HEGER DRY DOCK, INC - Port of San Franciscosfport.com/sites/default/files/Maritime/Docs/Shipyard...
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HEGER DRY DOCK, INC Structural/Marine Engineers 531 Concord Street Holliston, MA 01746 Tel 508-429-1800 Fax 508-429-1811 Letter 16-87L Page 1 16‐87L December 7, 2016 Attention: Eddie Goldman, Senior Dockmaster ([email protected] ) Justin Gleaton, Dockmaster ([email protected] ) Re: Request for HEGER Certification of Dry Dock No. 2 located in BAE San Francisco, CA References: (1) HEGER Structural and Mechanical/Electrical Control Inspection Report for FDD No. 2, Aug 2016 (2) INTERNATIONAL INSPECTION Ultrasonic Gauging Survey Report for FDD No. 2, Jan 2016 (3) DRYDOCK #2 Facility Certification Report, December 1987 (4) BRUCE S. ROSENBLATT & ASSOCIATES DD No. 2 Finite Element Analysis, August 2016 Enclosures: (1) HEGER Drawing Package (2) TRITON Mooring Limitations Gentlemen: HEGER DRY DOCK, INC. has been asked to commercially certify Dry Dock No. 2 at BAE SYSTEMS’s San Francisco Shipyard in accordance with USGC SFLC STD SPEC 8634. The certification of the floating dry dock will be based on the material and operational inspection performed by Waleed Sayed and Michael Naylor, both engineers at Heger Dry Dock, on August 8 th through the 12 th , 2016. See Reference 1 for more information on survey results. In order to issue a commercial capacity certification for Dry Dock No. 2, Heger Dry Dock conducted a design review to establish operational limitations based on the dock’s current condition. The objective of this letter is to present the results of HEGER’s design review. The review outlines the dry dock’s limitations and notable structural deficiencies of the dock’s current condition. The design review includes: Transverse bending analysis / FEA review Longitudinal bending analysis Local strength calculations based on hydrostatic head pressure Intact stability calculations Review of BAE’s mooring calculations and limitations HEGER has compiled a history of the dock’s drawings for the purpose of evaluating and performing the design review. Refer to the following drawings of Enclosure 1 for more information: A‐001 GENERAL ARRANGEMENT S‐301 SECTION ‐ TYPICAL TRANSVERSE S‐302 SECTION ‐ TRANSVERSE NWT BULKHEAD S‐303 SECTION ‐ TRANSVERSE WT/NWT BULKHEAD
Transcript of HEGER DRY DOCK, INC - Port of San Franciscosfport.com/sites/default/files/Maritime/Docs/Shipyard...
HEGER DRY DOCK, INC Structural/Marine Engineers
531 Concord Street Holliston, MA 01746
Tel 508-429-1800 Fax 508-429-1811
Letter 16-87L Page 1
16‐87L December7,2016Attention: EddieGoldman,SeniorDockmaster([email protected]) JustinGleaton,Dockmaster([email protected])Re: RequestforHEGERCertificationofDryDockNo.2locatedinBAESanFrancisco,CAReferences:
(1) HEGERStructuralandMechanical/ElectricalControlInspectionReportforFDDNo.2,Aug2016(2) INTERNATIONALINSPECTIONUltrasonicGaugingSurveyReportforFDDNo.2,Jan2016(3) DRYDOCK#2FacilityCertificationReport,December1987(4) BRUCES.ROSENBLATT&ASSOCIATESDDNo.2FiniteElementAnalysis,August2016
Enclosures:
(1) HEGERDrawingPackage(2) TRITONMooringLimitations
Gentlemen: HEGERDRYDOCK,INC.hasbeenaskedtocommerciallycertifyDryDockNo.2atBAESYSTEMS’sSanFranciscoShipyardinaccordancewithUSGCSFLCSTDSPEC8634.ThecertificationofthefloatingdrydockwillbebasedonthematerialandoperationalinspectionperformedbyWaleedSayedandMichaelNaylor,bothengineersatHegerDryDock,onAugust8ththroughthe12th,2016.SeeReference1formoreinformationonsurveyresults.InordertoissueacommercialcapacitycertificationforDryDockNo.2,HegerDryDockconductedadesignreviewtoestablishoperationallimitationsbasedonthedock’scurrentcondition.TheobjectiveofthisletteristopresenttheresultsofHEGER’sdesignreview.Thereviewoutlinesthedrydock’slimitationsandnotablestructuraldeficienciesofthedock’scurrentcondition.Thedesignreviewincludes:
Transversebendinganalysis/FEAreview Longitudinalbendinganalysis Localstrengthcalculationsbasedonhydrostaticheadpressure Intactstabilitycalculations ReviewofBAE’smooringcalculationsandlimitations
HEGERhascompiledahistoryofthedock’sdrawingsforthepurposeofevaluatingandperformingthedesignreview.RefertothefollowingdrawingsofEnclosure1formoreinformation: A‐001 GENERALARRANGEMENT
S‐301 SECTION‐TYPICALTRANSVERSE S‐302 SECTION‐TRANSVERSENWTBULKHEADS‐303 SECTION‐TRANSVERSEWT/NWTBULKHEAD
Heger Dry Dock, Inc. BAE Systems Ship Repair Holliston, MA San Francisco, CA
Letter 16-87L Page 2
DescriptionofDockDryDockNo.2isaonepiecetypesteelfloatingdrydock.ThedrydockwasconstructedbytheBethlehemSteelCorporationattheirSanFranciscoYardin1970.ThedesignofthedrydockwasdonebyEarlandWright,ConsultingEngineersofSanFrancisco.Thedock’spontoonisdividedintoforty(40)ballasttanks;twenty(20)porttanksandtwenty(20)starboardtanks.Eachballasttankis40’‐0”longx84’‐0”wide.Eachballasttankisfloodedviaa20”diameterbutterflyvalveoperatedbyanelectricactuatorlocatedonthesafetydeck.Eachballasttankisdewateredbyasingle‐stagemixedflowverticalshaftpumpwithanapproximatecapacityof6,000GPM.Thepumpsandvalvesareoperatedremotelybypushbuttonsinthecontrolhouse.Thereisan18’‐0”widebuoyancychamberlocatedalongthedock’scenterline.Thebuoyancychamberisdividedintofive(5)compartmentsofvaryinglengthslongitudinally.
PRINCIPALCHARACTERISTICSOFTHEDOCK
AgeofDock.....................................................................46yearsLengthOverall...............................................................900’‐0”LengthofPontoon.......................................................800’‐0”BreadthOverall.............................................................186’‐0”BreadthbetweenWingwalls...................................150’‐0”HeightofWingwallAboveKeel..............................66’‐0”PontoonDepth..............................................................20’‐0”DesignCapacity(18”Freeboard)..........................59,600LTDesignKeelLoadLineRating.................................84LT/ft
RefertoEnclosure1foraGeneralArrangementdrawingofthedrydock.BuoyantCapacityHEGERhasreviewedthedrydock’sbuoyantliftcalculationsshownintheFCR(seeReference3).Thedockhadanoriginaldesignbuoyantliftcapacityof59,600LT.Thedock’sFacilityCertificationReportassumedthefollowingdocklightweightproperties:
DockLightweight(NoBallast)................................15,500LTVerticalCenterofGravity.........................................25.00ftabovebaseline
FreeboardmeasurementstakenonJanuary3,1986showedthedockwascapableofachievingalightdraftof4.48feet.Thisrepresentsadocklightweightof17,400LT(dockweight&residualballastof1,900LT).Thedockhasanoperatingfreeboardof18inches(equivalenttoadockdraftof18.50feet).Atthisoperatingfreeboardthedockhasadisplacementof77,170LT.Basedonthe1986freeboardmeasurements,thedockwouldhaveabout59,670LTofbuoyantcapacityavailabletoliftavesselandtrimmingwater.DuringHEGER’sinspectionofthedock(August2016),asignificantamountofmuddepositwasobservedintheballasttanks.Someareashadmuddepositsofapproximatelytwofeet.Therehasalsobeenextensivestructuralmodificationtothedocksuchastheadditionof1/2“doublerplatestothepontoondeck,newwingwallcranes,andsix(6)stabilitysponsons.Theconcernisthatthemuddepositsandstructuralmodificationsovertheyearshaveincreasedthedock’slightweightandthe1986buoyantcapacityisnolongerachievableatthe18”operatingfreeboard.
