Rule Change Notice No. 1 January 2009

Transcription

1 COMMON STRUCTURAL RULES FOR BULK CARRIERS RULE CHANGE NOTICE NO.1 Common Structura Rues for Buk Carriers, Juy 008 Rue Change Notice No. 1 January 009 Notes: (1) These Rue Changes enter into force on 1 Juy 009. Copyright in these Common Structura Rues for Buk Carriers is owned by: American Bureau of Shipping Bureau Veritas China Cassification Society Det Norske Veritas Germanischer Loyd Korean Register of Shipping Loyd's Register Nippon Kaiji Kyokai Registro Itaiano Navae Russian Maritime Register of Shipping Copyright 006 The IACS members, their affiiates and subsidiaries and their respective officers, empoyees or agents are, individuay and coectivey, referred to in this cause as the IACS Members. The IACS Members, individuay and coectivey, assume no responsibiity and sha not be iabe to any person for any oss, damage or expense caused by reiance on the information or advice in this document or howsoever provided, uness that person has signed a contract with the reevant IACS Member entity for the provision of this information or advice and in that case any responsibiity or iabiity is excusivey on the terms and conditions set out in that contract. PAGE 1 OF 171

2 RULE CHANGE NOTICE NO.1 COMMON STRUCTURAL RULES FOR BULK CARRIERS Tabe of Contents Rue Change Notice No.1-1 (Hu Girder Strength)... 3 Technica Background for Rue Change Notice No.1-1(Hu Girder Strength) 19 Rue Change Notice No.1- (Hatch Covers) Technica Background for Rue Change Notice No.1- (Hatch Covers) Rue Change Notice No.1-3 (Stee Coi).. 41 Technica Background for Rue Change Notice No.1-3 (Stee Coi)...51 Rue Change Notice No.1-4 (Minimum Scanting, Side Frame and Grab).. 71 Technica Background for Rue Change Notice No.1-4 (Minimum Scanting, Side Frame and Grab)...79 Rue Change Notice No.1-5 (Direct Strength Anaysis)...83 Technica Background for Rue Change Notice No.1-5 (Direct Strength Anaysis) Rue Change Notice No.1-6 (Fatigue Check for Longitudinas) Technica Background for Rue Change Notice No.1-6 (Fatigue Check for Longitudinas) Rue Change Notice No.1-7 (Corrosion Additions) Technica Background for Rue Change Notice No.1-7 (Corrosion Additions) Rue Change Notice No.1-8 (Corrugated Bukhead) Technica Background for Rue Change Notice No.1-8 (Corrugated Bukhead) Rue Change Notice No.1-9 (Main Engine Foundation) Technica Background for Rue Change Notice No.1-9 (Main Engine Foundation) 169 PAGE OF 171

3 COMMON STRUCTURAL RULES FOR BULK CARRIERS RULE CHANGE NOTICE NO.1-1 Common Structura Rues for Buk Carriers, Juy 008 Rue Change Notice No.1-1 (Hu Girder Strength) Notes: (1) These Rue Changes enter into force on 1 Juy 009. Copyright in these Common Structura Rues for Buk Carriers is owned by: American Bureau of Shipping Bureau Veritas China Cassification Society Det Norske Veritas Germanischer Loyd Korean Register of Shipping Loyd's Register Nippon Kaiji Kyokai Registro Itaiano Navae Russian Maritime Register of Shipping Copyright 006 The IACS members, their affiiates and subsidiaries and their respective officers, empoyees or agents are, individuay and coectivey, referred to in this cause as the IACS Members. The IACS Members, individuay and coectivey, assume no responsibiity and sha not be iabe to any person for any oss, damage or expense caused by reiance on the information or advice in this document or howsoever provided, uness that person has signed a contract with the reevant IACS Member entity for the provision of this information or advice and in that case any responsibiity or iabiity is excusivey on the terms and conditions set out in that contract. PAGE 3 OF 171

4 RULE CHANGE NOTICE NO.1-1 COMMON STRUCTURAL RULES FOR BULK CARRIERS For technica background for Rue Changes in this present document, reference is made to separate document Technica Background for Rue Change Notice No.1-1. CHAPTER 5 HULL GIRDER STRENGTH Section 1 YIELDING CHECK. Hu girder stresses. Shear stresses.. Simpified cacuation of shear stresses induced by vertica shear forces The shear stresses induced by the vertica shear forces in the cacuation point are obtained, in N/mm, from the foowing formua: τ = 1 where: S I t ( Q + Q εδq ) δ SW WV C Y t : Minimum net thickness, in mm, of side and inner side pating, as appicabe according to Tab 1 δ : Shear distribution coefficient defined in Tab 1 ε = sgn( Q SW ) ΔQ C : Shear force correction (see Fig ) at the section considered. The shear force correction is to be considered independenty forward and aft of the transverse bukhead for the hod considered., which The shear force correction takes into account, when appicabe, the portion of oads transmitted by the doube bottom girders to the transverse bukheads: for ships with any non-homogeneous oading conditions, such as aternate hod oading conditions and heavy baast conditions carrying baast in hod(s): ΔQ C M = α ρt B H H LC Δ M = α ρt Q C LC, mh BH H for each non-homogeneous oading condition for other ships and homogeneous oading conditions: ΔQ C = 0 0 ϕ = , to be taken not greater than 3.7 b 0b0 α = g + ϕ b PAGE 4 OF 171

5 COMMON STRUCTURAL RULES FOR BULK CARRIERS RULE CHANGE NOTICE NO.1-1 0, b 0 : Length and breadth, respectivey, in m, of the fat portion of the doube bottom in way of the hod considered; b 0 is to be measured on the hu transverse section at the midde of the hod H B H M : Length, in m, of the hod considered, measured between the midde of the transverse corrugated bukheads depth : Ship s breadth, in m, measured at the eve of inner bottom on the hu transverse section at the midde of the hod considered : Tota mass of cargo, in t, in the hod of the section considered Mass, in t, in the considered section. Adjacent cargo hod is oaded in a non homogeneous oading condition for the condition under consideration M is to incude the tota mass in the hod and the mass of water baast in doube bottom tank, bounded by side girders in way of hopper tank pating or ongitudina bukhead. Other cases M is the tota mass in the hod. T LC T LC,mh : Draught, in m, measured verticay on the hu transverse section at the midde of the hod considered, from the mouded baseine to the waterine in the oading condition considered. ΔQ C Δ Q C _ F Fu hod Bukhead Corrected shear force Empty hod Bukhead Δ Q C _ E ΔQ C =ραt LC Bukhead Shear force obtained as specified in Ch 4, Sec 3 Δ Δ Q C _ F Q C _ E : shear force correction for the fu hod : shear force correction for the empty hod Figure : Shear force correction ΔQ C PAGE 5 OF 171

6 RULE CHANGE NOTICE NO.1-1 COMMON STRUCTURAL RULES FOR BULK CARRIERS Tabe 1: Shear stresses induced by vertica shear forces Ship typoogy Location t, in mm δ Singe side ship Sides t S 0,5 Doube side ship Sides t S 0.5( 1 φ) Inner sides t IS 0.5φ where: t S, t IS : Minimum net thicknesses, in mm, of side and inner side, respectivey t SM, t ISM : Mean net thicknesses, in mm, over a the strakes of side and inner side, respectivey. They are cacuated φ as Σ( i t i ) / Σ i, where i and t i are the ength, in m, and the net thickness, in mm, of the i th strake of side and inner side. t ISM : Coefficient taken equa to: φ = t SM..3 Shear stresses in fooded conditions of BC-A or BC-B ships This requirement appies to BC-A or BC-B ships, in addition to [..1] and [..]. The shear stresses, in the fooded conditions specified in Ch 4, Sec 3, are to be obtained at the cacuation any point, in N/mm, from the foowing formua: τ S ( Q + Q εδq ) δ 1 = SW, F WV, F ε = sgn ( Q SW,F ) C Ι Y t t ΔQ C : Shear force correction, to be cacuated according to [..],where the mass M is to incude the mass of the ingressed water in the hod considered is to be added to M and where the draught T LC T LC,mh is to be measured up to the equiibrium waterine. : Net thickness, in mm, of the side pating. 5. Permissibe sti water bending moment and shear force 5.1 Permissibe sti water bending moment and shear force stresses Permissibe sti water shear force - Simpified cacuation Where the shear stresses are obtained through the simpified procedure in [..], the permissibe positive or negative sti water shear force in intact condition at any hu transverse section is obtained, in kn, from the foowing formua: Q P where: ΙY t = ε 10 + ΔQ kδ S ε = sgn( Q SW ) C Q δ : Shear distribution coefficient defined in Tab 1 WV PAGE 6 OF 171

7 COMMON STRUCTURAL RULES FOR BULK CARRIERS RULE CHANGE NOTICE NO.1-1 t : Minimum net thickness, in mm, of side and inner side pating, as appicabe according to Tab 1 ΔQ C : Shear force corrections defined in [..], to be considered independenty forward and aft of the transverse bukhead. A ower vaue of the permissibe sti water shear force may be considered, if requested by the Shipbuider. PAGE 7 OF 171

8 RULE CHANGE NOTICE NO.1-1 COMMON STRUCTURAL RULES FOR BULK CARRIERS Appendix 1 - HULL GIRDER ULTIMATE STRENGTH Symbos For symbos not defined in this Appendix, refer to Ch 1, Sec 4. I Y : Moment of inertia, in m 4, of the hu transverse section around its horizonta neutra axis, to be cacuated according to Ch 5, Sec 1, [1.5.1] Z AB, Z AD : Section modui, in m 3, at bottom and deck, respectivey, defined in Ch 5, Sec 1, [1.4.]. R ehs R ehp As A p : Minimum yied stress, in N/mm, of the materia of the considered stiffener. : Minimum yied stress, in N/mm, of the materia of the considered pate. : Net sectiona area, in cm, of stiffener, without attached pating : Net sectiona area, in cm, of attached pating. Criteria for the cacuation of the curve M-χ.1 Simpified method based on a incrementa-iterative approach.1.1 Procedure The curve M-χ is to be obtained by means of an incrementa-iterative approach, summarised in the fow chart in Fig 1. In this approach, the utimate hu girder bending moment capacity M U is defined as the peak vaue of the curve with vertica bending moment M versus the curvature χ of the ship cross section as shown in Fig 1. The curve is to be obtained through an incrementa-iterative approach. Each step of the incrementa procedure is represented by the cacuation of the bending moment M i which acts on the hu transverse section as the effect of an imposed curvature χ i. For each step, the vaue χ i is to be obtained by summing an increment of curvature Δχ to the vaue reevant to the previous step χ i-1.this increment of curvature corresponds to an increment of the rotation ange of the hu girder transverse section around its horizonta neutra axis. This rotation increment induces axia strains ε in each hu structura eement, whose vaue depends on the position of the eement. In hogging condition, the structura eements above the neutra axis are engthened, whie the eements beow the neutra axis are shortened. Vice-versa in sagging condition. The stress σ induced in each structura eement by the strain ε is to be obtained from the oad-end shortening curve σ-ε of the eement, which takes into account the behaviour of the eement in the non-inear easto-pastic domain. The distribution of the stresses induced in a the eements composing the hu transverse section determines, for each step, a variation of the neutra axis position, since the reationship σ-ε is non-inear. The new position of the neutra axis reevant to the step considered is to be obtained by means of an iterative process, imposing the equiibrium among the stresses acting in a the hu eements. PAGE 8 OF 171

