U-boat

U-boat is an anglicised version of the German word U-Boot [ˈuːboːt] (listen), a shortening of Unterseeboot, literally "underseaboat." While the German term refers to any submarine, the English one (in common with several other languages) refers specifically to military submarines operated by Germany, particularly in the First and Second World Wars. Although at times they were efficient fleet weapons against enemy naval warships, they were most effectively used in an economic warfare role (commerce raiding) and enforcing a naval blockade against enemy shipping. The primary targets of the U-boat campaigns in both wars were the merchant convoys bringing supplies from Canada and other parts of the British Empire, and from the United States to the United Kingdom and (during the Second World War) to the Soviet Union and the Allied territories in the Mediterranean. German submarines also destroyed Brazilian merchant ships during World War II, causing Brazil to declare war on the Axis powers in 1944.

Austro-Hungarian navy submarines were also known as U-boats.

U995 2001 1
U-995, a typical U-boat

Early U-boats (1850–1914)

The first submarine built in Germany, the three-man Brandtaucher, sank to the bottom of Kiel harbor on 1 February 1851 during a test dive.[1][2] The inventor and engineer Wilhelm Bauer had designed this vessel in 1850, and Schweffel & Howaldt constructed it in Kiel. Dredging operations in 1887 rediscovered Brandtaucher; it was later raised and put on historical display in Germany.

There followed in 1890 the boats WW1 and WW2, built to a Nordenfelt design. In 1903 the Friedrich Krupp Germaniawerft dockyard in Kiel completed the first fully functional German-built submarine, Forelle,[3] which Krupp sold to Russia during the Russo-Japanese War in April 1904.[4] The SM U-1 was a completely redesigned Karp-class submarine and only one was built. The Imperial German Navy commissioned it on 14 December 1906.[5] It had a double hull, a Körting kerosene engine, and a single torpedo tube. The 50%-larger SM U-2 (commissioned in 1908) had two torpedo tubes. The U-19 class of 1912–13 saw the first diesel engine installed in a German navy boat. At the start of World War I in 1914, Germany had 48 submarines of 13 classes in service or under construction. During that war the Imperial German Navy used SM U-1 for training. Retired in 1919, it remains on display at the Deutsches Museum in Munich.[6]

World War I (1914–1918)

On 5 September 1914, HMS Pathfinder was sunk by SM U-21, the first ship to have been sunk by a submarine using a self-propelled torpedo. On 22 September, U-9 under the command of Otto Weddigen sank the obsolete British warships HMS Aboukir, HMS Cressy and HMS Hogue (the "Live Bait Squadron") in a single hour.

In the Gallipoli Campaign in early 1915 in the eastern Mediterranean, German U-boats, notably the U-21, prevented close support of allied troops by 18 pre-Dreadnought battleships by sinking two of them.[7]

For the first few months of the war, U-boat anticommerce actions observed the "prize rules" of the time, which governed the treatment of enemy civilian ships and their occupants. On 20 October 1914, SM U-17 sank the first merchant ship, the SS Glitra, off Norway.[8] Surface commerce raiders were proving to be ineffective, and on 4 February 1915, the Kaiser assented to the declaration of a war zone in the waters around the British Isles. This was cited as a retaliation for British minefields and shipping blockades. Under the instructions given to U-boat captains, they could sink merchant ships, even potentially neutral ones, without warning.

In February 1915, a submarine U-6 (Lepsius) was rammed and both periscopes were destroyed off Beachy Head by the collier SS Thordis commanded by Captain John Bell RNR after firing a torpedo.[9] On 7 May 1915, SM U-20 sank the liner RMS Lusitania. The sinking claimed 1,198 lives, 128 of them American civilians, and the attack of this unarmed civilian ship deeply shocked the Allies. According to the ship's manifest, Lusitania was carrying military cargo, though none of this information was relayed to the citizens of Britain and the United States who thought that the ship contained no ammunition or military weaponry whatsoever and it was an act of brutal murder. Munitions that it carried were thousands of crates full of ammunition for rifles, 3-inch artillery shells, and also various other standard ammunition used by infantry. The sinking of the Lusitania was widely used as propaganda against the German Empire and caused greater support for the war effort. A widespread reaction in the U.S was not seen until the sinking of the ferry SS Sussex. The sinking occurred in 1915 and the United States entered the war in 1917.

The initial U.S. response was to threaten to sever diplomatic ties, which persuaded the Germans to issue the Sussex pledge that reimposed restrictions on U-boat activity. The U.S. reiterated its objections to German submarine warfare whenever U.S. civilians died as a result of German attacks, which prompted the Germans to fully reapply prize rules. This, however, removed the effectiveness of the U-boat fleet, and the Germans consequently sought a decisive surface action, a strategy that culminated in the Battle of Jutland.

Although the Germans claimed victory at Jutland, the British Grand Fleet remained in control at sea. It was necessary to return to effective anticommerce warfare by U-boats. Vice-Admiral Reinhard Scheer, Commander in Chief of the High Seas Fleet, pressed for all-out U-boat war, convinced that a high rate of shipping losses would force Britain to seek an early peace before the United States could react effectively.

Willy Stöwer - Sinking of the Linda Blanche out of Liverpool
Sinking of the Linda Blanche out of Liverpool by SM U-21 (Willy Stöwer)

The renewed German campaign was effective, sinking 1.4 million tons of shipping between October 1916 and January 1917. Despite this, the political situation demanded even greater pressure, and on 31 January 1917, Germany announced that its U-boats would engage in unrestricted submarine warfare beginning 1 February. On 17 March, German submarines sank three American merchant vessels, and the U.S. declared war on Germany in April 1917.

Unrestricted submarine warfare in early 1917 was initially very successful, sinking a major part of Britain-bound shipping. With the introduction of escorted convoys, shipping losses declined and in the end the German strategy failed to destroy sufficient Allied shipping. An armistice became effective on 11 November 1918. Of the surviving German submarines 14 U-boats were scuttled and 122 surrendered[10].

