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World War II naval histories focus very intensely on the German U-boat force and the Allied efforts to defeat it. Ironically German admirals before the War wanted a big-gun surface fleet. Hitler with his penchant for military giganitism actually promised them just such as fleet, but then advanced the time table for war. Thus the Kreigsmarine unlike World war I began the War with only a small surface fleet. As a result of World War I, most German and British admirals did not believe the U-boat was a formidable weapon and this were still big-gun battleship enthusiasts. Admiral D�enitz thus had only a small U-boat force when Hitler launched the War, but they were very well trained. The U-boat proved again to be Germany's primary naval threat. Once this became apparent, Hitler ordered a massive U-boat construction program. Churchill after the War wrote that the u-boat campaign in the Battle of the Atlantic was the one threat that really worried him. The fall of France provided the Germans Atlantic ports that they were denied in World War I and which greatly greatly incrased the effectiveness and striking power of the growing U-boat fleet. The effectiveness of the U-boats can be seen when President Roosevelt ordered took the extrodinary action of ordering the U.S. Navy into an undeclared naval war in the Atlantic months before the United State actually entered the war. Even so, Hitler did every thing he could to avoid incidents with the Americans in the Atlantic. He was intent on keeping America out of the war until he completed the conquest of the Soviet Union. His anger at having to do this was so intense that it is probanly the primary reason that after the Japanese attack on Pearl Harbor that he so readily declared war on the United States. This freed the U-boats to launch a highly successful attack on shipping along the Amerucan Eastern Coast. The Battle of the Atlantic would be the decisive campaign waged by the Western Allies. Ironically while the German U-boat campaign is one of the great legends of World War II, endlssly chronicled in film and literature, it was the Americans in the Pacific who waged the only successful submarine campaign--a stark example of what the Germans might have achieved. All of the other Allied campaigns in Europe were contingent on defeating the U-boats in the North Atlantic.
World War II naval histories focus very intensely on the German-boat force and the Allied efforts to defeat it. Ironically German admirals before the War wanted a big-gun surface fleet. Hitler with his penchant for military giganitism actually promised them just such as fleet, but then advanced the time table for war. Thus the Kreigsmarine unlike World War I began the War with only a small surface fleet as well as a small-Uboat fleet. As a result of World War I, most German and British admirals did not believe the U-boat was a formidable weapon and this were still big-gun battleship enthusiasts.
Germany's small U-boat fleetproved a major challenge to the British Royal Navy in World War I. Early in the War, U-boats sank three British cruisers, astounding the public both in England and Germany. The Germans backed down from unconditional submarine warfare when America protested the sinking of the Lusitania (1915). There were 1,201 civilians, including 94 children killed. Among them were Americans and American public opinion was incensed. Although the British denied it, historians have since established that the Lusitania was carrying weapons and amunition. [Massie] The invasion of neurtal Belgium and the sinking of the Lusitania combined to create the image of Germans in the American mind as modern day Huns. Making another effort to win the War, Germany in 1917 reimplemented unrestricted submarine warfare (March 1917). The Germans feared the entry of America into the War, but in the end concluded that they could force the British and French to seek terms before the American Expeditionary Force could be created and brought to France. It proved to be a huge miscalculation. As a result, America declared war on Germany (April 1917). The U-boat fleet succeeded in sinking 5,000 ships. That was an amazing 25 percent of the Allied merchant fleet. The Allies attempted to determine how to sink U-boats and developed the depth charge. It was, however, the introduction of the convoy system that defeated the U-boat. The World War I U-boat was really a surfacre vessel that could sumbmerge. Against esorted convoys, World war I era U-boats had little chance of success. In the end the German Navy only served to bring Britain and America into the War, ensuring Germany's defeat. An embittered German naval office, Karl Donnietz, confined in a British POW camp in 1918 was already planning Germany's strategy in the next war.
Germny had a major industral base, but not large enough to fully prepare Germany for another world war. This priorities had to be made and the priority ws given to the Heer and Luftwaffe. The Kregsmarine was low on Hitler's prioritie. And the German admirals accepte the general inter-war assessment that sibmarines would not ply a major role in a futur war. What they wanted ws a surfce fleet ad big-gun battlehips to Chllenge the Royal Navy. As a result, most of the limitd resoirces advocated for naval building went for surface ships, especially shipslike Bismark and the planned Graf Zeppelin aircraft carrier. This accorded ith Hitle's personal preference ft gigantcisms such as large tanks and artullery piaces. This only limite resources were given to U-boat technology and production.