9 COMMON STRUCTURAL RULES FOR BULK CARRIERS RULE CHANGE NOTICE NO.1-1 Once the position of the neutra axis is known and the reevant stress distribution in the section structura eements is obtained, the bending moment of the section M i around the new position of the neutra axis, which corresponds to the curvature χ i imposed in the step considered, is to be obtained by summing the contribution given by each eement stress. The main steps of the incrementa-iterative approach described above are summarised as foows (see aso Fig 1): Step 1 Divide the transverse section of hu into stiffened pate eements. Step Define stress-strain reationships for a eements as shown in Tab 1 Step 3 Initiaize curvature χ 1 and neutra axis for the first incrementa step with the vaue of incrementa curvature (curvature that induces a stress equa to 1% of yied strength in strength deck) as: χ = Δ 1 χ ReH 0.01 = E z N D where: z D : Z co-ordinate, in m, of strength deck at side, with respect to reference co-ordinate defined in Ch 1, Sec 4, [4] Step 4 Cacuate for each eement the corresponding strain ε i = χ z i ε i = χ (z i -z NA ) and the corresponding stress Step 5 Step 6 Step 7 σ i Determine the neutra axis z NA_cur at each incrementa step by estabishing force equiibrium over the whoe transverse section as: ΣA i σ i = ΣA j σ j (i-th eement is under compression, j-th eement under tension) Cacuate the corresponding moment by summing the contributions of a eements as: M σ ( z z ) U = Ui Ai i NA _ cur Compare the moment in the current incrementa step with the moment in the previous incrementa step. If the sope in M-χ reationship is ess than a negative fixed vaue, terminate the process and define the peak vaue of M U. Otherwise, increase the curvature by the amount of Δχ and go to Step Modeing of the hu girder cross section Hu girder transverse sections are to be considered as being constituted by the members contributing to the hu girder utimate strength. Sniped stiffeners are aso to be modeed imaginariy, taking account that they doesn t contribute to the hu girder strength. The structura members are categorized into an ordinary stiffener eement, a stiffened pate eement or a hard corner eement. The pate pane incuding web pate of girder or side stringer is ideaized into either a stiffened pate eement, an attached pate of an ordinary stiffener eement or a hard corner eement. The pate pane is categorized into the foowing two kinds: - ongitudinay stiffened pane of which the onger side is in the ongitudina direction, and - transversey stiffened pane of which the onger side is in the perpendicuar direction to the ongitudina direction. PAGE 9 OF 171

10 RULE CHANGE NOTICE NO.1-1 COMMON STRUCTURAL RULES FOR BULK CARRIERS Hard corner eement Hard corner eements are sturdier eements composing the hu girder transverse section, which coapse mainy according to an easto-pastic mode of faiure (materia yieding); they are generay constituted by two pates not ying in the same pane. The extent of a hard corner eement from the point of intersection of the pates is taken equa to 0t p on transversey stiffened pane and to 0.5s on a ongitudinay stiffened pane. (See Fig 6) where: t p s : Gross offered thickness of the pate, in mm : Spacing of the adjacent ongitudina stiffener, in m Bige, sheer strake-deck stringer eements, girder-deck connections and face pate-web connections on arge girders are typica hard corners. Ordinary stiffener eement The ordinary stiffener constitutes an ordinary stiffener eement together with the attached pate. The attached pate width is in principe: - equa to the mean spacing of the ordinary stiffener when the panes on both sides of the stiffener are ongitudinay stiffened, or - equa to the width of the ongitudinay stiffened pane when the pane on one side of the stiffener is ongitudinay stiffened and the other pane is of the transversey stiffened. (See Fig 6) Stiffened pate eement The pate between ordinary stiffener eements, between an ordinary stiffener eement and a hard corner eement or between hard corner eements is to be treated as a stiffened pate eement. (See Fig 6) s -(s 1 +s 3 )/ s 1 =Min(0tp,s /) s - s 1 - s 3 / s 4 / s s 1 s 3 (Longitudinay (Transversey (Longitudinay stiffened pane) stiffened pane) stiffened pane) s (Transversey stiffened pane) s 3 s4 (Longitudinay stiffened pane) Ordinary stiffener eement Stiffened pate eement Hard corner eement Figure 6: Extension of the breadth of the attached pating and hard corner eement The typica exampes of modeing of hu girder section are iustrated in Figs 7 and 8. Notwithstanding the foregoing principe these figures are to be appied to the modeing in the vicinity of upper deck, sheer strake and hatch side girder. PAGE 10 OF 171

11 COMMON STRUCTURAL RULES FOR BULK CARRIERS RULE CHANGE NOTICE NO.1-1 s 1 s s 3 s 4 s 4 / s 6 s 4 / s 6 / s 1 / s 1 / s / s / s 3 / s 3 / s 6 / : Ordinary stiffener eement : Hard corner eement s 7 / s 7 / s 7 s 8 / s 8 / s 88 Figure 7: Extension of the breadth of the attached pating and hard corner eement Hard corner eement Ordinary stiffener eement Stiffened pate eement Figure 8: Exampes of the configuration of stiffened pate eements, ordinary stiffener eements and hard corner eements on a hu section PAGE 11 OF 171

12 RULE CHANGE NOTICE NO.1-1 COMMON STRUCTURAL RULES FOR BULK CARRIERS (Note) (1) In case of the knucke point as shown in Fig 9, the pating area adjacent to knuckes in the pating with an ange greater than 30 degrees is defined as a hard corner. The extent of one side of the corner is taken equa to 0t p on transversey framed panes and to 0.5s on ongitudinay framed panes from the knucke point. Knucke point α Figure 9: The case of pating with knucke point () Where the pate members are stiffened by non-continuous ongitudina stiffeners, the non-continuous stiffeners are considered ony as dividing a pate into various eementary pate panes. (3) Where the opening is provided in the stiffened pate eement, the openings are to be considered in accordance with Ch 5 Sec 1, [1..7], [1..8] and [1..9]. (4) Where attached pating is made of stees having different thicknesses and/or yied stresses, an average thickness and/or average yied stress obtained by the foowing formua are to be used for the cacuation. t1 s1 + ts =, s t R ehp = R t s ehp ts R t s ehp Where, R eh1, R eh, t 1, t, s 1, s and s are shown in Fig 10. s s 1 s t 1 t R ehp1 R ehp Figure 10: Eement with different thickness and yied strength. Load-end shortening curves σ-ε..1 Stiffened pate eement Pating panes and ordinary stiffeners eement Stiffened pate eement Pating panes and ordinary stiffener, eement composing the hu girder transverse sections may coapse foowing one of the modes of faiure specified in Tab 1. PAGE 1 OF 171

13 COMMON STRUCTURAL RULES FOR BULK CARRIERS RULE CHANGE NOTICE NO.1-1 Where the pate members are stiffened by non-continuous ongitudina stiffeners, the stress of the eement is to be obtained in accordance with [..3] to [..7], taking into account the non-continuous ongitudina stiffener. In cacuating the tota forces for checking the hu girder utimate strength, the area of non-continuous ongitudina stiffener is to be assumed as zero. Where the opening is provided in the stiffened pate eement, the considered area of the stiffened pate eement is to be obtained by deducting the opening area from the pating in cacuating the tota forces for checking the hu girder utimate strength. The consideration of the opening is in accordance with the requirement in Ch 5 Sec 1, [1..7] to [1..9]. For stiffened pate eement, the effective breadth of pate for the oad shortening portion of the stress-strain curve is to be taken as fu pate breadth, i.e. to the intersection of other pate or ongitudina stiffener not from the end of the hard corner eement nor from the attached pating of ordinary stiffener eement, if any. In cacuating the tota forces for checking the hu girder utimate strength, the area of the stiffened pate eement is to be taken between the hard corner eement and the ordinary stiffener eement or between the hard corner eements, as appicabe. Tabe 1: Modes of faiure of stiffened pate eement pating pane and ordinary stiffeners eement Eement Mode of faiure Curve σ ε defined in Lengthened stiffened pate eement transversey framed pating pane or ordinary stiffeners eement Easto-pastic coapse [..3] Shortened ordinary stiffeners eement Beam coumn bucking Torsiona bucking Web oca bucking of fanged profies Web oca bucking of fat bars [..4] [..5] [..6] [..7] Shortened stiffened pate eement transversey framed pating pane Pate bucking [..8].. Hard corners eement Hard corners are sturdier eements composing the hu girder transverse section, which coapse mainy according to an easto-pastic mode of faiure (materia yieding). These eements are generay constituted of two pates not ying in the same pane. Bige, sheer strake-deck stringer eements, girder-deck connections and face pate-web connections on arge girders are typica hard corners. The reevant oad-end shortening curve σ-ε is to be obtained for engthened and shortened hard corners according to [..3]. PAGE 13 OF 171