Heger Dry Dock, Inc. BAE Systems Ship Repair Holliston, MA San Francisco, CA
Letter 16-87L Page 3
MorerecentFEAreport(seeReference4)indicatesthedock’scurrentlightweighthasincreasedby3,750LTto:
DockLightweight(NoBallast)...............................................19,250LTVerticalCenterofGravity.........................................................26.22ftabovebaseline
Inordertogainadditionalliftcapacitythathasbeencompensatedbytheabove‐mentionedaddedweight,HEGERsuggestscertificationofthedock’sliftcapacityatalower12”ofpontoondeckfreeboard.Thereducedoperatingfreeboardwouldgain2,159LTofliftcapacity.Basedonthemostcurrentdocklightweightinformation,thedockwouldhaveabuoyantcapacityof58,000LTat12”ofoperatingfreeboardand55,800LTat18”ofoperatingfreeboard.Ifadditionalliftcapacityisdesired,ballasttankswouldhavetobemucked.Itisimportanttonotethatalthough12”ofoperatingfreeboardispermittedbyABSrules,MIL‐STDrulesmandatean18”operatingfreeboardforthiscapacitydock.HEGERwillneedtofieldverifyDryDockNo.2’scurrentdockweightandliftcapacitywithfieldmeasurementsatthenextsurveypriortoissuingacommercialcertification.IntactStabilityoftheDryDockDryDockNo.2wasrenovatedin2008byaddingsix(6)40’x12’sponsonsinordertoincreaseitstransverseintactstabilityfordockingphases3and4.HEGERhasdevelopedanallowableKGversusvesselweightcurveforthefloatingdrydockforaminimumGMof3.28feetasrequiredbyABS.ThestabilitycurveisshownFigure1below.Plottedpointsthatfallonorbelowthislineareacceptable,pointsaboveareunacceptable.
FIGURE1–IntactStabilityCurve
Heger Dry Dock, Inc. BAE Systems Ship Repair Holliston, MA San Francisco, CA
Letter 16-87L Page 4
MaximumSubmergenceDraftsDryDockNo.2’scurrentsubmergenceberthlimitsthedock’smaximumpossiblesubmergenceto59’‐6”,witha6‐fttide(accordingtoBAE).AllowableHeadPressuresBasedonthemaximumachievabledraftandthecorrespondinginternalballasttankwaterlevels,HEGERhascalculatedthemaximumallowableheadpressuretobeabout28‐ft,duringadockingevolutionofacapacityvessel,providedanengineeredpumpingplanisfollowed.Anemptydockorunloadedtankexperiencesahydrostaticheadpressureofabout10‐ft,duringasubmergenceevolutionprovidedanengineeredpumpingplanisfollowed.ExternalShellThedesignofthedock’sexternalshellthicknessrequirementistypicallygovernedbythestrengthrequiredtoresisthydrostaticheadpressuresexperiencedduringadockingevolution.HEGERhascalculatedtheallowablehydrostaticheadpressuretheexternalshellcansafelyresistforagivencorrodedplatethicknessusingthedock’sdesignedstiffenerspacing(typically25”).Theoriginaldesignthicknessofthewingwallsideshellplatingwas7/16”or0.44inches.TheallowableheadpressureisbasedonbasedonABSRulesforBuilding&ClassingSteelFloatingDryDocks2009.TheresultsareasfollowsandareshowninFigure2:
PlateThickness Corrosion AllowableHeadPressure
0.35inches 20% 28.2feet 0.30inches 31% 18.4feet 0.25inches 43% 10.7feet
FIGURE2–AllowableHeadPressurevs.PlateThicknessCurve
10.0
15.0
20.0
25.0
30.0
35.0
40.0
0.24 0.26 0.28 0.30 0.32 0.34 0.36 0.38 0.40
Allo
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le Head
Pressure (ft)
Plate Thickness (in)
mbell
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tmin[in] = (spacing[in] x sqrt(head[ft]))/511 + 0.09 inches Matches the chart below exactly. This simple formula is not as detailed as an FEA analysis. Also assumes a max stress of 22,600 psi per ABS rules, with no consideration for actual material yield strength. This is about 60% of A36 yield.
