Anti-Submarine Detection

Discussion in 'Research Material' started by CL1, Aug 15, 2022.

  1. CL1

    CL1 116th LAA and 92nd (Loyals) LAA,Royal Artillery

    Anti-Submarine Detection

    Between 1939 and 1943, German U-boats have a clear advantage over Allied escort ships. They can close in on convoys without being detected, fire torpedoes and escape without too much difficulty. To counter their devastating attacks, Allied scientists will develop underwater (ASDIC) or surface (radar) detection systems. Other systems can follow U-boats by plotting their radio signals on a map (HF/DF). Finally, the breaking of the Enigma code used for communications between U-boats and their HQ will allow Allied naval authorities to foresee and counter their attacks. It is only in 1943, though, that the Allies, with more ships, better armament and better detection systems will be able to regain control of the seas.
     
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  2. davidbfpo

    davidbfpo Patron Patron

    There were also the "own goals" that made life easier for the U-Boats. Such as the Germans reading the British convoy code books at the start of the war for sometime and the US reluctance to use convoys once Germany declared war on them after Pearl Harbour.

    Not to ignore the eventual closing of the mid-Atlantic gap for patrol aircraft, mainly, though not just in the North Atlantic.

    This not my area of focus, just a general interest and others will know far more.

    I did just glance at this mid-war document on: Submarine And Anti-Submarine
     
    Last edited: Aug 15, 2022
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  3. Harry Ree

    Harry Ree Very Senior Member

    Long Range Liberators eventually bridged the Atlantic gap although deliveries were behind schedule and Harris reluctantly had to transfer some of his bomber squadrons to Coastal Command in 1942 under pressure from Portal.

    Another U Boat detection tool which had some significant bearing in the U Boat battle was the introduction of ASV radar to locate U Boats from the air. The Kriegsmarine found it difficult to counter, the effect of the lack of long term investment of radar technology. The Metox Biscay Cross was a hurried response in attempting to pick up ASV radiations which brought a brief respite.

    Coastal Command aircraft commanders sometimes relied on visual sightings in the hours of daylight, ie ASV switched off giving no radiations for a U Boat to detect, which with good visibility the crew could pick up a U Boat on the surface of up to 5 miles. ASV with the Leigh Light was always a threat to U Boats while on the surface for battery charging during the hours of darkness.

    The successful modus operandi for attacking U Boats on the surface at night was to pick up the U Boat on ASV long range, work out a fix on the U Boat and switch off the ASV, Approach the position of the U Boat, switched on the ASV, Leigh Light available on automatic, triggered on by the good ASV return which resulted in an illuminated target for the U Boat to be straddled with depth charges .Some attacks were successful while others failed due to the flak put up by the U Boat sometimes leading to the loss of the aircraft. Overall, the flooding of ASV radiations in the Bay of Biscay made U Boat skippers reluctant to surface at night.

    In 1944,the Kreigsmarine introduced the Schnorkel boats which made it difficult to locate U Boats in rough seas .The British solved the problem by a reduction in the ASV wavelength which enabled the gear to pick up smaller targets.
     
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  4. Peter Clare

    Peter Clare Very Senior Member

    More details of the Leigh Light taken from 'The RAF In The Maritime War' (AIR 41 / 47)
     

    Attached Files:

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