14 RULE CHANGE NOTICE NO.1-1 COMMON STRUCTURAL RULES FOR BULK CARRIERS..3 Easto-pastic coapse of structura eements The equation describing the oad-end shortening curve σ-ε for the easto-pastic coapse of structura eements composing the hu girder transverse section is to be obtained from the foowing formua, vaid for both positive (shortening) and negative (engthening) strains (see Fig ): σ = Φ R eh σ = Φ R eha where: R eha : Equivaent minimum yied stress, in N/mm, of the considered eement, obtained by the foowing formua R eha R = ehp A A p p + R + A ehs s A s Φ ε ε E ε Y : Edge function, equa to: Φ = -1 for ε < 1 Φ = ε for 1 ε 1 Φ = 1 for ε > 1 : Reative strain, equa to: ε E ε = ε Y : Eement strain : Strain at yied stress in the eement, equa to: R eh R eha ε Y = E ε = Y E R eha -R eha Figure : Load-end curve σ-ε for easto pastic coapse..4 Beam coumn bucking The equation describing the oad-end shortening curve σ CR1 -ε for the beam coumn bucking of ordinary stiffeners composing the hu girder transverse section is to be obtained from the foowing formua (see Fig 3): σ CR1 where: = Φσ C1 A Stif A Stif + 10b E t + 10st p p σ CR1 = Φσ C1 A + A S S pe A + A p PAGE 14 OF 171

15 COMMON STRUCTURAL RULES FOR BULK CARRIERS RULE CHANGE NOTICE NO.1-1 Φ : Edge function defined in [..3] A Stif σ C1 : Net sectiona area of the stiffener, in cm, without attached pating : Critica stress, in N/mm, equa to: σ E C 1 = ε for σ ReH ε ReHB E1 σ E1 ε σ 1 R = eh ε ReH σ C1 ReH 1 for σ E1 > ε 4σ E 1 R = ehb ε ReHB σ C1 ReHB 1 for σ E1 > ε 4σ E 1 R ehb A pe1 : Equivaent minimum yied stress, in N/mm, of the considered eement, obtained by the foowing formua R ehb R = ehp A A pe1 pe pe1 pe + R ehs + A s se A : Effective area, in cm, equa to ApE = be1t p 1 10 s se pe se : Distance, in mm, measured from the neutra axis of the stiffener with attached pate of width b E1 to the bottom of the attached pate : Distance, in mm, measured from the neutra axis of the stiffener with attached pate of width b E1 to the top of the stiffener ε : Reative strain defined in [..3] σ E1 : Euer coumn bucking stress, in N/mm, equa to: σ E 4 1 = 10 E π E AE I I E b E1 : Net moment of inertia of ordinary stiffeners, in cm 4, with attached she pating of width b E1 : Effective width, in m, of the attached she pating, equa to: s be1 = for β E > 1. 0 β E b E 1 = s for β 1. 0 E β E 3 = 10 s t p εr E eh 3 β = 10 E s t p εr ehp E A E A pe : Net sectiona area, in cm, of ordinary stiffeners with attached she pating of width b E, equa to: A = 10b t pe E p PAGE 15 OF 171

16 RULE CHANGE NOTICE NO.1-1 COMMON STRUCTURAL RULES FOR BULK CARRIERS b E : Effective width, in m, of the attached she pating, equa to: b E s = β E β E for β > 1. 5 b E = s for β 1. 5 E E Figure 3: Load-end shortening curve σ CR1 -ε for beam coumn bucking..5 Torsiona bucking The equation describing the oad-end shortening curve σ CR -ε for the fexura-torsiona bucking of ordinary stiffeners composing the hu girder transverse section is to be obtained according to the foowing formua (see Fig 4). σ CR where: A = Φ Stiff σ A C Stiff + 10st pσ + 10st p CP σ CR Asσ C + Apσ = Φ A + A Φ : Edge function defined in [..3] A Stiff : Net sectiona area of stiffener, in cm, without attached pate σ C : Critica stress, in N/mm, equa to: σ E C = ε for ReH ε ReHs E σ E ε σ σ R = eh ε ReH σ C ReH 1 for σ E > ε 4σ E R = ehs ε ReHs σ C ReHs 1 for σ E > ε 4σ E σ E : Euer torsiona bucking stress, in N/mm, defined in Ch 6, Sec 3, [4.3] ε : Reative strain defined in [..3] σ CP : Bucking stress of the attached pating, in N/mm, equa to: σ CP = R eh CP = ehp β E β E βe βe s p CP σ R for β E > 1. 5 σ CP = R eh σ CP = ReHp for β E 1. 5 β E : Coefficient defined in [..4] PAGE 16 OF 171

17 COMMON STRUCTURAL RULES FOR BULK CARRIERS RULE CHANGE NOTICE NO.1-1 Figure 4: Load-end shortening curve σ CR -ε for fexura-torsiona bucking..6 Web oca bucking of ordinary stiffeners made of fanged profies The equation describing the oad-end shortening curve σ CR3 -ε for the web oca bucking of fanged ordinary stiffeners composing the hu girder transverse section is to be obtained from the foowing formua: σ CR3 = ΦR eh 10 3 bet p 3 st p 10 + h + h we w t t w w + b + b f f t t f f σ 10 b R 3 E p ehp CR3 = Φ 3 10 st p where Φ : Edge function defined in [..3] b E : Effective width, in m, of the attached she pating, defined in [..4] h we : Effective height, in mm, of the web, equa to: h we = h β w β w we h w w for β > 1. 5 h = for β 1. 5 w w t + ( h we w + h t t w w + b t ) R f f + b t f f ehs h β w = t w w ε R E eh h β w = t w w ε R E ehs ε : Reative strain defined in [..3]..7 Web oca bucking of ordinary stiffeners made of fat bars The equation describing the oad-end shortening curve σ CR4 -ε for the web oca bucking of fat bar ordinary stiffeners composing the hu girder transverse section is to be obtained from the foowing formua (see Fig 5): σ CR4 10stPσ CP + AStiffσ C 4 = Φ A + 10st Stiff P σ CR4 Apσ = Φ A CP p + A σ s + A where: Φ : Edge function defined in [..3] A Stiff : Net sectiona area of stiffener, in cm, without attached pate σ CP : Bucking stress of the attached pating, in N/mm, defined in [..5] σ C4 : Critica stress, in N/mm, equa to: σ E C 4 = ε for σ ReH E4 ε ReHs σ E 4 ε σ 4 s C 4 PAGE 17 OF 171

18 RULE CHANGE NOTICE NO.1-1 COMMON STRUCTURAL RULES FOR BULK CARRIERS R = eh ε ReH σ C 4 ReH 1 for σ E4 > ε 4σ E 4 R = ehs ε ReHs σ C 4 ReHs 1 for σ E 4 > ε 4σ E 4 σ E4 : Loca Euer bucking stress, in N/mm, equa to: t σ E4 = h ε : Reative strain defined in [..3]. w w Figure 5: Load-end shortening curve σ CR4 -ε for web oca bucking..8 Pate bucking The equation describing the oad-end shortening curve σ CR5 -ε for the bucking of transversey stiffened panes composing the hu girder transverse section is to be obtained from the foowing formua: σ σ ReH Φ = min s s ΦR + eh βe βe βe CR 5 1 ReHp Φ = min s s ΦR + + ehp βe βe βe CR5 1 where: Φ : Edge function defined in [..3]. 3 β = 10 E s t p εr E eh 3 β = 10 E s t p εr ehp E s : pate breadth, in m, taken as the spacing between the ordinary stiffeners : onger side of the pate, in m. PAGE 18 OF 171

19 COMMON STRUCTURAL RULES FOR BULK CARRIERS TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-1 Common Structura Rues for Buk Carriers, Juy 008 Technica Background for Rue Change Notice No.1-1 (Hu Girder Strength) Copyright in these Common Structura Rues for Buk Carriers is owned by: American Bureau of Shipping Bureau Veritas China Cassification Society Det Norske Veritas Germanischer Loyd Korean Register of Shipping Loyd's Register Nippon Kaiji Kyokai Registro Itaiano Navae Russian Maritime Register of Shipping Copyright 006 The IACS members, their affiiates and subsidiaries and their respective officers, empoyees or agents are, individuay and coectivey, referred to in this cause as the IACS Members. The IACS Members, individuay and coectivey, assume no responsibiity and sha not be iabe to any person for any oss, damage or expense caused by reiance on the information or advice in this document or howsoever provided, uness that person has signed a contract with the reevant IACS Member entity for the provision of this information or advice and in that case any responsibiity or iabiity is excusivey on the terms and conditions set out in that contract. PAGE 19 OF 171

20 TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-1 COMMON STRUCTURAL RULES FOR BULK CARRIERS Technica Background for the Changes Regarding Hu Girder Strength 1. Reason for the Rue Change in: 1.1 Chapter 5, Section 1, [..], [..3] and [5.1.3] These changes are made to carify the requirements (Refer to KC ID 353, 453 and 459). The way to consider any shear force corrections forward and aft of transverse bukheads is specified in [..] and [5.1.3]. It is specified that the tota mass M in those hods oaded in non-homogeneous oading conditions deadweight such as water baast and fue oi tank in doube bottom, bounded by side girders in way of hopper tank pating or ongitudina bukhead. In addition, the symbo T LC defined in Chapter 1 Section 4, [.1.1] is defined differenty in Chapter 5 Section Chapter 5, Appendix 1, Symbos, [.1.1], [.1.3], [..1] to [..8] These changes are made to carify the requirements (Refer to KC ID 499, 519 and 50). The position and extent of the hard corners is specified in order to provide the equivaent definition of hard corners used in the CSR for Buk Carriers regarding hu girder utimate strength cacuations to the one used in the CSR for Oi Tankers. The cacuation method is specified for those cases where any attached pating and stiffeners are made of stees having different yied stresses and/or thicknesses. The way to consider non-continuous stiffeners for the hu girder utimate strength cacuation is specified. In cases where attached pating and stiffeners are made of stee having different yied stresses, oad end shortening curves are to be separatey cacuated for the stiffeners and the attached pates, i.e. the method is simiar to the weighted average method on area in consideration of the net area of stiffeners and attached pates because this approach is very simpe and easy to understand. However, as described in Annex 1, this approach sometimes give a smaer utimate strength in comparison to the resuts attained from a 3D non-inear FEA in cases where the yied stress of stiffeners is smaer than that of any attached pates. This is because the area of such attached pates is greater than that of the stiffeners. Normay, such a case is scarcey found in actua designs. From the resuts of 3D non-inear FEA, it has been found that any underestimation of the oad end shortening curves for beam coumn bucking of such stiffened panes can be resoved by considering the first moment of such stiffened panes. In addition, oad end shortening curves for modes of faiure other than beam coumn bucking can be evauated by using the yied stress of stiffeners and attached pates, respectivey.. Summary of Rue Changes.1 Chapter 5, Section 1, [..], [..3] and [5.1.3] The shear force correction is to be considered independenty forward and aft of transverse bukheads for any hod considered. In addition, the tota mass M may incude masses of water baast in doube bottoms tanks, bounded by side girders in way of hopper tank pating or ongitudina bukheads, if such spaces are oaded for the non-homogeneous oading condition considered. Finay, the symbo T LC is changed to T LC_mh PAGE 0 OF 171

