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SM U-21

1915 WORLD WAR 1

History

The U-21 was the third of the four-class U-19 submarines to serve in the German Imperial Navy during the First World War (1914-1918). This class represents the design of pre-war German attack submarines and was the first submarine in service with the German Navy to use diesel engines as standard propulsion. The class entered service with the outbreak of war in July 1914, with its first kill in September - the U-21 was the first submarine in Navy history to record self-propelled torpedoes (HMS Pathfinder) destroying enemy surface ships ). U-21 was built by the Imperial Dockyard in Danzig and laid in 1910.

Her hull was launched on 8 February 1913 and officially commissioned on 22 October 1913.

As a full U-21, 720 tons (short) when surfaced and 923 tons when submerged. She is 210.5 feet long, has a beam of 20 feet, and has a draft of 11.8 feet. Power is provided by 2 MAN 8-cylinder diesel engines driving two axles for surface travel and 2 AEG engine generators for underwater use. Top speed (surfaced) is 15.5 knots (9.5 knots underwater). The U-21's crew consisted of 29 people, including four officers at the officer level.

Armament includes 4 x 500mm torpedo tubes and 1 x 88mm SK L/30 deck gun.

As the First World War began to unfold among many participants, U-21 found itself stationed near the Heligoland Islands off the northwest coast of Germany. With the Royal Navy's fleet posing a constant threat to German operations in the North Sea and the Atlantic, wartime patrols soon became a way of life for U-boat crews.

Her first patrol began in August, although no action was reported during that service and during her second wartime patrol. It wasn't until September 5, when the German U-boat first spotted prey, that the U-21 encountered the HMS Pathfinder near May Island.

After a period of maneuvering, the U-21 successfully torpedoed the Pathfinder, which in turn ignited one of the Pathfinder's magazines, causing them to explode. The attack killed 261 British sailors. In 1916, the U-21 received a second 88mm deck gun to improve surface attack capabilities.

From September 1914 to June 1917, the U-21 set a long-term kill record starting with the Pathfinder and ending with the Swedish ship Baltic. During her wartime career, U-21 conducted a total of 11 patrols and captured 38 merchant ships and 4 enemy warships. The total tonnage of merchant ships was nearly 88,000 tons, and 34,575 tons of warships were sunk. Her career took her from the North Sea in 1914 to the Mediterranean in 1915-17, where she and her crew were called to Turkey to support a new German ally. During the Battle of Gallipoli, the U-21 played a major role in threatening the concentration of useful close-support fire on Allied ships to land troops on the ground, sinking two (currently 18) former Dreadnoughts in the process.

She formed part of the Black Sea Fleet and then found herself appointed part of the Austro-Hungarian Navy, giving her freedom to attack Italian ships - Germany wasn't officially at war with Italy at the time, but the Italians were fighting German ally Austria-Hungary . She served under the Austro-Hungarian flag as "U-36" until Italy declared war on Germany on August 27, 1916. In 1917, she was recalled to the North Sea to attack British warships again.

In 1918, she became part of III. U-boat fleet, later in a training role for the remainder of the war - which ended with an armistice on November 11, 1918.

Following the surrender of Germany, U-21 was collected by the British, and during the operation to drag her into British waters, U-21 crashed and sank - completely ending her high seas career.