Get Our Extension

U-boat

From Wikipedia, in a visual modern way
U-995, a typical VIIC/41 U-boat on display at the Laboe Naval Memorial
U-995, a typical VIIC/41 U-boat on display at the Laboe Naval Memorial

U-boats were naval 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 targeted Brazilian merchant ships during both World Wars and, twice over, precipitated Brazil's decision to give up its neutral stance and declare war on Germany.[1]

The term is an anglicised version of the German word U-Boot [ˈuːboːt] (listen), a shortening of Unterseeboot (under-sea boat), though the German term refers to any submarine. Austro-Hungarian Navy submarines were also known as U-boats.

Discover more about U-boat related topics

World War I

World War I

World War I or the First World War, often abbreviated as WWI, was one of the deadliest global conflicts in history. It was fought between two coalitions, the Allies and the Central Powers. Fighting occurred throughout Europe, the Middle East, Africa, the Pacific, and parts of Asia. An estimated 9 million soldiers were killed in combat, plus another 23 million wounded, while 5 million civilians died as a result of military action, hunger, and disease. Millions more died as a result of genocide, while the 1918 Spanish flu pandemic was exacerbated by the movement of combatants during the war.

Commerce raiding

Commerce raiding

Commerce raiding is a form of naval warfare used to destroy or disrupt logistics of the enemy on the open sea by attacking its merchant shipping, rather than engaging its combatants or enforcing a blockade against them.

Blockade

Blockade

A blockade is the act of actively preventing a country or region from receiving or sending out food, supplies, weapons, or communications, and sometimes people, by military force. A blockade differs from an embargo or sanction, which are legal barriers to trade rather than physical barriers. It is also distinct from a siege in that a blockade is usually directed at an entire country or region, rather than a fortress or city and the objective may not always be to conquer the area.

Canada

Canada

Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's second-largest country by total area, with the world's longest coastline. It is characterized by a wide range of both meteorologic and geological regions. The country is sparsely inhabited, with most residing south of the 55th parallel in urban areas. Canada's capital is Ottawa and its three largest metropolitan areas are Toronto, Montreal, and Vancouver.

British Empire

British Empire

The British Empire was composed of the dominions, colonies, protectorates, mandates, and other territories ruled or administered by the United Kingdom and its predecessor states. It began with the overseas possessions and trading posts established by England between the late 16th and early 18th centuries. At its height it was the largest empire in history and, for over a century, was the foremost global power. By 1913, the British Empire held sway over 412 million people, 23 per cent of the world population at the time, and by 1920, it covered 35.5 million km2 (13.7 million sq mi), 24 per cent of the Earth's total land area. As a result, its constitutional, legal, linguistic, and cultural legacy is widespread. At the peak of its power, it was described as "the empire on which the sun never sets", as the Sun was always shining on at least one of its territories.

Submarine

Submarine

A submarine is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. The term is also sometimes used historically or colloquially to refer to remotely operated vehicles and robots, as well as medium-sized or smaller vessels, such as the midget submarine and the wet sub. Submarines are referred to as boats rather than ships irrespective of their size.

Austro-Hungarian Navy

Austro-Hungarian Navy

The Austro-Hungarian Navy or Imperial and Royal War Navy was the naval force of Austria-Hungary. Ships of the Austro-Hungarian Navy were designated SMS, for Seiner Majestät Schiff. The k.u.k. Kriegsmarine came into being after the formation of Austria-Hungary in 1867, and ceased to exist in 1918 upon the Empire's defeat and subsequent collapse at the end of World War I.

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.[2][3] Inventor and engineer Wilhelm Bauer had designed this vessel in 1850, and Schweffel and Howaldt constructed it in Kiel. Dredging operations in 1887 rediscovered Brandtaucher; she was later raised and put on historical display in Germany.

The boats Nordenfelt I and Nordenfelt II, built to a Nordenfelt design, followed in 1890. In 1903, the Friedrich Krupp Germaniawerft dockyard in Kiel completed the first fully functional German-built submarine, Forelle,[4] which Krupp sold to Russia during the Russo-Japanese War in April 1904.[5] 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.[6] 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 had 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, she remains on display at the Deutsches Museum in Munich.[7]

Discover more about Early U-boats (1850–1914) related topics

Brandtaucher

Brandtaucher

Brandtaucher was a submersible designed by the Bavarian inventor and engineer Wilhelm Bauer and built by Schweffel & Howaldt in Kiel for Schleswig-Holstein's Flotilla in 1850. The Brandtaucher is the oldest known surviving submarine in the world.

