U-boat
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- This article is about the German submarine. For other uses of U-boat, see U-boat (disambiguation).
U-boat is the anglicization of the German word U-Boot , itself an abbreviation of Unterseeboot (undersea boat). The primary targets of the U-boat campaigns in both world wars were the merchant convoys bringing supplies from Canada and the United States to Europe. Austrian submarines of World War I were also known as "U-boats".
The distinction between U-boat and submarine is common in English-language usage (where "U-Boat" is used to refer exclusively to the German naval sumbmarines of the First and Second World Wars) but unknown in German where the term U-Boot refers to any submarine.
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[edit] 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 became the first warship to be sunk by a torpedo attack from the U-21. Later on in September, U 9 sank the obsolete British warships Aboukir, Cressy and Hogue (the "Live Bait Squadron").
For the first few months of the war, U-boat anti-commerce actions observed the current "prize rules" which governed the treatment of enemy civilian ships and their occupants. 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, potentially neutral ones, without prior warning. A statement by the U.S. Government, holding Germany "strictly accountable" for any loss of American lives, made no material difference.
On May 7, 1915, U 20 sank the liner RMS Lusitania. Though there was a great deal of outrage at the sinking of an "innocent" merchant ship at the time, there is evidence that the Lusitania had munitions aboard, [1] making it a valid target under international law. Of the 1,198 lives lost, 128 were American civilians including noted theatrical producer Charles Frohman and Alfred Vanderbilt, member of the prestigious Vanderbilt family. This event turned American public opinion against Germany and was a significant factor in getting the United States involved in the war on the Allied side although nearly two years later.
The U.S. response, a threat to sever diplomatic relations persuaded the Germans to re-impose restrictions on U-boat activity. The U.S. reiterated its objections to German submarine warfare whenever their citizens died and the Germans fully re-applied 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.
Although the Germans could claim victory at Jutland, they were aware that the British Grand Fleet remained in control at sea. It was necessary to return to effective anti-commerce warfare, by U-boats. Vice-Admiral Reinhard Scheer, Commander in Chief, High Seas Fleet pressed for all-out U-boat war, persuaded 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 Germany announced, on 31 January 1917, that its U-boats would engage in unrestricted submarine warfare from February 1. On 17 March 1917, German submarines sank three American merchant vessels (see First Battle of the Atlantic) and the U.S. declared war in April 1917.
In the end, the German strategy failed to destroy Allied shipping before U.S. manpower and materiel could be brought to bear in France. An armistice became effective on 11 November 1918.
At the end of World War I, as part of the Paris Peace Conference, 1919, the Treaty of Versailles restricted the total tonnage of the German fleet. The treaty also restricted the independent tonnage of ships and forbade the construction of submarines. Before the start of World War II, Germany started rebuilding U-boats and training crews, hiding these activities as "research" or other covers, so that when World War II started, Germany already had a few U-Boats ready for warfare.
[edit] World War II
During World War II, U-boat warfare was the major component of the Battle of the Atlantic, which lasted the duration of the war. Germany had the largest submarine fleet in World War II, due to the Treaty of Versailles which limited the surface navy of Germany to six battleships (of less than 10,000 tonnes each), six cruisers and 12 destroyers. Although Winston Churchill, the United Kingdom's Prime Minister wrote "The only thing that really frightened me during the war was the U-Boat peril", evidence later accumulated showed that 98% of convoyed British ships in the first 28 months of the war crossed the Atlantic safely, and at no time was the U-boat force close to a successful blockade of the United Kingdom.[2]
In the early stages of the war the U-boats were extremely effective in destroying Allied shipping, ranging 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. 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 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 (ASW) tactics, was referred to by German submariners as the "happy time."