21 COMMON STRUCTURAL RULES FOR BULK CARRIERS TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-1. Chapter 5, Appendix 1, [.1.1], [.1.3], [..1] to [..8]..1 Chapter 5, Appendix 1, Symbos and [.1.1] (1) Definitions of necessary symbos are added in order to evauate stiffened panes in cases where any attached pating and stiffeners are made of stee having different stresses. () Editoria correction in [.1.1] is made... Ch 5 Appendix 5 [.1.3] The new paragraph [.1.3] is added for the modeing of hu girder cross sections. The extent of hard corner eements from corners is taken equa to 0t p on transversey framed panes and to 0.5s on ongitudinay framed panes. In cases where attached pating is made of stees having different thicknesses and/or yied stresses, average thickness and/or average yied stress are to be used in cacuations...3 Ch 5 Appendix 5, [..1] to [..8] The provisions regarding the definition of hard corners specified in [..] are shifted to a new paragraph [.1.3]. In addition, the ways to cacuate the oad-end shortening curves of the foowing cases are expained: in cases where attached pating and stiffener are made of stees having different yied stresses; in cases where pate members are stiffened by non-continuous ongitudina stiffeners; in cases where openings are provided in stiffened pate eements; and, in cases where stiffened pate eements are provided. 3. Impact on Scanting 3.1 Chapter 5, Section 1, [..], [..3] and [5.1.3] There is no change in terms of stee weight by comparing that before and after the proposed rue change. 3. Chapter 5, Appendix 1, [.1.1], [.1.3], [..1] to [..8] There is no change in terms of stee weight by comparing that before and after the proposed rue change. PAGE 1 OF 171

22 TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-1 COMMON STRUCTURAL RULES FOR BULK CARRIERS Annex 1: Evauation method of the oad end shortening curve for stiffened pane where the attached pate and stiffener are made of stee having different yied stresses 1. Introduction The evauation methodoogy of hu girder utimate strength in CSR-BC is based on Smith s method. In cases where any attached pates and stiffeners are made of stee having different yied stresses, the procedures and formuae for oad end shortening curves are not described in the current Rues. The foowing two methods to dea with such eements were considered. (1) Using ower yied stresses. () Considering pate eements and stiffener eements to be separate eements, and cacuating the oad-end shortening curves for the stiffener and the attached pating separatey as foows: For stiffeners: by adding attached pating having the same yied stress as the stiffener and then determining the shortening curve and the stress to be appied to the stiffener ony. For attached pating: by adding a stiffener having the same yied stress as the attached pating and then determining the shortening curve and the stress to be appied to the attached pating ony. Finay, oad end shortening curves for stiffened panes can be obtained by adding the oad end shortening curve for the stiffener to the oad end shortening curve for the attached pating and dividing the sum by the tota area of the stiffened pane. This method is caed Method A. It has been confirmed that any oad end shortening curve obtained by this method is neary equa to that obtained by using the average yied stress considering areas of any stiffeners and attached pates. It is obvious that the method specified in (1) above gives a conservative oad end shortening curve because the higher yied strengths of stiffeners or panes is not taking into account. On the other hand, because Method A is simpe and easy to understand, this method has been indicated in the IACS KC DB 50 as a practicabe approach to evauate the oad end shortening curves of stiffened panes with different yied stresses between attached pates and stiffeners However, there are some cases where Method A may give inadequate vaues of the oad end shortening curves of stiffened panes of different materias used for the attached pate and the stiffener. Specificay, in cases where stiffened pane eements consist of attached pates of HT36 and stiffeners of HT 3, the oad end shortening curves of such eements are sometimes overestimated in comparison to the resuts of 3D non-inear FEAs (FEA). On the contrary, in cases where eements consist of attached pates of HT3 and stiffeners of HT36, the oad end shortening curves of such stiffened pane eements are sometimes underestimated in comparison to the resuts of FEA. Athough stiffeners with yied stresses ower than that of attached pates are rarey used in actua ship design, any underestimated resut obtained by Method A shoud be resoved. Since the areas of attached pates are arger than that of stiffeners in most cases, the oad end shortening curve of the stiffened pane obtained by method A is affected by the yied strength of the attached pating. However, in reaity, the yied stress of the stiffener has great impact on its oad end shortening curve if beam-coumn bucking takes pace, the parameters other than the areas of stiffeners and attached pates shoud be considered to accuratey estimate the oad end shortening curves of stiffened panes of attached pates and stiffeners having different yied stresses In order to reduce the dependency on the areas of attached panes, the first moment of stiffened panes instead of the areas of attached pates and stiffeners are considered. This method is caed Method B. For exampe, using Method B, oad end shortening curves of beam coumn bucking are cacuated in the foowing manner: PAGE OF 171

23 COMMON STRUCTURAL RULES FOR BULK CARRIERS TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-1 Neutra Axis Stiffener A s se R ehs : yied stress of the stiffener A s : area of the stiffener se : distance to the top of the stiffener from the neutra axis of the stiffened pane having the attached pate with b E1. Equivaent yied stress R ehb of the stiffened pane can be expressed by the foowing formua: ReHp ApE1 pe + ReHs As se ReHB = ApE1 pe + As se The oad end shortening curve for the beam coumn bucking is obtained from the foowing formua: AS + ApE σ CR1 = Φσ C1 AS + Ap where: Φ and ε : defined in [..3], Ch 5 Appendix 1 of the Rues. σ C1 Attached pate : Critica stress, in N/mm, equa to: σ E C 1 = ε for ReHB ε E1 σ 1 b E1 σ R = ehb ε ReHB σ C1 ReHB 1 for σ E1 > ε 4σ E 1 A pe1 : Effective area, in cm, equa to 10 be 1 t p pe A pe R ehp : yied stress of the attached pate b E1 : effective width of the attached pate A pe : area of the attached pate with effective breadth b E1. pe : distance to the bottom of the attached pate from the neutra axis of the stiffened pane having the attached pate with b E1 σ E1 I E b E1 : Euer coumn bucking stress, in N/mm, equa to: σ E 4 1 = 10 E π E AE I : Net moment of inertia of ordinary stiffeners, in cm 4, with attached she pating of width b E1 : Effective width, in m, of the attached she pating, equa to: s be1 = for β E > 1. 0 β E b E 1 = s for β 1. 0 E 3 β = 10 E s t p εr ehp E PAGE 3 OF 171

24 TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-1 COMMON STRUCTURAL RULES FOR BULK CARRIERS A pe b E : Net sectiona area, in cm, of attached she pating of width b E, equa to: A = 10b t pe E p : Effective width, in m, of the attached she pating, equa to: b E s = β E β E for β > 1. 5 E b E = s for β 1. 5 E 3D non-inear FEAs are carried out for the purpose of verifying the accuracy of the utimate strength of stiffened panes obtained by Method B as we as Method A.. FEA 96 cases of the coapse anayses of the stiffened panes with non-inear FEM have been performed. The scantings of stiffened pates anaysed are isted in Tabe 1. As seen in Fig.1, the stiffened panes are modeed in the range of doube span doube bay. Periodica continuous conditions are imposed aong the edges of the mode in the ongitudina and transverse directions. The materia properties used in the anayses are as foows: Young s Moduus : E = N/mm Poisson s Ratio: n = 0.3 Strain Hardening Rate: Η =0 Case 1 : 315 N/mm for attached pate and 315 N/mm for stiffener Case : 315 N/mm for attached pate and HT 355 N/mm for stiffener (Different materia case) Case 3 : 355 N/mm for attached pate and HT 315 N/mm for stiffener (Different materia case) Case 4 : 355 N/mm for attached pate and 355 N/mm for stiffener Type Ange T-bar Fat-bar Stiffener Tabe 1 Scanting and yied strength of each anaysis case Size (mm) 50x90x1/16 400x10x13/18 300x15 Length a (mm) Breadth b (mm) Attached pate Aspect ratio (a/b) Thickness tp (mm) PAGE 4 OF 171

25 COMMON STRUCTURAL RULES FOR BULK CARRIERS TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO Fig.1 Mode of stiffened pane 3. Verification resuts of the two methods The resuts of the FEA, method A and Method B anayses are shown in Fig. to Fig. 7. In these figures, FEA resuts are indicated by a ine, the resuts of Method A and Method B are indicated by symbos. Generay, it was found that there is good agreement between the resuts obtained by both methods and those by FEA from these figures except those cases where the pate thickness is 10mm. However, considering the actua thickness of hu transverse members, both methods can be used for the evauation of utimate strength. Fig. Comparison on utimate strength (Ange a/b=3.0) PAGE 5 OF 171

26 TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-1 COMMON STRUCTURAL RULES FOR BULK CARRIERS Fig. 3 Comparison on utimate strength (Ange a/b=5.0) Fig. 4 Comparison on utimate strength (T-bar a/b=4.0) Fig. 5 Comparison on utimate strength (T-bar a/b=6.0) PAGE 6 OF 171

27 COMMON STRUCTURAL RULES FOR BULK CARRIERS TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-1 Fig. 6 Comparison on utimate strength (Fat-bar a/b=3.0) Fig. 7 Comparison on utimate strength (Fat-bar a/b=5.0) In order to discuss the accuracy of the resuts of Method A and Method B, a ratio obtained by dividing the resuts of both methods into that of FEA is given in Fig. 8 to Fig. 13. Here, we ca attention to the resuts of Case and Case 3 in cases where any attached pates and stiffeners are made of stees having different yied stresses. The utimate strengths of a of the cacuation conditions in Case 3 evauated by Method A aways are greater than those in Case 3. In addition, the error (difference) becomes greater in those cases where the thickness of the attached pate with arge aspect ratio becomes greater. This is because the utimate strength of the stiffened panes is strongy affected by the yied strengths of attached pates. On the other hand, the error of any resuts obtained by Method B seems to be smaer than those obtained by Method A, and any tendencies obtained by Method A cannot be observed in the resuts obtained by Method C. PAGE 7 OF 171