Heger Dry Dock, Inc. BAE Systems Ship Repair Holliston, MA San Francisco, CA
Letter 16-87L Page 5
TocreatethechartinFigure2,theassumptionisthattheanglestiffenersweldedtotheshellplatehave15%corrosionorless.HEGERhasreviewedthedock’smostrecentUTsurveyconductedbyInternationalInspectioninJanuary2016inordertoevaluatethedock’scurrentcondition,after45yearsofservice,withtheintentofdetermininganallowableheadpressureonatankbytankbasis.Allowableheadpressureisbasedonremainingmaterialthicknessoftheshellplate.TheUTsurveyresultsofthedock’sexternalshellplatingindicateareasofsignificantmetalthicknessloss.AreasofextensivecorrosionwereconfirmedbyHEGER’sAugust2016visualinspectionwithnumerousobservedholesintheplating.Themostnotableareasofcorrosionare:
OutboardShellPlating,specificallyinwayofthesplashzone(2‐ftbelowthepontoondeckto10‐
ftabovethepontoondeck)
Connectionoftheinboardwingwallsandthepontoondeck
Therehavebeenongoingrepaireffortstothedock’soriginalexternalplatingtofixareasofextensivecorrosionandholed‐throughplating.Somelocationshavebeenrepairedbyinstallingdoublerplatesoverlocalizedholes.Otherareasoftheexternalshellhavebeenrepairedbycroppingandreplacing40‐ftx10‐ftstiffenedplatepanels.Thethicknessofthenewplatepanelshasbeenincreasedto1/2”fromtheoriginal7/16”.ThemajorityoftheexternalshellrepairshavebeenmadetotheEastandWestoutboardshellswithabout20%ofthedock’soriginalplatepanelsbeingreplaced.NOTE:Theamountofvesselloadplacedoveratankgroupwilldirectlycorrelatetotheamountofheadpressurethattankgroupexperiencesinadockingevolution.Therefore,theamountofvesselloadthatcanbepositionedoveraspecifictankgroupwillbelimitedbytheminimummeasuredUltrasonicThickness(UT)measurementsurveyedinthattankgroup.