Admiral Raeder placed NAZI Germany's new U-boat fleet in the hands of Admiral Karl D�nitz, a fervant NAZI supporter. D�nitz was a decorated World War I U-boat commander who like many other naval commanders had been humiliated by Germany's defeat in World War I. He began to aggressivey build a new German submarine force. Resources were at first limited. Hitler's priorities were his Panzers and the Luftwaffe. Even within the Kriegsmarine resources were focused on surface ships. Yes the NAZI armaments program was so extensive that D�nitz was able to build a substantial number of modern U-boats. He wanted improved technology, but the German Admiralty both before and after Hitler's seizure of power gave scant attention or resources to U-noats. Their focus was on the surface fleet. Thus D�nit had only 56 U-boats at the outbreak of the War, mostly the Type 7 U-boat. These boats were the most advanced at the time. until the U.S. Nvy introduced the Gato-class submarines. The German subs had movable torpedo tubes and an analog targeting computer that was the most effoent in the world at the time. The Germans before the War had made an effrt to map the seabed, giving their subs an advantage when operating at depth. But for technology, D�nitz had to rely on the Afmiralty. So the U-boats that he would take to war in 1939 were bascically the same as those use in World War I. There were some improvements, but they were stil basically surface ships that could submrge. They had to spend somrthing like 90 percent of a cruise on the surface. And they began the war with unreliable torpedoes. New torpedoes would have to be developed during the War. First with percussion dentonators and latter with more effective magnettic denotanors. What was different were the tactics. D�nitz devised radically new tactics. Here he did not need assistance from the Admiralty. D�nitz decided to focus on surface attacks at night concluding that surface attacks would counter the British development of ASDAC (SONAR). He also spent a great deal of time in developing tactics to deal with technological advances. He also developed a highly effective training regime. He developed very demanding training program through which only the most competent officers and men were allowed into the force. U-boat men came to look on each other as the cream of the German navy. D�nitz by the end of 1935 had 13 U boats which were housed in especially designed concrete submarine pens. The limitations of the 1935 Naval Agreement with the British was on tonnage. Doenitz did not see this as a major limitation, reasoning that a larger number of smaller U-boats was more effective force han a small number of large boats. The new German U-boat force was a volunteer force.
Admiral Karl D�nitz commanded the Kriegsmarine U-Boat fleet which came very close to victory in the North Atlantic. D�nitz commanded a U-boat in World War I. After neing captured by the British his thoughts immediately turned to developing ideas about how to win the next war. Hitler gave him his chance. Not only the British Admiralty but Hitler and the German Admiralty did not believe that U-boats would play an important role in the coming War. They had been defeated in World War I and thus they were not seen as a threat. D�ntiz is widely credited with conceiving the tactics that almost defeated the Allies. From the beginning of the War, the daring eploits of U-bost commandrs helped give the U-boat force the aura of an elite force. D�nitiuz also becamne enormously popular. And D�ntitz was delivering victories after the Heer and Luftwaffe were only reporting defeats. Less commonly mentioned is his inflexibility. Unlike the Allies he did not adapt to the changing military situation as the Battle of the Atlantic was fought out. The tactics D�nietz employed at the start of the War (1939) were the same he used later when the U-boats were decisively defeated (1943). Especially costly to his U-boat commanders was his excessive use of communications. This assisted the Allies in locating U-boats and providing the volume of messages needed to crack Emigma. D�nitz was the most cautious of all the German commanders about Enigma, adding a third rotor. Ironically his penchant for closely directing his U-boats played a role in defeating them. Because of the failure of the German surface fleet and the fact D�nitz was an ardent NAZI, Hitler appointed D�nitz as overall naval commander. It was an honorary post because not much was left of the surfsce fkeet when he took commnbd. Then Hitler before shooting himself, named him as the new head of state, but not the second F�hrer. D�nitz had no allusion about the military situation. His only real task as F�hrer was to arange Germany's surrender. He seems to have some illusions about forming an occupation government that would be recognized by the Allies. For the week he theoretically controled NAZI Germany, his chief concern was to get as much of the Wehrmacht as far west as possible so that they could surrender to the British and Americans raher than the Soviets. The NAZIs seemed to have leaned where the post-War occupation zone boundaries would be drawn. The Allies were unablre to try Hitler at the Nurenberg War Crime Trials, but they did try D�nitz. He was not tried for his brief stint as F�hrer, however, but for his war time activities. This proved complicated, however, because of the American submarine campaign in the Pacific. Additional information has surfaced about D�nitz after the Nuremberg Trials. He liked to distribute the booty from the Jews murdered at the death camps to his U-boat crews.
Admiral D�enitz thus had only a small U-boat force when Hitler launched the War, but they were very well trained. The U-boat proved again to be Germany's primary naval threat. Churchill after the War wrote that the u-boat campaign in the Battle of the Atlantic was the one threat that really worried him.