28 TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-1 COMMON STRUCTURAL RULES FOR BULK CARRIERS Fig. 8 Comparison on accuracy of estimation method (Ange a/b=3.0) Fig. 9 Comparison on accuracy of estimation method (Ange a/b=5.0) Fig. 10 Comparison on accuracy of estimation method (T-bar a/b=4.0) PAGE 8 OF 171

29 COMMON STRUCTURAL RULES FOR BULK CARRIERS TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-1 Fig. 11 Comparison on accuracy of estimation method (T-bar a/b=6.0) Fig. 1 Comparison on accuracy of estimation method (Fat-bar a/b=3.0) Fig. 13 Comparison on accuracy of estimation method (Fat-bar a/b=5.0) For the purpose of confirming the accuracy of any resuts obtained by Method A and Method B, average vaues and coefficients of variation (COV) are cacuated and those resuts are given in Figure 14 and 15. PAGE 9 OF 171

30 TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-1 COMMON STRUCTURAL RULES FOR BULK CARRIERS Fig. 14 Averages of Utimate Strength in Each Case Fig. 15 Coefficients of Variation in Each Case From Figure 15, it is obvious that the variance of any resuts obtained by method B is sma. This means the accuracy of any resuts obtained by Method B is higher than those resuts obtained by Method A. 4. Concusion Two methods to estimate the utimate strength of stiffened panes in cases where attached pates and stiffeners are made of stee having different yied stresses are considered. One is Method A, where the yied stress used in the estimation of beam-coumn bucking is cacuated so as to be the weighted average vaue of the yied stresses of the stiffener and the attached pating according to their area. The other is method B, where the yied stress in the estimation of beam-coumn bucking is set to the weighted average vaue of the yied stresses of the stiffener and the attached pating according to the product of their areas and their distances from the neutra axis. In order to evauate the accuracy of the utimate strength of the stiffened pane obtained by both methods, the resuts obtained by both methods are compared to those obtained by 3D non-inear FEAs. From these comparison works, the foowing findings are obtained. (1) The method A is very simpe and practicabe, but it may overestimated the utimate strength in the case that the yied strength of the stiffener is ower than that of the attach pating () Method B is not as simpe and practicabe as Method A, but it gives more accurate utimate strength vaues for stiffened panes in comparison to those obtained by Method A. Therefore, in cases where attached panes and stiffeners are made of stee having different yied stresses, Method B shoud be used for the evauation of the oad end shortening curve thereof. The text in the RCP is based on this. PAGE 30 OF 171

31 COMMON STRUCTURAL RULES FOR BULK CARRIERS RULE CHANGE NOTICE NO.1- Common Structura Rues for Buk Carriers, Juy 008 Rue Change Notice No.1- (Hatch Covers) Notes: (1) These Rue Changes enter into force on 1 Juy 009. Copyright in these Common Structura Rues for Buk Carriers is owned by: American Bureau of Shipping Bureau Veritas China Cassification Society Det Norske Veritas Germanischer Loyd Korean Register of Shipping Loyd's Register Nippon Kaiji Kyokai Registro Itaiano Navae Russian Maritime Register of Shipping Copyright 006 The IACS members, their affiiates and subsidiaries and their respective officers, empoyees or agents are, individuay and coectivey, referred to in this cause as the IACS Members. The IACS Members, individuay and coectivey, assume no responsibiity and sha not be iabe to any person for any oss, damage or expense caused by reiance on the information or advice in this document or howsoever provided, uness that person has signed a contract with the reevant IACS Member entity for the provision of this information or advice and in that case any responsibiity or iabiity is excusivey on the terms and conditions set out in that contract. PAGE 31 OF 171

32 RULE CHANGE NOTICE NO.1- COMMON STRUCTURAL RULES FOR BULK CARRIERS For technica background for Rue Changes in this present document, reference is made to separate document Technica Background for Rue Change Notice No.1-. CHAPTER 9 OTHER STRUCTURES Section 5 HATCH COVERS Symbos For symbos not defined in this Section, refer to Ch 1, Sec 4. p S : Sti water pressure, in kn/m, defined in [4.1] p W : Wave pressure, in kn/m, defined in [4.1] p C : Pressure acting on the hatch coaming, in kn/m, defined in [6.] F S, F W : Coefficients taken equa to: F S = 0 and F W = 0.9 for baast water oads on hatch covers of the cargo baast hod F S = 1.0 and F W = 1.0 in other cases s : Length, in m, of the shorter side of the eementary pate pane b p w A sh : Length, in m, of the onger side of the eementary pate pane : Effective width, in m, of the pating attached to the ordinary stiffener or primary supporting member, defined in [3] : Net section moduus, in cm 3, of the ordinary stiffener or primary supporting member, with an attached pating of width b p : Net shear sectiona area, in cm, of the ordinary stiffener or primary supporting member m : Boundary coefficient for ordinary stiffeners and primary supporting members, taken equa to: m = 8, in the case of ordinary stiffeners and primary supporting members simpy supported at both ends or supported at one end and camped at the other end m = 1, in the case of ordinary stiffeners and primary supporting members camped at both ends t C : Tota corrosion addition, in mm, defined in [1.4] σ a, τ a : Aowabe stresses, in N/mm, defined in [1.5] 1. Genera 1.5 Aowabe stresses Ref. ILLC, as amended (Resoution MSC.143(77) Reg. 15(6) and 16(5)) The aowabe stresses σ a and τ a, in N/mm, are to be obtained from Tab. PAGE 3 OF 171

33 COMMON STRUCTURAL RULES FOR BULK CARRIERS RULE CHANGE NOTICE NO.1- Tabe Aowabe stresses, in N/mm Members of Subjected to σ a, in N/mm τ a, in N/mm Weathertight hatch cover Externa pressure, as defined in Ch 0.80 R eh 0.46 R eh Pontoon hatch cover 4, Sec 5, [][5..1] 0.68 R eh 0.39 R eh Weathertight hatch cover and pontoon hatch cover Other oads, as defined in Ch 4,Sec 5, [5.1.1] and Ch 4, Sec 6, [] 0.90 R eh 0.51 R eh 5. Strength check 5. Pating 5..3 Critica bucking stress check The compressive stress σ in the hatch cover pating, induced by the bending of primary supporting members, parae to the direction of ordinary stiffeners is to compy with the foowing formua: σ 0.88 S σ C 1 where: S : Safety factor defined in Ch 6, Sec 3 σ C1 : Critica bucking stress, in N/mm, taken equa to: σ = σ for C1 E1 σ E1 R eh R = eh σ C1 ReH 1 for 4σ E 1 σ E1 R > eh σ E1 t = 3.6 E 1000s t : Net thickness, in mm, of pate pane The compressive stress σ in the hatch cover pating, induced by the bending of primary supporting members, perpendicuar to the direction of ordinary stiffeners is to compy with the foowing formua: σ 0.88 S σ C where: S : Safety factor defined in Ch 6, Sec 3 σ C : Critica bucking stress, in N/mm, taken equa to: σ = σ for C E σ E R eh R = eh σ C ReH 1 for 4σ E σ E > R eh σ E t = 0.9 m E 1000s s PAGE 33 OF 171

34 RULE CHANGE NOTICE NO.1- COMMON STRUCTURAL RULES FOR BULK CARRIERS m t s s s ψ : Coefficient taken equa to: m = c 1 + s s s.1 ψ : Net thickness, in mm, of pate pane : Length, in m, of the shorter side of the pate pane : Length, in m, of the onger side of the pate pane : Ratio between smaest and argest compressive stress c : Coefficient taken equa to: c = 1.3 when pating is stiffened by primary supporting members c = 1.1 when pating is stiffened by ordinary stiffeners of ange or T type c = 1.1 when pating is stiffened by ordinary stiffeners of bub type c = 1.05 when pating is stiffened by fat bar c = 1.30 when pating is stiffened by ordinary stiffeners of U type. The higher c vaue but not greater than.0 may be taken if it is verified by bucking strength check of pane using non-inear FEA and deemed appropriate by the Society. An averaged vaue of c is to be used for pate panes having different edge stiffeners. In addition, Tthe bi-axia compression stress in the hatch cover pating, when cacuated by means of finite eement anaysis, is to compy with the requirements in Ch 6, Sec Ordinary stiffeners 5.3. Minimum net thickness of web The web net thickness of the ordinary stiffener, in mm, is to be not ess than the minimum vaues given in [5..] 4mm. 5.4 Primary supporting members 5.4. Minimum net thickness of web The web net thickness of primary supporting members, in mm, is to be not ess than the minimum vaues given in [5..] 6mm. PAGE 34 OF 171

35 COMMON STRUCTURAL RULES FOR BULK CARRIERS TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1- Common Structura Rues for Buk Carriers, Juy 008 Technica Background for Rue Change Notice No.1- (Hatch Covers) Copyright in these Common Structura Rues for Buk Carriers is owned by: American Bureau of Shipping Bureau Veritas China Cassification Society Det Norske Veritas Germanischer Loyd Korean Register of Shipping Loyd's Register Nippon Kaiji Kyokai Registro Itaiano Navae Russian Maritime Register of Shipping Copyright 006 The IACS members, their affiiates and subsidiaries and their respective officers, empoyees or agents are, individuay and coectivey, referred to in this cause as the IACS Members. The IACS Members, individuay and coectivey, assume no responsibiity and sha not be iabe to any person for any oss, damage or expense caused by reiance on the information or advice in this document or howsoever provided, uness that person has signed a contract with the reevant IACS Member entity for the provision of this information or advice and in that case any responsibiity or iabiity is excusivey on the terms and conditions set out in that contract. PAGE 35 of 171

