U-boat

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"U-boat" is also a nickname for some diesel locomotives built by GE; see List of GE locomotives

U-boat is the anglicization of the German word Template:Audio, itself an abbreviation of Unterseeboot (its literal meaning: "undersea boat"), the German word for submarine. 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 but unknown in German where the term U-Boot refers to any submarine.

1 World War I
2 World War II
3 Popular culture
4 See also
5 References
6 External links

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World War I

Image:U9Submarine.jpg 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, historians now believe the Lusitania had 10 tons of weapons aboard, making it a valid target under international law. Of the 1,195 lives lost, 128 were American civilians, including a noted theatrical producer and a 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.

With the United States already on the side of the Allies, Germany announced on 31 January 1917 that its U-boats would engage in unrestricted submarine warfare. On 17 March 1917, German submarines sank three American merchant vessels. See First Battle of the Atlantic.

At the end of WWI, 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 WWII, Germany started rebuilding U-boats and training crews hiding these activities under research or other false motives, so as when WWII started, Germany already had a few U-Boats ready for warfare.

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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), six cruisers and 12 destroyers. Winston Churchill, the United Kingdom's Prime Minister for most of the war, was quoted as saying, "The only thing that really frightened me during the war was the U-Boat peril."

In the early stages of the war the U-boats were extremely effective in destroying allied shipping, 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. Contary to popular notion, the most common u-boat attack (especially in the early years of the war) was conducted on the surface and at night.

The U-boat (and modern attack submarines) are essentially sophisticated launch platforms for their 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 staight line until they either impacted with a target or ran out of energy. Torpedoes were fitted with two 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 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 accoustic 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 were probably sunk by their own torpedoes. U-boats also adopted "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 in case the weapon missed its primary target.

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, the cracking of the German Enigma code, the introduction of the Leigh Light and the range of escort aircraft, 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).

Image:Uboat sinking survivors.png 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 some even able to reach the Eastern seabord of the United States. With the type XXI "elektroboat," German sub designers finally 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. It also posessed a "schnorkel" which allowed the boat to run its diesels while submerged at periscope depth, reducing the possibility of detection.

U-505 was a Type IXC, notable for its capture by the United States Navy in 1944. It is presently a museum ship in Chicago, Illinois at the Museum of Science and Industry. The capture of U-505 was noteworthy due to the capture of her codebooks, but somewhat unnecessary because the British already had the ability to read recent German codes. U-110, a Type IXB, had been captured in 1941 by the United Kingdom's Royal Navy, helping to stay on top of the German Enigma code upgrades, before the entry of the US into World War II.

Two significant attacks took place in 1942 when German U-boats attacked four allied ore carriers at Bell Island, Newfoundland. The carriers S.S. Saganaga and the S.S. Lord Strathcona were sunk by U-513 on September 5, 1942, while the S.S. Rosecastle and P.L.M 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.

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Popular culture

Silent Hunter III, a submarine simulation for the computer, centers on the German U-boat of WW2. Medal of Honor: Frontline featured a level in which the player fought their way through a German U-boat. Many movies and television shows have focused on this topic as well, such as the critically acclaimed 1981 German movie Das Boot.
"U Boat" is also the name of the final track on the album Kasabian by the band of the same name.

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References

Stern, Robert C. (1999). Battle Beneath the Waves: U-boats at war. Arms and Armor/Sterling Publishing. ISBN 1854092006.
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 0-375-50858-93
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