Of the 373 German submarines that had been built, 178 were lost by enemy action. Of these 41 were sunk by mines, 30 by depth charges and 13 by Q-ships. 515 officers and 4894 enlisted men were killed. They sank 10 battleships, 18 cruisers and several smaller naval vessels. They further destroyed 5,708 merchant and fishing vessels for a total of 11,108,865 tons and the loss of about 15,000 sailors[11]. The Pour le Mérite, the highest decoration for gallantry for officers, was awarded to 29 U-boat commanders[12]. 12 U-boat crewmen were decorated with the Goldene Militär-Verdienst-Kreuz, the highest bravery award for non-commissioned officers and enlisted men[13]. The most successful U-boat commanders of World War I were Lothar von Arnauld de la Perière (189 merchant vessels and two gunboats with 446,708 tons), followed by Walter Forstmann (149 ships with 391,607 tons), and Max Valentiner (144 ships with 299,482 tons)[14]. Their records have never been surpassed by anyone in any later conflict so far.

Classes

Surrender of the fleet

Under the terms of armistice, all U-boats were to immediately surrender. Those in home waters sailed to the British submarine base at Harwich. The entire process was done quickly and in the main without difficulty, after which the vessels were studied, then scrapped or given to Allied navies. Stephen King-Hall wrote a detailed eyewitness account of the surrender.[15]

Interwar years (1919–1939)

The Treaty of Versailles ending World War I signed at the Paris Peace Conference in 1919 restricted the total tonnage of the German surface fleet. The treaty also restricted the independent tonnage of ships and forbade the construction of submarines. However, a submarine design office was set up in the Netherlands and a torpedo research program was started in Sweden. Before the start of World War II, Germany started building U-boats and training crews, labeling these activities as "research" or concealing them using other covers. When this became known, the Anglo-German Naval Agreement limited Germany to parity with Britain in submarines. When World War II started, Germany already had 65 U-boats, with 21 of those at sea, ready for war.

World War II (1939–1945)

During World War II, U-boat warfare was the major component of the Battle of the Atlantic, which began in 1939 and ended with Germany's surrender in 1945. The Armistice of November 11th, 1918 ending World War I had scuttled most of the old Imperial German Navy and the subsequent Treaty of Versailles of 1919 limited the surface navy of Germany's new Weimar Republic to only six battleships (of less than 10,000 tons each), six cruisers, and 12 destroyers. To compensate, Germany's new navy, the Kriegsmarine, developed the largest submarine fleet going into World War II.[16] British Prime Minister Winston Churchill later wrote "The only thing that really frightened me during the war was the U-boat peril."

In the early stages of the war the U-boats were extremely effective in destroying Allied shipping due to the large gap in mid-Atlantic air cover. Cross-Atlantic trade in war supplies and food was extensive and critical for Britain's survival. The continuous action surrounding British shipping became known as the Battle of the Atlantic, as the British developed technical defences such as ASDIC and radar, and the German U-boats responded by hunting in what were called "wolfpacks" where multiple submarines would stay close together, making it easier for them to sink a specific target. Britain's vulnerable shipping situation existed until 1942, when the tides changed as the U.S. merchant marine and Navy entered the war, drastically increasing the amount of tonnage of supplies sent across the Atlantic. The combination of increased tonnage and increased naval protection of shipping convoys made it much more difficult for U-boats to make a significant dent in British shipping. Once the United States entered the war, U-boats ranged from the Atlantic coast of the United States and Canada to the Gulf of Mexico, and from the Arctic to the west and southern African coasts and even as far east as Penang. The U.S. military engaged in various tactics against German incursions in the Americas; these included military surveillance of foreign nations in Latin America, particularly in the Caribbean, to deter any local governments from supplying German U-boats.

Because speed and range were severely limited underwater while running on battery power, U-boats were required to spend most of their time surfaced running on diesel engines, diving only when attacked or for rare daytime torpedo strikes. The more ship-like hull design reflects the fact that these were primarily surface vessels that could submerge when necessary. This contrasts with the cylindrical profile of modern nuclear submarines, which are more hydrodynamic underwater (where they spend the majority of their time), but less stable on the surface. While U-boats were faster on the surface than submerged, the opposite is generally true of modern submarines. The most common U-boat attack during the early years of the war was conducted on the surface and at night. This period, before the Allied forces developed truly effective antisubmarine warfare tactics, which included convoys, was referred to by German submariners as "die glückliche Zeit" or The First Happy Time[17]

U534
U-534, Birkenhead Docks, Merseyside, England

Torpedoes

The U-boats' main weapon was the torpedo, though mines and deck guns (while surfaced) were also used. By the end of the war, almost 3,000 Allied ships (175 warships; 2,825 merchant ships) were sunk by U-boat torpedoes.[18] Early German World War II torpedoes were straight runners, as opposed to the homing and pattern-running torpedoes that were fielded later in the war. They were fitted with one of two types of pistol triggers: impact, which detonated the warhead upon contact with a solid object, and magnetic, which detonated upon sensing a change in the magnetic field within a few meters.

One of the most effective uses of magnetic pistols would be to set the torpedo's depth to just beneath the keel of the target. The explosion under the target's keel would create a detonation shock wave, which could cause a ship's hull to rupture under the concussive water pressure. In this way, even large or heavily armored ships could be sunk or disabled with a single, well-placed hit.

Initially the depth-keeping equipment and magnetic and contact exploders were notoriously unreliable. During the first eight months of the war torpedoes often ran at an improper depth, detonated prematurely, or failed to explode altogether—sometimes bouncing harmlessly off the hull of the target ship. This was most evident in Operation Weserübung, the invasion of Norway, where various skilled U-boat commanders failed to inflict damage on British transports and warships because of faulty torpedoes. The faults were largely due to a lack of testing. The magnetic detonator was sensitive to mechanical oscillations during the torpedo run, and to fluctuations in the Earth's magnetic field at high latitudes. These early magnetic detonators were eventually phased out, and the depth-keeping problem was solved by early 1942 with improved technology.[19]

Later in the war, Germany developed an acoustic homing torpedo, the G7/T5. It was primarily designed to combat convoy escorts. The acoustic torpedo was designed to run straight to an arming distance of 400 m and then turn toward the loudest noise detected. This sometimes ended up being the U-boat itself; at least two submarines may have been sunk by their own homing torpedoes. Additionally, these torpedoes were found to be only effective against ships moving at greater than 15 knots (28 km/h). The Allies countered acoustic torpedoes with noisemaker decoys such as Foxer, FXR, CAT and Fanfare. The Germans, in turn, countered this by introducing newer and upgraded versions of the acoustic torpedoes, like the late-war G7es, and the T11. However, the T11 did not see active service.[20]

U-boats also adopted several types of "pattern-running" torpedoes that ran straight out to a preset distance, then traveled in either a circular or ladder-like pattern. When fired at a convoy, this increased the probability of a hit if the weapon missed its primary target.

