U-boat
Overview
 
U-boat is the anglicized version of the German word U-Boot ˈuːboːt, itself an abbreviation of Unterseeboot (undersea boat
Submarine
A submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...

), and refers to military submarine
Submarine
A submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...

s operated by Germany, particularly in World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

 and World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

. Although in theory U-boats could have been useful fleet weapons against enemy naval warships, in practice they were most effectively used in an economic warfare role (commerce raiding
Commerce raiding
Commerce raiding or guerre de course is a form of naval warfare used to destroy or disrupt the logistics of an enemy on the open sea by attacking its merchant shipping, rather than engaging the combatants themselves or enforcing a blockade against them.Commerce raiding was heavily criticised by...

), enforcing a naval blockade
Blockade
A blockade is an effort to cut off food, supplies, war material or communications from a particular area by force, either in part or totally. A blockade should not be confused with an embargo or sanctions, which are legal barriers to trade, and is distinct from a siege in that a blockade is usually...

 against enemy shipping.
Timeline

1917    World War I: Germany announces its U-boats will engage in unrestricted submarine warfare.

1939    World War II: A German U-boat ''U 29'' sinks the British aircraft carrier {{HMS|Courageous|50|6}}.

1941    World War II: The destroyer USS ''Reuben James'' is torpedoed by a German U-boat near Iceland, killing more than 100 United States Navy sailors. It is the first U.S. Navy vessel sunk by enemy action in WWII.

1946    World War II: Operation Deadlight ends after scuttling 121 of 154 captured U-boats.

1954    The German U-Boat U-505 begins its move from a specially constructed dock to its final site at Chicago's Museum of Science and Industry.

Encyclopedia
U-boat is the anglicized version of the German word U-Boot ˈuːboːt, itself an abbreviation of Unterseeboot (undersea boat
Submarine
A submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...

), and refers to military submarine
Submarine
A submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...

s operated by Germany, particularly in World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

 and World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

. Although in theory U-boats could have been useful fleet weapons against enemy naval warships, in practice they were most effectively used in an economic warfare role (commerce raiding
Commerce raiding
Commerce raiding or guerre de course is a form of naval warfare used to destroy or disrupt the logistics of an enemy on the open sea by attacking its merchant shipping, rather than engaging the combatants themselves or enforcing a blockade against them.Commerce raiding was heavily criticised by...

), enforcing a naval blockade
Blockade
A blockade is an effort to cut off food, supplies, war material or communications from a particular area by force, either in part or totally. A blockade should not be confused with an embargo or sanctions, which are legal barriers to trade, and is distinct from a siege in that a blockade is usually...

 against enemy shipping. The primary targets of the U-boat campaigns in both wars were the merchant convoys bringing supplies from Canada, the British Empire
British Empire
The British Empire comprised the dominions, colonies, protectorates, mandates and other territories ruled or administered by the United Kingdom. It originated with the overseas colonies and trading posts established by England in the late 16th and early 17th centuries. At its height, it was the...

 and the United States to the islands of Great Britain. Austrian
Austria-Hungary
Austria-Hungary , more formally known as the Kingdoms and Lands Represented in the Imperial Council and the Lands of the Holy Hungarian Crown of Saint Stephen, was a constitutional monarchic union between the crowns of the Austrian Empire and the Kingdom of Hungary in...

 submarines of World War I were also known as U-boats.

The distinction between U-boat and submarine is common in several languages, including English (where U-boat refers exclusively to the German vessels of the World Wars) but is unknown in German, in which the term U-Boot refers to any submarine.

Pre-War

The first submarine built in Germany was the two man submarine Brandtaucher
Brandtaucher
Brandtaucher was a submersible designed by the German inventor and engineer Wilhelm Bauer and built by Schweffel & Howaldt in Kiel for Schleswig-Holstein's Flotilla in 1850....

, which sank to the bottom of Kiel
Kiel
Kiel is the capital and most populous city in the northern German state of Schleswig-Holstein, with a population of 238,049 .Kiel is approximately north of Hamburg. Due to its geographic location in the north of Germany, the southeast of the Jutland peninsula, and the southwestern shore of the...

 harbor during its first test dive. The vessel was designed in 1850 by the inventor and engineer
Engineer
An engineer is a professional practitioner of engineering, concerned with applying scientific knowledge, mathematics and ingenuity to develop solutions for technical problems. Engineers design materials, structures, machines and systems while considering the limitations imposed by practicality,...

 Wilhelm Bauer
Wilhelm Bauer
Wilhelm Bauer was the German inventor and engineer, who built several hand-powered submarines.-Biography:...

 and built by Schweffel & Howaldt
August Howaldt
August Ferdinand Howaldt was a German engineer and ship builder.-Biography:Born in Braunschweig, the son of the silversmith David Ferdinand Howaldt, with whom he got his first practice working in metal, Howaldt made an apprenticeship in Hamburg and became a practical mechanicus.In 1838 he moved to...

 in Kiel
Kiel
Kiel is the capital and most populous city in the northern German state of Schleswig-Holstein, with a population of 238,049 .Kiel is approximately north of Hamburg. Due to its geographic location in the north of Germany, the southeast of the Jutland peninsula, and the southwestern shore of the...

 for the German Navy
German Navy
The German Navy is the navy of Germany and is part of the unified Bundeswehr .The German Navy traces its roots back to the Imperial Fleet of the revolutionary era of 1848 – 52 and more directly to the Prussian Navy, which later evolved into the Northern German Federal Navy...

. Brandtaucher was later rediscovered during dredging operations in 1887, and subsequently raised sixteen years later and placed into a museum in Germany, where it rests today.