Kiel

Kiel

Kiel is the capital and most populous city in the northern German state of Schleswig-Holstein, with a population of 246,243 (2021).

Engineer

Engineer

Engineers, as practitioners of engineering, are professionals who invent, design, analyze, build and test machines, complex systems, structures, gadgets and materials to fulfill functional objectives and requirements while considering the limitations imposed by practicality, regulation, safety and cost. The word engineer is derived from the Latin words ingeniare and ingenium ("cleverness"). The foundational qualifications of an engineer typically include a four-year bachelor's degree in an engineering discipline, or in some jurisdictions, a master's degree in an engineering discipline plus four to six years of peer-reviewed professional practice and passage of engineering board examinations.

August Howaldt

August Howaldt

August Ferdinand Howaldt was a German engineer and ship builder. The German sculptor Georg Ferdinand Howaldt was his brother.

Dredging

Dredging

Dredging is the excavation of material from a water environment. Possible reasons for dredging include improving existing water features; reshaping land and water features to alter drainage, navigability, and commercial use; constructing dams, dikes, and other controls for streams and shorelines; and recovering valuable mineral deposits or marine life having commercial value. In all but a few situations the excavation is undertaken by a specialist floating plant, known as a dredger.

Friedrich Krupp Germaniawerft

Friedrich Krupp Germaniawerft

Friedrich Krupp Germaniawerft was a German shipbuilding company, located in the harbour at Kiel, and one of the largest and most important builders of U-boats for the Kaiserliche Marine in World War I and the Kriegsmarine in World War II. The original company was founded in 1867 but went bankrupt and was bought out by Friedrich Krupp. Krupp was very interested in building warships and in the time before the First World War built a number of battleships for the Kaiserliche Marine, including SMS Posen, SMS Prinzregent Luitpold, SMS Kronprinz, and SMS Sachsen. A total of 84 U-boats were built in the shipyard during the war. After the war it returned to the normal production of yachts and transports.

Russian submarine Forel

Russian submarine Forel

Forel was a midget submarine designed by Raimundo Lorenzo de Equevilley Montjustín and built by Krupp in Kiel, Germany. The design was an experimental design built as a private venture by Krupp in hopes of attracting a contract from the Imperial German Navy. Although the design proved moderately successful, the submarine did not attract German naval attention. She was purchased by the Imperial Russian Navy (IRN) in 1904 and served with the IRN until she was lost in a diving accident in 1910. She had the distinction of being the first submarine to have been built in Germany, preceding SM U-1. Forel was succeeded in service by the Krab class.

Krupp

Krupp

The Krupp family was a prominent 400-year-old German dynasty from Essen, noted for its production of steel, artillery, ammunition and other armaments. The family business, known as Friedrich Krupp AG, was the largest company in Europe at the beginning of the 20th century, and was the premier weapons manufacturer for Germany in both world wars. Starting from the Thirty Years' War until the end of the Second World War, it produced battleships, U-boats, tanks, howitzers, guns, utilities, and hundreds of other commodities.

Karp-class submarine

Karp-class submarine

The Karp class were a class of submarines built by Krupp Germaniawerft for the Imperial Russian Navy. The class, composed of three boats were ordered in the 1904 emergency programme as a result of the Russo-Japanese War. The design was a twin hull type powered by a kerosene-electric power plant with a 16-fathom diving limit. The boats were delivered late for the war and transferred to the Black Sea Fleet by rail in 1908. In 1909, Kambala was lost. The other two submarines remained in service until their withdrawal in March 1917. They were taken over in April 1918 by the Ukrainian State before being captured by the German Empire in May and transferred to the British following the German surrender in November. The British scuttled Karp and Karas in 1919 to prevent their capture by the Soviets.

Imperial German Navy

Imperial German Navy

The Imperial German Navy or the Imperial Navy was the navy of the German Empire, which existed between 1871 and 1919. It grew out of the small Prussian Navy, which was mainly for coast defence. Kaiser Wilhelm II greatly expanded the navy. The key leader was Admiral Alfred von Tirpitz, who greatly expanded the size and quality of the navy, while adopting the sea power theories of American strategist Alfred Thayer Mahan. The result was a naval arms race with Britain, as the German navy grew to become one of the greatest maritime forces in the world, second only to the Royal Navy.