Once the effectiveness of the U-boats became apparent, Hitler ordered a massive U-boat construction program. Germany had the largest submarine fleet during World War II. The Germans built nearly 1,200 U-boats. The Treaty of Versailles had prohibited U-boat construction. Only after the Naval Treaty with Britain was it possible to resume construction (1935). The German Admiralty based on Hitler's instructions believed that it had several years to prepare for war and would have time to build a substantial surface fleet for a war that would not begin until the mid-1940s. Thus the Ubootwaffe (U-boat force) was only a small mpart of the German Navy. Thus the Germans began the War with a very small Ubootwaffe. Only after tge War began and the U-bosts scired important priorities was priority given to U-bost construction. U-boats were relatively small ships and could be built more quickly than larger surface vessels. It took most of 1940 to expand the production facilities and begin the mass production of U-boats. The success of the U-boats in the early years of the War did not prove decisive because of the small size of the Ubootwaffe. The Germans had steadily increased U-boat construction in 1940-42 anf by 1943 had a very substantial force which had not been significantly reduced by Allied ASW efforts. German U-boat construction reached full capacity (Spring 1943). It is at this time that Allied ASW effirts begin to become increasingly effective. In addition, the American 8th Airforce joined RAF Bomber Command in the around the Clock strategic bombing campaign. U-boat construction sites were one of the bombing priorities. And unlike other major targets were located in coastal cities especially vulnerable to bombing attacks.
The Germans built several different types of U-boats for service in World War II. This included both small coastal boats and medium-sized ocean-going boats as well as large cargo boats (the Milk Cows) for supplying ships at sea in the Atlantic. Small boats included the Type IIs, small boats of about 250 ton. They were used for training and reconisance. The work horse of Admiral D�nitz's U-boat force was the Type VIIC which fought out the Battle of the Atlantic. Type VII was a medium-sized boat and the principal U-boat deployed by the Kriegsmarine. They were boats from 500-750 ton with a crew of 56. They had twin diesel engines of 1400 HP which could drive the boat on the suface at 17 knots. They also had twin electric engiines 750 HP giving speeds 8 knots under water. They carried 11-14 torpedoes which the Germans called eels. (American submariners called them fish.) There were four bow torpedo tubes and one stern tube. They were armed with the German 88-mm gun, the most effective artillery piece of the War. The Type VIIs was the U-boat D�entiz wanted to fight the Battle of the Atlantic. I was an effective boat at the onset of the war, but by 1943 advances in Allied technomogy truning it into a deathtrap. Yjr principal problems was that design features created a very large and easily detectable sonar sinature. And it was not designed to fight inderwater. But surfced it was easily detectable by Allied radar which ncause of air cover encompased the North atlntic. Cracking the Naval Enigmas also exposed the boats. Do�nitz had to withdraw the U-boats fron the North atlantic (mid-1943). The principa large boat was the Type IX. Miliitary experts generally report that the larger Type IXB ws the most successful. The Type IX was the larger boats ranging from 1,100 1,400 tons. OKM insisted on building quite a number of type IX U-boats. They were not the ones was D�entiz wanted. The Germans were constantly trying to improve their U-boats and put some of their best scientists on the effort. They were at a serious disadvantage, however, because most of the U-boats lost to the highly sccessful Allid ASW effort were lost at Sea so the Germans were unsure just what Allied ASW develop,ments were suceedinding in sinking U-boats. They had, however, a fairly good idea. And D�nitz put a techinal genius on designing an improved U-boat--Hellmuth Walter. Earlier German U-bpats were basically a surface ship capable of diving. What Walter set out to produce was a true sibmarine capable of fighting underwater and remaining submerged for extended periods. His work led to a high performance protype and two advanced U-boat types. The Type XVIII solved the the need to surface by shifting from diesel fuel to hydrogen peroxide. This created, however, a varirety of problems, but the insolvable one was Germany's limitedcapacity to produce hyfrogen peroxide and the priority given tothe V-2 program. Walter used the many design innovations developed for the Type-XVIII to produce the Type XXI Elektro boat. Hitler ordered priority given to the TYpe XXI program. They had the capability of remaining submerged for long periods and had a small sonar signature. The Germans did not achieve this on purpose, but the streamline design llowing the bot to increase submerged speeds, lso reduced the sonar signture. Some claim that if introduced earlier it could have won the Battle of the Atlantic. There were, however, major design and manufacturing flaws as a result of the rush to produce . The Allied strategic bombing campaign greatly complicated manufacturing projects, especially large operations which slowed the production process. Shipyards were priority targets for the Allied bombers. The Germans launched quite a number of these boats, but only a few were actually deployed by the time the the NAZIs surendered. The Tyupe XXI hull design was highly inflential in the U.S. Navy nuclear Natalus design. The Soviet Navy went down the Type XVIII hydrogen peroxide dead end.
