SM U-103 was an Imperial Germany 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-boat

U-boat

U-boat is the anglicized version of the German word U-Boot , itself an abbreviation of Unterseeboot , and refers to military submarines operated by Germany, particularly in World War I and World War II...

 during the First World War. U-103 was built on AG Weser

AG Weser

Aktien-Gesellschaft Weser was one of the great German shipbuilding companies, located at the Weser River in Bremen. Founded in 1873 it was finally closed in 1983. Altogether, AG Weser built about 1400 ships of different types, including many war ships...

 in Bremen

Bremen

The City Municipality of Bremen is a Hanseatic city in northwestern Germany. A commercial and industrial city with a major port on the river Weser, Bremen is part of the Bremen-Oldenburg metropolitan area . Bremen is the second most populous city in North Germany and tenth in Germany.Bremen is...

, launched on 9 June 1917 and commissioned 15 July 1917. She completed 5 tours of duty under Commander Claus Rücker and sank 8 ships for a total of .

Loss

In the early hours of 12 May 1918, the U-103 prepared to launch torpedoes from her stern tubes at RMS Olympic

RMS Olympic

RMS Olympic was the lead ship of the Olympic-class ocean liners built for the White Star Line, which also included Titanic and Britannic...

, the sister ship of the ill-fated RMS Titanic which was en route for France with US troops on board. However, the crew was unable to flood the two stern torpedo tubes, and the submarine was sighted on the surface by Olympic, whose gunners opened fire as Olympic turned to ram.

U-103 crash dived to 30 m (98.4 ft) and turned to a parallel course, but almost immediately afterwards was struck just aft of her conning tower and Olympic's port propeller sliced through U-103's pressure hull. The crew of U-103 blew her ballast tanks and scuttled and abandoned their sinking submarine. Olympic did not stop to pick up the survivors, but continued on to Cherbourg. The USS Davis

USS Davis (DD-65)

USS Davis was a Sampson-class destroyer in the United States Navy during World War I. She was the second Navy ship named for Rear Admiral Charles Henry Davis . She served with the United States Coast Guard as '....

 later sighted a distress flare and took on board the 31 survivors. This was the only known sinking of a warship

Warship

A warship is a ship that is built and primarily intended for combat. Warships are usually built in a completely different way from merchant ships. As well as being armed, warships are designed to withstand damage and are usually faster and more maneuvrable than merchant ships...

 by a merchant vessel

Merchant vessel

A merchant vessel is a ship that transports cargo or passengers. The closely related term commercial vessel is defined by the United States Coast Guard as any vessel engaged in commercial trade or that carries passengers for hire...

during the First World War.

U-103's wreck lies at position 49°16′N 4°51′W.