U-boat developments

During World War II, the Kriegsmarine produced many different types of U-boats as technology evolved. Most notable is the Type VII, known as the "workhorse" of the fleet, which was by far the most-produced type, and the Type IX boats, an enlarged VII designed for long-range patrols, some traveling as far as Japan and the east coast of the United States.

With the increasing sophistication of Allied detection and subsequent losses, German designers began to fully realise the potential for a truly submerged boat. The Type XXI "Elektroboot" was designed to favor submerged performance, both for combat effectiveness and survival. It was the first true submersible. The Type XXI featured an evolutionary design that combined several different strands of the U-Boat development program, most notably from the Walter U-boats, the Type XVII, which featured an unsuccessful yet revolutionary hydrogen peroxide air-independent propellant system. These boats featured a streamlined hull design, which formed the basis of the later USS Nautilus nuclear submarine, and was adapted for use with more conventional propulsion systems. The larger hull design allowed for a greatly increased battery capacity, which enabled the XXI to cruise submerged for longer periods and reach unprecedented submerged speeds for the time.

Throughout the war, an arms race evolved between the Allies and the Kriegsmarine, especially in detection and counterdetection. Sonar (ASDIC in Britain) allowed Allied warships to detect submerged U-boats (and vice versa) beyond visual range, but was not effective against a surfaced vessel; thus, early in the war, a U-boat at night or in bad weather was actually safer on the surface. Advancements in radar became particularly deadly for the U-boat crews, especially once aircraft-mounted units were developed. As a countermeasure, U-boats were fitted with radar warning receivers, to give them ample time to dive before the enemy closed in, as well as more anti aircraft guns. However, by early to mid-1943, the Allies switched to centimetric radar (unknown to Germany), which rendered the radar detectors ineffective. U-boat radar systems were also developed, but many captains chose not to use them for fear of broadcasting their position to enemy patrols and lack of sufficient electronic countermeasures.

Early on, the Germans experimented with the idea of the Schnorchel (snorkel) from captured Dutch submarines, but saw no need for them until rather late in the war. The Schnorchel was a retractable pipe that supplied air to the diesel engines while submerged at periscope depth, allowing the boats to cruise and recharge their batteries while maintaining a degree of stealth. It was far from a perfect solution, however. Problems occurred with the device's valve sticking shut or closing as it dunked in rough weather; since the system used the entire pressure hull as a buffer, the diesels would instantaneously suck huge volumes of air from the boat's compartments, and the crew often suffered painful ear injuries. Waste disposal was a problem when the U-boats spent extended periods without surfacing, as it is today. Speed was limited to 8 knots (15 km/h), lest the device snap from stress. The Schnorchel also had the effect of making the boat essentially noisy and deaf in sonar terms. Finally, Allied radar eventually became sufficiently advanced that the Schnorchel mast could be detected beyond visual range.

Several other pioneering innovations included acoustic- and electro-absorbent coatings to make them less of an ASDIC or RADAR target. The Germans also developed active countermeasures such as facilities to release artificial chemical bubble-making decoys, known as Bold, after the mythical kobold.

Classes

Countermeasures

Advances in convoy tactics, high-frequency direction finding (referred to as "Huff-Duff"), radar, active sonar (called ASDIC in Britain), depth charges, ASW spigot mortars (also known as "hedgehog"), the intermittent cracking of the German Naval Enigma code, the introduction of the Leigh light, the range of escort aircraft (especially with the use of escort carriers), the use of mystery ships, and the full entry of the U.S. into the war with its enormous shipbuilding capacity, all turned the tide against the U-boats. In the end, the U-boat fleet suffered extremely heavy casualties, losing 793 U-boats and about 28,000 submariners (a 75% casualty rate, the highest of all German forces during the war).

Uboat sinking survivors
Survivors from German submarine U-175 after being sunk by USCGC Spencer, 17 April 1943

At the same time, the Allies targeted the U-boat shipyards and their bases with strategic bombing.

Enigma machine

The British had a major advantage in their ability to read some German naval Enigma codes. An understanding of the German coding methods had been brought to Britain via France from Polish code-breakers. Thereafter, code books and equipment were captured by raids on German weather ships and from captured U-boats. A team including Alan Turing used special purpose "Bombes" and early computers to break new German codes as they were introduced. The speedy decoding of messages was vital in directing convoys away from wolf packs and allowing interception and destruction of U-boats. This was demonstrated when the Naval Enigma machines were altered in February 1942 and wolf-pack effectiveness greatly increased until the new code was broken.

The German submarine U-110, a Type IXB, was captured in 1941 by the Royal Navy, and its Enigma machine and documents were removed. U-559 was also captured by the British in October 1942; three sailors boarded her as she was sinking, and desperately threw all the code books out of the submarine so as to salvage them. Two of them, Able Seaman Colin Grazier and Lieutenant Francis Anthony Blair Fasson, continued to throw code books out of the ship as it went under water, and went down with it. Further code books were captured by raids on weather ships. U-744 was boarded by crew from the Canadian ship HMCS Chilliwack on 6 March 1944, and codes were taken from her, but by this time in the war, most of the information was known.[22] The U-505, a Type IXC, was captured by the United States Navy in June 1944. It is now a museum ship in Chicago at the Museum of Science and Industry.

