Rules for the Classification of Floating Docks - Boat Design Net

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Chapter 4Table 1 : Documentation to be submittedDocumentDocument detailsMidship SectionScantling planWatertight subdivision bulkheads• required class characteristics• openings on decks and shell• corrosion protection• minimum and extreme drafts• loads on decks• block deckopenings, if anyWatertight and wash bulkheads of ballast tanks • location of air vents• tanks intended to be partially filled• procedures for tank filling and level and pressure controlMachinery foundationsmass of machineryDetails of section connections(constructional drawing)Wall shutters and similarGeneral plan of external doors and scuttlesGeneral plan of ventilation and manholesArrangement for handling of loadsStructure of load elevatorsuse of roomsrelevant hull stiffeningSea water intakes and overboard discharges in generalHydrostatic test planPumping diagramsStability calculations1.4 Operating Manual1.4.1 An Operating Manual is to be prepared for eachfloating dock, describing the operating condition.In addition to the characteristic elements of the floatingdock itself, the Manual, to be sent for information to RINA,is to report the basic data assumed for the strength calculations(design lifting capacity, load distribution, etc.) andinformation for verification of stability in the various operativeconditions.2 General requirements for design2.1 Stability2.1.1 GeneralFloating docks having a length equal to or greater than 24 mare to be provided with suitable transverse stability characteristicscomplying with the requirements of this item [2.1].2.1.2 Loading conditionsStability calculations are to analyse the most severe operativeconditions, taking into account the heaviest weightpositions, including hanging loads and the possible effectsof free surfaces of liquids in tanks.In particular, for dry docks, the loading conditions whichconsider water levels lapping the top edge of the block deckand the top part of the blocks themselves are to be considered.Moreover, RINA may, at its discretion, request to carry out astability calculation for the case of an emerged floatingdock with displacement as close as possible to full load displacement,with a flooded compartment, eccentric and atone end of the dock, i.e. selected among those involvingthe most severe conditions from the point of view of stability.2.1.3 Intact stability requirementsIn general, for dry docks the initial metacentric transversalheight GM0 of the system ship plus dry dock, consideringall the corrections for liquid free surface effects, is to be notless than 1,5 m for docks with design lifting capacity up to10000 t.The above-mentioned metacentric height may be linearlyreduced for lifting capacities over 10000 t, up to a minimumof 1,0 m for lifting capacities equal to 50000 t orabove.2.1.4 Severe wind and rolling criterion (weathercriterion)a) AssumptionsThe ability of a floating dock to withstand the combinedeffects of beam wind and rolling is to be demonstrated14 Rules for floating docks 2010
Chapter 4for each standard condition of loading, with reference toFig 1 as follows:• the dock is subjected to a steady wind pressure actingperpendicular to the dock's centreline whichresults in a steady wind heeling lever (l w1 );• from the resultant angle of equilibrium (θ 0 ), the dockis assumed to roll owing to wave action to an angleof roll (θ 1 ) to windward;• the dock is then subjected to a gust wind pressurewhich results in a gust wind heeling lever (l w2 );• free surface effects are to be accounted for in thestandard conditions of loading.Figure 1 : Severe wind and rollingLeverb) CriteriaUnder the assumptions of a) above, the following criteriaare to be complied with:• the area "b" is to be equal to or greater than the area"a",where:a : Area above the GZ curve and below l w2 ,between θ R and the intersection of l w2with the GZ curveb : Area above the heeling lever l w2 andbelow the GZ curve, between the intersectionof l w2 with the GZ curve and θ 2 .• the angle of heel under action of steady wind (θ 0 ) isto be limited to 16° or 80% of the angle of deckedge immersion, whichever is the lesser.c) Heeling leversThe wind heeling levers l w1 and l w2 , in m, referred to inb) above, are constant values at all angles of inclinationand are to be calculated as follows:l w1andl w2 = 1,5 l w1where:P : 504 N/m 2The value of P used for docks positioned inprotected locations may be reduced subjectto the approval of RINAGZθ 2 θ caAngle of heelθ 0θ 1PAZ= --------------------1000g∆blw 1lw 2A : Projected lateral area, in m 2 , of the portionof the dock and deck cargo above the waterline;Z : Vertical distance in m, from the centre of Ato the centre of the underwater lateral areaor approximately to a point at one half thedraught;∆ : Displacement, in t;g : 9,81 m/s 2 .d) angles of heel:For the purpose of calculating the criteria of b) above,the angles in Fig 1 are defined as follows:θ 0 : Angle of heel, in degrees, under action ofsteady windθ 1 : Angle of roll, in degrees, to windward dueto wave action, calculated as follows:θ 2 : Angle of downflooding (θ f ) in degrees, either50° or θ c , whichever is the lesserθ f : Angle of heel in degrees, at which openingsin the hull, superstructures or deckhouseswhich cannot be closed weathertightimmerse. In applying this criterion, smallopenings through which progressive floodingcannot take place need not be consideredas open;θ c : Angle in degrees, of second interceptbetween wind heeling lever l w2 and GZcurvesθ R = θ 0 = θ 1x 1 : Coefficient defined in Tab 2x 2 : Coefficient defined in Tab 3k : Coefficientk = 1,0 for a round-bilged dock having nobilge or bar keelsk = 0,7 for a dock having sharp bilgeFor a dock having no bilge keels, a bar keelor both, k is defined in Tab 4.DG : Distance in m, between the centre of gravityand the waterline (positive if centre of gravityis above the waterline, negative if it isbelow)T 1 : Mean moulded draught in m, of the docks : Factor defined in Tab 5.Note 1: The angle of roll θ 1 for docks with anti-rolling devices is tobe determined without taking into account the operations ofthese devices.Note 2: The angle of roll θ 1 may be obtained, in lieu of the aboveformula, from model tests or full scale measurements.The rolling period T R , in s, is calculated as follows:T Rwhere:2CB= -------------GMθ 1 = 109kX 1 X 2 rsRules for floating docks 2010 15
Page 1 and 2: Rules for the Classificationof Floa
Page 3 and 4: Definitions:"Rules" in these Genera
Page 5: RULES FOR THE CLASSIFICATION OFFLOA
Page 8 and 9: CHAPTER 2 CLASSIFICATION1 Premise 1
Page 10 and 11: CHAPTER 4 HULL, STABILITY AND MATER
Page 12 and 13: CHAPTER 6 FIRE PROTECTION1 Applicat
Page 14 and 15: Chapter 2CHAPTER 2CLASSIFICATION1 P
Page 16 and 17: Chapter 3scope of the annual machin
Page 20 and 21: Chapter 4C = 0,373 + 0,023 B/T 1 -
Page 22 and 23: Chapter 4Table 7 : Table 7 : Grades
Page 24 and 25: Chapter 4Figure 5Figure 6h 1ihFFF=5
Page 26 and 27: Chapter 5CHAPTER 5MACHINERY AND SYS
Page 28 and 29: Chapter 6only, may reach every part

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