German propaganda film without dead or wounded; many details about submarine warfare in World War I. Room 40: original documents, photos and maps about World War I German submarine warfare and British Room 40 Intelligence from The National Archives, Kew, Richmond, UK. German Type U 31 submarines U-boats commissioned in 1914 Maritime incidents in 1918 U-boats sunk in 1918 World War I submarines of Germany World War I shipwrecks in the Mediterranean Sea U-boats sunk by depth charges U-boats sunk by British warships 1914 ships Ships built in Kiel Ships lost with all hands