SECTION1INTRODUCTION
1General
Thisclassguideline(CG)shouldbeconsideredinconnectionwithDNVRulesforClassificationofShips,DNV-
RU-SHIPPt.3HullandDNV-RU-SHIPPt.5Ch.2Sec.1ContainerShips.
ThisCGdescribesthescopeandmethodsrequiredforstructuralanalysisofcontainershipsandthe
backgroundforhowsuchanalysesshouldbecarriedout.Thedescriptionisbasedonrelevantrulesfor
classificationofships.
TheDNVrulesforclassificationofshipsmayrequiredirectstructuralstrengthanalysesincaseofacomplex
structuralarrangement,orunusualvesselsize.
StructuralanalysescarriedoutinaccordancewiththeprocedureoutlinedhereandinDNV-CG-0127Finite
ElementAnalysiswillfulfiltherequirementstocalculationsasrequiredbytherules.
Wherethetextreferstotherulesforclassificationofships,thereferencesrefertothelatesteditionofthe
rulesforclassificationofships.
2Containershipcharacteristics
2.1Containershipcategories
Containershipsareshipsdesignedforthetransportationofcontainercargoesandarrangedwithcellguides
inholds.Containersarestandardisedinseveralsizes,e.g.20’,40’,45’and48’containersarecommon.The
mostcommonsizesare20’(TEU:Twenty-footequivalentunit)and40’(FEU:Forty-footequivalentunit)
containers.Thesizeofthecontainershipwillbeinfluencedbythecharacteristicsoftherouteandtrade
patternforwhichtheshipisoperating.Theshipsmaybecategorisedasfollowsaccordingtothesizegroup:
— Feedercontainership:Acontainershipwhichcancarryapproximately100TEU-3.000TEUandis
mainlydeployedforshortvoyagesbetweenhubportsandsmallportsinthelocalarea.Theshipsmaybe
equippedwithcranesforservingsmallerportswheregantrycranesarenotavailable.
— Panamax:Acontainershipwhichcancarryuptoabout5.500TEU.Maindimensionsarelimitedtothe
PanamaCanal(B=32.2m,Loa=294m,T=12.0).Ballastrequirementstomaintainacceptablestability
areaconcernofthePanamaxduetoitshighlengthtobeamratio.
— Post-Panamax:AcontainershipexceedingthePanamaCanallimits.Post-Panamaxcontainerships
typicallyhaveacapacitygreaterthan5000TEU.
— NPX,NewPanamax:AcontainershipwithdimensionsallowingittopassthenewPanamaCanallocks,
withLoa=366m,B=49mandT=15.2,withasizeof12.500–14.500TEU.
— Ultralargecontainerships(ULCS):designsexceedingtheNPXlimits.Thebiggestcontainerships
deployedhavecontinuouslyincreasedinsizeoverthedecades.
2.2Operationalpatternsthatmayhaveimpactonthedesign
Containershipsarenormallyoperatedonregularroutesbetweendesignatedports.Thetimescheduleis
extremelyimportantfortheoperationofcontainerships.Theweatherandseaconditionsvary,dependingon
wheretheshipistrading.
Variationsintheloadingconditionswillalsoaffectthebehaviouroftheshipatsea,makingitcomplexto
predicttheactuallong-termloadingonthehullstructure.
Thisclassificationguidelinefocusesontypicalloadcombinationsestablishedtopreventstructuralproblems
duringregulartradearoundtheworld.
Shipownersandoperators,iftheyhavespecificknowledgeaboutpossibleloadingconditions,traderoutes,
preferredGMvaluesduringoperationetc.,shouldgivesuchinformationtothedesignersinshipyardsand
classasearlyaspossiblewhenplanninganewproject.Byprovidingsuchinformation,theamountof
Section1
Classguideline—DNV-CG-0131.EditionAugust2021 Page5
Strengthanalysisofhullstructureincontainerships
DNVAS