Körting Hannover

Körting Hannover

Körting Hannover AG is a long-standing industrial engineering company in Hanover.

Kerosene

Kerosene

Kerosene, paraffin, or lamp oil is a combustible hydrocarbon liquid which is derived from petroleum. It is widely used as a fuel in aviation as well as households. Its name derives from Greek: κηρός (keros) meaning "wax", and was registered as a trademark by Canadian geologist and inventor Abraham Gesner in 1854 before evolving into a generic trademark. It is sometimes spelled kerosine in scientific and industrial usage. The term kerosene is common in much of Argentina, Australia, Canada, India, New Zealand, Nigeria, and the United States, while the term paraffin is used in Chile, eastern Africa, South Africa, Norway, and in the United Kingdom. The term lamp oil, or the equivalent in the local languages, is common in the majority of Asia and the Southeastern United States. Liquid paraffin is a more viscous and highly refined product which is used as a laxative. Paraffin wax is a waxy solid extracted from petroleum.

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.[8]

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, SS Glitra, 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 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 after firing a torpedo.[9] On 7 May 1915, SM U-20 sank the liner RMS Lusitania. The sinking claimed 1,198 lives, 123 of them American civilians, and the attack of this unarmed civilian ship deeply shocked the Allies.[10] 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 she carried were thousands of crates full of ammunition for rifles, 3-inch (76 mm) artillery shells, and 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 attack on the ferry SS Sussex, which carried many citizens of the United States.

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. Returning to effective anticommerce warfare by U-boats resumed. 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.

Sinking of the Linda Blanche out of Liverpool by SM U-21 (Willy Stöwer)
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.[11]

Of the 373 German submarines that had been built, 178 were lost by enemy action. Of these, 40 were sunk by mines, 30 by depth charges, and 13 by Q-ships; 512 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. Twelve U-boat crewmen were decorated with the Goldene Militär-Verdienst-Kreuz, the highest bravery award for noncommissioned officers and enlisted men.[12] 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). Their records have not been surpassed in any subsequent conflict.

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.[13]

Discover more about World War I (1914–1918) related topics

HMS Pathfinder (1904)

HMS Pathfinder (1904)

HMS Pathfinder was the lead ship of her class of two British scout cruisers, and was the first ship ever to be sunk by a self-propelled torpedo fired by submarine. She was built by Cammell Laird, Birkenhead, launched on 16 July 1904, and commissioned on 18 July 1905. She was originally to have been named HMS Fastnet, but was renamed prior to construction. During the beginning of World War I, the Pathfinder was sunk on 5 September 1914 by a German U-boat, the SM U-21.

Action of 22 September 1914

Action of 22 September 1914

The Action of 22 September 1914 was an attack by the German U-boat U-9 that took place during the First World War. Three obsolete Royal Navy cruisers, of the 7th Cruiser Squadron, manned mainly by Royal Naval Reserve part-time reservists and sometimes referred to as the Live Bait Squadron, were sunk by U-9 while patrolling the southern North Sea.

Otto Weddigen

Otto Weddigen

Otto Eduard Weddigen was an Imperial German Navy U-boat commander during World War I. He was awarded the Pour le Mérite, Germany's highest honour, for sinking four British warships.

HMS Aboukir (1900)

HMS Aboukir (1900)

HMS Aboukir was a Cressy-class armoured cruiser built for the Royal Navy around 1900. Upon completion she was assigned to the Mediterranean Fleet and spent most of her career there. Upon returning home in 1912, she was placed in reserve. Recommissioned at the start of the First World War, she played a minor role in the Battle of Heligoland Bight a few weeks after the beginning of the war. Aboukir was sunk by the German submarine U-9, together with two of her sister ships, on 22 September 1914; 527 men of her complement died.

HMS Cressy (1899)

HMS Cressy (1899)

HMS Cressy was a Cressy-class armoured cruiser built for the Royal Navy around 1900. Upon completion she was assigned to the China Station. In 1907 she was transferred to the North America and West Indies Station before being placed in reserve in 1909. Recommissioned at the start of World War I, she played a minor role in the Battle of Heligoland Bight a few weeks after the beginning of the war. Cressy and two of her sister ships were torpedoed and sunk by the German submarine U-9 on 22 September 1914 with the loss of 560 of her crew.

