Vessel Name: MC(less than 24m)

Transcription

1 Freeboard Calculation Report Vessel Name: MC(less than 24m) SECTION A: RESULTS SUMMARY Summer Freeboard = mm Max. Summer Draft as per freeboard requirements = 941 mm Minimum Bow Height Required = 635 mm

2 SECTION B: INPUTS 1. Principal Particulars Property Value Type of Vessel: Type B Breadth (m): 4.85 Depth(moulded) at freeboard deck, D (m): 1.5 D1 = 85% of Depth Moulded (m) : Length of Waterline at 85% of moulded depth (m): 14 Dist. from C.L. of Rudder Stock to Fore Side of Stem (m)): 12.5 Thickness of Fbd Deck, tfbd (mm): 8 Thickness of Keel Plate, tkeel (mm): 8 Volume at 85% mld Depth, V85 (cu.m.): 75 Waterplane Area Fwd of L/2 at 85% mld Depth, Awp (sq.m.): Sheer Line of Freeboard Deck Location Value of Sheer (mm) A.P. 0 L/6 from A.P. 0 (L = 13.44m) L/3 from A.P. 0 (L = 13.44m) Amidship 0 L/3 from F.P. (L 0 = 13.44m) L/6 from F.P. (L 0 = 13.44m) F.P Superstructures and Trunks Superstructure Type Mean Length(in Effective Height(in m) m) Length(in m) Forecastle Superstructure Poop Superstructure Bridge Superstructure Superstructure Superstructure Raised Qtr Deck Superstructure Trunk 1 Trunk Trunk 2 Trunk Trunk 3 Trunk 0 0 0

3 1. Basic Parameters SECTION C: CALCULATIONS 1.1. Freeboard Length, L L is given by the following: L is greater of L1 and L2, where L1 = 96% of the total length on a waterline at 85% of the least moulded depth measured from the top of the keel L2 = the length from the fore-side of the stem to the axis of the rudder stock on that waterline. Here, L1 = 0.96 X LWL = 0.96 x 14 = L2 = 12.5 => L = Block Coefficient, Cb Cb is given by the following: Cb = V85/ (Lfbd X B X d1 X 1.025) => Cb = 75/ (13.44 X 4.85 X X ) Cb = Coefficient of Half-Waterplane Area, Cwf Cwf is given by the following: Cwf = Awf/( Lfbd/2 X B) => Cwf = 33.95/ (13.44 /2 X 4.85 ) Cwf = Freeboard Depth, Dfbd Dfbd is given by the following: Dfbd = D + tfbd => Dfbd = Dfbd = 1.508

4 2. Tabular Freeboard, Ft, Regulation 28.2 Vessel Type: Type B From Table Tabular Freeboard for ship of Length < 24 (UK Gov Loadline Instructions MSIS 1, Part 4, Rev 1.02). Length = m, Ft = ( x L/24) mm = 134 mm 2.1. Correction for Type B ships with freeboard length < 100 m and effective length of superstructure(excluding trunks) < 35% of Length, F_TypeB, Regulation 38 Total Effective Length of Superstructure excluding trunks, Le1 (m) = 0 Le1/L = 0 Correction = 7.5 X (100 - L) X ( Le1/L) => F_TypeB = => Tabular Freeboard Corrected with Flush Deck Penalty = Ft + F_TypeB = Corrections to Freeboard 3.1. Correction for Block Coefficient, F_Cb, Regulation 30 Where the block coefficient (Cb) exceeds 0.68, the tabular freeboard Ft is multiplied by the factor gamma = (Cb )/1.36 => Correction for Cb = = Ft X (gamma 1) Here, Cb = => F_Cb = Correction for Depth, F_D, Regulation 31.1 Where D exceeds L/15 the freeboard shall be increased by (D-L/15)R mm, where R is L/0.48 at lengths less than 120 m and 250 at 120 m length and above. Where D is less than L/l5 no reduction shall be made except when the Condition 1 Below is satisfied: Condition1: The Ship has enclosed superstructure covering at least 0.6 L amidships, with a complete trunk, or combination of detached enclosed superstructures and trunks which extend all fore and aft, where the freeboard shall be reduced by (D-L/15)R mm. Here, L = => R = 28 Also, D = 1.5 and L/15 = Since D > L/15, so the Freeboard is increased by (D-L/15) X R => F_D = Correction for Superstructure and Trunks, F_Super, Regulation 37 The Length, Height and Standard Height of the superstructure are as below: Superstructure Type Mean Length(in m) Effective Length(in m) Height(in m) Standard Height(in m) Forecastle Superstructure Poop Superstructure Bridge Superstructure Superstructure Superstructure Raised Qtr Deck Superstructure Trunk 1 Trunk Trunk 2 Trunk