Battle of Bell Island

Two events in the battle took place in 1942 when German U-boats attacked four allied ore carriers at Bell Island, Newfoundland. The carriers SS Saganaga and SS Lord Strathcona were sunk by U-513 on 5 September 1942, while the SS Rosecastle and PLM 27 were sunk by U-518 on 2 November with the loss of 69 lives. When the submarine launched a torpedo at the loading pier, Bell Island became the only location in North America to be subject to direct attack by German forces in World War II.

Operation Deadlight

"Operation Deadlight" was the code name for the scuttling of U-boats surrendered to the Allies after the defeat of Germany near the end of the war. Of the 154 U-boats surrendered, 121 were scuttled in deep water off Lisahally, Northern Ireland, or Loch Ryan, Scotland, in late 1945 and early 1946.

Memorial

Möltenort U-Boat Memorial

Post–World War II and Cold War (after 1945)

U15 Kieler Woche 2007 1
U-15, a Type 206 submarine, of the German Navy at the Kiel Week 2007
U Boot 212 HDW 1
Type 212 submarine with air-independent propulsion of the German Navy in dock at HDW/Kiel

From 1955, the West German Bundesmarine was allowed to have a small navy. Initially two sunken Type XXIIIs and a Type XXI were raised and repaired. In the 1960s, the Federal Republic of Germany (West Germany) re-entered the submarine business. Because West Germany was initially restricted to a 450 tonne displacement limit, the Bundesmarine focused on small coastal submarines to protect against the Soviet Union (Russian) threat in the Baltic Sea. The Germans sought to use advanced technologies to offset the small displacement, such as amagnetic steel to protect against naval mines and magnetic anomaly detectors.

The initial Type 201 was a failure because of hull cracking; the subsequent Type 205, first commissioned in 1967, was a success, and 12 were built for the German navy. To continue the U-boat tradition, the new boats received the classic U designation starting with the U-1.

With the Danish government's purchase of two Type 205 boats, the West German government realized the potential for the submarine as an export. Three of the improved Type 206 boats were later sold to the Israeli Navy, becoming the Gal-class. The German Type 209 diesel-electric submarine was the most popular export-sales submarine in the world from the late 1960s into the first years of the 21st century. With a larger 1,000–1,500 tonne displacement, the class was very customizable and has seen service with 14 navies with 51 examples being built as of 2006.

Germany has brought the U-boat name into the 21st century with the new Type 212. The 212 features an air-independent propulsion system using hydrogen fuel cells. This system is safer than previous closed-cycle diesel engines and steam turbines, cheaper than a nuclear reactor and quieter than either. While the Type 212 is also being purchased by Italy, the Type 214 has been designed as the follow-on export model and has been sold to Greece, South Korea and Turkey.

In July 2006, Germany commissioned its newest U-boat, the U-34, a Type 212.

See also

References

  1. ^ Showell, p. 23
  2. ^ Compare: Chaffin, Tom (2010). The H. L. Hunley: The Secret Hope of the Confederacy. Macmillan. p. 53. ISBN 9781429990356. Retrieved 2016-07-14. Bauer's boat made a promising start, diving in tests in the Baltic Sea's Bay of Kiel to depths of more than fifty feet. In 1855, during one of those tests, the boat malfunctioned. The Brandtaucher plunged fifty-four vertical feet and refused to ascend from the seafloor. Bauer and his crew – leaving their craft on the bottom – barely escaped with their lives.
  3. ^ Showell, p. 201
  4. ^ Showell, pp. 22, 23, 25, 29
  5. ^ Showell, p. 30
  6. ^ Showell, pp. 36 & 37
  7. ^ "Archived copy". Archived from the original on 27 December 2008. Retrieved 2 November 2008.
  8. ^ "WWI U-Boats U-17". Uboat.net. Retrieved 2008-03-24.
  9. ^ Haley Dixon (21 June 2013). "Story of Captain's courage resurfaces after 98 years". Daily Telegraph. Retrieved 22 June 2013.
  10. ^ Micheal Clodfelter, Warfare and Armed Conflicts: A Statistical Encyclopedia of Casualty and Other Figures, 1492–2015, 4th ed., McFarland, 2017, p. 428
  11. ^ Micheal Clodfelter, Warfare and Armed Conflicts: A Statistical Encyclopedia of Casualty and Other Figures, 1492–2015, 4th ed., McFarland, 2017, p. 428
  12. ^ https://uboat.net/wwi/men/decorations/2.html
  13. ^ Bruno Fischer, Ehrenbuch des Orden vom Militär-Verdienst-Kreuz e.V. und die Geschichte der Ordens-Gemeinschaft, Die Ordens-Sammlung, 1960, p. 16
  14. ^ https://uboat.net/wwi/men/commanders/most_successful.html
  15. ^ "Full text of "A North Sea diary, 1914–1918 / Commander Stephen King-Hall"".
  16. ^ Hakim, Joy (1998). A History of Us: War, Peace and all that Jazz. New York: Oxford University Press. pp. 100–104. ISBN 0-19-509514-6.
  17. ^ Military History Online
  18. ^ Crocker III, H. W. (2006). Don't Tread on Me. New York: Crown Forum. p. 310. ISBN 978-1-4000-5363-6.
  19. ^ Karl Dönitz. Memoirs: Ten Years and Twenty Days. Naval Institute Press. p. 482. ISBN 0-87021-780-1.
  20. ^ "The Torpedoes".
  21. ^ Stern, Robert Cecil (1991). Type VII U-boats (First U.S. & Canada ed.). Annapolis, Maryland 21402: Naval Institute Press. p. 155. ISBN 1-55750-828-3. Retrieved 1 January 2019.
  22. ^ Helgason, Gudmundur "Captured U Boats" UBoat.Net http://uboat.net/fates/captured.htm

