SALVAGE OF THE SALVAGE OF THE BATTLESHIPBATTLESHIPUSS USS OKLAHOMAOKLAHOMAFOLLOWING THE ATTACK FOLLOWING THE ATTACK ON PEARL HARBORON PEARL HARBOR19421942--4646 The USS Oklahoma was our first battleship equipped with 14-inch rifle main batterySecond unit of the Nevada Class, built at Camden, New Jersey in 1914-16. Commissioned in May 1916The Oklahoma was 583 feet long with a maximum beam of 95 feet. She had a maximum displacement of 27,500 Tons. This shows gunnery training in 1917, during World War IUSS OklahomaUSS Oklahoma--The Oklahoma was extensively modernized in 1927-29 to make her less vulnerable to air and torpedo attack -In July 1936, she was dispatched to Europe to evacuate US citizens during the Spanish Civil WarAttack on Pearl HarborAttack on Pearl HarborJapanese torpedo exploding against hull of the OklahomaJapanese torpedo exploding against hull of the OklahomaThe Oklahoma’s berth provided the clearest approach path for Japanese torpedo bombers along battleship rowATTACK ON BATTLESHIP ROWATTACK ON BATTLESHIP ROWThe The OklahomaOklahomawas hit by 9 torpedoes because of was hit by 9 torpedoes because of her position opposite the inner harbor, which her position opposite the inner harbor, which allowed Japanese bombers a clear approach path allowed Japanese bombers a clear approach pathEach torpedo struck the Oklahoma’s port side at higher levels Each torpedo struck the Oklahoma’s port side at higher levels because the ship began listing soon after the first torpedo detobecause the ship began listing soon after the first torpedo detonated. nated. This plot was assembled by John F. This plot was assembled by John F. DeVirgilioDeVirgilio(1991). (1991).Capsized hull of the Oklahoma outboard of the battleship Maryland, which received almost no damageDamage Assessment: Aerial view of battleship row, showing capsized hull of Oklahoma (arrow)The Oklahoma had her bilge inspection covers removed for a schedThe Oklahoma had her bilge inspection covers removed for a scheduled uled inspection the following day (Dec 8inspection the following day (Dec 8thth). This precluded counter flooding ). This precluded counter flooding to prevent her from capsizing . Although 32 sailors wee saved ato prevent her from capsizing . Although 32 sailors wee saved after 3 fter 3 days, 415 of her crewmen perisheddays, 415 of her crewmen perishedSituation when salvage beganSituation when salvage began--19421942Salvage efforts concentrated on the least damaged ships first, the Oklahoma and Utahwere the last ships to receive serious attention USS OklahomaUSS OklahomaThe Navy contracted with Pacific The Navy contracted with Pacific Bridge Company of San FranciscoBridge Company of San Francisco••Refloating Methods ConsideredRefloating Methods Considered••Sealing the holesSealing the holes••PontoonsPontoons••CounterweightCounterweight••Floating Dry DocksFloating Dry Docks••Power winches on shore and rigging direct to the Power winches on shore and rigging direct to the ship; This technique was previously employed to ship; This technique was previously employed to recover an overturned 19,000 ton caisson during recover an overturned 19,000 ton caisson during construction of the Midconstruction of the Mid--Hudson suspension bridge Hudson suspension bridge at Poughkeepsie, NY in 1930at Poughkeepsie, NY in 1930--3131Final design of AFinal design of A--frame attachments frame attachments to the overturned hullsto the overturned hullsSoil from this area had to be progressively removed to allow final rightingWinch DesignWinch Design21 Compound pulleys 21 Compound pulleys 429 ton capacity each429 ton capacity eachWinch motors taken Winch motors taken from Honolulu from Honolulu streetcarsstreetcarsMotors had to respond Motors had to respond precisely to individual precisely to individual controlcontrolOperator stationed at Operator stationed at each wincheach winchVariableVariable--voltage drives voltage drives 3“ cable between the 3“ cable between the sheaves and the shipsheaves and the ship1” steel cable on the 1” steel cable on the wincheswinchesSuccessful Successful RightingRightingof the Oklahomaof the OklahomaFirst Pull configuration began 8 March 1943Final Pull configuration from 20 May 194374 days used to turn ship overA-frames dropped out around 70 degreesPreparing the hull for Preparing the hull for refloatingrefloatingPlacing the first cofferdam patch over torpedo damaged hull’s port side. Each patch was custom made to fit a certain portion of the deformed hullThe ship was about 10 feet below water level after righting operations were completedCaptain Homer N. Captain Homer N. WallinWallin, , USN Naval Academy USN Naval Academy Class of 1917 Served Class of 1917 Served initially on battleshipsinitially on battleshipsPost graduate degree in Post graduate degree in Naval Architecture from Naval Architecture from MITMITPrior to Pearl Harbor Prior to Pearl Harbor attack he was the Material attack he was the Material Officer on staff of the Officer on staff of the Commander, Battle Force Commander, Battle Force ––PacificPacificADM ADM NimitzNimitzpromoted him promoted him to Captain and made him to Captain and made him the Fleet Salvage Officer the Fleet Salvage Officer and Salvage and Salvage SuperintendentSuperintendentSalvage ProblemsSalvage ProblemsRefloatingRefloatingof the sunken hull required all hull of the sunken hull required all hull leaks to be patchedleaks to be patchedGaping torpedo holes were covered with Gaping torpedo holes were covered with enormous timber cofferdamsenormous timber cofferdamsConcrete patches used beneath the Concrete patches used beneath the cofferdams cofferdams Biggest challenge was gaps between hull Biggest challenge was gaps between hull plates because frame was distorted by plates because frame was distorted by capsizing and salvage roll overcapsizing and salvage roll overDivers stuffed kapok into gaps between hull Divers stuffed kapok into gaps between hull plates as water was pumped from hull. This plates as water was pumped from hull. This eventually workedeventually workedMk V Deep Sea Diver Mk V Deep Sea Diver rig was used in much rig was used in much of the underwater of the underwater salvage work salvage work Many of the salvage Many of the salvage techniques used techniques used today were developed today were developed by these divers by these divers during World War II, during World