36 TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1- COMMON STRUCTURAL RULES FOR BULK CARRIERS Technica Background for the Change Regarding Hatch Covers 1. Reason for the Rue Changes 1.1 Symbos To consider the interna pressure due to baast water in baast hod, the oad combination coefficients are introduced in Symbos. The rue change is made to carify the appication of the symbos Fs and Fw. 1. Tabe Aowabe stresses According to ILLC and IACS UR S1, the externa pressure is ony externa wave pressure acting on the hatch cover. However, as the pressure is referred to Ch 4 Sec 5 [] which are mentioned not ony the wave pressure on exposed deck but aso other distributed oad and concentrated oads. This rue change is made according to the answer in KC ID 537 in order to be in ine with ILLC and IACS UR S Critica bucking stress Appication of bucking check When the bi-axia compression stress in the hatch cover pating cacuated by means of finite eement anaysis, bucking check is to be carried out in accordance with the requirement in Ch 6 Sec 3. This check is aternative check to the bucking check using the compression stress obtained by a griage anaysis as specified in IACS UR S1. This rue change is made according to the answer in KC ID 477 in order to be in ine with IACS UR S c or F1 factor for ordinary stiffener of U type There are many hatch covers stiffened by ordinary stiffener of U type. As the ordinary stiffener of U-type has the merit of being more resistant to rotationa effect than other ordinary stiffener of fat bar, ange type or T type. However, the coefficient c is taken equa to 1.05 to 1. corresponding to the type of stiffener. Regarding this issue, the interpretation is made according to the resuts as shown in Annex Minimum thickness of ordinary stiffener and 5.4. Minimum thickness of Primary supporting member The definition of the web minimum thickness of ordinary stiffeners and primary supporting members was inked to the minimum requirements for the hatch cover pating, as defined in URS 1 and ILLC Reg. 16 (5.b). These rues contain no requirement for minimum web thickness for ordinary stiffeners and primary supporting members. But the rues for hatch covers of CSR-BC shoud have such a minimum requirement, comparabe to the approach for the ship structure. The reason is the change to the net thickness concept, which has not taken into account for the stiffeners. Hatch cover manufactures demand that the minimum net thickness of ordinary stiffeners pus the corrosion margin of mm has not to be greater than the we proven gross thickness of 6mm. In addition, the reation to the distance between ordinary stiffeners (t min = 10s) is ony vaid for the hatch cover pating. The rue change is made in accordance with the answer in KC ID Summary of the Rue Change.1 Symbos The use of the coefficients Fs=0 and Fw=0.9 are imited for hatch covers of the baast hod in case scanting check is done against the baast water pressure. PAGE 36 OF 171

37 COMMON STRUCTURAL RULES FOR BULK CARRIERS TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-. Tabe The reference is changed to Ch 4 Sec 5 [5..1] from Ch 4 Sec 5 [] and carification of other oad is made Critica bucking stress.3.1 Appication of bucking check The used stress for bucking check is carified as foows. For uni-axia compression stress, the stress is obtained by a griage anaysis. For bi-axia compression stress, the stresses are obtained by a FEA.3. c or F1 factor for ordinary stiffener of U type According to the resuts specified in Annex 1, the coefficient c for ordinary stiffener of U- type can be taken to higher vaue than 1.3. However, c vaue depends on the aspect ratio as shown in Annex 1. Therefore, the coefficient c is taken equa to 1.3 as a minimum, but the higher vaue may be used if it is verified by bucking strength check of pane using non-inear FEA and deemed appropriate by the Society. In addition, the treatment of the different edge stiffeners is added according to Tabe 1 in Ch 6 Sec Minimum thickness of web of ordinary stiffener and 5.4. Minimum thickness of Primary supporting member (1) The reation to the distance between ordinary stiffeners (t min = 10s) is ony vaid for the hatch cover pating. Therefore this requirement is deeted the reference to the minimum thickness of hatch cover pate for ordinary stiffeners and primary supporting. () In addition to the change, described in (1) above, the minimum net web thickness of ordinary stiffener of 6mm has been changed to 4mm. (3) In addition to the change, described in () above, the minimum net thickness of 6mm is specified in the requirement for web of primary supporting member, but the vaue is the same as the current Rue. 3. Effects and impact on scanting due to this definition 3.1 Items in.1,. and.3.1 mentioned above As the rue change is ony made for the carification, there is no scanting impact due to these changes. 3. Items in.3. mentioned above Regarding the U-type stiffeners, the coefficient c is to be an appropriate vaue deemed by the Society because the factor of such stiffeners are not defined in CSR and IACS UR S1. The minimum vaue is newy defined by this rue change athough the used vaue sti depends on the discretion of the Society. Therefore, the scanting impact due to this change can not be estimated. 3.3 Item in.4 The minimum web thickness for ordinary stiffeners and primary supporting members is decreased. The impact on scanting can not be estimated in genera. Depending on the hatch cover type, the hatch cover size and oads, different design criteria determine the dimensions of the structure. One manufacturer estimates the weight increase when using the current CSR approach with 40% for ordinary stiffeners (KC-ID. 535). PAGE 37 OF 171

38 TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1- COMMON STRUCTURAL RULES FOR BULK CARRIERS Annex 1: Technica Background for the Changes regarding F1 factor for transverse compressed pate fieds in bucking check of hatch cover pating 1. Reason for the Rue Change in Ch 9 Sec 5 [5..3] It was requested to make an interpretation for the factor c in case of U-type stiffener in bucking assessment of hatch covers. The factor c considers the torsion stiffness of the ongitudina stiffener of an eementary pate pane under transverse compression oads. The foowing vaues are given in the URS 11: c = 1.3 when pating is stiffened by primary supporting members c = 1.1 when pating is stiffened by ordinary stiffeners of ange or T type c = 1.1 when pating is stiffened by ordinary stiffeners of bub type c = 1.05 when pating is stiffened by fat bar The intention of this RC is to make a proposa for the c factor for U-type stiffener. Summary of the Rue Change The derivation of the c -factor for U-type stiffeners based on noninear FE-anayses shoud be treated as a future deveopment, because this work is beyond the capabiity of CSR PT1. CSR PT1 proposes to make a comparison study to estimate a F1 vaue by comparing the bucking oad case (BLC) 9 (camped edges) with the reference BLC (simpy supported). Both bucking oad cases BLC and BLC 9 are theoretica cases and the rea boundary condition of the U-Profie is in between these extreme cases. As a short term soution we propose to use the mean bucking reduction factor κ y vaue of both BLC's to estimate the c - factor for U-type stiffeners. The foowing diagrams show the bucking reduction factors of BLC 1 and 9 together with the mean vaue and the c -factors as a function of c = κ y (9) / κ y (1) and c = κ y (mean) / κ y (1) for different pate thicknesses and aspect ratios. PAGE 38 OF 171

39 COMMON STRUCTURAL RULES FOR BULK CARRIERS TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1- kappa, F1,0 1,8 1,6 1,4 1, 1,0 0,8 0,6 0,4 0, 0,0 Infuence of ongitudina stiffeners with high torsiona stiffness of the bucking behaviour of transverse oaded pate panes (t=5mm) apha kappa BLC kappa BLC 9 c=f(blc,9) kappa mean c_mean kappa, F1 3,0,5,0 1,5 1,0 Infuence of ongitudina stiffeners with high torsiona stiffness of the bucking behaviour of transverse oaded pate panes (t=15mm) kappa BLC kappa BLC 9 c=f(blc,9) kappa mean c_mean 0,5 0, apha PAGE 39 OF 171

40 TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1- COMMON STRUCTURAL RULES FOR BULK CARRIERS 4,0 Infuence of ongitudina stiffeners with high torsiona stiffness of the bucking behaviour of transverse oaded pate panes (t=7mm) kappa, F1 3,5 3,0,5,0 1,5 1,0 kappa BLC kappa BLC 9 c=f(blc,9) kappa mean c_mean 0,5 0, apha The diagrams show the foowing dependencies With decreasing thickness the c factor increases With decreasing thickness the range of a constant c factor increases Different hatch cover designs show aspect ratios between 3 and 8 with a majority of ratios between 3 and 6. The pate thickness is typicay beow 10mm. For these parameter ranges a c factor of.0 may be assumed. To be in ine with the simpe definitions of c in URS 11 a constant c vaue of 1.3 can be used regardess of the thickness and aspect ratio. The diagrams eads to the assumption, that a higher vaue might be possibe, taking the aspect ratio and pate thickness into account. But this has to be verified as a future deveopment for CSR-BC. 3. Effects and impact on scanting due to this definition The highest vaue for c, given in the URS 11 is 1.3 for primary supporting members. Higher vaues are not aowed by IACS up to now. Defining a constant vaue of 1.3 for U- type stiffeners regardess of pate fied aspect ratios or thicknesses, we do not change the resut of the pate bucking check for hatch covers and this definition has no impact on scanting. With the seection of a higher c vaue for such kind of stiffeners, the bucking strength of hatch cover pating, stiffened with U-type stiffeners increases with respect to transverse oaded pate fieds. PAGE 40 OF 171

41 COMMON STRUCTURAL RULES FOR BULK CARRIERS RULE CHANGE NOTICE NO.1-3 Common Structura Rues for Buk Carriers, Juy 008 Rue Change Notice No.1-3 (Stee Coi) Notes: (1) These Rue Changes enter into force on 1 Juy 009. Copyright in these Common Structura Rues for Buk Carriers is owned by: American Bureau of Shipping Bureau Veritas China Cassification Society Det Norske Veritas Germanischer Loyd Korean Register of Shipping Loyd's Register Nippon Kaiji Kyokai Registro Itaiano Navae Russian Maritime Register of Shipping Copyright 006 The IACS members, their affiiates and subsidiaries and their respective officers, empoyees or agents are, individuay and coectivey, referred to in this cause as the IACS Members. The IACS Members, individuay and coectivey, assume no responsibiity and sha not be iabe to any person for any oss, damage or expense caused by reiance on the information or advice in this document or howsoever provided, uness that person has signed a contract with the reevant IACS Member entity for the provision of this information or advice and in that case any responsibiity or iabiity is excusivey on the terms and conditions set out in that contract. PAGE 41 OF 171

42 RULE CHANGE NOTICE NO.1-3 COMMON STRUCTURAL RULES FOR BULK CARRIERS For technica background for Rue Changes in this present document, reference is made to separate document Technica Background for Rue Change Notice No.1-3. CHAPTER 4 DESIGN LOADS Section SHIP MOTION AND ACCELERATIONS. Ship absoute motions and acceerations.1 Ro.1.1 The ro period T R, in s, and the singe ro ampitude θ, in deg, are given by: T R.3kr = GM ( 0.05T ) θ = ( B + 75)π R f p k b where: k b k r GM : Coefficient taken equa to: k b = 1. for ships without bige kee k b = 1.0 for ships with bige kee : Ro radius of gyration, in m, in the considered oading condition. When k r is not known, the vaues indicated in Tab 1 may be assumed. : Metacentric height, in m, in the considered oading condition. When GM is not known, the vaues indicated in Tab 1 may be assumed. Tabe 1: Vaues of k r and GM Loading condition k r GM Fu oad condition (Aternate or homogeneous oading) 0.35B 0.1B Stee coi oading 0.4B 0.4B Norma baast condition 0.45B 0.33B Heavy baast condition 0.40B 0.5B PAGE 4 OF 171

