Early U-boats (1850–1914)
The first submarine built in Germany, the three-man
Brandtaucher, sank to the bottom of
Kiel harbor on 1 February 1851 during a test dive.
Wilhelm Bauer had designed this vessel in 1850, and
Schweffel & Howaldt constructed it in
Dredging operations in 1887 rediscovered Brandtaucher; it was later raised and put on historical display in Germany.
There followed in 1890 the boats WW1 and WW2, built to a
Nordenfelt design. In 1903 the
Friedrich Krupp Germaniawerft dockyard in Kiel completed the first fully functional German-built submarine,
Krupp sold to Russia during the
Russo-Japanese War in April 1904.
SM U-1 was a completely redesigned
Karp-class submarine and only one was built. The
Imperial German Navy commissioned it on 14 December 1906.
 It had a double hull, a
kerosene engine, and a single torpedo tube. The 50%-larger
SM U-2 (commissioned in 1908) had two torpedo tubes. The
U-19 class of 1912–13 saw the first
diesel engine installed in a German navy boat. At the start of World War I in 1914, Germany had 48 submarines of 13 classes in service or under construction. During that war the Imperial German Navy used SM U-1 for training. Retired in 1919, it remains on display at the
Deutsches Museum in Munich.