HMS Hogue (1900)

HMS Hogue (1900)

HMS Hogue was a Cressy-class armoured cruiser built for the Royal Navy around 1900. Upon completion she was assigned to the Channel Fleet and the China Station. In 1906 she became a training ship for the North America and West Indies Station before being placed in reserve in 1908. Recommissioned at the start of World War I, she played a minor role in the Battle of Heligoland Bight a few weeks after the beginning of the war. Hogue was sunk by the German submarine U-9, together with two of her sister ships, on 22 September 1914.

Pre-dreadnought battleship

Pre-dreadnought battleship

Pre-dreadnought battleships were sea-going battleships built between the mid- to late- 1880s and 1905, before the launch of HMS Dreadnought in 1906. The pre-dreadnought ships replaced the ironclad battleships of the 1870s and 1880s. Built from steel, protected by case-hardened steel armour, and powered by coal-fired triple-expansion steam engines, pre-dreadnought battleships carried a main battery of very heavy guns in fully enclosed rotating turrets supported by one or more secondary batteries of lighter weapons.

Commerce raiding

Commerce raiding

Commerce raiding is a form of naval warfare used to destroy or disrupt logistics of the enemy on the open sea by attacking its merchant shipping, rather than engaging its combatants or enforcing a blockade against them.

SM U-17 (Germany)

SM U-17 (Germany)

SM U-17 was a German submarine during World War I. U-17 sank the first British merchant vessel in the First World War, and also sank another ten ships, damaged one ship and captured two ships, surviving the war without casualty.

Blockade

Blockade

A blockade is the act of actively preventing a country or region from receiving or sending out food, supplies, weapons, or communications, and sometimes people, by military force. A blockade differs from an embargo or sanction, which are legal barriers to trade rather than physical barriers. It is also distinct from a siege in that a blockade is usually directed at an entire country or region, rather than a fortress or city and the objective may not always be to conquer the area.

Beachy Head

Beachy Head

Beachy Head is a chalk headland in East Sussex, England. It is situated close to Eastbourne, immediately east of the Seven Sisters.

SM U-20 (Germany)

SM U-20 (Germany)

SM U-20 was a German Type U 19 U-boat built for service in the Imperial German Navy. She was launched on 18 December 1912, and commissioned on 5 August 1913. During World War I, she took part in operations around the British Isles. U-20 became infamous following her sinking of the British ocean liner RMS Lusitania on 7 May 1915, an act that dramatically reshaped the course of World War I.

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. A submarine design office, though, 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.[14]

Discover more about Interwar years (1919–1939) related topics

Treaty of Versailles

Treaty of Versailles

The Treaty of Versailles was a peace treaty signed on 28 June 1919. As the most important treaty of World War I, it ended the state of war between Germany and most of the Allied Powers. It was signed in the Palace of Versailles, exactly five years after the assassination of Archduke Franz Ferdinand, which led to the war. The other Central Powers on the German side signed separate treaties. The United States never ratified the Versailles treaty and made a separate peace treaty with Germany. Although the armistice of 11 November 1918 ended the actual fighting, it took six months of Allied negotiations at the Paris Peace Conference to conclude the peace treaty. Germany was not allowed to participate in the negotiations—it was forced to sign the final result.

NV Ingenieurskantoor voor Scheepsbouw

NV Ingenieurskantoor voor Scheepsbouw

NV Ingenieurskantoor voor Scheepsbouw, usually contracted to IvS, was a Dutch dummy company set up in The Hague and funded by the Reichsmarine after World War I in order to maintain and develop German submarine know-how and to circumvent the limitations set by the Treaty of Versailles. The company designed several submarine types for paying countries, including the Soviet S-class submarine, as well as the prototypes for the German Type II submarines and Type VII submarines.

Netherlands

Netherlands

The Netherlands, informally Holland, is a country located in northwestern Europe with overseas territories in the Caribbean. It is the largest of four constituent countries of the Kingdom of the Netherlands. The Netherlands consists of twelve provinces; it borders Germany to the east, and Belgium to the south, with a North Sea coastline to the north and west. It shares maritime borders with the United Kingdom, Germany and Belgium in the North Sea. The country's official language is Dutch, with West Frisian as a secondary official language in the province of Friesland. Dutch, English and Papiamento are official in the Caribbean territories.

Anglo-German Naval Agreement

Anglo-German Naval Agreement

The Anglo-German Naval Agreement (AGNA) of 18 June 1935 was a naval agreement between the United Kingdom and Germany regulating the size of the Kriegsmarine in relation to the Royal Navy.