This was followed in 1890 by W1 and W2, built to a Nordenfelt design. In 1903, Germaniawerft dockyard in Kiel completed Germany's first fully functional submarine, Forelle which was sold to Russia during the Russo-Japanese War
Russo-Japanese War
The Russo-Japanese War was "the first great war of the 20th century." It grew out of rival imperial ambitions of the Russian Empire and Japanese Empire over Manchuria and Korea...

 in April 1904. The first works were carried out by the Spanish engineer Raymondo Lorenzo d'Equevilley Montjustin (submarine Narval), who based the German Navy's first U-boat design, U1 on the Russian export models bound for the Russo-Japanese War. U1 was commissioned into the Imperial German Navy on 14 December 1906. This was the Karp
Karp class submarine
The Karp Class were a group of submarines built by Krupp Germaniawerft for the Imperial Russian Navy. The boats were ordered in the 1904 emergency programme as a result of the Russo-Japanese War. The design was a twin hull type with 7 ballast tanks and a 16 fathom diving limit. The boats were...

-class which had a double hull, was powered by a Körting kerosene
Kerosene
Kerosene, sometimes spelled kerosine in scientific and industrial usage, also known as paraffin or paraffin oil in the United Kingdom, Hong Kong, Ireland and South Africa, is a combustible hydrocarbon liquid. The name is derived from Greek keros...

 engine and armed with a single torpedo tube. It was designated , with the 50% larger design having two tubes. A diesel engine was not installed in a German Navy boat until the U-19-class of 1912–13. At the start of World War I, Germany had 48 submarines of 13 classes in service or under construction. Germany's first U-boat, , was retired from the Imperial Navy
Imperial Navy
The phrase Imperial Navy may refer to:*The Austro-Hungarian Navy*The German Navy between 1872 and 1918*The Imperial Japanese Navy from 1869 until 1947*The Imperial Navy of Imperial Qing government*The Imperial Navy from the fictional Star Wars universe....

 in 1919, and is currently on display at the Deutsches Museum
Deutsches Museum
The Deutsches Museum in Munich, Germany, is the world's largest museum of technology and science, with approximately 1.5 million visitors per year and about 28,000 exhibited objects from 50 fields of science and technology. The museum was founded on June 28, 1903, at a meeting of the Association...

 in Munich.

World War I

At the start of World War I, Germany had twenty-nine U-boats; in the first ten weeks, five British cruisers had been lost to them. On 5 September 1914, HMS Pathfinder
HMS Pathfinder (1904)
HMS Pathfinder was the lead ship of the Pathfinder class scout cruisers, and was the first ship ever to be sunk by a torpedo fired by submarine . She was built by Cammell Laird, Birkenhead, launched on 16 July 1904, and commissioned on 18 July 1905...

 was sunk by U-21
SM U-21 (Germany)
SM U-21 was one of the most famous U-boats to serve in the Imperial German Navy in World War I. She was the first submarine to sink a ship with a self-propelled torpedo. She also sank the British battleships HMS Triumph and HMS Majestic...

, the first ship to have been sunk by a submarine using a self-propelled torpedo. On 22 September, U-9 sank the obsolete British warships HMS Aboukir
HMS Aboukir (1900)
HMS Aboukir was a Cressy-class armoured cruiser. She was built by Fairfield Shipbuilding & Engineering Co Ltd, Govan, Scotland in 1902.-First World War:...

, Cressy
HMS Cressy (1899)
HMS Cressy was a Cressy-class armoured cruiser in the Royal Navy. Cressy was sunk by the German U-boat U-9 in September 1914.-Service history:...

 and Hogue
HMS Hogue (1900)
HMS Hogue was a Cressy-class armoured cruiser in the Royal Navy. Hogue was sunk by the German U-boat U-9 on 22 September 1914.-Service history:...

 (the "Live Bait Squadron") in a single hour.

In the Gallipoli Campaign in the spring of 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.

For the first few months of the war, U-boat anti-commerce actions observed the "prize rules"
Rules of Prize Warfare
Prize rules or cruiser rules govern the taking of prizes: vessels captured on the high seas during war. They are intertwined with the blockade rules.Customary rules were originally laid down in the days of sailing ships...

 of the time which governed the treatment of enemy civilian ships and their occupants. On 20 October 1914, U-17 sank the first merchant ship, the SS Glitra
SS Glitra
SS Glitra was a steam ship that was the first British merchant vessel to be sunk by a German submarine in the First World War.-History:...

, off Norway. 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 blockade
Blockade
A blockade is an effort to cut off food, supplies, war material or communications from a particular area by force, either in part or totally. A blockade should not be confused with an embargo or sanctions, which are legal barriers to trade, and is distinct from a siege in that a blockade is usually...

s. Under the instructions given to U-boat captains, they could sink merchant ships, even potentially neutral ones, without warning. A statement by the U.S. Government, holding Germany "strictly accountable" for any loss of American lives, made no material difference.

On 7 May 1915, U-20 sank the liner RMS Lusitania
RMS Lusitania
RMS Lusitania was a British ocean liner designed by Leonard Peskett and built by John Brown and Company of Clydebank, Scotland. The ship entered passenger service with the Cunard Line on 26 August 1907 and continued on the line's heavily-traveled passenger service between Liverpool, England and New...

 with a single torpedo
Torpedo
The modern torpedo is a self-propelled missile weapon with an explosive warhead, launched above or below the water surface, propelled underwater towards a target, and designed to detonate either on contact with it or in proximity to it.The term torpedo was originally employed for...

 hit, although it is debated whether a second explosion was due to flammable cargo or another torpedo. The sinking claimed 1,198 lives, 128 of them American civilians, including noted theatrical producer Charles Frohman
Charles Frohman
Charles Frohman was an American theatrical producer. Frohman was producing plays by 1889 and acquired his first Broadway theatre by 1892. He discovered and promoted many stars of the American theatre....

 and Alfred Vanderbilt
Alfred Gwynne Vanderbilt
Alfred Gwynne Vanderbilt I was an extremely wealthy sportsman and a member of the famous Vanderbilt family of philanthropists. He died on the .-Life:...

