German submarine Bremen

Commander of the Bremen, Karl Schwartzkopf
History
German Empire
Name:	Bremen
Builder:	Flensburger Schiffbau
Fate:	Disappeared at sea, September 1916
General characteristics
Class and type:	German Type U 151 submarine
Displacement:	2,272 t (2,236 long tons)
Length:	65 m (213 ft) (o/a)
Beam:	8.90 m (29.2 ft)
Draught:	5.30 m (17.4 ft)
Propulsion:	800 PS (588 kW; 789 bhp)
Speed:	Surfaced 10 knots (19 km/h; 12 mph) submerged 6.7 knots (12.4 km/h; 7.7 mph)
Range:	12,000 nmi (22,000 km; 14,000 mi)
Test depth:	50 m (160 ft)
Capacity:	700 tons

Bremen was a blockade-breaking German merchant submarine of World War I. Developed with private funds and operated by the North German Lloyd Line, she was one of the first of seven U-151 class U-boats built and one of only two used as unarmed cargo submarines.

Bremen was built together with her sister ship 'Deutschland in 1916 by the Deutsche Ozean-Reederei, a private shipping company created for the enterprise, a subsidiary company of the North German Lloyd shipping company (now Hapag-Lloyd) and the Deutsche Bank. She was constructed without armaments, with a wide beam to provide space for cargo. The cargo capacity was 700 tons (much of it outside the pressure hull), relatively small compared to surface ships.

Bremen was one of seven submarines designed to carry cargo between the United States and Germany in 1916, through the naval blockade of the Entente Powers. Mainly enforced by Great Britain's Royal Navy, the blockade had led to great difficulties for German companies in acquiring raw materials which could not be found in quantity within the German sphere of influence, and thus substantially hindered the German war effort.

Five of the submarine freighters were converted into long-range cruiser U-boats (U-kreuzers) equipped with two 105mm deck guns, and only two were completed according to the original design: the Deutschland and the Bremen.

The Bremen departed Bremerhaven in September 1916 for Norfolk, Virginia, commanded by Kapitänleutnant Karl Schwartzkopf, and reportedly carrying financial credits for Simon Lake to begin building cargo submarines for Germany. She did not complete this voyage and her fate is a mystery. Several views have been put forth as to the nature of her fate.