The U-boat crews considered themselves to be the elite of the Kriegsmarine. This was not the situation at the outset of the War. OKM was focused on big-gun battleships. But as the war developed it was soon realized that the Ubootwaffe (U-boat force) was the potentiall war-winning force in the hands of the Kriegsmarine. Amd D�nitz and his captains cme perilously close to pefecring the craft of underwater naval combat. Fromom the beginning, life aboard a German U-boat was hellish. The air, smalls, food, sanitary conditions, and claustraphobic cra,ped conditions were essentially intolerable. One historian writes, "Once committed to the Ubootwaffe, each man soon understood and accepted that he would be a proud part of a unique brotherhood. Doing so was essential; he was about to set out, in claustrophobic, unsanitary hellish conditions, on a voyage--an adventure--that would challenge and strech his mental and physical endurance to the very limits, one that he was unlikely to survive. And, if he did return, he drew very little comfort from family or friends, trapped in the knowledge that another, possibly fatal patrol awaited him." [Kaplan] The horific conditions aboard a U-boat did not change as the War progressed. What did change was the chance of the men to survive. U-boat losses were light at the start of the War and through two 'Happy Times". This gradually changed as the llies perfected their ASW methods. After the tide of the Battle of the Atlantic changed (mid-1943), the change of a U-boat sailor to survice thear was minimal. dmiral D�nitz sent some 39,000 men to sea in U-boats, including two sons. Over 27,000 of those men died in action. There wre few wounded. If a U-boat was sunk, in most cases the entire crew perished. The Germans deployed 863 U0boars during the War, the Allies destroyed 754 or nearl0 percent. With the eception of Japanese Kamikazees, it was the most dangerous service of the War.
The Wolf Pack tatics (Rudeltaktik) wasDeveloped U-boat commander Karl D�nitz The tactic proved a devastating against Allied convoys. The concoy system had helped defeat the U-boats in World War I. The Wolf Packs was D�nitz's response to defeat the convoys. He did not begin to implement th tactic until after he fall of France (June 1940) when he Germans gained direct access to the North Atlantic convoy routes. D�nitz had been thinking about it for years beginning during World War I. He had plenty of time to think about posibletactics as he languished in a British POW camp. He worked on ideas a to how to defeat the British convoy system. The convoy was devised by the British to protect shipping. A convoy is a group of ships that sailed together with Admiralty direction under the protection of escort vessels. This meant that the U-boats could no longer find isolated, unprotected targets that were easy to attack. And when individual U-boats lucked upon a convoy, they had difficulty attacking. Not only could armed merchant ships offer mutual support against a single U-boat, but there escorts tat could defeat a single U-boat. D�nitz'idea was for U-boats to operate in groups he called wolf packs. They would form a north-south line across the sea lanes. This increased the chances of potting a convoy. Once spotted, a U-boat would not immedately attack, it became the 'shadower' and while maintainig contact with the convoy would radio the position to the Befehlshaber der Unterseeboote (U-boat Command HQ--BdU). BdU would then issue orders as to which U-boats would converge on the convoy. The shadower would maintain contact, but remain out of the visible range so the convoy could not spot them, usually running submerged during the day and runing on the surface at night. When a suficent number of U-boats had reavjed the convoy, BdU would order an attack, usually at in the dark as the U-boats were so difficult to detect. The attacking U-boats would stage a coordinated attack as a group. The massed attack was designed to overwhelm the escorts by the number and surprise. If successful the convoy defenses would be thrown into disarray.
The British needed deliveries of about 1,000 merchant ships monthly to stay in the war. Based on their World War I experience the British armed their merchant men and introduced a new convoy system. ediately introduced a convoy system. This was probably a mistake. The German U-boat force at the onset of the War was very small. Thus disruptions in rapidly adopting the convoy system werre probably greater than the damage that the small German force could inflict. The convoy system was, however, critical as the German force mounted and acquired French ports from which to operate (June 1940). The convoys sailed in zig-zag patterns and were generally organized in four rows surrounded by escort vessels. There were both fast and slow convoys. The convoys were limited to the speed of the slowest vessel. If a ship was hit by a torpedo or developed engine trouble it would be abandoned by the convoy. The crews from sunken vessels were not picked up by the convoy. Stopping would endanger the rest of the convoy. The early convoys provided only limited protection. The Royal Navy was woefully short of escorts. Air ptotection was virtually non existant. The Royal Navy had inadequate convoy escorts. The early Asdac could not determine depth providing little help in setting depth charges.
The fall of France provided the Germans Atlantic ports that they were denied in World War I and which greatly greatly incrased the effectiveness and striking power of the growing U-boat fleet. The U-boats could no longer be bottled up in the North Sea. Within days of the French surrender (June 22), Admiralm D�nitz was in France, surveying the Atlantic ports to privide facilitoes for his U-boats. The Germans set about building bomb-proff U-boat pens all along the French coast with direct access to the Atlantic. This provided D�nitz's U-boats a huge advantage that they did not have in World War I. These pens became major targets of RAF Bomber Command, but the facilities were so massive that the bombing had little affect. More effective was targeting transportation links to the pens. With the fall of France, the Royal Navy stood alone againt the German and Italian navies. The immediate naval concern was the French fleet, but U-boat access to the French ports would become a major factor in the critifal Battle of the Atlantic.