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 11 November 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.[15] British Prime Minister Winston Churchill later wrote "The only thing that really frightened me during the war was the U-boat peril."[16]

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", in which multiple submarines would stay close together, making sinking a specific target easier for them. 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 tonnage of supplies sent across the Atlantic. The combination of increased tonnage and increased naval protection of shipping convoys made making a significant dent in British shipping much more difficult for U-boats. 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 under water (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]

U-534, Birkenhead Docks, Merseyside, England
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) had been 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 became available 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; 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; 17 mph). 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, such as the late-war G7es, and the T11, but the T11 did not see active service.

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.

Oil painting of a Kriegsmarine U-boat, by Augusto Ferrer-Dalmau
Oil painting of a Kriegsmarine U-boat, by Augusto Ferrer-Dalmau

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. Waste disposal was a problem when the U-boats spent extended periods without surfacing, as it is today.

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 antiaircraft guns, but 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. 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

Captured Type VII and Type IX U-boats outside their pen in Trondheim, Norway, 19 May 1945
Captured Type VII and Type IX U-boats outside their pen in Trondheim, Norway, 19 May 1945

Countermeasures

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

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). 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 codebreakers. 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. 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.

U-570 a Type VIIC was captured by the British in mid-1941. Although the crew managed to destroy their Enigma machine, the British captured a quantity of papers that proved extremely useful to the cryptanalysts at Bletchley Park. The Royal Navy were able to tow the sinking submarine to Iceland, where it was salvaged and later commissioned into the Royal Navy as HMS Graph, carrying out three war patrols before being relegated to training duties. Mock-ups of the submarine interior were created to train specialist Royal Navy boarding parties in the event a U-boat was blown to the surface to reverse any scuttling attempts by the crew, and to search quickly for cryptographic equipment and documents.

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.

Discover more about World War II (1939–1945) related topics

Battle of the Atlantic

Battle of the Atlantic

The Battle of the Atlantic, the longest continuous military campaign in World War II, ran from 1939 to the defeat of Nazi Germany in 1945, covering 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. The campaign peaked from mid-1940 through to the end of 1943.

Battleship

Battleship

A battleship is a large armored warship with a main battery consisting of large caliber guns. It dominated naval warfare in the late 19th and early 20th centuries.

Cruiser

Cruiser

A cruiser is a type of warship. Modern cruisers are generally the largest ships in a fleet after aircraft carriers and amphibious assault ships, and can usually perform several roles.

Destroyer

Destroyer

In naval terminology, a destroyer is a fast, manoeuvrable, long-endurance warship intended to escort larger vessels in a fleet, convoy, or battle group and defend them against powerful short-range attackers. They were originally developed in 1885 by Fernando Villaamil for the Spanish Navy as a defense against torpedo boats, and by the time of the Russo-Japanese War in 1904, these "torpedo boat destroyers" (TBDs) were "large, swift, and powerfully armed torpedo boats designed to destroy other torpedo boats". Although the term "destroyer" had been used interchangeably with "TBD" and "torpedo boat destroyer" by navies since 1892, the term "torpedo boat destroyer" had been generally shortened to simply "destroyer" by nearly all navies by the First World War.

Kriegsmarine

Kriegsmarine

The Kriegsmarine was the navy of Germany from 1935 to 1945. It superseded the Imperial German Navy of the German Empire (1871–1918) and the inter-war Reichsmarine (1919–1935) of the Weimar Republic. The Kriegsmarine was one of three official branches, along with the Heer and the Luftwaffe, of the Wehrmacht, the German armed forces from 1935 to 1945.

Submarine pen

Submarine pen

A submarine pen is a type of submarine base that acts as a bunker to protect submarines from air attack.

Saint-Nazaire

Saint-Nazaire

Saint-Nazaire is a commune in the Loire-Atlantique department in western France, in traditional Brittany.

Radar

Radar

Radar is a radiolocation system that uses radio waves to determine the distance (ranging), angle (azimuth), and radial velocity of objects relative to the site. It is used to detect and track aircraft, ships, spacecraft, guided missiles, and motor vehicles, and map weather formations, and terrain. A radar system consists of a transmitter producing electromagnetic waves in the radio or microwaves domain, a transmitting antenna, a receiving antenna and a receiver and processor to determine properties of the objects. Radio waves from the transmitter reflect off the objects and return to the receiver, giving information about the objects' locations and speeds.

