines, established stock levels were inadequate.

The fact that after the sinking of the Belgrano, there was no further involvement of the Argentine surface fleet in the sea battle was testament to the value of the SSNs, in addition to their role in intelligence gathering, and the advantage they had shown by being able to arrive early and establish the Maritime Exclusion Zone. They posed a threat which the Argentines were never able to measure let alone oppose. While little real evidence of ASW weapon performance was available, as in for example the choice made by the captain of Conqueror, the Tigerfish torpedo retained its reputation for unreliability

Many depth charges had been used in response to sonar noises, often leading to attacks on whales. Some 200 anti-submarine torpedoes had been launched with no effect. On one occasion, on 12 May, Antrim’s Sea King did launch a torpedo at what it was sure was a submarine (and so probably Soviet) shadowing the amphibious force as it steamed to the South Atlantic. It should be said that there is no corroboration for this and certainly nothing was hit.