The effectiveness of the U-boats can be seen when President Roosevelt ordered took the extrodinary action of ordering the U.S. Navy into an undeclared naval war in the Atlantic months before the United State actually entered the war. Even so, Hitler did every thing he could to avoid incidents with the Americans in the Atlantic. He was intent on keeping America out of the war until he completed the conquest of the Soviet Union. His anger at having to do this was so intense that it is probably the primary reason that after the Japanese attack on Pearl Harbor that he so readily declared war on the United States.
The Japanese carrier attack on Pearl Harbor occurred at the same time that the Soviet Red Army staged a massive Winter counter-offensive before Moscow. Four days later Hitler declared war on America. Thus within a week, Barbarossa had failed deep in the Soviet Union and America was thrust into the War. Historians debate why Hitler having failed in the Soviet Union would declare war on America. No one will ever know, butthe frustation of holding back in the North Atlantic was surely a factor. Odering the U-boats to avoid firing on Anerican ships until the Red Army had been smashed, not only frustrated the U-boat commanders, but Hitler himself. His decesion was surely a way of striking out even thugh it made no sence. Hitler's instinctive response was to strike out at his enemies. It was often restrained by caculation. In this case his frutration caused him to throw away all caution and calculation. The U.S. Navy was unprepared for what followed and the British-hating Admiral King rejected the Royal Navy suggestion of instituting convoys. Unlike World War I, the United States coud not focus its naval power solely on the North Atlantic, it had to wage a twi ocean war. But unlike World War I, American participation in World War II allowed time for America to gear up its industry for war,. Existg shipyas were enlarged and new yards oened. And within a year a vast pnoply of new shis were being delivered to the Amercan and Allied navies and mercant marines. Even before the U-noat menace was defeated, American yards were delivering merchnt shiping faster thn the U-boats could sink them.
Admiral D�nitez after the declaration of War dispatched a U-boat force to the coast of America (December 1941). The U.S. Navy was unprepared. Naval planners did not expect an attack off the U.S. coast. There were no convoys at the time. The U-boats mostly attacked at night. City lights were kept on, coastal shipping used the lights. The lights also perfectly siloutted the American ships. The U-boats in particular focused on the tankers. The U-boats attacks began January 13 and achieved considerable success against the unprepared Americans. NAZI Propaganda Minister Josef Goebbels having to contend with the disater on the Eastern Front was delighted. He wrote in his diary, "WE have issued a special communiqu� to the effect that the German submarines have succeeded in sinking 125,000 tons of enemy shipping off the American Atlantic coast. That is an exceedingly good piece of news for the German people. It bears testimony to the tremendous activity of our submarines and their widely extendended radius of action, as well as to the fact that German heorism conquers even the widest oceans. At last a special bulletin! We certainly needed it, and it acts like rain on parched land. Everybody regards the communiqu� as a very effective answer to the warmonger Roosevelt, whom the whole German people curse. Many people are in a quandry as to whether they ought to hate him or Churchill more." [January 25, 1942--Goebbels, p. 45.] Notice that he does not mention Stalin. The Germans in 5 months succeeded in sinking around 400 merchant vessels and tankers--about 2.5 million GRT of shipping. All that damage was done with an incredibly small force, never more than 12 U-boats. Blimps, yachts, PT boats, and other vessels were deployed for coastal patrol. Amrican Naval commander Ernest King was not as committed to convoy as the British. This was especially the case because the Navy did not have sufficent escort vessels to both convoy troop ships and war equipment to Britain and to convoy coastal merchant vessels. The U.S. Navy in early 942 was also hard-pressed in the Pacific after Pearl Harbor. King finally decided that poorly defended convoys were worse than no convoys at all. While coastal shipping suffered, America did not lose troop ships to the U-boats. The U.S. Navy began organizing coastal convoys when more escort craft became available (May 1942), after which the attacks ceased.
The Battle of the Atlantic would be the decisive campaign waged by the Western Allies .The naval campaigns are often given superficial coverage in assessments of World War II in Europe. In fact, the most important battle of the War was the Battle of the Atlantic. Churchill was to write after the War that it was the the loss Battle of the Atlantic that was the only thing he feared. Battles could be lost or won, but the cutting of Britain's life lines to the Dominions and especially America would have made it impossible for Britain to have continued the War. It was no accident that Anglo-American military cooperation began in the North Atlantic well before America entered the War. Hitler on the other hnd gave lttle attention to the U-boat fleet until after the War began. Hitler and approved Plan-Z, a secret plan to prepare the Kriegsmarine for war with Britain by 1944. It involved the construction of seizemassive capital ships and two aircraft carriers. The Germans with U-boats, surface fleet, and long range aircraft hope to cut off Britain from its Empire and supply from the United States. Although neutral in the early years of the War, President Roosevelt was determine to support the Allies. A few days after the fall of France in 1940, a sjocked American Congress approvd the Naval Construction Act. The immediate impact of the fall of France in 1940 tremendosly increased the effectiveness of the German naval campaign, providing indespenseable French Atlantic ports. The Royal Navy had ben strongly depleted during the inter-war era by naval limitations traties. After France fell, the Royal Navy stood alone againt the German ans Italian navies. The Germans had a growing surface fleet and the Italian a fast modrn fleet that threatened to seize control of the Mediterannean. The the German u-boat operations proved highly effective, despite the fact that Hitler launched the War years beore the Kriegsmarine was prepared. Even before America entered the War, the U.S. Navy was deployed in the North Atlantic to protect British convoys. Anglo-American naval and scientific cooperaion resulted in the defeat of the u-boat campain by 1943. Combined with American construction of liberty ships, not only was Britain kept supplied, but America assembled a massive force of men and supplies in England that in 1944 was unleased on Hitler's Atlantic Wall.
