EntityQ2457011· pop 7· linked from 378 articlesUD-3Sign in to save1940 O 21-class submarineConnectionsGerman invasion of the NetherlandsEntityNorwayCountryWorld War IIConceptNazi GermanyConceptRotterdamEntityInternational Standard Book NumberEntityBergenEntityKielEntitysubmarineEntityelectric motorEntityLorientEntityknotEntitydiesel engineEntitynautical mileEntityKriegsmarineEntitygross register tonnageEntityAdmiral HipperEntitytorpedo tubeEntityEmdenEntityGerman occupation of NorwayEntityCategories1939 shipsMaritime incidents in May 1940Maritime incidents in May 1945Naval ships of the Netherlands captured by Germany during World War IIO 21-class submarinesOperation Regenbogen (U-boat)Submarines built by Wilton-FijenoordWorld War II submarines of GermanyWorld War II submarines of the Netherlands