Pack tactics

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Pack tactics (also wolf pack tactics ) were tactics used by German submarines during World War II . The alternative name wolf pack tactics is derived from the English term "wolfpack". The British used the term after German submarine attacks; The Americans also for attacks by the USS Flounder (SS-251) as part of an American wolf pack .

origin

In the last months of the war, the German submarines used in the Mediterranean during the First World War began to attack enemy convoys no longer individually, but in groups. This was the reaction to the increased patrol flights of the enemy, made possible by the technical development, with which the shipping routes were secured. One of the German submarine commanders operating in the Mediterranean was the then 23-year-old Karl Dönitz , commander of UB 68 , a UB II submarine . The experiences made by the later commander of the submarines and the Grand Admiral became the basis for his introduction of pack tactics in the new submarine weapon that was developed from 1935 and of which he became commander in 1936. Otto Ciliax , a Dönitz crewmate , criticized the pack tactics as being too fragile even before they were established, since their functioning was "too dependent on radio traffic". However , Dönitz felt his assessments were confirmed by the first exercises in the North Sea, during which Günther Prien stood out .

The early convoy system

As early as August 26, 1939 - before the start of open hostilities - the British Admiralty had placed the entire British merchant shipping under its command. Immediately after the Athenia was sunk , the Allies established a convoy system in the North Atlantic to ensure supplies to the British Isles.

  • HX and SC convoys drove from Nova Scotia to Great Britain.
  • OA and OB convoys went back to North America from there.
  • SL convoys were assembled outside Sierra Leone and headed for Great Britain.
  • HG convoys from Gibraltar accordingly .
  • OG convoys from Great Britain back to there.

The experiences of the First World War had shown that German submarines were the real threat to these convoy trains. The British Navy had therefore equipped more than a hundred of its ships with submarine location systems (see ASDIC ). In the first years of the war there were initially only a few ships available as escort vessels - this task was often taken over by hastily converted fishing trawlers.

First experience

The pack tactic was first used in October 1939. At that time, six boats were operating in the North Atlantic : three each of the submarine class VII B and three submarine class IX . The boats were supposed to attack the convoy KJF 3 , which had been assembled off Kingston . Two boats were already lost before the convoy was tracked: U 42 was sunk by two destroyers called for help following a gun battle with the merchant ship Stonepool, and U 40 sank in a minefield in the English Channel . Of the four remaining boats, U 45 , U 48 and U 37 took up the battle with the ships of the convoy, which were not protected by any escort ships, and sank several freighters. The fourth boat, U 46 , failed to track down KJF 3 . From the experience of this first attempt, the conceptual instruction resulted that the first boat that tracks down the enemy should not attack immediately, but should wait until further boats have been brought up by signals.

Principles

The main aim of the pack tactic was to enable the joint use of several submarines on the enemy. This was based on the fundamental tactical endeavor to be superior to the enemy at the scene of the battle. Hence the ideal time for such a joint attack was night; because then the submarines were difficult to see by the enemy, especially because of their low silhouette, which was below the horizon when the vehicles were sufficiently close to one another.

The joint operation was initiated by one of the submarines, which discovered the enemy - ideally several potential targets - but did not attack yet, but first brought more boats. A submarine group that was supposed to operate according to the pack tactics could arise in two ways. On the one hand, based on a report from a patrolling boat or aircraft, several submarines could be ordered to the respective sea area. Much more often, however, such submarine groups were "at the green table" in response to the intelligence service, e. B. by the naval intelligence service , compiled message received from a convoy and then ordered to the appropriate position.

Search strip

In the case of such a submarine group, the individual boats initially formed a "search field" or a "search strip" approx. 15 km apart . If one of the submarines had sighted a convoy , it then reported it to the other boats with a short signal consisting of 20 characters, which in addition to the weather, location, course, speed, number of ships and escort security of the convoy also informed the other boats about the amount of fuel available from the reporting boat of the group and from now on submitted this report every two hours in order to maintain contact with the other submarines approaching the convoy (ie “bring them”).

Proceed further

While the "search strip" was possibly still very stretched, as many submarines as possible came together around a convoy before the actual battle, whereby it was optimal if the middle boat of the "search field" took over the sighting. The subsequent attacks of the individual submarines of the pack, however, were only partially organized - the only "organization" of the attacks was essentially to have the other submarines "brought in" by the contact holder , which the other boats through his sending out beacons also indicated the position from which all subsequently opened the battle together.

Emergence and attack at night

The attacks themselves were initially mostly carried out at night and over water, as the submarines at this time of day were almost invisible to the guards of the convoys (e.g. destroyers) without their radar, which was only available later : the Allied ships did have them The ASDIC was already a device that made it possible to locate a submerged submarine up to a distance of 1,500 meters - however, it was not able to detect submarines that had surfaced .

Examples

successes

By the summer of 1940, the submarine command in the Atlantic had too few submarines available to attack the Allied convoys using the principles of pack tactics. It was less the increased construction than the conquest of the French Atlantic ports that made it possible to set up the first submarine groups that could operate according to the pack tactics. Accordingly, when the first submarine groups attacked convoys in the fall of 1940, the sinking rates rose. In August, the individually operating boats sank a total of 267,618 GRT. The use of coordinated U-boat groups in four convoy battles increased the successes in September to 295,335 GRT and in October to 352,407 GRT. At the same time only two German submarines were lost, one of them -  U 57  - without enemy action in a collision in front of the Brunsbüttel lock .