The Battle of the Atlantic was of course a naval campaign, but there was an important air compnent to it. The Luftwaffe contributed small forces to the Battle of the Atlantic. Tghe Allies devoted much larger air forces. The British and susequently the Americans had coastal patrols to cover convoys. And air cover from islands such as Bermuda and Iceland covered ocean areas as well. The Destroyers for Bases deal gave the U.S. Navy additional facilities for ocean patrol. Allies like Brazil were also important. The Brazilians and American personnel in Brazil heped close the Atlantic Narrows. Long range American Catalinas and B-24 Liberators played important roles. The British got Catalinas even before America entered the War. It was an American Catalina with Americans part of the crew that found Bismarck. The U.S, Navy also used blimps. There was a substantial mid-ocean gap through 1943 where the convoys had no air cover. The Kriegsmarine after the fall of France (June 1940) rushed to open U-boat bases in French ports, including Accueil, Bordeaux, Brest, La Rochelle, L'Orient, and St. Nazaire. This greatly increased the striking power of the still fairly small U-boat fleet at the time. Operating from French ports meant that the lengthy trip back to German/Norwegian ports was no longer necessary. And by 1941 the number of U-boats was increasing substantially. The Luftwaffe attempted to support the U-boats by attacking convoys and ports. Here they had some success at attacking ports as part of the Blitz, but convoy attacks were limited by the small number of long-range bombers and British counter-measures like ship launched fighters. And the Luftwaffe was shifted east as part of the run up to Barbarossa (April 1941). Luftflotte 5 was more successful in attacks on the Arctic convoys. Germany did not have the industrial potential to build long-range bombers to attack the convoys and British ports in force. In contrast the Allies, especially the United States, did have the industrial capacity to build the aircraft needed for the Battle of the Atlantic. The Allies could not cover convoys with fleet carriers, but the innovation of jeep (small) carriers helped provide air cover for the convoys. Technical advances in radar (especially aircraft radar sets), sonar, and ASW weapons (including air dropped weapons) as well as code breaking forced D�nitz to withdraw his U-boats from the Atantic (July 1943). The U-boats were not completely withdrawn because a small number of U-boats forced the Allies to devote considerable resources to protecting the convoys. As the Luftwaffe was shifted east for Barbarossa and the Americans joined the British in the air war, the U-boat bases in France came under extensive attack. The U-boat pens thenmselves were hardened, but the rail lines leading to them were not. And Allied air patrols as radar and ASW weapons improved were able to attack the U-boats leaving and returning to these bases. The French bases despite the heavy bombardment continued to function until the D-Day landings and Allied breakout forced the Germans to withdraw (July 1944).
Admiral D�nitz's faced the combined forces of the British Royal Navy and the United States Navy an unenviable combination for any country, especially a country which began the War with only a small Navy. At the onset of the War the United states was neutral and France which had a substantial navy was allied with the British. The fall lf France knocked France out if the War and for about a year the Royal Navy was on its own against the growing U-boat threat. The U.S. Navy joined the fight, however, months before Pear Harbor and Hitler's declararion of war. Often ignored in the Battle of the Atlabtic is Canada's vital cintribution. Canada and the other Dominions joined the British at the onset of the War. After Dunkrk the Cananadian 1st Division was the only combat ready division availale to repel the expected German invasion. Canada at the time virtually did not have a navy. But in one if the most remarable developments of the War, Canada had already begun to build one of the largest navies in the world in terms of numbers of ships. The Canadian Navy would play a key role in escorting the vital North Atlantic convoys to Britain. There were also ships of the various occupied countries involved in the fight.