, a member of the prestigious Vanderbilt family
Vanderbilt family
The Vanderbilt family is an American family of Dutch origin prominent during the Gilded Age. It started off with the shipping and railroad empires of Cornelius Vanderbilt, and expanded into various other areas of industry and philanthropy...

. The sinking deeply shocked the Allies
Allies of World War I
The Entente Powers were the countries at war with the Central Powers during World War I. The members of the Triple Entente were the United Kingdom, France, and the Russian Empire; Italy entered the war on their side in 1915...

 and their sympathizers because an unarmed civilian merchant and passenger vessel was attacked. According to the ship's manifest, Lusitania was carrying military cargo. After further investigations, it has been confirmed that the Lusitania was in fact carrying ammunition for the allies to use against the Germans. However, this was not known at the time and the Lusitania was mistaken for a troopship. It was not until the sinking of the ferry Sussex that there was a widespread reaction in the USA.

The initial U.S. response was to threaten to sever diplomatic ties, which persuaded the Germans to issue the Sussex pledge
Sussex pledge
The Sussex pledge was a promise made in 1916 during World War I by Germany to the United States prior to the latter's entry into the war. Early in 1916, Germany had instituted a policy of unrestricted submarine warfare, allowing armed merchant ships – but not passenger ships – to be torpedoed...

 that re-imposed 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 re-apply prize rules. This, however, removed the effectiveness of the U-boat fleet, and the Germans consequently sought a decisive surface action, a strategy which culminated in the Battle of Jutland
Battle of Jutland
The Battle of Jutland was a naval battle between the British Royal Navy's Grand Fleet and the Imperial German Navy's High Seas Fleet during the First World War. The battle was fought on 31 May and 1 June 1916 in the North Sea near Jutland, Denmark. It was the largest naval battle and the only...

.

Although the Germans claimed victory at Jutland, the British Grand Fleet
British Grand Fleet
The Grand Fleet was the main fleet of the British Royal Navy during the First World War.-History:It was formed in 1914 by the British Atlantic Fleet combined with the Home Fleet and it included 35-40 state-of-the-art capital ships. It was initially commanded by Admiral Sir John Jellicoe...

 remained in control at sea. It was necessary to return to effective anti-commerce warfare by U-boats. Vice-Admiral Reinhard Scheer
Reinhard Scheer
Reinhard Scheer was an Admiral in the German Kaiserliche Marine. Scheer joined the navy in 1879 as an officer cadet; he progressed through the ranks, commanding cruisers and battleships, as well as major staff positions on land. At the outbreak of World War I, Scheer was the commander of the II...

, Commander in Chief of the High Seas Fleet
High Seas Fleet
The High Seas Fleet was the battle fleet of the German Empire and saw action during World War I. The formation was created in February 1907, when the Home Fleet was renamed as the High Seas Fleet. Admiral Alfred von Tirpitz was the architect of the fleet; he envisioned a force powerful enough to...

, 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.

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
Unrestricted submarine warfare
Unrestricted submarine warfare is a type of naval warfare in which submarines sink merchantmen without warning, as opposed to attacks per prize rules...

 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 the spring of 1917 was initially very successful, sinking a major part of Britain-bound shipping. Nevertheless 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 and all surviving German submarines were surrendered. Of the 360 submarines that had been built, 178 were lost but more than 11 million tons of shipping had been destroyed.

Classes

  • Körting kerosene-powered boats
    • Type U 1, Type U 2, Type U 3, Type U 5, Type U 9, Type U 13, Type U 16, Type U 17
  • Mittel-U MAN diesel boats
    • Type U 19, Type U 23, Type U 27, Type U 31
      German Type U 31 submarine
      U 31 was a class of U-boats built during World War I by the Kaiserliche Marine.U 31 U-boats carried 6 torpedoes and were originally armed with one geck gun, which was replaced in 1916/17 by a deck gun...

      , Type U 43, Type U 51, Type U 57, Type U 63, Type U 66
      German Type U 66 submarine
      The Type U 66 was a class of five submarines or U-boats operated by the German Imperial Navy during World War I. The class is alternately referred to as the U-66-class or the Type UD. The class was built by Germaniawerft of Kiel to their 506d design as the U-7-class for the Austro-Hungarian Navy...

      , Type Mittel U
      German Type Mittel U submarine
      Mittel U was a class of U-boats built during World War I by the Kaiserliche Marine.Mittel U U-boats carried 16 torpedoes and had various arrangements of deck guns. Some had only one 88mm gun while others had a single 105mm gun - but most had both originally...

  • U-Cruisers and Merchant U-boats
    • Type U 139
      German Type U 139 submarine
      U-139, originally designated "Project 46", was a class of large, long-range U-boats built during World War I by the Kaiserliche Marine.-Description:Three large U-cruisers, designated Type 139, were ordered from Germaniawerft, Kiel, in August 1916...

      , Type U 142, Type U 151
      German Type U 151 submarine
      Type U 151 U-boats were a class of large, long-range submarines constructed during World War I by the Kaiserliche Marine.-Background:In addition to the cargo-carrying submarine Deutschland, six further large cargo submarines were ordered, originally designed to ship material to and from locations...

      , Type UD 1
  • UB coastal torpedo attack boats
    • Type UB I
      German type UB I submarine
      The Type UB I was a class of small coastal submarines built in Germany at the beginning of the First World War. Twenty boats were constructed, most of which went into service with the German Imperial Navy. Boats of this design were also operated by the Austro-Hungarian Navy and the Bulgarian...

      , Type UB II
      German type UB II submarine
      The UB II type submarine was a class of U-boat built during World War I by the Kaiserliche Marine. They were enlarged from the preceding type UB I and were more effective vessels. The boats were a single hull design with a 50 metre maximum diving depth and a 30-45 second diving time...

