german type submarine boat german_imperial_navy german kaiserliche_marine world war sunk british ship disguised fishing august ordered october laid shipyard kiel 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 conducted sortie flanders flotilla april sank ship credited flotilla sank ships mid april mid august august surfaced near british ship sunk gunfire sailing vessel crewmen survived attack design construction german_army rapid advance north_sea coast earliest stages world war german_imperial_navy found suitable submarines operated narrow shallow environment 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 tonnes long tons torpedo tubes initial submarines numbered ordered october shy months planning class began laid kiel 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 early sections shipped antwerp assembly typically week process assembled launched march loaded barge taken canals underwent trials service career submarine commissioned german_imperial_navy march command year old time boat commander soon joined boats comprising 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 including english channel sunk vessels neutral countries attacked definitively identified enemy vessels operating false flag kicked operations new flotilla departed patrol april following day sank ship credited flanders flotilla ton british chartered headed norfolk virginia united_states ballast delivering relief supplies came steamer hook holland pulled yards despite fact ship pass safe conduct germany marked words belgian relief flying white flag wording gross torpedoed vessel warning sank minutes allowed time launch dutch american steamer picked survivors head relief committee reported organization charter ship ended delivery cargo expressed disbelief ship victim torpedo attack given distinct assurance ships engaged relief effort master man crew died attack largest ship sunk career followed sinking sinking greek ship steamer gross register tons grt route amsterdam sunk gross april german boats sank tons shipping june contribute totals add ship ton tally july sank belgian ship load coal july ton steamer sailed headed sunk nautical miles sinking august ton british fishing stopped boat boarded sunk explosives nautical miles east northeast according website attack likely operating area fourteenth patrol regardless identity attacker approach group vicinity day unbeknownst commander gross fishing vessels actually british ship ship majesty armed outfitted concealed pounder gun drew yards gross conning tower shouted commands crew german waiting right moment royal_navy gunner command ordered white ensign raised gave command open fire burst rounds pounder scored hits conning tower second destroying bridge sending gross water helm drifted clear pounder fired shots hull point blank range small arms fire crew submarine boat began going bow nearly vertical disappearing surface member crew attempted rescue unable reach went meeting fate thirteen crewmen went hulk nets deployed appearance real fishing boat essentially place ship crew having wireless set board sent word encounter followed releasing messenger following morning requesting instructions thought boat rejected nets cut freeing sink wreck lies position awarded sinking crewmen split submarine bounty paid admiralty summary raiding history
SM UB-4