Science played a major role in World War II. And one of the most critical such effort was deployed in the North Atlantic by both Allied and German scientists. The Royal Navy and the U.S. Navy did very little work on ASW during the Inter-War Era. Many naval experts though that SONAR (ASDIC) developed during World War I had made submarines obsolete. And the Versailles Treaty prohibited the Germans from building submarines. Even when Britain agreed to allow the German Navy to have submarines in the Anglo-Germah Naval treaty (1935), the British made little effort to modernize ASW. And D�nitzhad worked on new tactics, emphasizing surface attacks. The sucess of German U-boats early in the War shocked the British and they began a major scientific effort to address the U-boat challenge (1939). When Churchill became primeminiter he made the decision to share Britain's weapons research with America which then joined Britain in the scientific effort (1940). America not only had a substantial scietific capability, but perhaps een more importantly, it had the industrial capacity to actually build the devices and weapons the scientists developed and build them in great quantities. Thus a group of some 100 British and American scientists set about perfecting the ideas that would defeat Admiral D�ntiz's vaunted Wolf Packs. Perhaps the most important of these scientists was British expeimental physicist Patrick Blackett, a committed Socialist and future Nobel Prize laurelate. He directed the Royal Navy's opperational research. Not only did he and his teams focus on the key problems, but they introduced the scientific approach to solving the many problems. He concentrated on basic mathematics and probability theory. Their unconventional insights were at first resisted by the Admiralty, but ultimately adopted. [Budiansky] German scientists were also deployed in the Battle of the Atlantic. The German scientists, however, labored under some major disadvantages. First, Hitler was most willing to devote resources to projects that gave him the ability to strike back at Britain and Anerica, such as the V weapons. Second, because the British and Americans controlled the seas, the German scientists with more resources were often operating in the dark. They were never sure just why their U-boats were being destroyed. All they knew was that a-boat failed to respond to radio signals. Thus the German scientists did not know precisely what Allied weapons they needed to counter. And some of their innovations actually made matters worse. Third, The German scientists did not have the resources to match the Anglo-American effort, especially after Hitler decided to make his major effort in the East. Grmany had achieved superiority in many areas because the Allied politicans were reluctant to massively increase military spending. The single most important Allkied scienticic development was radar sets in large numbers and small enough to be placed on esort ships and eventually aircraft.
Both the British and Germans worked on each others naval codes. The German naval code was one of the highest priorities of British code breakers at Blechly Park. The naval enigma machines proved more difficult to crack than the Wehrmacht and Luftwaffe enigmas. The Kriegsmarine was more security conscious. Codes were changed every month and security procedures wre very closely foilowed. Finally the Royal Navy succeeded in taking the German weather boat Munchen off Norway and with it code books (May 7, 1941). The next dy the Navy took the U-110 and with it a priceless enigma machine (May 8, 1941). The Germans were unaware of this and surprised with the U-boats begn to have trouble locating convoys. The Germans had been sinking an average of 58 merchant vessels monthly, but this fill to 17 in July 1941. The Germans 6 months later changed their enigma machines to include a third encryption wheel (November 1941). This change meant that the Blechley Park Ultra team could no longer read neaval nessages. Until the team again unraveled the emigma code, the Royal Navy was in the dark for much of 1942. It took Ultra code breakers 9 months to begin to read the Germn naval code agaun (July 1942). Eventually it was the Ultra decripts that helped the Allies locate the wolfpacks. This allowed naval authorities to route the convoys and to deploy hunter-killer groups. Ultra also helped located the milch-cow U-boats that helped the wolf-packs supplied. The Germans also worked on British naval codes. The British introduced Naval Cipher 3 (October 1941). The Germans managed to break the code in 3 months. At the height of the Battle of the Atlantic this provided D�nitz's U-boat fleet invaluable information.