Further reading

  • John Abbatiello. Anti-Submarine Warfare in World War I: British Naval Aviation and the Defeat of the U-Boats (2005)
  • Buchheim, Lothar-Günther, Das Boot (original German edition 1973, eventually translated into English and many other Western languages). Movie adaptation in 1981, directed by Wolfgang Petersen
  • Gannon, Michael (1998) Black May. Dell Publishing. ISBN 0-440-23564-2
  • Gannon, Michael (1990) Operation Drumbeat. Naval Institute Press. ISBN 978-1-59114-302-4
  • Gray, Edwyn A. The U-Boat War, 1914–1918 (1994)
  • Hans Joachim Koerver. German Submarine Warfare 1914–1918 in the Eyes of British Intelligence, LIS Reinisch 2010, ISBN 978-3-902433-79-4
  • Kurson, Robert (2004). Shadow Divers: The True Adventure of Two Americans Who Risked Everything to Solve One of the Last Mysteries of World War II. Random House Publishing. ISBN 0-375-50858-9
  • Möller, Eberhard and Werner Brack. The Encyclopedia of U-Boats: From 1904 to the Present (2006) ISBN 1-85367-623-3
  • O'Connor, Jerome M. "Inside the Grey Wolves' Den." Naval History, June 2000. The US Naval Institute Author of the Year feature describes the building and operation of the German U-boat bases in France.
  • Preston, Anthony (2005). The World's Greatest Submarines.
  • Stern, Robert C. (1999). Battle Beneath the Waves: U-boats at war. Arms and Armor/Sterling Publishing. ISBN 1-85409-200-6.
  • Showell, Jak Mallmann. The U-boat Century: German Submarine Warfare, 1906–2006 (2006) ISBN 1-59114-892-8
  • van der Vat, Dan. The Atlantic Campaign. Harper & Row, 1988. Connects submarine and antisubmarine operations between World War I and World War II, and suggests a continuous war.
  • Von Scheck, Karl. U122: The Diary of a U-boat Commander. Diggory Press ISBN 978-1-84685-049-3
  • Georg von Trapp and Elizabeth M. Campbell. To the Last Salute: Memories of an Austrian U-Boat Commander (2007)
  • Westwood, David. U-Boat War: Doenitz and the evolution of the German Submarine Service 1935–1945 (2005) ISBN 1-932033-43-2
  • Werner, Herbert. Iron Coffins: A Personal Account of the German U-Boat Battles of World War II ISBN 978-0-304-35330-9

External links

11th U-boat Flotilla

The 11th U-boat Flotilla (German 11. Unterseebootsflottille) was formed on 15 May 1942 in Bergen, Norway. The flotilla operated mainly in the North Sea and against the Russian convoys (JW-, PQ-, QP- and RA series) in the Arctic Sea. The flotilla operated various marks of the Type VII U-boat until September 1944, when it had an influx of some Type IX boats from France. It also was the only flotilla to field the Type XXI U-boat for operational use, but the war ended before U-2511 saw action. The Flotilla was disbanded on 9 May 1945 with the German surrender.

4th U-boat Flotilla

The 4th U-boat Flotilla (German 4. Unterseebootsflottille) was formed in May 1941 in Stettin under the command of Kapitänleutnant Werner Jacobsen. The flotilla was a training flotilla and nearly 300 boats received their basic training. The flotilla was disbanded in May 1945.

5th U-boat Flotilla

The 5th U-boat Flotilla (German 5. Unterseebootsflottille), also known as Emsmann Flotilla, was a U-boat flotilla of Nazi Germany's Kriegsmarine during World War II.

The flotilla was formed in December 1938 in Kiel under the command of Korvettenkapitän Hans-Rudolf Rösing. It was named in honour of Oberleutnant zur See Hans Joachim Emsmann, a U-boat commander during World War I, who died on 28 October 1918 after his U-boat UB-116 was sunk by a mine. The flotilla was disbanded in January 1940 and the boats were all transferred to 1st Flotilla.

The flotilla was re-formed as "5th U-boat Flotilla" in June 1941 under the command of Kapitänleutnant Karl-Heinz Moehle as a training flotilla with her base in Kiel. In 1946 Moehle was sentenced to five years in prison, after being found guilty of passing the Laconia Order to new U-boat commanders before they went out on patrol. He was released in November 1949.

7th U-boat Flotilla

The 7th U-boat Flotilla (German 7. Unterseebootsflottille), also known as Wegener Flotilla, was the seventh operational U-boat combat unit in Nazi Germany's Kriegsmarine. Founded on June 25, 1938, under the command of Korvettenkapitän Werner Sobe, it was named in honour of Kapitänleutnant Bernd Wegener. Wegener, a U-boat commander during World War I, died on August 19, 1915, after his submarine U-27 was sunk by British Q-ship HMS Baralong, which was an atrocity and war crime itself.

The flotilla, under the name "Wegener Flotilla", was founded in Kiel in June 1938. In September 1940, the flotilla left its base in Kiel and moved to St. Nazaire in France. After the change in location, the flotilla was renamed "7th U-boat Flotilla".

This flotilla had one of the most famous emblems from World War II. The "snorting bull" emblem was first used by U-47, which is famous for sinking the British battleship HMS Royal Oak in October 1939. The emblem, based on a picture seen in a comic book, was adopted by the flotilla while based in St. Nazaire.

8th U-boat Flotilla

The 8th U-boat Flotilla (German 8. Unterseebootsflottille) was formed in June 1941 in Königsberg under the command of Kapitänleutnant Georg-Wilhelm Schulz, who also at this time commanded the 6th U-boat Flotilla in Danzig. It was primarily a training flotilla but in the last months of the war some flotilla boats were in combat against the Soviet Navy in the Baltic Sea. The flotilla was disbanded in January 1945.

Atlantic U-boat campaign of World War I

The Atlantic U-boat campaign of World War I (sometimes called the "First Battle of the Atlantic", in reference to the World War II campaign of that name) was the prolonged naval conflict between German submarines and the Allied navies in Atlantic waters—the seas around the British Isles, the North Sea and the coast of France.

Initially the U-boat campaign was directed against the British Grand Fleet. Later U-boat fleet action was extended to include action against the trade routes of the Allied powers. This campaign was highly destructive, and resulted in the loss of nearly half of Britain's merchant marine fleet during the course of the war. To counter the German submarines, the Allies moved shipping into convoys guarded by destroyers, blockades such as the Dover Barrage and minefields were laid, and aircraft patrols monitored the U-boat bases.

