# Type UB II submarine

The UB II type submarine was a class of U-boat built during World War I by the German Imperial Navy. They were enlarged from the preceding type UB I and were more effective vessels. The boats were a single hull design with a 50-metre maximum diving depth and a 30-45 second diving time. In 1915 and 1916, 30 were built at two different shipyards.

## Design

The design of type UB II addressed many of the problems apparent in the preceding type UB I class. The UB II boats featured a two-shaft drive with a much larger battery capacity and larger engines. Storage batteries were placed forward of the central diving tanks to compensate for the much heavier engine installation.
The armament of the type UB II consisted of 50 cm G torpedoes launched from two bow tubes. The torpedo tubes were installed one above the other to allow for a bow design that would create optimal surface efficiency. A 5 cm gun was provided on the deck for surface use.
The weight of the boat was increased to 270 tons of surface displacement to accommodate these improvements. Saddle tanks were fitted to the sides of the pressure hull to allow greater fuel storage area.

## List of Type UB II submarines

There were 30 Type UB II submarines commissioned into the German Imperial Navy.
* SM UB-18 - Rammed and sunk by trawler Ben Lawer December 1917
* SM UB-19 - Sunk by Q-ship HMS Penshurst November 1916
* SM UB-20 - Struck a mine and sank during diving trial July 1917
* SM UB-21 - Foundered on way to breakers 1920
* SM UB-22 - Struck a mine January 1918
* SM UB-23 - Interned at Corunna, Spain July 1917; broken up 1921
* SM UB-24 - Surrendered to France November 1918; broken up 1921
* SM UB-25 - Sunk after collision with SMS V26 March 1917, salvaged, surrendered to the Allies November 1918; broken up 1919
* SM UB-26 - Sunk and raised by French Navy repaired as Roland Morillot BU 1931
* SM UB-27 - Sunk by HMS Halcyon July 1917
* SM UB-28 - Surrendered to Britain November 1918; broken up 1919-1920
* SM UB-29 - Previously thought being sunk by HMS Landrail, but likely mined December 1916 (wreck discovered in 2017, which contradicts the credit to Landrail. Landrail probably mistook UB-29 for another submarine, possibly the UC-19.
* SM UB-30 - Depth charged by HMS Landrail August 1918
* SM UB-31 - Struck a mine May 1918
* SM UB-32 - Possibly sunk by aircraft September 1917, but was more likely sunk by a mine
* SM UB-33 - Sunk by mines April 1918
* SM UB-34 - Surrendered November 1918; broken up 1922
* SM UB-35 - Sunk by British warships including HMS Leven January 1918
* SM UB-36 - Sunk by mines May 1917
* SM UB-37 - Sunk by Q-ship Penshurst January 1917
* SM UB-38 - Struck a mine February 1918
* SM UB-39 - Struck a mine May 1917
* SM UB-40 - Scuttled October 1918
* SM UB-41 - Possibly struck a mine October 1917
* SM UB-42 - Surrendered November 1918; broken up in 1920
* SM UB-43 - Sold to Austria-Hungary July 1917; turned over to France as war reparation in 1920 and broken up
* SM UB-44 - Missing after 8 August 1916; possibly sunk by a torpedo boat
* SM UB-45 - Struck a mine November 1916
* SM UB-46 - Struck a Russian mine December 1916. Wreck raised in 1993 and put on display in Çanakkale Turkey.
* SM UB-47 - Sold to Austria-Hungary July 1917; turned over to France as war reparation in 1920 and broken up