SECTION 1 - Boat Design Net

Pt B, Ch 1, Sec 2SECTION 2SYMBOLS AND DEFINITIONS1 UnitsTable 1 : Units1.1 Units definition1.1.1 Unless otherwise specified, the units used in theRules are those defined in Tab 1.2 Symbols2.12.1.1 The main symbols are used in the present Rules are:L : Rule length, in m, defined in [3.2]L WL : Waterline length, in m, measured with the shipat rest in calm water, at the full load displacement,as defined in [3.2]L LL : Length according to International Rules asdefined in Pt A, Ch 2, Sec 1, [2.2.1]L h : Length according to EC Directive as defined inPt A, Ch 2, Sec 1, [2.2.1]L HULL : Hull length, in m, defined in [3.3]B : Moulded breadth, in m, defined in [3.5]B WL : Greatest moulded breadth on waterline atdraught T, in m, defined in [3.5]D : Depth, in m, defined in [3.6]T : Full load draught, in m, defined in [3.7]Δ : Full load displacement, in tonnes, at draught T,in sea water (density ρ = 1,025 t/m 3 ).C B : Total block coefficient. For catamarans, C B is tobe calculated for a single hull, assuming Δequal to one half of the ship’s displacementC B =Δ-------------------------------1025 , LB WL TC W : Wave height, in m, defined in [3.10]V : Maximum speed, in knots, of the yachtLCG : Ship’s longitudinal centre of gravitya CG : Design vertical acceleration, in g, defined in [3.11]H S : Significant wave height, in m, defined in [3.10].3 Definitions3.1 Moulded base line3.1.1 The moulded base line is the horizontal referenceline tangent to the upper face of bottom plating at midship.In the case of yacht with a solid bar keel, the moulded baseline is to be taken at the intersection between the upper faceof the bottom plating with the solid bar keel at the middle oflength L.Designation3.2 Rule length3.2.1 The rule length L is equal to L WL where L WL is thewaterline length measured with the yacht at rest in calmwater, at the full load displacement.3.3 Hull lengthUsualsymbol3.3.1 The hull length L HULL is equal to the total hull length,from the extreme foreward part of the hull, excluding anyoutfitting protusing, and the extreme aft part.3.4 Ends of rule length L WL and midshipUnitsShip’s dimensions See [2] mHull girder section modulus Z m 3Density ρ t/m 3Concentrated loads P kNLinearly distributed loads q kN/mSurface distributed loads p kN/m 2Thicknesses t mmSpan of ordinary stiffeners andprimary supporting membersSpacing of ordinary stiffeners andprimary supporting membersBending moment M kN.mShear force Q kNStresses σ, τ N/mm 2Section modulus of ordinary stiffenersand primary supporting membersSection area of ordinary stiffenersand primary supporting members3.4.1 Fore endThe fore end (FE) of the rule length L WL (see Fig 1) is the perpendicularto the full load waterline at the forward side ofthe stem.3.4.2 Aft endThe aft end (AE) of the rule length L WL (see Fig 1, is the perpendicularto the full load waterline at a distance L WL aft ofthe fore end.3.4.3 MidshipThe midship is the perpendicular to the waterline at a distance0,5L WL aft of the fore end (see Fig 1).lsmmw cm 3Acm 2July 2006 with February 2008 Amendments Bureau Veritas Rules for Yachts 71