43 COMMON STRUCTURAL RULES FOR BULK CARRIERS RULE CHANGE NOTICE NO.1-3 CHAPTER 6 HULL SCANTLING Section 1 PLATING. Genera requirements.7 Inner bottom oaded by stee cois on a wooden support.7.1 Genera The net thickness of inner bottom, bige hopper soping pate and inner hu for ships intended to carry stee cois is to compy with [.7.] to [.7.4]. The provision is determined by assuming Fig as the standard means of securing stee cois. In case where stee cois are ined up two or more tier, formuae in [.7.] and [.7.3] can be appied to the case that ony owest tier of stee cois is in contact with hopper soping pate or inner hu pate. In other cases, scantings of pate thickness are cacuated by direct strength anaysis or other procedures. Figure : Inner bottom oaded by stee cois.7.1 bis1 Acceerations In order to cacuate the acceerations, the foowing coordinates are to be used for the centre of gravity. xg sc = 0.75 H forward of aft bukhead, where the hod of which the mid position is ocated forward from 0,45L from A.E. PAGE 43 OF 171

44 RULE CHANGE NOTICE NO.1-3 COMMON STRUCTURAL RULES FOR BULK CARRIERS xg sc = 0.75 H afterward of fore bukhead, where the hod of which the mid position is ocated afterward from 0,45L from A.E. y G sc Bh = ε 4 z G sc = h DB + ( n 1) d sc where: ε : 1.0 when a port side structura member is considered, or -1.0 when a starboard side structura member is considered. B h d sc h DB H : breadth in m, at the mid of the hod, of the cargo hod at the eve of connection of bige hopper pate with side she or inner hu : diameter of stee cois, in m : height of inner bottom, in m : Cargo hod ength, in m Vertica acceeration a Z, in m/s,.are to be cacuated by the formuae defined in Ch 4, Sec, [3.] and tangentia acceeration a R due to ro, in m/s.is to be cacuated by the foowing formua. a π π R = θ yg _ SC T R where: θ, T R and R: as defined in Ch 4 Sec, [3.]. R.7. Inner bottom pating The net thickness of pating of ongitudinay framed inner bottom is to be not ess than the vaue obtained, in mm, from the foowing formua: t = K1 t = K 1 ( g + a ) P Z Y λ R F { g( cos( C Φ) cos( C θ )) + a } ZP λ R P Y ZR z F where: K 1 : Coefficient taken equa to: K 1 = 1.7sK s K ( ' ) ( s + K ) 0.73 ' a Z : Vertica acceeration, in m/s, defined in Ch 4, Sec, [3.] [.7.1 bis1] Φ : Singe pitch ampitude, in deg, defined in Ch 4, Sec, [.] θ : Singe ro ampitude, in deg, defined in Ch 4, Sec, [.1] C ZP,C ZR : Load combination factor defined in Ch 4, Sec 4, [.] PAGE 44 OF 171

45 COMMON STRUCTURAL RULES FOR BULK CARRIERS RULE CHANGE NOTICE NO.1-3 F : Force, in kg, taken equa to: F Wn n 1 = K S for 10 n 3 n and n 5 3 = W for 10 > F K S n1 S n or n 5 λ P : Coefficient defined in Tab 6 K S : Coefficient taken equa to: K S = 1.4 when stee cois are ined up in one tier with a key coi K S = 1.0 in other cases W : Mass of one stee coi, in kg 3 > n 1 n : Number of tiers of stee cois : Number of oad points per eementary pate pane of inner bottom (See Figs 3 and 4), taken equa to. When n 3 5, n can be obtained from Tab 3 according to the vaues of n 3 and / S in case of stee cois oaded as shown in Fig 3, n is obtained from Tab 3 according to the vaues of n 3 and / S n 3 S K in case of stee cois oaded as shown in Fig 4, n = n 3 : Number of dunnages supporting one stee coi : Length of a stee coi, in m : Coefficient taken equa to: K s s = s ' 1.33 : Distance, in m, between outermost oad points per eementary pate pane of inner bottom pate in ship ength, taken equa to: (See Figs 3 and 4). When n 10 and n 3 5, can be obtained from Tab 4 according to the vaues of, S, n and n 3. When n > 10 or n 5 3 >, is to be taken equa to. in case of stee cois oaded as shown in Fig 3, is obtained from Tab 4 according to the vaues of, S, n and n 3 in case of stee cois oaded as shown in Fig 4, is the actua vaue..7.3 Bige hhopper soping pate and inner hu pateing The net thickness of pating of ongitudinay framed bige hopper soping pate and inner hu is to be not ess than the vaue obtained, in mm, from the foowing formua: t = K 1 [ g cos( θ ) + a sinθ ] θ F 1 λ R P Y Y 1 t = K 1 a hopper F' λ Ry p PAGE 45 OF 171

46 RULE CHANGE NOTICE NO.1-3 COMMON STRUCTURAL RULES FOR BULK CARRIERS where: K 1 : Coefficient defined in [.7.] θ 1 θ h : Ange, in deg, between inner bottom pate and bige hopper soping pate or inner hu pateing θ : Singe ro ampitude, in deg, defined in Ch 4, Sec, [.1] a Y : Transverse acceeration, in m/s, defined in Ch 4, Sec, [3.] a hopper = C YR a R sin tan 1 y G _ sc R θ h + g cos( θh C YG θ ) cos( C XG Φ) + C YS a sway sin θ h a R : tangentia acceeration defined in [.7.1 bis1]. a sway : Transverse acceeration due to sway, in m/s, defined in Ch 4, Sec, [.4] C XG, C YS, C YR, C YG : Load combination factors defined in Ch 4, Sec 4, [.] y G_sc : Centre of gravity in transverse direction, in m, defined in [.7.1 bis1] R : Coefficient defined in Ch 4 Sec, [3..1] F : Force, in kg, taken equa to: WnCk F = for n 10 and n 3 5 n 3 F = CkW ' for n 10 or n 5, λ P : Coefficient defined in Tab 6 W, n, n 3, Φ and θ : As defined in [.7.] S > 3 > C k : Coefficient taken equa to: C k = when stee cois are ined up two or more tier, or when stee cois are ined up one tier and key coi is ocated second or third from bige hopper soping pate or inner hu pate C k =.5.0 for other cases Dunnage Stee coi n and are given by Tabes 3 and 4 Foor Inner bottom Bottom Figure 3: Loading condition of stee cois (Exampe of n = 4, n 3 = 3) PAGE 46 OF 171

47 COMMON STRUCTURAL RULES FOR BULK CARRIERS RULE CHANGE NOTICE NO.1-3 Dunnage Stee coi ' Foor Inner bottom Bottom Figure 4: Loading condition of stee cois (Exampe of n = 3, n 3 = 3).7.4 Where the number of oad points per eementary pate pane n is greater than 10 and/or the number of dunnages n 3 is greater than 5, the inner bottom may be considered as oaded by a uniform distributed oad. In such a case, the thickness of the inner bottom pating is to be obtained according to [3..1]. (void) PAGE 47 OF 171

48 RULE CHANGE NOTICE NO.1-3 COMMON STRUCTURAL RULES FOR BULK CARRIERS Tabe 3: Number n of oad points per eementary pate pane n n 3 = n 3 = 3 n 3 = 4 n 3 = < 0. 5 S 0.5 < 1. S 3 1. < 1. 7 S <. 4 S 5.4 <. 9 S 6.9 < 3. 6 S < 4. 1 S < 4. 8 S < 5. 3 S < 6. 0 S 0 < 0.33 S 0.33 < 0.67 S 0.67 < 1. S 1. < 1.53 S 1.53 < 1.87 S 1.87 <.4 S.4 <.73 S.73 < 3.07 S 3.07 < 3.6 S 3.6 < 3.93 S 0 < 0.5 S 0.5 < 0.5 S 0.5 < 0.75 S 0.75 < 1. S 1. < 1.45 S 1.45 < 1.7 S 1.7 < 1.95 S 1.95 <.4 S.4 <.65 S.65 <.9 S 0 < 0. S 0. < 0.4 S 0.4 < 0.6 S 0.6 < 0.8 S 0.8 < 1. S 1. < 1.4 S 1.4 < 1.6 S 1.6 < 1.8 S 1.8 <.0 S.0 <.4 S Tabe 4: Distance between oad points in ship ength direction per eementary pate pane of inner bottom n Actua breadth of dunnage 0.5 S 0.33 S 0.5 S 0. S 3 1. S 0.67 S 0.50 S 0.4 S S 1.0 S 0.75 S 0.6 S 5.4 S 1.53 S 1.0 S 0.8 S 6.9 S 1.87 S 1.45 S 1. S S.40 S 1.70 S 1.4 S S.73 S 1.95 S 1.6 S S 3.07 S.40 S 1.8 S S 3.60 S.65 S.0 S n 3 PAGE 48 OF 171

49 COMMON STRUCTURAL RULES FOR BULK CARRIERS RULE CHANGE NOTICE NO.1-3 Section ORDINARY STIFFENERS. Genera requirements.5 Ordinary stiffeners of inner bottom oaded by stee cois on a wooden support.5.1 Genera The requirements of this sub-artice appy to the ordinary stiffeners ocated on inner bottom pate, bige hopper soping pate and inner hu pate when oaded by stee cois on a wooden support (dunnage), as indicated in Fig of Ch 6, Sec 1. In case where stee cois are ined up two or more tier, formuae in [.5.] and [.5.3] can be appied to the case that ony owest tier of stee cois is in contact with hopper soping pate or inner hu pate. In other cases, scantings of net section moduus and net shear section area are cacuated by direct strength anaysis or other procedures..5. Ordinary stiffeners ocated on inner bottom pating The net section moduus w, in cm 3, and the net shear sectiona area A sh, in cm, of singe span ordinary stiffeners ocated on inner bottom pating are to be not ess than the vaues obtained from the foowing formuae: w = K A sh = w = K A sh = 3 where: 3 ( g + a ) S Z 8λ R Y F ( g + a ) F 3 5 τ a sin Zφ 10 [ g cos( C Φ) cos( C θ ) + a ] ZP 8 λ R S Y ZR Z F [ g cos( C Φ) cos( C θ ) + a ] F 3 5 ZP ZR Z τ sin φ a 10 K 3 : Coefficient defined in Tab 1. When n is greater than 10, K 3 is to be taken equa to /3 a Z : Vertica acceeration, in m/s, defined in Ch 4, Sec, [3.] Ch 6, Sec 1, [.7.1 bis1] Φ : Singe pitch ampitude, in deg, defined in Ch 4, Sec, [.] θ : Singe ro ampitude, in deg, defined in Ch 4, Sec, [.1] C ZP,C ZR : Load combination factor defined in Ch 4, Sec 4, [.] F : Force, in kg, defined in Ch 6, Sec 1, [.7.] λ S : Coefficient defined in Tab 3 φ : Ange, in deg, defined in [3..3]. PAGE 49 OF 171

