New Classification Rules For Composite Tween Deck

New Classification Rules for Composite Tween DeckELASS SeminarDr. Philippe Noury28 January 20211DNV GL 202126 January 2021SAFER, SMARTER, GREENER

ContentTween deckBackgroundMotivationsRules for classification of shipsClass guidelineFuture work2DNV GL 202126 January 2021

In (Be)Tween deck3DNV GL 202126 January 2021SAFER, SMARTER, GREENER

IKNOWTween deck4DNV GL 202126 January 2021SAFER, SMARTER, GREENER

BackgroundStatutory ApprovalComposite hatch coverconcept for OshimaECO-Ship 2020for fire safety grantedby Panama Flag StateReg.1720132011-2013Approval in Principleby DNV GL5DNV GL 202126 January 2021Composite tween deckdesign, constructionand approval2016–201720132018–2021Composite tween deckconcept and feasibility

Motivations for a composite designLighterLarger paneland smallercranes ( )Quicker toinstall andmoveHEACLess time inportMaximiseutilisation andreduce costLOW HANGING FRUIT: Technologyeasier to implement than hatchcovers as low risk i.e. steppingstone6DNV GL 202126 January 2021

Why new rules for composite tween deck?Fibre-reinforced-polymer composite materialsbehave differentlyDifferent failure mechanism as opposed to justyielding and bucklingLower stiffness, nonlinear behaviourViscoelastic responseLimited means available for NDESensitive to localised lateral loads due to thelower stiffnessConnections between different materialscomposite / steel elementsCombustible resin and fire safetyDNVGL-ST-C501, Composite components7DNV GL 202126 January 2021

New rules – 2 DocumentsClass guidelinesRules8DNV GL 202126 January 2021

Rules - Foremost requirements A short section in the rules forclassification of ships Rules reference are introduced Material, loads, structural capacity, firesafety etc. Part 3, Chapter 12, Section 3.3 of DNV GLRules for Ships9DNV GL 202126 January 2021

Rules10DNV GL 202126 January 2021

Class guideline - Detailed requirements Detailed requirements DNVGL-CG-0556– Composite Tween Deck– published in September 2020 Many references to exiting rules– concise, 22-pages document 8 main sections:– General– Materials– Loads– Structural capacity– Connections– Metallic components– Fire safety– Manufacturing11DNV GL 202126 January 2021

Section 1 - General Provides general information i.e.purpose, scope, applicability,documentation and certification to besubmitted for approval Application for bulk carrier and drycargo ships Documentation requirements– Vessel GA– Tween deck: design basis, GA,equipment, design analysis, materialspecs, data sheets etc. Compliance requirements12DNV GL 202126 January 2021

Section 2 - Materials Short section and specifiesrequirements to quality of (raw)composite materials and metallicmaterials. References to exiting ship rules andhigh speed craft (HSC) rules for steelmaterials and raw composite materials. Type Approval Certificates need for allraw materials13DNV GL 202126 January 2021

Section 3 - Loads Reference to existing ship rules for loads,load cases and cargo lashing List of load types to be considered asminimum– selfweight, uniform cargo load, projectcargo, ship acceleration, thermalexpansions Accidental loads– dropped object Design load cases– beams seas, head seas and obliqueseas– highest accelerations with fully loadedtween deck– lifting– when stored on deck, sea pressure,stacking– forklift– lashing14DNV GL 202126 January 2021

Section 4 - Structural capacity Metallic componentsHEAC– Reference to existing ship and HSCrules for structural design andstructural assessment Composites components:– For simple approach, reference toexisting rules for structural designand structural assessment of highspeed craft– More advanced approach: referenceto standard DNVGL-ST-C501 Importance of addressing all relevantfailure modes and mechanism and notonly fibre failure.15DNV GL 202126 January 2021HEAC

Section 5 - Connections Important chapter Reference to existing rules Connections types:– hull connection– insert– between deck component Examples of local connections– lifting points– lashing points– stacking socket or pins, when tweendecks stored on weather deck– between panels, for composite tweendeck composed of several panels– resting sockets or pins Bolted connections Bonded connections16DNV GL 202126 January 2021

Section 6 - Metallic components For all essential structural elements– steel plates– lifting eye and sockets– bolts Reference to existing ship rules Type-approved and from an approvedmanufacturer as per DNV GL rules forclassification of shipsHEAC17DNV GL 202126 January 2021

Section 7 - Fire safety Reference to existing ship rules Alternative design– To be evaluated on a case-by casebasis if there is a need for analternative design approach on firesafety, by DNV GL or Flag State– References– Ch.II-2 Reg.17 of SOLAS– IMO MSC/Circ.1002– IMO MSC.1/Circ.157418DNV GL 202126 January 2021

Section 8 – Manufacturing Reference to existing ship rules Requirements for manufacturers to beapproved by DNV GL as per DNVGL-CP0421. Quality is safety!19DNV GL 202126 January 2021

Production quality and production damageResin-rich corners20DNV GL 202126 January 2021Wrinkles

Microscopy of resin-rich corners21DNV GL 202126 January 2021

Future workIKNOWFor 2021, new sections: Section 8 – Improvement on assembly andfactory acceptance tests (FATs) Section 9 – Installation onboard2022–20232021IKNOWFor 2022-2023, additional scopehatch cover New title: DNVGL-CG-0556, CompositeHatch Cover and Tween Deck22DNV GL 202126 January 2021

JIP / Acknowledgement JIP consortium– DNV GL (Norway)– Oshima Shipbuilding (Japan)– Compocean (Norway)– HEAC (Norway)– Masterbulk (Norway)– Innovation Norway (Norway)23DNV GL 202126 January 2021

Thank you !Dr. Philippe Nouryphilippe.noury@dnvgl.com 47.48.29.99.21www.dnvgl.comSAFER, SMARTER, GREENER24DNV GL 202126 January 2021

Section 2 - Materials Short section and specifies requirements to quality of (raw) composite materials and metallic materials. References to exiting ship rules and high speed craft (HSC) rules for steel materials and raw composite materials. Type Approval Ce