The U-boat campaign was not able to cut off supplies before the US entered the war in 1917 and in later 1918, the U-boat bases were abandoned in the face of the Allied advance.

The tactical successes and failures of the Atlantic U-boat Campaign would later be used as a set of available tactics in World War II in a similar U-boat war against the British Empire.

Battle of the Atlantic

The Battle of the Atlantic was the longest continuous military campaign in World War II, running from 1939 to the defeat of Germany in 1945, and was a major part of the Naval history of World War II. At its core was the Allied naval blockade of Germany, announced the day after the declaration of war, and Germany's subsequent counter-blockade. It was at its height from mid-1940 through to the end of 1943.

The Battle of the Atlantic pitted U-boats and other warships of the Kriegsmarine (Navy) and aircraft of the Luftwaffe (Air Force) against the Royal Canadian Navy, Royal Navy, United States Navy, and Allied merchant shipping. Convoys, coming mainly from North America and predominantly going to the United Kingdom and the Soviet Union, were protected for the most part by the British and Canadian navies and air forces. These forces were aided by ships and aircraft of the United States beginning September 13, 1941. The Germans were joined by submarines of the Italian Royal Navy (Regia Marina) after their Axis ally Italy entered the war on June 10, 1940.

As an island nation, the United Kingdom was highly dependent on imported goods. Britain required more than a million tons of imported material per week in order to be able to survive and fight. In essence, the Battle of the Atlantic was a tonnage war: the Allied struggle to supply Britain and the Axis attempt to stem the flow of merchant shipping that enabled Britain to keep fighting. From 1942 onward, the Axis also sought to prevent the build-up of Allied supplies and equipment in the British Isles in preparation for the invasion of occupied Europe. The defeat of the U-boat threat was a prerequisite for pushing back the Axis. The outcome of the battle was a strategic victory for the Allies—the German blockade failed—but at great cost: 3,500 merchant ships and 175 warships were sunk in the Atlantic for the loss of 783 U-boats (the majority being Type VII submarines) and 47 German surface warships, including 4 battleships (Scharnhorst, Bismarck, Gneisenau, and Tirpitz), 9 cruisers, 7 raiders, and 27 destroyers. Of the U-boats, 519 were sunk by British, Canadian, or other allied forces, while 175 were destroyed by American forces; 15 were destroyed by Soviets and 73 were scuttled by their crews before the end of the war for various causes.The Battle of the Atlantic has been called the "longest, largest, and most complex" naval battle in history. The campaign started immediately after the European war began, during the so-called "Phoney War", and lasted six years, until the German Surrender in May 1945. It involved thousands of ships in more than 100 convoy battles and perhaps 1,000 single-ship encounters, in a theatre covering millions of square miles of ocean. The situation changed constantly, with one side or the other gaining advantage, as participating countries surrendered, joined and even changed sides in the war, and as new weapons, tactics, counter-measures and equipment were developed by both sides. The Allies gradually gained the upper hand, overcoming German surface raiders by the end of 1942 and defeating the U-boats by mid-1943, though losses due to U-boats continued until the war's end.

Das Boot

Das Boot (German pronunciation: [das ˈboːt], German: "The Boat") is a 1981 German submarine film written and directed by Wolfgang Petersen, produced by Günter Rohrbach, and starring Jürgen Prochnow, Herbert Grönemeyer, and Klaus Wennemann. It has been exhibited both as a theatrical release and as a TV miniseries (1985), in several different home video versions of various running times, and in a director's cut version supervised by Petersen in 1997.

An adaptation of Lothar-Günther Buchheim's 1973 German novel of the same name, the film is set during World War II and follows German U-boat U-96 and its crew, as they set out on a hazardous patrol in the Battle of the Atlantic. It depicts both the excitement of battle and the tedium of the fruitless hunt, and shows the men serving aboard U-boats as ordinary individuals with a desire to do their best for their comrades and their country.

Development began in 1979. Several American directors were considered three years earlier before the film was shelved. During production, Heinrich Lehmann-Willenbrock, the captain of the real U-96 and one of Germany's top U-boat "tonnage aces" during the war, and Hans-Joachim Krug, former first officer on U-219, served as consultants. One of Petersen's goals was to guide the audience through "a journey to the edge of the mind" (the film's German tagline Eine Reise ans Ende des Verstandes), showing "what war is all about".

Produced with a budget of 32 million DM (about $18.5 million), the film's high production cost ranks it among the most expensive films in the history of German cinema. It was the second most expensive up until that time, after Metropolis. The film enjoyed financial success and grossed over $80 million worldwide. Columbia Pictures released both a German version and an English-dubbed version in the United States theatrically, but the film's German version actually grossed much higher than the English-dubbed version at the United States box office. The film received highly positive reviews and was nominated for six Academy Awards, two of which (for Best Director and Best Adapted Screenplay) went to Petersen himself; he was also nominated for a BAFTA Award and DGA Award. Today, the film is seen as one of the greatest of all German films.

German submarine U-505

U-505 is a German Type IXC U-boat built for Germany's Kriegsmarine during World War II. She was captured by the U.S. Navy on 4 June 1944.

In her uniquely unlucky career with the Kriegsmarine, she had the distinction of being the "most heavily damaged U-boat to successfully return to port" in World War II (on her fourth patrol) and the only submarine in which a commanding officer took his own life in combat conditions (on her tenth patrol, following six botched patrols).She was one of six U-boats that were captured by Allied forces during World War II. She was captured on 4 June 1944 by United States Navy Task Group 22.3 (TG 22.3). All but one of U-505's crew were rescued by the Navy task group. The submarine was towed to Bermuda in secret and her crew was interned at a US prisoner-of-war camp where they were denied access to International Red Cross visits. The Navy classified the capture as top secret and prevented its discovery by the Germans. Her codebooks, Enigma machine, and other secret materials found on board helped the Allied codebreakers.In 1954, U-505 was donated to the Museum of Science and Industry in Chicago, Illinois. She is now one of four German World War II U-boats that survive as museum ships, and, along with U-534, just one of two Type IXCs still in existence.

