german type submarine boat german_imperial_navy german kaiserliche_marine world war submarine disappeared august ordered october laid shipyard bremen november little metres length displaced tonnes long tons depending surfaced submerged carried torpedoes bow torpedo tubes armed deck mounted machine gun broken sections shipped rail antwerp launched commissioned march spent entire career sank merchant ships half british fishing vessels boat responsible sinking british destroyer early converted replacement torpedo tubes disappeared august design construction german_army rapid advance north_sea coast earliest stages world war german_imperial_navy found suitable submarines operated narrow shallow seas flanders project design effort begun mid august produced type design small submarine shipped rail port operations quickly assembled constrained railroad size limitations design called boat metres long displacing long tons torpedo tubes initial seven submarines numbered ordered october shy months planning class began laid bremen november built metres long metres draft metres single brake horsepower cylinder diesel engine surface travel single shaft horsepower electric motor underwater travel attached single propeller shaft speeds knots mph surfaced knots mph submerged moderate speeds sail nautical miles surface nautical miles submerged batteries like boats class rated diving depth metres completely seconds armed centimeter torpedoes bow torpedo tubes outfitted single millimeter machine gun deck standard complement consisted officer thirteen enlisted men work complete yard rail shipment process shipping boat involved breaking submarine essentially knock kit boat broken approximately pieces loaded railway february sections shipped antwerp assembly typically week process assembled launched march loaded barge taken canals underwent trials early career submarine commissioned german_imperial_navy march command year old time boat commander april joined flanders flotilla german des organized march joined flotilla germany midst submarine offensive begun february campaign enemy vessels german defined war zone german encompassed waters united_kingdom sunk vessels neutral countries attacked definitively identified enemy vessels operating false flag july sank british fishing vessels patrolling nautical miles east northeast sunken ships sailing vessels traditionally rigged red sails stopped boarded crewmen sunk explosives similarly sank pair august trio august november succeeded command kiel command sank ships february ton belgian fishing ship largest sunk date pair british sank largest ship gross register tons grt april british registered ship route hull philadelphia ballast kiel torpedoed warning little nautical mile kilometers ships picked survivors hall men lost later month admiral newest commander chief high_seas_fleet called merchant shipping offensive ordered boats sea return boats port remain grand_fleet ambush attempts mid completed plans draw german high seas fleet sortie raid british fleet nests submarines fields support operation flanders boats set midnight form line nautical miles east group intercept attack british light forces sortie north join battle unfortunately germans british admiralty intelligence reports departure submarines coupled absence attacks shipping aroused british suspicions delayed departure german high seas fleet sortie failure boats stationed north receive coded message warning british advance caused anticipated ambush complete disappointing failure group sighted forces far away mount attack failure submarine ambush sink british capital ships allowed grand fleet engage numerically inferior high seas fleet battle jutland took place june took command june kiel assigned command new submarine months later admiral set ambush british fleet plans high seas fleet raid original intention german fleet planned depart late day august shell military targets morning group intended attack forces boats forming second line boats stationed morning august british intelligence given warning impending attack ambush causing grand_fleet sortie august hours german fleet sailed faulty intelligence caused initially divert eventually operation boats north sank british light cruisers group played action september led sinking ships capturing ship prize ton norwegian steamer sunk september ton sunk 28th dutch ship seized prize 7th conversion sister boats converted submarines dockyard november january likely boat converted conversion involved removing bow section containing pair torpedo tubes boat replacing new bow containing capable carrying mines process boats lengthened feet displacement increased long tons surface long tons surface time transferred replaced early november turn replaced january march newly converted submarine begun laying mines french coast french_navy struck mines march sank days later british auxiliary sank loss men laid march destroyer struck mines went loss men patrol english channel night surface noted large underwater explosion miles away british minefield failed return bases flanders flotilla reported likely demise hands british april found victims added tally 20th british auxiliary lost mines near days later british steamer mined loaded pit props destined ton cargo ship largest ship sunk hall sunk previous april sank ships command june july steamer carrying coal london mined sunk loss men june month later french patrol vessel mined ships credited mines fourteen months fate activities year documented specific record found english language sources known period helmed different commanders final officer assuming command command departed august lay mines downs coast returned according british source mined august author considers unlikely given near route taken downs postwar german study concluded likely struck british destroyed mines deployment considers possible diving accident related conversion months presumed loss credited sinking final ship october weeks end war ton british ship struck mines near elbow sank summary raiding history external links project research world war submarines
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