      , Type UB III
      German type UB III submarine
      The Type UB III submarine was a class of U-boat built during World War I by the Kaiserliche Marine.UB III boats carried 10 torpedoes and were armed with one 88 mm deck gun. They carried a crew of 34 and had a cruising range of around 9,000 miles...

      , Type UF, Type UG
  • UC coastal minelayers
    • Type UC I
      German Type UC I submarine
      The Type UC I submarines were a class of small coastal minelaying U-boats built in Germany during the early part of World War I. They were the first operational minelaying submarines in the world . A total of fifteen boats were built...

      , Type UC II
      German Type UC II submarine
      Type UC II minelaying submarines were used by the Kaiserliche Marine during the World War I. They displaced 417 tons, carried 7 torpedoes and up to 18 mines...

      , Type UC III
  • UE ocean minelayers
    • Type UE 1, Type UE 2

Surrender of the Fleet

Under the terms of the Armistice, all U-boats were to immediately surrender. Those in home waters sailed to the British submarine base at Harwich
Harwich
Harwich is a town in Essex, England and one of the Haven ports, located on the coast with the North Sea to the east. It is in the Tendring district. Nearby places include Felixstowe to the northeast, Ipswich to the northwest, Colchester to the southwest and Clacton-on-Sea to the south...

. The entire process was done quickly and in the main without difficulty, after which the vessels were studied, scrapped, or given to Allied navies. Stephen King-Hall
Stephen King-Hall
Sir William Stephen Richard King-Hall, Baron King-Hall of Headley was a British naval officer, writer, politician and playwright. -Life:...

 wrote a detailed eyewitness account of the surrender.

Inter-war

At the end of World War I, as part of the Paris Peace Conference, 1919
Paris Peace Conference, 1919
The Paris Peace Conference was the meeting of the Allied victors following the end of World War I to set the peace terms for the defeated Central Powers following the armistices of 1918. It took place in Paris in 1919 and involved diplomats from more than 32 countries and nationalities...

, the Treaty of Versailles
Treaty of Versailles
The Treaty of Versailles was one of the peace treaties at the end of World War I. It ended the state of war between Germany and the Allied Powers. It was signed on 28 June 1919, exactly five years after the assassination of Archduke Franz Ferdinand. The other Central Powers on the German side of...

 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 Holland and a torpedo research programme 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
Anglo-German Naval Agreement
The Anglo-German Naval Agreement of June 18, 1935 was a bilateral agreement between the United Kingdom and German Reich regulating the size of the Kriegsmarine in relation to the Royal Navy. The A.G.N.A fixed a ratio whereby the total tonnage of the Kriegsmarine was to be 35% of the total tonnage...

 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

During World War II, U-boat warfare was the major component of the Battle of the Atlantic (1939–1945), which lasted the duration of the war. Germany had the largest submarine fleet in World War II, since the Treaty of Versailles
Treaty of Versailles
The Treaty of Versailles was one of the peace treaties at the end of World War I. It ended the state of war between Germany and the Allied Powers. It was signed on 28 June 1919, exactly five years after the assassination of Archduke Franz Ferdinand. The other Central Powers on the German side of...

 had limited the surface navy of Germany to six battleships (of less than 10,000 tons each), six cruisers and 12 destroyers. Prime Minister Winston Churchill
Winston Churchill
Sir Winston Leonard Spencer-Churchill, was a predominantly Conservative British politician and statesman known for his leadership of the United Kingdom during the Second World War. He is widely regarded as one of the greatest wartime leaders of the century and served as Prime Minister twice...

 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
Allies of World War II
The Allies of World War II were the countries that opposed the Axis powers during the Second World War . Former Axis states contributing to the Allied victory are not considered Allied states...

 shipping, initially in the mid-Atlantic, where there was a large gap in air cover. There was an extensive trade in war supplies and food across the Atlantic, which was critical for Britain's survival. This continuous action became known as the Battle of the Atlantic
Battle of the Atlantic
Battle of the Atlantic may refer to either of two naval campaigns:* The Atlantic U-boat Campaign during the First World War * The Battle of the Atlantic during the Second World War...

, as the British developed technical defences such as ASDIC and RADAR
Radar
Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...

, 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. Later, when the USA entered the war, the U-boats ranged from the Atlantic coast of the United States and Canada to the Gulf of Mexico
Gulf of Mexico
The Gulf of Mexico is a partially landlocked ocean basin largely surrounded by the North American continent and the island of Cuba. It is bounded on the northeast, north and northwest by the Gulf Coast of the United States, on the southwest and south by Mexico, and on the southeast by Cuba. In...

, and from the Arctic
Arctic
The Arctic is a region located at the northern-most part of the Earth. The Arctic consists of the Arctic Ocean and parts of Canada, Russia, Greenland, the United States, Norway, Sweden, Finland, and Iceland. The Arctic region consists of a vast, ice-covered ocean, surrounded by treeless permafrost...

 to the west and southern African coasts and even as far east as Penang
Penang
Penang is a state in Malaysia and the name of its constituent island, located on the northwest coast of Peninsular Malaysia by the Strait of Malacca. It is bordered by Kedah in the north and east, and Perak in the south. Penang is the second smallest Malaysian state in area after Perlis, and the...

. The U.S. military
United States armed forces
The United States Armed Forces are the military forces of the United States. They consist of the Army, Navy, Marine Corps, Air Force, and Coast Guard.The United States has a strong tradition of civilian control of the military...

 engaged in various tactics against German incursions in the Americas
Americas
The Americas, or America , are lands in the Western hemisphere, also known as the New World. In English, the plural form the Americas is often used to refer to the landmasses of North America and South America with their associated islands and regions, while the singular form America is primarily...

