SM U-4 (Germany) explained

SM U-4 was one of the 329 submarines serving in the Imperial German Navy in World War I. She was partially broken up in 1919 with her hull being sold on.^[1]

Bibliography

• Book: Gröner. Erich. Jung. Dieter. Maass. Martin. Thomas. Keith. Magowan. Rachel. 1991. U-boats and Mine Warfare Vessels. 2. German Warships 1815–1945. London. Conway Maritime Press. 0-85177-593-4. CITEREFGröner1991.
• Book: Rössler, Eberhard. Die deutschen U-Boote und ihre Werften: U-Bootbau bis Ende des 1. Weltkriegs, Konstruktionen für das Ausland und die Jahre 1935–1945 . The German Submarines and Their Shipyards: Submarine Construction Until the End of the First World War. I. Bernard & Graefe. Koblenz. 1985. 3-7637-5213-7. de.

Notes and References

1. 4. U 4. 1sub. 21 January 2010.