German submarine U-625

U-625 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II. The submarine was laid down on 28 July 1941 at the Blohm & Voss yard in Hamburg, launched on 15 April 1942, and commissioned on 4 June 1942 under the command of Oberleutnant zur See Hans Benker.

After training with 8th U-boat Flotilla, U-625 was transferred to 3rd U-boat Flotilla for front-line service on 1 October 1942. She was soon transferred again, to 11th U-boat Flotilla on 1 November 1942, then again to 13th U-boat Flotilla on 1 June 1943, and finally to 1st U-boat Flotilla on 1 November 1943.

U-625 completed nine patrols, torpedoed three merchant ships, and sank two auxiliary warships with mines. The boat was sunk on 10 March 1944 off the west coast of Ireland by depth charges from a Canadian Sunderland patrol bomber EK591 "2U" from No. 422 Squadron RCAF.

German submarine U-96 (1940)

German submarine U-96 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II. Her keel was laid down on 16 September 1939, by Germaniawerft, of Kiel as yard number 601. She was commissioned on 14 September 1940, with Kapitänleutnant Heinrich Lehmann-Willenbrock in command. Lehmann-Willenbrock was relieved in March 1942 by Oberleutnant zur See Hans-Jürgen Hellriegel, who was relieved in turn in March 1943 by Oblt.z.S. Wilhelm Peters. In February 1944, Oblt.z.S. Horst Willner took command, turning the boat over to Oblt.z.S. Robert Rix in June of that year. Rix commanded the boat until February 1945. During 1941, war correspondent Lothar-Günther Buchheim joined U-96 for a single patrol.

German submarine U-977

German submarine U-977 was a World War II Type VIIC U-boat of Nazi Germany's Kriegsmarine which escaped to Argentina after Germany's surrender. The submarine's voyage to Argentina led to many legends, apocryphal stories and conspiracy theories that together with U-530 it had transported escaping Nazi leaders (including Adolf Hitler himself) and/or Nazi gold to South America, that it had made a 66-day passage without surfacing, that it had made a secret voyage to Antarctica, or even that it would be involved in the sinking of Brazilian cruiser Bahia as the last act of the Battle of the Atlantic.

Karl Dönitz

Karl Dönitz (sometimes spelled Doenitz German: [ˈdøːnɪts] (listen); 16 September 1891 – 24 December 1980) was a German admiral who played a major role in the naval history of World War II. Dönitz briefly succeeded Adolf Hitler as the head of state of Nazi Germany.

He began his career in the Imperial German Navy before World War I. In 1918, he was commanding UB-68 when she was sunk by British forces. Dönitz was taken prisoner. While in a prisoner of war camp, he formulated what he later called Rudeltaktik ("pack tactic", commonly called "wolfpack"). At the start of World War II, he was the senior submarine officer in the Kriegsmarine. In January 1943, Dönitz achieved the rank of Großadmiral (grand admiral) and replaced Grand Admiral Erich Raeder as Commander-in-Chief of the Navy.

On 30 April 1945, after the death of Adolf Hitler and in accordance with Hitler's last will and testament, Dönitz was named Hitler's successor as head of state, with the title of President of Germany and Supreme Commander of the Armed Forces. On 7 May 1945, he ordered Alfred Jodl, Chief of Operations Staff of the OKW, to sign the German instruments of surrender in Reims, France. Dönitz remained as head of the Flensburg Government, as it became known, until it was dissolved by the Allied powers on 23 May.

Despite his postwar claims, Dönitz was seen as supportive of Nazism during the war, and he is known to have made a number of anti-Semitic statements. Following the war, Dönitz was indicted as a major war criminal at the Nuremberg Trials on three counts: (1) conspiracy to commit crimes against peace, war crimes, and crimes against humanity; (2) planning, initiating, and waging wars of aggression; and (3) crimes against the laws of war. He was found not guilty on count (1) of the indictment, but guilty on counts (2) and (3). He was sentenced to ten years' imprisonment; after his release, he lived in a village near Hamburg until his death in 1980. For nearly seven decades, Dönitz was the only head of state to be convicted by an international tribunal until the conviction of Liberia's Charles Taylor in April 2012.

Submarine pen

A submarine pen (U-Boot-Bunker in German) is a type of submarine base that acts as a bunker to protect submarines from air attack. The term is generally applied to submarine bases constructed during World War II, particularly in Germany and its occupied countries, which were also known as U-boat pens (after the phrase "U-boat" to refer to German submarines).

Type II submarine

The Type II U-boat was designed by Nazi Germany as a coastal U-boat, modeled after the CV-707 submarine, which was designed by the Dutch dummy company NV Ingenieurskantoor voor Scheepsbouw den Haag (I.v.S) (set up by Germany after World War I in order to maintain and develop German submarine technology and to circumvent the limitations set by the Treaty of Versailles) and built in 1933 by the Finnish Crichton-Vulcan shipyard in Turku, Finland. It was too small to undertake sustained operations far away from the home support facilities. Its primary role was found to be in the training schools, preparing new German naval officers for command. It appeared in four sub-types.

Type IX submarine

The Type IX U-boat was designed by Nazi Germany's Kriegsmarine in 1935 and 1936 as a large ocean-going submarine for sustained operations far from the home support facilities. Type IX boats were briefly used for patrols off the eastern United States in an attempt to disrupt the stream of troops and supplies bound for Europe. It was derived from the Type IA, and appeared in various sub-types.

Type IXs had six torpedo tubes; four at the bow and two at the stern. They carried six reloads internally and had five external torpedo containers (three at the stern and two at the bow) which stored ten additional torpedoes. The total of 22 torpedoes allowed U-boat commanders to follow a convoy and strike night after night. Some of the IXC boats were fitted for mine operations; as mine-layers they could carry 44 TMA or 66 TMB mines.

Secondary armament was provided by one 10.5 cm (4.1 in) deck gun with 180 rounds. Anti-aircraft armament differed throughout the war. They had two periscopes in the tower. Types IXA and IXB had an additional periscope in the control room, which was removed in Type IXC and afterward.

These long range boats were frequently equipped with Focke-Achgelis Fa 330 spotter planes.

Type VII submarine

Type VII U-boats were the most common type of German World War II U-boat. U-boat stands for Unterseeboot, which means "submarine" in German.