Heger Dry Dock, Inc. BAE Systems Ship Repair Holliston, MA San Francisco, CA
Letter 16-87L Page 6
PontoonDeck&TransverseBendingStrengthThedock’soriginalpontoondeckisseverelycorrodedasreflectedinthemostrecentultrasonicthickness(UT)measurementssurveyedbyInternationalInspectioninJanuary2016(seeReference2).UTmeasurementsweretakeninternallyandmeasuredthethicknessoftheoriginaldeckplateonly.Doublerplateshavebeeninstalledonthetopsideofthedrydock’soriginalpontoondeckplateoverabout65%ofthesurfacewithaconcentrationtowardsthedock’scenterline.Thedoublerplatesare1/2”inthicknessandareconnectedtothedock’soriginalpontoondeckplatevia2”x6”slotweldslocatedalongtransverseandlongitudinalstructure.Theseslotsweldsareconsideredessentialastheyprovidethedoublerplateswithrequiredbucklingcapacity.Thehalf‐inchdoublerplateswereinstalledtofortifytheoriginaldeckplateasanalternativetoremovingandreplacingthecorrodedplatingandstiffeners.HEGERhasanalyzedthedrydock’spontoondeckforbothlocalhydrostaticpressureandtransversestrengthrequirementswhenliftingakeellineloadingatthedock’scenterline.Hydrostaticpressurethicknessrequirementsaresimilartothoseoutlinedintheexternalshellsectionofthisletterasthestiffenerspacingissimilar.Anallowableheadpressureratingof28feetisrecommendedataminimum.Thetransversebendingcalculationswereanalyzedusingaloadingof68LT/fttoverifythelocalstructuralcapacitysuggestedbythedock’smostrecentFEAreport(seeReference4).IntheFEAreport,thedock’stransversecapacityisgovernedbyaconservativeremainingthicknessassumptionofthepontoonbottomplating.Thelatest2016UTmeasurementsshow20%corrosioninthemostsuspectplaces;theFEAanalysismodeledportionsofthebottomat50%toallowforfuturecorrosion.Belowisthepontoondeckthicknessrequirementstosupport68LT/FTbasedonlocationoffofdockcenterlinefromtheanalysis.
*Controlledbyhydrostaticheadpressureof28feet. Areviewofallowablepontoondeckvehiculartrafficlimitationswasnotconductedaspartofthisdesignreviewasitdoesnotinfluencethesafetyofthevesselindrydock.
LocationoffDockCenterline(ft)
PlateThicknessRequired(in)
0‐1.5 0.431.5‐3.5 0.383.5‐9 0.369‐27 0.4027‐32 0.35*32‐44 0.35*44‐50 0.35*50‐54 0.35*54‐67 0.35*
Heger Dry Dock, Inc. BAE Systems Ship Repair Holliston, MA San Francisco, CA
Letter 16-87L Page 7
MooringInordertomeetHEGERcertificationrequirements,adrydockneedstobeadequatelymooredtothepier.InMayof2016,TroyGillum,PEofTritonEngineering,Inc.conductedanengineeringanalysisofDryDockNo.2’smooringtodeterminetheoperationalwindspeedrestrictions,basedonafewdifferentvesseltypesondrydockandthedirectionofthewind.SeeEnclosure2formoreinformation.ToobtainandmaintainHEGERcertification,BAEwillberequiredtoadheretothesewindspeedrestrictionstomaintainasafeoperationofthedrydock.Thismayprecludedockinglargervesselsuntilthemooringisstrengthened.Inaddition,ifavessel’ssailarealimitstheallowablewindspeedfromanydirectiontobelow65knots,basedonmooringstrength,itshouldnotbedocked.Ifwindeventsareforecastedthatmayexceedtheallowedwindspeedforaparticularvessel’ssailarea,proceduresneedtobeinplacetoundockthatvesselbeforethepredictedeventoccurs.The65knotlimitationisbasedona10yearmeanrateofoccurrencefortheSanFranciscolocationaccordingtotheAppliedTechnologyCouncil.HEGERrecommendsthatBAEbeginexploringmethodsofstrengtheningtheirmooringdolphinsinordertoincreasethemaximumallowablewindspeedstomeetcurrentASCEcriterion.LongitudinalStrengthHEGERhasreviewedthedrydock’slongitudinalbendingcalculationsshownintheFCR(seeReference3).Thedock’soriginaldeflectionlimitwas+/‐3inches.HEGERhasperformedcorrespondinglongitudinalstrengthcalculationtoverifythedockhasadequatelongitudinalstrength.BasedonUTreports,wehaveassumedalldockstructureiscorroded15%oforiginalthicknesswiththeexceptionofthepontoondeckwhichwehaveassumedtobe50%corroded.HEGERhasconcludedthedockhasadequatelongitudinalstrengthforthecurrent+/‐3inchesdeflectionlimit.Thedock’slongitudinaldeflectionshouldbemonitoredduringalldockoperationstoensurethelimitationsarenotexceeded.Anengineeredpumpingplanshouldbedevelopedfordockingandundockingevolutionstominimizelongitudinalstressanddeflection.ConclusionandRequiredRepairsforHEGERCertificationHEGER’sprimaryconcernwiththedock’scurrentstructuralconditionistheseverelycorrodedshellplating,withnumberofholed‐throughareas.Theholes,locatedthroughoutthedock,impedethewatertightintegrityofnumerousballasttanksandraisethefollowingconcerns:
1. Thedockcannotholddraftwithoutoperatingpumpstooffsettheleakingofballasttanks.ThiswasconfirmedandobservedinHEGER’ssubmergencetestconductedinthe2016controlinspection.