Gulf of Mexico

Gulf of Mexico

The Gulf of Mexico is an ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of the United States; on the southwest and south by the Mexican states of Tamaulipas, Veracruz, Tabasco, Campeche, Yucatan, and Quintana Roo; and on the southeast by Cuba. The Southern U.S. states of Texas, Louisiana, Mississippi, Alabama, and Florida, which border the Gulf on the north, are often referred to as the "Third Coast" of the United States.

Arctic

Arctic

The Arctic is a polar region located at the northernmost part of Earth. The Arctic consists of the Arctic Ocean, adjacent seas, and parts of Canada, Danish Realm (Greenland), northern Finland (Lapland), Iceland, northern Norway, Russia, northernmost Sweden and the United States (Alaska). Land within the Arctic region has seasonally varying snow and ice cover, with predominantly treeless permafrost containing tundra. Arctic seas contain seasonal sea ice in many places.

Penang

Penang

Penang is a Malaysian state located on the northwest coast of Peninsular Malaysia, by the Malacca Strait. It has two parts: Penang Island, where the capital city, George Town, is located, and Seberang Perai on the Malay Peninsula. They are connected by Malaysia's two longest road bridges, the Penang Bridge and the Sultan Abdul Halim Muadzam Shah Bridge; the latter is also the second longest oversea bridge in Southeast Asia. The second smallest Malaysian state by land mass, Penang, is bordered by Kedah to the north and the east, and Perak to the south.

Nuclear submarine

Nuclear submarine

A nuclear submarine is a submarine powered by a nuclear reactor, but not necessarily nuclear-armed. Nuclear submarines have considerable performance advantages over "conventional" submarines. Nuclear propulsion, being completely independent of air, frees the submarine from the need to surface frequently, as is necessary for conventional submarines. The large amount of power generated by a nuclear reactor allows nuclear submarines to operate at high speed for long periods, and the long interval between refuelings grants a range virtually unlimited, making the only limits on voyage times being imposed by such factors as the need to restock food or other consumables.

Memorial

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

U-15, a Type 206 submarine, of the German Navy at the Kiel Week 2007
U-15, a Type 206 submarine, of the German Navy at the Kiel Week 2007

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 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, so 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, developing a customized version Type 207. Small and agile submarines were built during the Cold War to operate in the shallow Baltic Sea, resulting in the Type 206. Three of the improved Type 206 boats were later sold to the Israeli Navy, becoming the Type 540. 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 continued to reap successes with derivations or on the basis of the successful type 209, as are the Type 800 sold to Israel and the TR-1700 sold to Argentina.

Germany continued to succeed as an exporter of submarines as the Klasse 210 sold to Norway, considered the most silent and maneuverable submarines in the world. This demonstrated its capacity and put its export seal on the world.

Type 212 submarine with air-independent propulsion of the German Navy in dock at HDW/Kiel
Type 212 submarine with air-independent propulsion of the German Navy in dock at HDW/Kiel

Germany has brought the U-boat name into the 21st century with the new Type 212; it 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[20] and Norway,[21] the Type 214 has been designed as the follow-on export model and has been sold to Greece, South Korea, and Turkey, and based on it would get the Type U 209PN sold to Portugal.

In recent years Germany introduced new models such as the Type 216 and the Type 218, the latter being sold to Singapore.

In 2016, Germany commissioned its newest U-boat, the U-36, a Type 212.

Discover more about Post–World War II and Cold War (after 1945) related topics

German Navy

German Navy

The German Navy is the navy of Germany and part of the unified Bundeswehr, the German Armed Forces. The German Navy was originally known as the Bundesmarine from 1956 to 1995, when Deutsche Marine became the official name with respect to the 1990 incorporation of the East German Volksmarine. It is deeply integrated into the NATO alliance. Its primary mission is protection of Germany's territorial waters and maritime infrastructure as well as sea lines of communication. Apart from this, the German Navy participates in peacekeeping operations, and renders humanitarian assistance and disaster relief. It also participates in anti-piracy operations.

Kiel Week

Kiel Week

The Kiel Week or Kiel Regatta is an annual sailing event in Kiel, the capital of Schleswig-Holstein, Germany. It is the largest sailing event in Europe, and also one of the largest Volksfeste in Germany, attracting millions of people every year from all over Germany and neighbouring countries.