Type XXI submarine

Type XXI U-boats were a class of German diesel–electric Elektroboot (German: "electric boat") submarines designed during the Second World War. One hundred and eighteen were completed, with four being combat ready. During the war only two were put into active service and went on patrols, but these were not used in combat.

They were the first submarines designed to operate primarily submerged, rather than spending most of their time as surface ships that could submerge for brief periods as a means to escape detection. They incorporated a large number of batteries to increase the time they could spend under water, to as much as several days, and they only needed to surface to periscope depth for recharging via a snorkel. The design included many general improvements as well: much greater underwater speed by an improved hull design, greatly improved diving times, power-assisted torpedo reloading and greatly improved crew accommodations.

After the war, several navies obtained XXIs and operated them for decades in various roles and large navies introduced new submarine designs based on them. These include the Soviet Whiskey, US Tang, UK Porpoise and Swedish Hajen classes, all based on the Type XXI design to some extent. The design remains the basis for modern diesel-electric submarines.

Uncompleted U-boat projects

During World War II, Nazi Germany's Kriegsmarine considered various submarine designs for specialized operations or improving U-boat performance. Many of these designs did not come to fruition for various reasons. Some were abandoned due to practical considerations. Others towards the end had to be abandoned, as the yards were overrun by allied forces.

The Type III U-boat was a 1934 project for a purpose-built minelayer based on the Type IA U-boat. The Type III U-Boat would have been similar to the Type IA, but with a hull lengthened by 7.5 m, and a total displacement of 970 tons. The Type III U-Boat was planned to carry an armament of 54 to 75 mines (depending on the type carried), two 105-mm deck guns, and one 20-mm antiaircraft gun.

The Type IIIA U-boat was a planned minelayer similar to the Type IA U-boat. It would have had a larger outer hull than the Type IA, and featured a large, watertight cylindrical hangar on the aft deck, which would have carried two small motor torpedo boats. The boat would have carried 48 mines, and used the smaller boats to help lay and recover mines. The project was dropped as impractical.

The Type IV U-boat was a planned resupply and repair U-boat, intended to meet other U-boats at sea and resupply them with torpedoes, fuel, food/water, and spare parts, and also be capable of performing light repair work.

The Type V U-boat was an experimental midget submarine designed by Hellmuth Walter using his hydrogen peroxide-fuelled turbine. Only one vessel, the V-80, was built.

The Type VI U-boat was a planned conversion of Type IA U-boats to run both submerged and surfaced from steam propulsion.

The Type VIIE U-boat was planned to make use of a lightweight engine, and with the saved weight, increase the thickness of the pressure hull - thus allowing for greater diving depths. The project was cancelled.

Little information is available on the Type VIII U-boat, other than it was planned for production in the event of mobilization in 1935.

The Type XI U-boat was planned as an artillery boat; its main armament would have been four 128-mm guns, in two twin gun turrets. It would have also carried an Arado Ar 231 collapsible floatplane. Four boats (U-112, U-113, U-114, and U-115) were laid down in 1939, but cancelled at the outbreak of World War II. Had the Type XI U-boat been constructed, it would have had a completely new hull design and a submerged displacement of 4,650 tons – she would have been by far the largest of the U-boats and the second-largest diesel submarine after the Japanese I-400-class submarine. Its purpose was to engage ships (including escorts) in artillery duels at relatively long range, then dive away if they came within a certain threshold distance. Many anti-submarine escorts of WW2 including the Flower corvettes would have been too small and too poorly equipped with forward guns to cope with this approach.

The Type XII fleet U-boat was a design from 1938. It had eight torpedo tubes, six at the bow and two at the stern, and was to carry 20 torpedoes. The gun armament was to be the same as for the type IX boats. Designed size equal to the later, larger type IX version IXD model, but with even more powerful engines and motors planned, allowing faster speeds both above and below the surface. No contracts were granted for these boats.

The Type XIII was a further development of the type II coastal U-boat, with four torpedo tubes and one 20-mm antiaircraft gun. No contracts were granted for these boats.

The Type XV and XVI U-boats were intended for very large transport and repair boats (5,000-ton and 3,000-ton, respectively) intended to carry torpedoes, food, and oil as cargo. The engine layout was to be the same as for the VIIC. No contracts were granted for these boats.

The Type XVIII U-boat was a project for an attack boat using the Walter propulsion system. Two boats (U-796 and U-797) were laid down in 1943, but construction was cancelled in March 1944.

The Type XIX was a project for an unarmed transport U-boat, based on the Type XB mine layer.

The Type XX was another project for a transport U-boat based on the Type XB; it would have had a shorter hull than the Type XB, but had a greater beam and draft. Thirty Type XX U-boats were laid down in 1943, but construction stopped in 1944. In August 1944, construction on three Type XX U-boats (U-1701, U-1702, and 1703) resumed, but again stopped in early 1945.

The Type XXII U-boat was intended for coastal and Mediterranean use. They used the Walter propulsion system and would have had a crew of two officers and 10 men. They were to have three torpedo tubes, two at the bow (below the CWL) and one aft of the bridge (above the CWL). Initially, 72 contracts were awarded to Howaldtswerke (36 to the yard in Hamburg and 36 in Kiel), but of those, only two had been laid down and had received U-boat numbers (U-1153 and U-1154) before they were all cancelled in late 1943.

The Type XXIV was a 1943 design for an ocean-going U-boat using the Walter system. It was to have 14 torpedo tubes, six at the bow, and four each side aft.

The Type XXV U-boats were intended to be electric propulsion-only boats for coastal use. The design was 160 tons with a crew of about 58 men and would have had two torpedo tubes fitted at the bow.

The Type XXVI was a high-seas U-boat propelled by the Walter system. They would have had a crew of three officers and 30 men, with ten torpedo tubes, four at the bow and six in a so-called Schnee organ, and no deck guns; 100 contracts were initially awarded to the Blohm & Voss yard in Hamburg (U-4501 through U-4600) and sections were under construction for U-4501 through U-4504 when the war ended. The other contracts had been cancelled.

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