2. Theholed‐throughplatingcreateslocalhydrostaticstrengthdeficiencieswhichputcorrodedareasofthedockatriskoffailure.Duetolackofmaterialstrength,thereisthepotentialfortheseholestoenlargesignificantlyduringadockingevolution,toapointwheretheamountofexternalleakagecannotbeoffsetbythedock’spumps.Itshouldalsobenotedthatthedockdoesnothaveemergencycross‐connectvaluesintheevent
Heger Dry Dock, Inc. BAE Systems Ship Repair Holliston, MA San Francisco, CA
Letter 16-87L Page 8
anindividualtank’spumpislost,thuslosingtheabilitytooffsetexternalleakage.InorderforHEGERtocertifythisdock,BAEwillberequiredtorepairthestructurallydeficientareasoftheexternalshellandmakerepairstoholesintheexternalshelltore‐establishthedock’swatertightintegrityandensuresafedockoperations.BasedonHEGER’sknowledgeofthedock’sdesignreview,visualconditionsurvey,andmostrecentUTsurvey,areasofthedock’sstructuraldeficiencieshavebeenmappedoutontheinboardandoutboardwingshellsandthepontoondeckinthedrawingslistedbelow.HEGERhasassignedaPriority1or2totheareasofmoststructuralconcern.Priority1areaswillneedtoberepairedpriortoHEGERcertification.Theseareasareeitherheavilycorrodedasindicatedbythedock’sUTsurveyorcontainholesorotherdeficienciesnotedinthe2016controlinspection.ThesquarefootageofPriority1areasisapproximately21,600sqft.Priority2areaswillneedtoberepairedbeforethesubsequentHEGERre‐certification.Theseareasalsoshowsignsofsignificantcorrosion.Untilthepriority2areasarerepaired,therewillneedtobeoperationalrestrictionsregardingallowedheadpressureintheseareas.ThesquarefootageofPriority2areasisapproximately41,400sqft.Inthedrawingslistedbelow,allareasaregenerallymappedoutonatankbytankbasis.Itisrecommendedtheexternalshellintheseareasbecroppedoutandreplacedwithafabricatedinsertplatetoproperlyrepairthearea.Intheeventofsmallisolatedholes,adoublerplatemaybeinstalledasatemporaryfix.SeethefollowingdrawingsinEnclosure1formoreinformationonUTmeasurementsandPriority1or2repairareas:
A‐002 PONTOONDECK‐1OF2A‐003 PONTOONDECK‐2OF2A‐004 WESTOUTBOARDWINGWALLA‐005 EASTOUTBOARDWINGWALLA‐006 WESTINBOARDWINGWALLA‐007 EASTINBOARDWINGWALLA‐008 PONTOONBOTTOM‐1OF2A‐009 PONTOONBOTTOM‐2OF2
Themajorityofthepontoondeckhasbeencoveredwitha1/2"doublerplate.Thisisnotaviablelongtermsolutionforthedock.HEGERrecommendsamaintenanceplanbedevelopedtoproperlyreplacethecorrodeddeckpanelswithinsertplates.Notethatthedockwasoriginallydesignedwith1/2”highstrengthsteel(yieldpointof50ksi).HEGERrecommendsanypontoondeckreplacementsbe3/4"highstrengthsteel.Notethatthismaycorrespondtoasmallreductionintheliftcapacityofthedockduetoanincreaseindockweight,butwillbuildinadditionalcorrosionallowance.SeeSection4.1ofHegerDryDock’s2016controlinspectionreport(Reference3)foratankbytanklistofnoteddeficiencies.Allrepairsrecommendedtobeaccomplishedassoonaspossibleinsection6ofthereportshouldbeconsideredPriority1andaddressedpriortoHEGERcertification.