The Battle of the Atlantic was finally decided with climatic convoy battles (May 1943). Allied naval escorts and aircraft with improving technology managed to destroy substantial numbers of U-boats during Wolf Pack attacks on convoys. The turning pount was ONS-5. The convoy manages to fight off the U-boat wolf packs with only a small escort force. Other losses occured during May and with expaned aerial covrage, the U-boat losses were unsustainable. D�nitz did not withdraw completely from the Atalantic. He calculted that a minor continued commitment would force the Allies to maintain major forces in the Atlantic. The Allies greatly expanded their air coverage, both long range aircraftnd escort catrriers. Both the Americns and British formed formidable hunter-killer groups. As Allied ASW capabilities continued to improve, many of the U-boas that did go out never returned. The hunter became the hunted. And Allied air patrols were no longer limited to visual spotting, but radar capable of oicking yo even a persisope. The U-boat service became the most dangerous service of the War. The last important opportunity that D�nitz's U-boats had to play in the War was the Allied cross-Channel invasion D-Day. The plan was once the invasion began that the U-boats would mass in the Channel and sink Allied shipping. The Landwirte Group of 36 U-boats was given the task of atttacking invasin shipping. Unlike the land forces, they did not need to know which landing beach and when. The U-boat effort, hwever, was a total failure. The Allied plugged both ends of the Chnnel with mines, destroyers abd escorts wth ASW capability, and aerial patrols--Operation Cork. As a result, very few U-boats broke into the Channel after D-Day. [Schofield] Few of the U-boats succeeded. There wwre a few successful attacks: HMS Blackwood, Columbine, SS Maid of Orleans, and a few smll ships. Several more ships were damaged. Given the Dimensions of the Allied naval force, the whole effort was ineffectual. The Germans worked on technical innovations of their own. They developed a stealth U-boat with ruberized coverings of the hull. The U-480 was fitted with this covring. It was effective, but developed too late to have any real impact. U-480 was sunk by a minefieldin the Channel laid as a result of Enigma decrypts (February 1945). By 1945, Allied ASW capabilities were so advanced that it was nearly a death sentence for a German crew to take a stabndard U-boat out on patrol in a standard U-boat. The Germans developed the Type-XXI Elektroboot. It had nmany advanhced features, but had a range of problems. And the Allied strategic bombing campaign delayed and complicated construction. Thus the few boats built never went out on a combat patrol. The primary use of the U-boats after D-day was to ship secret technology and enriched uranium to the Japanese. Rumors after the War circulated that U-boats were being used to help top NAZIs escape. There is no evidence of this. Until commiting suiside, Hitler was having people shot for admitting defeat. And there is no evidence that D�nitz facilitated the escape of any NAZI war criminal. The last U-boat sunk by the Allies was the U-3523, a Tyoe XXI. It was sunk by a British crewed B-24 Librator in Danish waters -- the Skagerrak Straits (May 6, 1945).
Ironically while the German U-boat campaign is one of the great legends of World War II, endlssly chronicled in film and literature, it was the Americans in the Pacific who waged the only successful submarine campaign--a stark example of what the Germans might have achieved. All of the other Allied campaigns in Europe were contingent on defeating the U-boats in the North Atlantic. American submariners often do not get the appreciation due. As Admiral Nimitz explained, it was the submarine force that held the line while America rebuilt its fleet. American submarines, however, were hampered by poor strategic and tactical concepts and ineffective torpedoes in 1942. The American submarines by 1943, however, began to significantly affect the delivery of raw materials to Japan. The American submarines targeted the Japanese merchant marine (maru) fleet. While the big fleet carriers got the headlines. The American submarines sunk over 50 percent of all Japanese vessels destroyed during the War. The Japanese merchant marine was almost completely destroyed, cutting the country's war industries off from supplies and bringing the country close to starvation by 1945. The American submarines did to Japan what the German u-boats tried to do to Britain. Surprisingly the Japanese submarine fleet had little impact on the Pacific campaign. Unlike the Americans, the Japanese began the War with the effective Type 93 Long-Lance Torpedo. The Japanese Navy never used their submarines to interdict American supply vessels. Rather they were used to target fighting ships with only limited success because of their tactical deployment. The Japanese used theor submarines as scouts and to targer warships. As the American offensive moved toward the Home Islands, the Japanese used their submarines to supply bypassed island garisons, some of which were near starvation. They were also used to supply bypassed islasnd bases where garrisons were close to starvation. They also managed to get some secret German military technology to Japan late in the war (1944).
Adm. D�nitz was indicted by the Internationa Military Tribunal (IMT) on Counts One, Two and Three. He was found innocent of count One, waging aggressive war. He of course did age aggressive war, but he was a soldier carrying out orders and not part of the NAZI cabal planning the war. He was found guilty of Counts Two anbd Three (2. Crimes Against Peace and 3. War Crimes). This essential anounted to conducting unresricted submarine warfare. This was contrary to the Naval Protocol of 1936 to which Germany acceded. The Protcol reaffirmed the rules of submarine warfare laid down in the London Naval Agreement of 1930. Now there is no doubt that D�nitz was guilty. And American and British officials played up the ruthlessmess of the German U-boat arm as they did in Wirld War I. It was German unrestricted submarime warfare that ultimately brought America into World War I. German U-boats in World War II did not have the same impact on the American public that it did in World War I. Most Americans eanted to stay out of World War II and U-boat sinkings did not change their mind, even when Presuident Roosevelt called them the 'Rattlesnakes of the Atlantic'. Obies an priopaganda depicted German U-boat crews machine gunning the srviviors of the ships sunk. U-boat commnders varied. Some were rdent NAZIs. Others were rdent nationalists, but not NAZis. At abny rate, D�nitz despite Hitler's instructions, never issued orders to machine-gun survivors. We have heard reports thahe destibuted gold watches take from Jewish victims of the Death Camps to to decrated U-boat officers, but cn niot yet confirm this. The biggest probklem for the procecution was the fact that the U.S. Navy conducted a sunmrine campign every bit as ruthless in the Pacific. Adm Nimitz wrote the IMT advisuing advising them of this.
Kaplan, Philip. Grey Wolves: The U-boat War 1939-45 (2014), 240p.
Schofield, Brian Betham. Operation Neptune (Casemate Publishers: 2008)/
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