Coastal submarine

Coastal submarine

A coastal submarine or littoral submarine is a small, maneuverable submarine with shallow draft well suited to navigation of coastal channels and harbors. Although size is not precisely defined, coastal submarines are larger than midget submarines, but smaller than sea-going submarines designed for longer patrols on the open ocean. Space limitations aboard coastal submarines restrict fuel availability for distant travel, food availability for extended patrol duration, and number of weapons carried. Within those limitations, however, coastal submarines may be able to reach areas inaccessible to larger submarines, and be more difficult to detect.

Baltic Sea

Baltic Sea

The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden and the North and Central European Plain.

Ferromagnetism

Ferromagnetism

Ferromagnetism is a property of certain materials that results in a significant, observable magnetic permeability, and in many cases, a significant magnetic coercivity, allowing the material to form a permanent magnet. Ferromagnetic materials are familiar metals that are noticeably attracted to a magnet, a consequence of their substantial magnetic permeability. Magnetic permeability describes the induced magnetization of a material due to the presence of an external magnetic field. This temporarily induced magnetization, for example, inside a steel plate, accounts for its attraction to the permanent magnet. Whether or not that steel plate acquires a permanent magnetization itself depends not only on the strength of the applied field but on the so-called coercivity of the ferromagnetic material, which can vary greatly.

Naval mine

Naval mine

A naval mine is a self-contained explosive device placed in water to damage or destroy surface ships or submarines. Unlike depth charges, mines are deposited and left to wait until they are triggered by the approach of, or contact with, any vessel or a particular vessel type, akin to anti-infantry vs. anti-vehicle mines. Naval mines can be used offensively, to hamper enemy shipping movements or lock vessels into a harbour; or defensively, to protect friendly vessels and create "safe" zones. Mines allow the minelaying force commander to concentrate warships or defensive assets in mine-free areas giving the adversary three choices: undertake an expensive and time-consuming minesweeping effort, accept the casualties of challenging the minefield, or use the unmined waters where the greatest concentration of enemy firepower will be encountered.

Magnetic anomaly detector

Magnetic anomaly detector

A magnetic anomaly detector (MAD) 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 ; military MAD equipment is a descendant of geomagnetic survey or aeromagnetic survey instruments used to search for minerals by detecting their disturbance of the normal earth-field.

Denmark

Denmark

Denmark is a Nordic constituent country in Northern Europe. It is the most populous and politically central constituent of the Kingdom of Denmark, a constitutionally unitary state that includes the autonomous territories of the Faroe Islands and Greenland in the North Atlantic Ocean. Metropolitan Denmark is the southernmost of the Scandinavian countries, lying south-west and south of Sweden, south of Norway, and north of Germany, with which it shares a short land border, its only land border.

Kobben-class submarine

Kobben-class submarine

The Kobben class is a customized version of the German Type 205 submarine. Fifteen vessels of this class were built for use by the Royal Norwegian Navy in the 1960s. The class later saw service with Denmark and Poland. The boats have since been withdrawn from service in the Norwegian and Danish navies. The Polish Navy operateed two Kobben-class submarines until 2021.

Israeli Navy

Israeli Navy

The Israeli Navy is the naval warfare service arm of the Israel Defense Forces, operating primarily in the Mediterranean Sea theater as well as the Gulf of Eilat and the Red Sea theater. The current commander in chief of the Israeli Navy is Aluf David Sa'ar Salama. The Israeli Navy is believed to be responsible for maintaining Israel's offshore nuclear second strike capability.

Gal-class submarine

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 Type 540 at the Vickers shipyards in Barrow-in-Furness in the UK rather than Germany for political reasons. "Gal" was the name of the son of Abraham (Ivan) Dror, 3rd commander of the squadron and head of the project.

Dolphin-class submarine

Dolphin-class submarine

The Dolphin class is a diesel-electric submarine developed in Israel and constructed by Howaldtswerke-Deutsche Werft AG (HDW) in Kiel, Germany, for the Israeli Navy. The first boats of the class were based on the export-only German 209-class submarines, but modified and enlarged. The Dolphin 1 sub-class is slightly larger than the German Navy Type 212 in length and displacement. The three newer air-independent propulsion (AIP) equipped boats are similar to the Type 212 vessels in underwater endurance, but are 12 metres (39 ft) longer, nearly 500 tonnes heavier in submerged displacement and have a larger crew than either the Type 212 or the Type 214.

Source: "U-boat", Wikipedia, Wikimedia Foundation, (2023, March 6th), https://en.wikipedia.org/wiki/U-boat.

Enjoying Wikiz?