; these included military surveillance of foreign nations in Latin America, particularly in the Caribbean, in order 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 engine
Diesel engine
A diesel engine is an internal combustion engine that uses the heat of compression to initiate ignition to burn the fuel, which is injected into the combustion chamber...

s, diving only when attacked or for rare daytime torpedo strikes. The most common U-boat attack during the early years of the war was conducted on the surface and at night, see submarine warfare
Submarine warfare
Naval warfare is divided into three operational areas: surface warfare, air warfare and underwater warfare. The latter may be subdivided into submarine warfare and anti-submarine warfare as well as mine warfare and mine countermeasures...

. This period, before the Allied forces developed truly effective antisubmarine warfare (ASW) tactics, was referred to by German submariners as "die glückliche Zeit" or "the happy time."

Torpedoes

The U-boats' main weapon was the torpedo
Torpedo
The modern torpedo is a self-propelled missile weapon with an explosive warhead, launched above or below the water surface, propelled underwater towards a target, and designed to detonate either on contact with it or in proximity to it.The term torpedo was originally employed for...

, though mines and deck gun
Deck gun
A deck gun is a type of artillery cannon mounted on the deck of a ship or submarine.The deck gun was used as a defensive weapon against smaller boats or ships and in certain cases where torpedo use was limited. Typically a crew of three; gunner, loader, and layer, operated the gun, while others...

s (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. Early German World War II torpedoes were straight runners, as opposed to the homing and pattern-running torpedoes which were fielded later in the war. They were fitted with one of two types of pistol trigger: impact, which detonated the warhead upon contact with a solid object, and magnetic
Magnetic pistol
Magnetic pistol is the term for the device on a torpedo or naval mine that detects its target by its magnetic field, and triggers the fuse for detonation...

, 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 shock wave, and the ship could break in two. In this way, even large or heavily-armored ships could be sunk or disabled with a single well-placed hit. In practice, however, the depth-keeping equipment and magnetic and contact exploders were notoriously unreliable in the first eight months of the war. Torpedoes would often run at an improper depth, detonate prematurely, or fail 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 at high latitudes fluctuations in the Earth's magnetic field. These were eventually phased out, and the depth-keeping problem was solved by early 1942.

Later in the war, Germany developed an acoustic homing torpedo, the G7/T5
G7e torpedo
The G7e or more appropriately the G7e/T2, G7e/T3, and G7e/T4 Falke torpedoes were, with the exception of the T4 model, the standard torpedoes for Germany during World War II...

. It was primarily designed to combat convoy escorts. The acoustic torpedo was designed to run straight to an arming distance of 400 meters 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. (Problems with steering mechanisms on normal torpedoes made them occasionally lethal to the firing boat as well). Additionally, it was found these torpedoes were only effective against ships moving at greater than 15 knots (29.4 km/h). At any rate, the Allies countered acoustic torpedoes with noisemaker decoys such as Foxer
Foxer
Foxer, was the codename for a British built acoustic decoy, used to confuse German acoustic homing torpedoes like the G7es torpedo during the Second World War. A US version codenamed FXR was deployed in 1943. A Canadian version was also built called the CAT...

, FXR, CAT and Fanfare
Fanfare (decoy)
The T-Mk 6 Fanfare is a towed sonar decoy developed after the Second World War by the United States Navy. It replaced the Foxer noisemaker. It was more effective than the Foxer, producing a sound similar to a ship's propeller, rather than wideband noise....

. The Germans, in-turn, countered this by introducing newer and upgraded versions of the acoustic torpedoes, like the late war G7es
G7es torpedo
The G7es or Zaunkönig T-5 was a torpedo employed by German U-boats during World War II. It was known as the GNAT to the British.- Description :...

.

U-boats also adopted several types of "pattern-running" torpedoes which ran to a preset distance, then travelled 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
Kriegsmarine
The Kriegsmarine was the name of the German Navy during the Nazi regime . It superseded the Kaiserliche Marine of World War I and the post-war Reichsmarine. The Kriegsmarine was one of three official branches of the Wehrmacht, the unified armed forces of Nazi Germany.The Kriegsmarine grew rapidly...

produced many different types of U-boats as technology evolved. Most notable are Type VII, known as the "workhorse" of the fleet, which was by far the most-produced type; Type IX boats were larger and specifically designed for long-range patrols, some traveling as far as Japan and the east coast of the United States. With the Type XXI "Elektroboot", German designers realized the U-boat depended on submerged ability both for combat effectiveness and survival. The Type XXI featured a revolutionary streamlined hull design and propulsion system with a large battery which allowed it to cruise submerged for long periods and reach unprecedented submerged speeds. A larger battery was possible because the space it occupied was originally intended to store hydrogen peroxide for a Walter turbine which was unsuccessful on the Type XVII
German Type XVIIB submarine
The Type XVII U-boats were small coastal submarines which used Hellmuth Walter's high test peroxide propulsion system, which offered a combination of air-independent propulsion and high submerged speeds.-Background:...

.

Throughout the war an arms race
Arms race
The term arms race, in its original usage, describes a competition between two or more parties for the best armed forces. Each party competes to produce larger numbers of weapons, greater armies, or superior military technology in a technological escalation...

 evolved between the Allies and the Kriegsmarine, especially in detection and counter-detection. Sonar
Sonar
Sonar is a technique that uses sound propagation to navigate, communicate with or detect other vessels...

 (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
Radar
Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...

 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. However, at some point the Allies switched to centimetric radar (unbeknownst to Germany) which rendered the radar detectors ineffective. U-boat radar systems were also developed, but many captains chose not to utilize them for fear of broadcasting their position to enemy patrols.

The Germans took the idea of the Schnorchel
Submarine snorkel
A submarine snorkel is a device which allows a submarine to operate submerged while still taking in air from above the surface. Navy personnel often refer to it as the snort.-History:...

 (snorkel) from captured Dutch submarines, though they did not begin to implement it on their own boats until rather late in the war. The Schnorchel was a retractable pipe which supplied air to the diesel engines while submerged at periscope
Periscope
A periscope is an instrument for observation from a concealed position. In its simplest form it consists of a tube with mirrors at each end set parallel to each other at a 45-degree angle....

 depth, allowing the boats to cruise and recharge their batteries while maintaining a degree of stealth. It was far from a perfect solution, however. There were problems 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. Speed was limited to 8 knots (15.7 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 such that the schnorchel head itself could be detected.