5 Trunk 3 Trunk Total effective length of Superstructure, Le = 0 Since Le = 0 so correction for Superstructures and trunks = 0 => F_Super = Correction for Sheer profile, F_Sheer, Regulation 380 Sheer Correction,F_Sheer = (St + So) * ( (Le / (2 * L)) Where, Le = Total Effective Length of Superstructures = 0 L = Freeboard Length = St = Excess/Deficiency due to Sheer Profile And, So = Sheer Credit for Superstructure a) Excess/Deficiency due to Sheer Profile, St: Station Standard Actual Height formula Ordinate, S(mm) Simpsons Multiplier, M Product, S X M(mm) Ordinate, S(mm) A.P X (L/3 L/ X (L/3 L/3 2.8 X (L/3 Deficiency of Aft Sheer from Standard Profile = (Aa-As)/8 = -121 Deficiency of Fwd Sheer from Standard Profile = (Fa-Fs)/8 = -241 b) Sheer Credit for Superstructure: The sheer credit for a superstructure can be given for poop or forecastle, using the formula: s = (y/3 X L'/L), where y = Difference between actual and standard height of poop/forecastle at end of sheer L' = Mean enclosed length of Poop or Forecastle upto a maximum of 0.5 L L = Freeboard Length Calculation for Forecastle Standard Height of Forecastle = 1.8 Actual Height of Forecastle = 0 => y(fcle) = -1.8 Effective Length of Forecastle, L'(fcle) = Minimum of (Forecastle Length, 0.5L) = 0 => y(fcle) = -1.8 Simpsons Multiplier, M Amidship Sum, As = 966 Sum, Aa = 0 Amidship L/3 5.6 X (L/ L/ X (L/ F.P X (L/ Sum, Fs = 1932 Sum, Fa = 0 Product, S X M(mm)

6 => Sheer credit for forecastle, s(fcle) = 0 Calculation for Poop Standard Height of Poop = 1.8 Actual Height of Poop = 0 => y(poop) = -1.8 Effective Length of Poop, L'(poop) = Minimum of (Poop Length, 0.5L) = 0 => Sheer credit for poop, s(poop) = 0 => Total Sheer excess/deficiency at FWD = (Fa-Fs)/8 + 2 X forecastle credit = => Total Sheer excess/deficiency at AFT = (Aa-As)/8 + 2 X poop credit = => Total Deficiency of Sheer, St = (Fwd Sheer + Aft Sheer)/2 => St = Sheer Correction = St * ( (S / (2 * L)) Where S = Total mean length of enclosed superstructures, excluding trunks, S = 0 => df_sheer =

7 4. Final Freeboard Freeboard = Tabular Freeboard + Corrections Freeboard = Ft + df_typeb + df_cb + df_d + df_super + df_sheer = => Summer Freeboard = mm Thus, the max. moulded summer draft as per freeboard requirements is: Summer Draft = Freeboard Depth - Summer Freeboard = => Summer Draft = 941 mm 4.1 Tropical Freeboard Tropical Freeboard = Summer Freeboard - 1/48 X Summer Draft = 548 mm 4.2 Freshwater Freeboard Freshwater Freeboard = Summer Freeboard - (Displacement at Summer Draft)/(40 X TPcm at summer Draft) if Displacement and TPI values are available, else it is same as Tropical Freeboard Displacement at Summer Draft = 0 MT Tons per cm of immersion at Summer Draft (TPcm) = 0 MT/cm => Freshwater Freeboard = 548 mm 4.3 Tropical Freshwater Freeboard Tropical Freshwater Freeboard = Freshwater Freeboard - 1/48 X Summer Draft = 528 mm 4.4 Winter Freeboard Winter Freeboard = Summer Freeboard + 1/48 X Summer Draft = 587 mm 4.5 Winter North Atlantic (WNA) Freeboard Winter North Atlantic Freeboard = (Winter Freeboard + 50) for L <=100. For L > 100, it is same as Winter Freeboard. => Winter North Atlantic Freeboard = 637 mm

8 5. Minimum Bow Height Requirements, Regulation 39 The minimum Bow Height formula is given by: => Minimum Bow Height, Fb = 635 mm *****************COMPLETED*****************