Enjoying Wikiz?

Get our FREE extension now!

See also
References
  1. ^ Mattos, Carlos de Meira. "O Brasil na II Guerra Mundial". Exército Brasileiro. Ministério da Defesa - Exército Brasileiro. Retrieved 6 March 2023.
  2. ^ Showell, p. 23
  3. ^ Compare: Chaffin, Tom (2010). The H. L. Hunley: The Secret Hope of the Confederacy. Macmillan. p. 53. ISBN 9781429990356. Retrieved 14 July 2016. Bauer's boat made a promising start, diving in tests in the Baltic Sea's Bay of Kiel to depths of more than 50 feet. In 1855, during one of those tests, the boat malfunctioned. The Brandtaucher plunged 54 vertical feet and refused to ascend from the seafloor. Bauer and his crew – leaving their craft on the bottom – barely escaped with their crewmates' lives.
  4. ^ Showell, p. 201
  5. ^ Showell, pp. 22, 23, 25, 29
  6. ^ Showell, p. 30
  7. ^ Showell, pp. 36 & 37
  8. ^ "Story of the U-21". Archived from the original on 27 December 2008. Retrieved 2 November 2008.
  9. ^ Haley Dixon (21 June 2013). "Story of Captain's courage resurfaces after 98 years". Daily Telegraph. Archived from the original on 21 June 2013. Retrieved 22 June 2013.
  10. ^ Kramer, Andrew E.; Prickett, Ivor (8 April 2022). "Russian Blunders in Chernobyl: 'They Came and Did Whatever They Wanted.'". The New York Times. ISSN 0362-4331. Retrieved 9 April 2022.
  11. ^ a b Micheal Clodfelter (2017). Warfare and Armed Conflicts: A Statistical Encyclopedia of Casualty and Other Figures, 1492–2015 (4th ed.). McFarland. p. 428.
  12. ^ Bruno Fischer, Ehrenbuch des Orden vom Militär-Verdienst-Kreuz e.V. und die Geschichte der Ordens-Gemeinschaft, Die Ordens-Sammlung, 1960, p. 16
  13. ^ King-Hall, Stephen (19 May 2021). "A North Sea diary, 1914-1918 / Commander Stephen King-Hall". London, [Eng.] : Newnes – via Internet Archive.
  14. ^ "NOVA Online | Hitler's Lost Sub | Map of Lost U-Boats (frameless)". www.pbs.org. Retrieved 25 April 2019.
  15. ^ 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.
  16. ^ Churchill 2005, p. 529.
  17. ^ "Military History Online". www.militaryhistoryonline.com. Retrieved 4 February 2019.
  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 (1990). Memoirs: Ten Years and Twenty Days. Naval Institute Press. p. 482. ISBN 0-87021-780-1.
  20. ^ "Naval Technology on the Todaro class". Retrieved 9 March 2019.
  21. ^ Berg Bentzrød, Sveinung (3 February 2017). "Forsvaret kjøper nye ubåter fra Tyskland" [The Armed Forces are purchasing new submarines from Germany]. Aftenposten (in Norwegian). Oslo: Aftenposten AS. Retrieved 9 March 2019.
Further reading
  • Abbatiello, John (2005) Anti-Submarine Warfare in World War I: British Naval Aviation and the Defeat of the U-Boats
  • 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. (1994) The U-Boat War, 1914–1918
  • Hans Joachim Koerver (2010) German Submarine Warfare 1914–1918 in the Eyes of British Intelligence, LIS Reinisch, 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 (2006) The Encyclopedia of U-Boats: From 1904 to the Present, ISBN 1-85367-623-3
  • O'Connor, Jerome M. (June 2000) "Inside the Grey Wolves' Den." Naval History. 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 (2006) The U-boat Century: German Submarine Warfare, 1906–2006, ISBN 1-59114-892-8
  • van der Vat, Dan (1988) The Atlantic Campaign. Harper & Row. 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 (2007) To the Last Salute: Memories of an Austrian U-Boat Commander
  • Westwood, David (2005) U-Boat War: Doenitz and the evolution of the German Submarine Service 1935–1945, 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

The content of this page is based on the Wikipedia article written by contributors..
The text is available under the Creative Commons Attribution-ShareAlike Licence & the media files are available under their respective licenses; additional terms may apply.
By using this site, you agree to the Terms of Use & Privacy Policy.
Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization & is not affiliated to WikiZ.com.