The later U-boats were covered in a sound-absorbent rubber coating to make them less of an ASDIC target. They also had the facility to release a chemical bubble-making decoy, known as Bold, after the mythical kobold
Kobold
The kobold is a sprite stemming from Germanic mythology and surviving into modern times in German folklore. Although usually invisible, a kobold can materialise in the form of an animal, fire, a human being, and a candle. The most common depictions of kobolds show them as humanlike figures the size...

.

Classes

  • Type I
    German Type I submarine
    The Type I U-boat was the first post-World War I attempt by the German Kriegsmarine to produce an ocean going submarine. Only two Type IAs were built, but the decision to halt production on further boats is believed to be because of political decisions and not because of major faults in the Type I...

  • Type II
    German Type II submarine
    The Type II U-boat was designed by 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 and built in 1933 by the...

  • Type V
    Uncompleted U-boat projects
    During World War II the German Navy considered a number of submarine designs for specialized operations or improving U-boat performance. However, many of these designs did not come to fruition for various reasons. Some were abandoned due to practical considerations...

  • Type VII
    German Type VII submarine
    Type VII U-boats were the most common type of German World War II U-boat. The Type VII was based on earlier German submarine designs going back to the World War I Type UB III, designed through the Dutch dummy company Ingenieurskantoor voor Scheepsbouw den Haag which was set up by Germany after...

     - Known as the 'workhorse' of the U-boats, with 700 active in WW2
  • Type IX
    German Type IX submarine
    The Type IX U-boat was designed by Germany 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...

     - These ocean-going U-boats operated as far as the Indian Ocean with the Japanese (Monsun Gruppe
    Monsun Gruppe
    The Monsun Gruppe or Monsoon Group was a force of German U-boats that operated in the Pacific and Indian Oceans during World War II...

    ), and the South Atlantic.
  • Type X
    German Type X submarine
    Type X U-boats were a special type of German submarine . Although intended as long-range mine-layers, they were later used as long-range cargo transports, a task they shared with the Type IXD and Italian Romolo-class submarines.-History:...

  • Type XI
    Uncompleted U-boat projects
    During World War II the German Navy considered a number of submarine designs for specialized operations or improving U-boat performance. However, many of these designs did not come to fruition for various reasons. Some were abandoned due to practical considerations...

  • Type XIV
    German Type XIV submarine
    The Type XIV U-boat was a modification of the Type IXD, designed to resupply other U-boats. They were nicknamed "Milchkuh/Milchkühe " . They had no torpedo tubes or deck guns, only anti-aircraft guns. Due to its large size, the Type XIV could resupply other boats with 400 tons of fuel, four...

     - Used to resupply other U-boats; nicknamed the Milk Cow
  • Type XVII
    Uncompleted U-boat projects
    During World War II the German Navy considered a number of submarine designs for specialized operations or improving U-boat performance. However, many of these designs did not come to fruition for various reasons. Some were abandoned due to practical considerations...

  • Type XVIII
  • Type XXI
    German Type XXI submarine
    Type XXI U-boats, also known as "Elektroboote", were the first submarines designed to operate primarily submerged, rather than as surface ships that could submerge as a means to escape detection or launch an attack.-Description:...

     - Known as the Elektroboot.
  • Type XXIII
    German Type XXIII submarine
    German Type XXIII submarines were the first so-called elektroboats to become operational. They were small coastal submarines designed to operate in the shallow waters of the North Sea, Black Sea and Mediterranean Sea, where larger Type XXI Elektro boats were at risk in World War II. They were so...

  • Type XXVI
  • Midget submarines, including Biber, Hai
    Hai (midget submarine)
    The Hai was an advanced model of the Marder-class midget submarines created in Germany during World War II and operated by the K-Verband. Its prototype performed poorly during test runs and therefore no other boats were produced....

    , Molch
    Molch
    The Molch was an unsuccessful, one-man series of German midget submarines created during World War II...

    , Seehund
    Seehund
    The Seehund , also known as Type XXVII, was a successful series of German midget submarines created during World War II...

    .
  • Uncompleted U-boat projects
    Uncompleted U-boat projects
    During World War II the German Navy considered a number of submarine designs for specialized operations or improving U-boat performance. However, many of these designs did not come to fruition for various reasons. Some were abandoned due to practical considerations...


Counter-measures

Advances in convoy tactics, high frequency direction finding (referred to as "Huff-Duff
Huff-Duff
High-frequency direction finding, usually known by its abbreviation HF/DF is the common name for a type of radio direction finding employed especially during the two World Wars....

"), radar
Radar
Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...

, active sonar
Sonar
Sonar is a technique that uses sound propagation to navigate, communicate with or detect other vessels...

 (called ASDIC in Britain), depth charge
Depth charge
A depth charge is an anti-submarine warfare weapon intended to destroy or cripple a target submarine by the shock of exploding near it. Most use explosives and a fuze set to go off at a preselected depth in the ocean. Depth charges can be dropped by either surface ships, patrol aircraft, or from...

s, ASW spigot mortars (also known as "hedgehog"
Hedgehog (weapon)
The Hedgehog was an anti-submarine weapon developed by the Royal Navy during World War II, that was deployed on convoy escort warships such as destroyers to supplement the depth charge. The weapon worked by firing a number of small spigot mortar bombs from spiked fittings...

), the intermittent cracking of the German Naval Enigma code, the introduction of the Leigh Light
Leigh light
The Leigh Light was a British World War II era anti-submarine device used in the Second Battle of the Atlantic.It was a powerful carbon arc searchlight of 24 inches diameter fitted to a number of the British Royal Air Force's Coastal Command patrol bombers to help them spot surfaced...

