The ''O 21'' class was a
class
Class or The Class may refer to:
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* Class (philosophy), an analytical concept used differently ...
of seven
submarines, built for the
Royal Netherlands Navy. The boats were still incomplete at the start of the German invasion of the Netherlands ''O 21'', ''O 22'', ''O 23'' and ''O 24'' were hastily launched and escaped to the United Kingdom. ''O 25'', ''O 26'' and ''O 27'' were not able to escape and were captured by the German forces. The ''
Kriegsmarine
The (, ) was the navy of Germany from 1935 to 1945. It superseded the Imperial German Navy of the German Empire (1871–1918) and the inter-war (1919–1935) of the Weimar Republic. The was one of three official branches, along with th ...
'' ordered the completion of the boats and they entered German service as ''UD-3'', ''UD-4'' and ''UD-5''. The submarines diving depth was .
Design
One of the requirements the
Royal Netherlands Navy set for the ''O 21''-class was that it had to be able to dive deeper than the previous class, which was the
''O 19''-class submarine.
[Gerretse and Wijn, p. 9]
Construction
The ships were built by three different shipyards. ''O 21'' and ''O 22'' were built by the
''Koninklijke Maatschappij''.
''O 23'', ''O 24'', ''O 26'' and ''O 27'' by
''R.D.M, Rotterdam'' and ''O 25'' also in Rotterdam at
''Fijenoord'' shipyard.
References
Bibliography
*
*
External links
Description of class
{{WWII Dutch ships
Submarines of the Netherlands