Countermeasures

In response to a submarine sighting, several escort vehicles were usually sent to hunt down the submarine, during which they were many miles away from the convoy. If the convoy changed course during this time - because of suspected or even actual submarine attacks - it could happen that the escorts initially did not find their "herd" again. In response to the pack tactics, the British Admiralty set up units that were trained in joint action against submarines. These so-called escort groups practiced escort protection off the coasts of Scotland and Ireland and their officers were trained in the corresponding tactics in a school founded especially in Liverpool .

Obsolescence

The pack tactic was the logical answer to the tactic of convoy formation. The massive use of submarines was ultimately outweighed by technical developments and the decrypted Enigma codes on the Allied side in the course of the Second World War, which was reflected in massive numbers of submarines and in (comparatively) low losses on merchant ships from May 1943.

The pack tactics became less important when, at the end of 1942, the radar (in the case of the bomber initially combined with the Leigh light ) and the sonar ( ASDIC etc.) on the British side had matured and could be used ever more successfully. Nevertheless, there were still several convoy battles up to May 1943, which, despite high submarine losses, were clearly decided in favor of the Germans. With the introduction of the HFDF radio direction finder Huff-Duff by the Allies, the task for the touching boat became extremely dangerous and even impossible. The end of the war partly anticipated the widespread use of advanced submarine development (snorkel, target-seeking torpedo , quiet boats, battery capacity).

Quotes on pack tactics

“That is the meaning of the famous pack tactic, which, however, should not be interpreted in such a way that the operation is carried out under uniform management in a closed association. The common ground is based exclusively on the introduction of weapons that are still on the side. Once on the convoy, each boat acts independently. This makes it possible to wipe out convoys of 50 or more ships in Atlantic battles that last for days. "

- Heinz Schaeffer : Commander of U 977 in his book "U 977 - Secret trip to South America" ​​(1950)

“Because even in a pack, one boat knows little more than nothing about the other, unless you analyze the radio messages or the group condenses within sight, a rare case. You think you are alone on a wide corridor, a little dot in the endless Atlantic [...] You know that even more comrades with their boats have the same goal, but you lack an overview. All threads came together at the BdU . "

- Peter-Erich Cremer : Commander of U 152 , U 333 and U 2519 in his book "U 333" (1982)

See also

literature

  • Dan van der Vat: Battlefield Atlantic . Heyne, Munich 1990, ISBN 3-453-04230-1
  • Elmar B. Potter, Chester W. Nimitz , Jürgen Rohwer : Sea power - a naval war history from antiquity to the present . Manfred Pawlak Verlag, Herrsching, 1982, ISBN 3-88199-082-8
  • Karl Dönitz: 40 questions for Karl Dönitz . Bernard & Graefe, Munich 1980, ISBN 3-7637-5182-3
  • Arthur O. Bauer, Ralph Erskine, Klaus Herold: Radio direction finding as an Allied weapon against German submarines 1939-1945 . How weaknesses and failures in the radio control of the submarines contributed to the outcome of the “Battle of the Atlantic”. Liebich Funk, Rheinberg 1997, ISBN 3-00-002142-6 (eyewitness reports by Alfred T. Collett, Oliver Nelson, Derekek Wellman, the German translation from the Dutch original was authorized by the author, first edition self-published by Arthur O. Bauer, Diemen NL 1997).
  • Winston S. Churchill : The Second World War . With an epilogue about the post-war years. 4th edition. Scherz, Berlin / Munich / Vienna 1996, ISBN 3-502-19132-8 (Original title: The Second World War . Translated by Eduard Thorsch, a one-volume, self-edited version from 1960 of his previously six-volume memoirs from 1948, later also as Fischer- Paperback 16113, Frankfurt am Main 2003, ISBN 3-596-16113-4 ).

Web links

Wiktionary: pack tactics  - explanations of meanings, word origins, synonyms, translations

References and comments

  1. ^ Van der Vat, p. 117
  2. ↑ Dönitz: 40 questions , p. 15
  3. ^ D. Hartwig: Grand Admiral Karl Dönitz. Legend and reality . Schöningh, 2010, p. 35
  4. ↑ Potter, Nimitz, Rohwer: p. 522
  5. ^ Bernard Ireland: Battle of the Atlantic . Naval Institute PRess, Annapolis 2003, ISBN 1-59114-032-3 , pp. 46-47
  6. ↑ Potter, Nimitz, Rohwer: p. 521
  7. ^ Van der Vat, p. 236
  8. ↑ Dönitz: 40 questions , p. 67
  9. ↑ van der Vat, p. 242
  10. ^ Heinz Schaeffer: U 977 secret trip to South America . Heyne, Munich 1979, p. 80
  11. ↑ P.-E. Cremer, F. Brustat-Naval: Ali Cremer: U 333 . Ullstein, Frankfurt 1986, p. 162