Heger Dry Dock, Inc. BAE Systems Ship Repair Holliston, MA San Francisco, CA
Letter 16-87L Page 9
OncePriority1repairshavebeenaccomplished,HEGERwillfieldverifytheconditionofthedockandtakelightdockfreeboardsinordertocertifythedockinaccordancewithUSGCSFLCSTDSPEC8634iftheconditionsowarrants.Basedontheresultsofthisdesignreviewthedockisexpectedtohavethefollowingoperationallimitations:
LiftCapacity(18”Freeboard).................................................55,800LTLiftCapacity(12”Freeboard).................................................58,000LTMaxKeelLineLoad.....................................................................68LT/ft ExternalWaterDifferential.....................................................varies,max28feet InternalWaterDifferential......................................................20ftMaxSubmergenceDraft(on6’tide)....................................59’‐6”LongitudinalDeflection.............................................................+/‐3inchesMaxTrim.........................................................................................2ftper100ftMaxList............................................................................................2degreesAllowedWindSpeed..................................................................variesbyship,65knotsmin.required
Duetotheextentoftheexternalshellplatecorrosion,thedockwillhavemaximumexternalheadpressurerestrictiononatankbytankbasis.Themaximumheadpressurethatcanbeappliedtoatankwillbegovernedbytheleastmaterialthicknessmeasurementofthattank.Theexternalheadpressurelimitationswilldirectlyaffecttheamountofvesselloadthatcanbeappliedtothetank.Anemptydockseesapproximately10‐ftofheadpressure.Asmorevesselloadisappliedtothetank,theheadpressureincreases.Eachdockingwillhavetobecarefullylookedattoensurethatatank’soperationalrestrictionisnotexceeded.Duetothevariousoperationalrestrictionspresentedinthisreview,thecertificationissuedbyHEGERwillincludeaclausethatdockingplansandcalculationsforanyvesselexceeding60%ofthedock’sratedliftcapacitywillneedtobereviewedandapprovedbyaHEGERengineerpriortoitsdocking(untilPriority2repairsarecomplete).Pleasecontactmeifyouhaveanyquestionsorcommentsregardingthisletter.
Sincerely,HEGERDRYDOCK,Inc.MichaelNaylorEngineer
ENCLOSURE1HEGERDrawingPackage
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BAE SYSTEMS SHIP REPAIR
SAN FRANCISCO, CA.
COMMERCIAL CERTIFICATION OF FLOATING DRY DOCK #2
DRYDOCK #2 OPERATIONAL LIMITSGENERAL DRAWING INDEX
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DETAIL C1
DETAIL C4
ENCLOSURE2TRITONMooringLimitations
PROJECT:
FOR:
CLIENT:
DRY DOCK NO. 2 WIND STUDY
BAE Systems, Inc. San Francisco Ship Repair
BAE SYSTEMS, INC.
Contact: Justin Gleaton, Dockmaster
6-30-16
May 27, 2016
Troy E. Gillum, P.E.