The U-boat was essentially a sophisticated launch platform for its main weapon, the torpedo. World War II torpedoes suffered from many limitations: they could only be launched from periscope depth or while surfaced; until later on in the war they were completely unguided, travelling in a straight line until they either collided with an object or ran out of energy. Torpedoes were fitted with one of two types of fuses, one which detonated the warhead upon impact with a solid object and another which detonated magnetically, upon sensing a large metal object nearby. Ideally, when using magnetic torpedoes, the commander would know the target ship's draft (how low its keel sits in the water) and set the torpedo's depth so that it passed just underneath, detonating via the magnetic fuse. The explosion would create a temporary gas bubble underneath the suddenly unsupported keel, which would split as a result. In this way, even large or heavily-armored ships could be sunk or disabled with a single well-placed hit. In practice, however, both the depth-keeping equipment and magnetic fuses were notoriously unreliable in the early part of the war. Torpedoes would all too often run at an improper depth, detonate prematurely or even bounce harmlessly off the target's hull. Many commanders lost all faith in their torpedoes and the problems took some time to be fully rectified.
In the later years, Germany developed an acoustic homing torpedo which was designed to run to an arming distance of 400 meters and then zero in on the loudest noise it heard. This sometimes turned out to be the U-boat itself, and at least two submarines were probably sunk by their own torpedoes. U-boats also adopted "pattern-running" torpedoes which ran 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 in case the weapon missed its primary target.
[edit] Counter-measures
Advances in convoy tactics, the full entry of the U.S. into the war with its enormous ship-building capacity, high frequency direction finding (referred to as "Huff-Duff"), radar, sonar (called ASDIC in Britain), depth charges, ASW spigot mortars (aka "hedgehog") the cracking of the German Enigma code, the introduction of the Leigh Light, and the range of escort aircraft (especially with the use of escort carriers), all turned the tide against the U-boats. In the end, the U-boat fleet suffered extremely heavy casualties, losing 743 U-boats and about 30,000 submariners (a 75% casualty rate).
[edit] Technical developments
During World War II, the Kriegsmarine produced many different types of U-boats as technology evolved. Most notable are type VII 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. With the type XXI "Elektroboot", German sub designers realized that the U-boat depended on its submerged ability both for survival and lethality. The XXI featured a revolutionary streamlined hull design and propulsion system which allowed it to cruise submerged for long periods and reach unprecedented submerged speeds.
Throughout the war an arms race evolved between the Allies and the Kriegsmarine, especially in the arenas of detection and counter-detection. 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 detection antennas which were intended to give them ample time to dive before the enemy closed in. U-boat radar was also developed, but many captains chose not to utilize it for fear of broadcasting their position to enemy patrols.
The Germans took the idea of the "Schnorchel" (snorkel) from captured Dutch submarines. The Schnorchel was a retractable pipe which allowed U-boats to run on diesel power while submerged at periscope depth, thus reducing the possibility of detection. It was far from a perfect solution, however; there were problems with the device's valve sticking shut or closing as it went underwater in rough weather; when this happened, the diesels would instantaneously suck volumes of air from the boat's compartments and the crew often suffered painful ear injuries. The schnorchel also had the effect of making the boat essentially blind, noisy, and deaf. Finally, allied radar eventually became sufficiently advanced that the profile of the schnorchel itself could be detected from a distance.
[edit] Enigma
The British had a major advantage in their ability to read the German naval Enigma codes. An understanding of the German 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 led by Alan Turing used 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 sinkings greatly increased until the new code was broken.
The U-110, a Type IXB, was captured in 1941 by the United Kingdom's Royal Navy and its Enigma machine and documents were removed. The U-505, a Type IXC, was captured by the United States Navy in 1944. It is presently a museum ship in Chicago at the Museum of Science and Industry. 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.
[edit] Battle of the St. Lawrence
Two significant attacks took place in 1942 when German U-boats attacked four allied ore carriers at Bell Island, Newfoundland. The carriers SS Saganaga and the SS Lord Strathcona were sunk by U 513 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 fired 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.
[edit] Major U-boat classes
- Type I
- Type II
- Type V
- Type VII
- Type IX
- Type X
- Type XI
- Type XIV
- Type XVII
- Type XVIII
- Type XXI
- Type XXIII
- Midget submarines, including Biber, Hai, Molch, Seehund.