, the range of escort aircraft (especially with the use of escort carriers), 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).
At the same time, the Allies targeted the U-boat shipyards and their bases with strategic bombing
Strategic bombing
Strategic bombing is a military strategy used in a total war with the goal of defeating an enemy nation-state by destroying its economic ability and public will to wage war rather than destroying its land or naval forces...

.

Enigma machine

The British had a major advantage in their ability to read some German naval Enigma
Enigma machine
An Enigma machine is any of a family of related electro-mechanical rotor cipher machines used for the encryption and decryption of secret messages. Enigma was invented by German engineer Arthur Scherbius at the end of World War I...

 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
Alan Turing
Alan Mathison Turing, OBE, FRS , was an English mathematician, logician, cryptanalyst, and computer scientist. He was highly influential in the development of computer science, providing a formalisation of the concepts of "algorithm" and "computation" with the Turing machine, which played a...

 used special purpose "Bombe
Bombe
The bombe was an electromechanical device used by British cryptologists to help decipher German Enigma-machine-encrypted signals during World War II...

s" and early computer
Computer
A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...

s 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 U-110, a Type IXB, was captured in 1941 by the Royal Navy
Royal Navy
The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...

, and its Enigma machine and documents were removed. Further code books were captured by raids on weather ships. The U-505, a Type IXC, was captured by the United States Navy
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...

 in 1944. It is presently a museum ship
Museum ship
A museum ship, or sometimes memorial ship, is a ship that has been preserved and converted into a museum open to the public, for educational or memorial purposes...

 in Chicago at the Museum of Science and Industry
Museum of Science and Industry (Chicago)
The Museum of Science and Industry is located in Chicago, Illinois, USA in Jackson Park, in the Hyde Park neighborhood adjacent to Lake Michigan. It is housed in the former Palace of Fine Arts from the 1893 World's Columbian Exposition...

. The U-505 was captured along with the current codebooks, but there were fears that a security breach would alert the Germans to the capture of their codes.

Battle of the St. Lawrence

Two events in the battle took place in 1942 when German U-boats attacked four allied ore
Ore
An ore is a type of rock that contains minerals with important elements including metals. The ores are extracted through mining; these are then refined to extract the valuable element....

 carriers at Bell Island
Bell Island
Bell Island is a Canadian island located off Newfoundland's Avalon Peninsula in Conception Bay.Measuring 9 km in length and 3 km in width, Bell Island has an area of 34 km²...

, Newfoundland
Newfoundland and Labrador
Newfoundland and Labrador is the easternmost province of Canada. Situated in the country's Atlantic region, it incorporates the island of Newfoundland and mainland Labrador with a combined area of . As of April 2011, the province's estimated population is 508,400...

. The carriers
Cargo ship
A cargo ship or freighter is any sort of ship or vessel that carries cargo, goods, and materials from one port to another. Thousands of cargo carriers ply the world's seas and oceans each year; they handle the bulk of international trade...

 SS Saganaga and the SS Lord Strathcona were sunk by U-513
German submarine U-513
U-513 was a German U-boat built for service in the Kriegsmarine during World War II. She was sunk in Brazilian waters off São Francisco do Sul, Santa Catarina state on 19 July 1943, with seven survivors including her captain Friedrich Guggenberger, and rediscovered on 14 July 2011, at a depth of ,...

 on September 5, 1942, while the SS Rosecastle and PLM 27 were sunk by U-518 on November 2 with the loss of 69 lives. When the submarine launched a torpedo at the loading pier, Bell Island
Bell Island
Bell Island is a Canadian island located off Newfoundland's Avalon Peninsula in Conception Bay.Measuring 9 km in length and 3 km in width, Bell Island has an area of 34 km²...

 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.

Post World War II

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, West Germany re-entered the submarine business. Because Germany was initially restricted to a 450 tonne displacement limit, the Bundesmarine focused on small coastal submarines to protect against the Soviet
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....

 threat in the Baltic Sea
Baltic Sea
The Baltic Sea is a brackish mediterranean sea located in Northern Europe, from 53°N to 66°N latitude and from 20°E to 26°E longitude. It is bounded by the Scandinavian Peninsula, the mainland of Europe, and the Danish islands. It drains into the Kattegat by way of the Øresund, the Great Belt and...

. The Germans sought to use advanced technologies to offset the small displacement, such as amagnetic
Ferromagnetism
Ferromagnetism is the basic mechanism by which certain materials form permanent magnets, or are attracted to magnets. In physics, several different types of magnetism are distinguished...

 steel
Steel
Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...

 to protect against naval mines and magnetic anomaly detector
Magnetic anomaly detector
A magnetic anomaly detector is an instrument used to detect minute variations in the Earth's magnetic field. The term refers specifically to magnetometers used by military forces to detect submarines ; the military MAD gear is a descendent of geomagnetic survey instruments used to search for...

s.

The initial Type 201
Type 201 submarine
The Type 201 was Germany's first class of military submarines built after World War II. They were built out of amagnetic steel to counter the threat of magnetic naval mines...

 was a failure because of hull cracking; the subsequent Type 205
Type 205 submarine
The Type 205 was a class of diesel-electric German hunter-killer U-boat submarines. They were single-hull vessels optimized for the use in the shallow Baltic Sea. The Type 205 is a direct evolution of the Type 201 class with lengthened hull, new machinery and sensors...

, 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 German government realized the potential for the submarine as an export. Three of the improved Type 206
Type 206 submarine
The Type 206 is a class of diesel-electric submarines developed by Howaldtswerke-Deutsche Werft . Its design is based on the preceding Type 205 submarine class. These small and agile submarines were built during the Cold War to operate in the shallow Baltic Sea and attack Warsaw Pact shipping if...

 boats were sold to the Israeli Navy becoming the Gal-class
Gal class submarine
The Type 540 Gal Class submarine is a slightly modified variant of the German HDW Type 206 submarine class , modified for Israeli requirements. The Gal class submarines were built to Israeli specifications as the Vickers shipyards Type 540 at Barrow in Furness in the UK rather than Germany for...