[edit] Post-WWII
In the 1960s Germany (then 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 threat in the Baltic sea. The Germans sought to use advanced technologies to offset the small displacement with one of the first being amagnetic steel to protect against naval mines and MAD.
While the initial Type 201 was a failure due to hull cracking the subsequent Type 205, first commissioned in 1967, was a success with 12 being built for the German navy. To continue the U-Boat tradition and "brand name" 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 realised the potential for the submarine as an export commodity. Three of the improved Type 206 boats were sold to the Israeli Navy becoming the Gal class. The German Type 209 diesel-electric submarine was the most popular export-sales submarine in the world from the late 1960s into the first years of the 21st century. With a larger 1000-1500 tonne displacement the class was very customizable and has seen service with 14 Navies with 51 examples being built as of 2006.
Germany has brought the U-Boat name into the 21st century with the new Type 212. The 212 features an air-independent propulsion system using hydrogen fuel cells. This system is safer than previous closed cycle diesel engines and steam turbines, cheaper than a nuclear reactor and quieter than both. The Type 212 is considered to be the quietest submarine in the world.[citation needed] While the Type 212 is also being purchased by Italy, the Type 214 has been designed as the follow-on export model and has been sold to Greece and South Korea.
In July 2006 Germany will commission its newest U-boat, the U 34, a Type 212.
[edit] Popular culture
- Das Boot (1981) is a critically acclaimed German movie adapted from a mini-series about life aboard a U-Boat. The mini-series itself was adapted from a novel of the same name by war correspondent Lothar-Günther Buchheim.
- The Enemy Below and the more recent U-571, are movies revolving around WWII submarine warfare.
- Silent Hunter III, a computer submarine simulation game, centers on the German U-boat of WWII.
- Medal of Honor: Frontline, a First-person shooter computer game, featured a level in which the player fought their way through a German U-boat.
- In episode 4 of the anime Black Lagoon, the characters attempt to retrieve a lost painting from a sunken Type IXC U-Boat.
[edit] See also
- Submarine warfare
- List of U-boats
- List of the most successful U-boats
- Foreign U-Boats
- Karl Dönitz
- Operation Deadlight
- S. S. Athenia
- Laconia incident
- Accumulatoren-Fabrik AFA
- The last U-boats surrender in Mar del Plata, Argentina.
- http://www.karldoenitz.com/
- Hunt for the Red October
[edit] Notes
- ^ http://www.lusitania.net/ Lusitania.net
- ^ Blair, Clay: "Hitler's U-Boat War: The Hunters, 1939-1942", pp 426-7. Random House Press, 1996.
[edit] References
- John Abbatiello. Anti-Submarine Warfare in World War I: British Naval Aviation and the Defeat of the U-Boats (2005)
- Buchheim, Lothar-Günther, Das Boot (Original German edition 1973, eventually translated into English and many other Western languages). Movie adaptation in 1981, directed by Wolfgang Petersen
- Gannon, Michael (1998) Black May. Dell Publishing. ISBN 0-440-23564-2
- Gray, Edwyn A. The U-Boat War, 1914-1918 (1994)
- 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
- Stern, Robert C. (1999). Battle Beneath the Waves: U-boats at war. Arms and Armor/Sterling Publishing. ISBN 1-85409-200-6.
- van der Vat, Dan. The Atlantic Campaign Harper & Row, 1988. Connects submarine and antisubmarine operations between WW1 and WW2, and suggests a continuous war.
[edit] External links
- http://www.uboat.net/
- http://www.karldoenitz.com/
- The storage battery plant for submarines in Hagen, Germany
- Subsim.com
- http://ubootwaffe.net
- The Diary of a U-boat Commander – Project Gutenberg edition (WWI)
- German U-Boats 1935–1945 (in German)
- Book excerpt: U-Boat Attack
- U-Boat U-35 and Prisoners-of-War, WWII
- U-Boat U-434, POWs in Canada
- German U-Boat and Battle of the Atlantic
- German Midget submersible-MOLCH