. The German Type 209
Type 209 submarine
The Type 209 is a class of diesel-electric attack submarine developed exclusively for export in the late 1960s by Howaldtswerke-Deutsche Werft of Germany...

 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
Type 212 submarine
The German Type 212 class, also Italian Todaro class, is a highly advanced design of non-nuclear submarine developed by Howaldtswerke-Deutsche Werft AG and Fincantieri S.p.a. for the German and Italian Navy. It features diesel propulsion and an additional air-independent propulsion system using...

. The 212 features an air-independent propulsion
Air-independent propulsion
Air-independent propulsion is a term that encompasses technologies which allow a submarine to operate without the need to surface or use a snorkel to access atmospheric oxygen. The term usually excludes the use of nuclear power, and describes augmenting or replacing the diesel-electric propulsion...

 system using hydrogen
Hydrogen
Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...

 fuel cell
Fuel cell
A fuel cell is a device that converts the chemical energy from a fuel into electricity through a chemical reaction with oxygen or another oxidizing agent. Hydrogen is the most common fuel, but hydrocarbons such as natural gas and alcohols like methanol are sometimes used...

s. This system is safer than previous closed-cycle diesel engines and steam turbines, cheaper than a nuclear reactor and quieter than both. While the Type 212 is also being purchased by Italy, the Type 214
Type 214 submarine
The Type 214 is a diesel-electric submarine developed by Howaldtswerke-Deutsche Werft GmbH . It features diesel propulsion with an air-independent propulsion system using Siemens polymer electrolyte membrane hydrogen fuel cells...

 has been designed as the follow-on export model and has been sold to Greece, South Korea and Turkey
Turkey
Turkey , known officially as the Republic of Turkey , is a Eurasian country located in Western Asia and in East Thrace in Southeastern Europe...

.

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

See also

  • U-8047
    U-8047
    U-8047 is a Replica Submarine, which is moored at Clarence Dock UK. The name U-8047 was the brainchild of Laurel Howarth, secretary of and represents a car number plate distorted version of U-boat...

  • Submarine warfare
    Submarine warfare
    Naval warfare is divided into three operational areas: surface warfare, air warfare and underwater warfare. The latter may be subdivided into submarine warfare and anti-submarine warfare as well as mine warfare and mine countermeasures...

  • U-8047 Replica Submarine
    U-8047 Replica Submarine
    U-8047 Replica Submarine is a floating museum that has travelled along the Leeds Liverpool Canal, to facilitate historical education to children. Currently moored at Clarence Dock UK, the 45 foot narrowboat has been converted, both inside and out, in to a replica submarine, which opens its doors...

  • List of German U-boats
  • List of U-boats never deployed
  • List of successful U-boats
  • List of successful U-boat commanders
  • Aces of the Deep
    Aces Of The Deep
    Aces of the Deep is a World War II Submarine simulator game developed and published by Dynamix for MS-DOS in 1994."Aces of the Deep" was the last installment of Dynamix's "Aces" series, which included the flight simulators Red Baron, Aces of the Pacific, and Aces over Europe...

  • Karl Dönitz
    Karl Dönitz
    Karl Dönitz was a German naval commander during World War II. He started his career in the German Navy during World War I. In 1918, while he was in command of , the submarine was sunk by British forces and Dönitz was taken prisoner...

  • Orkney Wireless Museum
    Orkney Wireless Museum
    The Orkney Wireless Museum in Kirkwall, Orkney houses a collection of domestic and military wireless equipment. It developed from the private collection of the late Jim MacDonald from St Margaret's Hope and marks the importance of wireless communications in Orkney during World War II.-Museum:The...

     contains an example of a U-boat radio
  • List of Knight's Cross recipients of the U-boat service
  • Sieglinde (decoy)
    Sieglinde (decoy)
    Sieglinde was a decoy used during the Second World War by German U-boats.Similar to the Bold device, except that it was powered by electric motors allowing to move at 6 knots as well as rise and fall. The effect was that it appeared like a moving U-boat on Sonar.This allowed the real U-boat to...

  • Bold (decoy)
  • Monsun Gruppe
    Monsun Gruppe
    The Monsun Gruppe or Monsoon Group was a force of German U-boats that operated in the Pacific and Indian Oceans during World War II...

  • U-boat Campaign (World War I)
    U-boat Campaign (World War I)
    The U-boat Campaign from 1914 to 1918 was the World War I naval campaign fought by German U-boats against the trade routes of the Entente Powers...

  • Battle of the Atlantic (1939–1945)
  • Das Boot
    Das Boot
    Das Boot is a 1981 German epic war film written and directed by Wolfgang Petersen, produced by Günter Rohrbach, and starring Jürgen Prochnow, Herbert Grönemeyer, and Klaus Wennemann...


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
    Das Boot
    Das Boot is a 1981 German epic war film written and directed by Wolfgang Petersen, produced by Günter Rohrbach, and starring Jürgen Prochnow, Herbert Grönemeyer, and Klaus Wennemann...

     in 1981, directed by Wolfgang Petersen
    Wolfgang Petersen
    Wolfgang Petersen is a German film director and screenwriter. His films include The NeverEnding Story, Enemy Mine, Outbreak, In the Line of Fire, Air Force One, The Perfect Storm, Troy, and Poseidon...

  • 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 978-3902433794
  • 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
  • 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 978-1846850493
  • 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 978-0304353309

External links

  • uboat.net Comprehensive reference source for WW I and WW II U-boat information.
  • uboat-bases.com The German U-boat bases of the WW-II in France : Brest, Lorient, St-Nazaire, La Rochelle, Bordeaux.
  • ubootwaffe.net Comprehensive reference source for WW II U-boat information.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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