50 RULE CHANGE NOTICE NO.1-3 COMMON STRUCTURAL RULES FOR BULK CARRIERS.5.3 Ordinary stiffeners ocated on bige hopper soping pate or inner hu pateing The net section moduus w, in cm 3, and the net shear sectiona area A sh, in cm, of singe span ordinary stiffeners ocated on bige hopper soping pate and inner hu pate are to be not ess than the vaues obtained from the foowing formuae: w = K 3 [ g ( θ θ ) + a sinθ ] cos 1 Y 1 8λ R S Y F' A sh = τ a 5aY F' 3 10 sin ϕ sin φ w = K 3 a hopper 8λ R S F' Y A sh = 5ahopper F' 3 10 τ a sin φ where: K 3 : Coefficient defined in Tab 1. When n > 10, K 3 is taken equa to /3. θ 1, θ : Anges, in deg, defined in Ch 6, Sec 1, [.7.3] θ h : Ange, in deg, between inner bottom pate and bige hopper soping pate or inner hu pate a Y : Transverse acceeration, in m/s, defined in Ch 4, Sec, [3.] a hopper : Acceeration, in m/s, defined in Ch 6 Sec 1, [.7.3] F ' : Force, in kg, defined in Ch 6, Sec 1, [.7.3] λ S : Coefficient defined in Tab 3 φ : Ange, in deg, defined in [3..3] φ : Ange, in deg, between inner bottom pating and hopper soping pate or inner hu pating. ' : Distance, in m, between oad points per eementary pate pane of inner bottom pate in ship ength, soping pate or inner hu pating, as defined in Ch 6, Sec 1, [.7.]. : Distance, in m, between outermost oad points per eementary pate pane in ship ength Tabe 1 : Coefficient K 3 n K 3 ' ' 3 5 ' 9 ' 7 ' 15 4 ' 9 3 ' 7 5 ' 1 11 ' Where the number of oad points per eementary pate pane n is greater than 10 and/or the number of dunnages n 3 is greater than 5, the inner bottom may be considered as oaded by a uniform distributed oad. In such a case, the scanting of the inner bottom ordinary stiffeners is to be obtained according to [3..3]. (void) PAGE 50 OF 171

51 COMMON STRUCTURAL RULES FOR BULK CARRIERS TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-3 Common Structura Rues for Buk Carriers, Juy 008 Technica Background for Rue Change Notice No.1-3 (Stee Coi) Copyright in these Common Structura Rues for Buk Carriers is owned by: American Bureau of Shipping Bureau Veritas China Cassification Society Det Norske Veritas Germanischer Loyd Korean Register of Shipping Loyd's Register Nippon Kaiji Kyokai Registro Itaiano Navae Russian Maritime Register of Shipping Copyright 006 The IACS members, their affiiates and subsidiaries and their respective officers, empoyees or agents are, individuay and coectivey, referred to in this cause as the IACS Members. The IACS Members, individuay and coectivey, assume no responsibiity and sha not be iabe to any person for any oss, damage or expense caused by reiance on the information or advice in this document or howsoever provided, uness that person has signed a contract with the reevant IACS Member entity for the provision of this information or advice and in that case any responsibiity or iabiity is excusivey on the terms and conditions set out in that contract. PAGE 51 OF 171

52 TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-3 COMMON STRUCTURAL RULES FOR BULK CARRIERS Technica Background for the Change Regarding Scanting Formua for Stee Coi Loading 1. Background of Rue change regarding stee coi oading 1.1 Addition of GM and k r vaue for stee coi oading to the note of Tabe 1 in Ch 4, Sec, [.1.1] Ro radius of gyration ( k r ) and metacentric height ( GM ) in the considered oading condition is used for the cacuation of the parameters regarding the ship s absoute motion and acceerations. When these vaues are not known, the defaut vaues specified in Tabe 1 in Ch 4, Sec, [.1.1] may be assumed in the current CSR. However, these defaut vaues specified in the Tabe do not correspond to the stee coi oading condition because the stee coi oad is normay concentrated near the inner bottom. The rue change is made to set the GM vaue based on the actua design vaues given in Tabe 1 and the averaged vaues of GM and k r is about 0.4B and 0.4B, respectivey. Tabe 1 Actua GM Vaue B Actua GM GM = X*B B Actua GM GM = X*B B Actua GM GM = X*B The GM and k r vaue for stee coi oading are newy added to Tabe 1 in Ch 4, Sec, [.1.1] as a defaut vaue. 1. Modification of the requirements in Ch 6, Sec 1, [.7.1] and Ch 6, Sec, [.5.1] The 3 rd sentence and the 4 th sentence in Ch 6, Sec 1, [.7.1] and the nd sentence and the 3 rd sentence in Ch 6, Sec, [.5.1] are deeted due to the foowing reasons. (a) As the term of the acceeration in the scanting formua is revised in order to accommodate any oading pattern of stee coi as mentioned in Annex 1, the imitation of the rue appication regarding the oading pattern is not necessary. (b) In addition, CSR does not permit overruing the scanting determined by the prescriptive requirement by FEA. 1.3 Carification of the treatment of centre of gravity for stee coi oading If the actua centre of gravity in stee coi oaded condition is known, it is better to use the actua one in cacuating the acceeration. Therefore, this treatment has been added to the text. If the actua centre of gravity is not known, the standard vaue of the centre of gravity is needed. Then the centre of gravity ( x, y, z) is set up ( mid hod, ε Bh 4, hdb + ( 1+ ( n1 1) 3 ) d SC ) as a conservative manner, where B h is defined as a breadth of the cargo hod and ε is 1.0 when a port side structura member is considered, or -1.0 when a starboard side structura member is considered. PAGE 5 OF 171

53 COMMON STRUCTURAL RULES FOR BULK CARRIERS TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO Amendment of the formuae for pating and ordinary stiffeners of inner bottom, bige hopper and inner hu In the current formuae for inner bottom pating and ordinary stiffeners (inner bottom ongitudinas), oad cases H and F are ony considered but the oad cases R and P is not considered. The rue change is made to consider the a oad cases. The current formuae for pating and ordinary stiffeners of bige hopper and inner hu give the excessive scanting due to the account of gravity acceeration in dupicate and conservative coefficient C. In addition, formua for shear area of the ordinary stiffeners is modified. k 1.5 Amendment of the treatment which the number of oad points per eementary pate pane is greater than 10 and/or the number of dunnages is greater than 5. In the current requirements, the number of oad points per eementary pate pane n is greater than 10 and/or the number of dunnages n 3 is greater than 5, the scanting of pating and ordinary stiffeners may be checked by the formuae based on uniform distributed oads. However, this assumption is inappropriate because the scanting formua for stee coi is based on the ine oad which is transformed from the concentrated oads due to stee coi acting on the most severe ocations of an eementary pate pane. Even if the number of oad points becomes arger than 10, this assumption for the oad mode shoud be kept. Therefore, the texts of Ch 6, Sec 1, [.7.4] and Ch 6, Sec, [.5.4] are deeted. Furthermore, in order to carify the treatment where the number of oad points per eementary pate pane is greater than 10 and/or the number of dunnages is greater than 5, the reevant text is revised. The technica backgrounds of these modifications are described in Annex 1.. Summary of Rue Changes.1 Ch 4, Sec, Tabe 1 The GM and k r vaues are added to Tabe 1 as averaged vaues based on the investigation resuts of actua ships data.. Ch 6, Sec 1, [.7.1] The 3 rd and the 4 th sentences are deeted..3 Ch 6, Sec 1, [.7.], [.7.3], [.7.4] The new paragraph [.7.1 bis1] is added for cacuating the acceeration and the paragraph [.7.4] is deeted. The tangentia acceeration due to ro is added. π π R = θ ysc T R a R Where, Bh y G_SC : Centre of gravity in transverse direction, in m, is taken equa to yg sc = ε 4 R: Coefficient defined in Ch 4 Sec, [3..1] of the Rues T R : Ro period, in s, defined in Ch 4, Sec, [.1.1] of the Rues B h : breadth in m, at the mid of the hod. In order to consider the acceeration of pitch, athough the effect is very sma because the hod ength is reative short, the definition of x G_SC is added as foows. xg sc = 0.75 H forward of aft bukhead, where the hod of which the mid position is ocated forward from 0,45L from A.E. PAGE 53 OF 171

54 TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-3 COMMON STRUCTURAL RULES FOR BULK CARRIERS xg sc = 0.75 H afterward of fore bukhead, where the hod of which the mid position is ocated afterward from 0,45L from A.E The backgrounds of these modifications are described in Annex 1.4 Ch 6, Sec 1, [.7.] The scanting formua for oad cases H and F is revised in order to consider a oad cases. In addition, the interpretation of the case where n >10 or n 3 >5 is added. { g( cos( C Φ) cos( C θ )) + a } F t = K 1 ZP λ R Where, For n <=10 and n 3 <=5, For n >10 or n 3 >5 P Y ZR z F = K S F = K S n1 Wn1n n 3 W Definitions of a symbos are specified in the Rue text. S.5 Ch 6, Sec 1, [.7.3] In the current formua, the gravity component is accounted in dupicate because the acceeration a y contains the component of gravity acceeration. The formua is corrected to consider the gravity acceeration component correcty and to correspond to the a oad case. In addition, the coefficient ck is changed based on the experimenta data. t = K 1 a hopper F' λ Ry p Where, For n <=10 and n 3 <=5, For n >10 or n 3 >5 WnCk F' = n3 F ' = CkW yg _ SC 1 ahopper = CYRaR sin tan θ h + g cos( ϑh CYGθ )cos( C R Definitions of a symbos are specified in the Rue text. S XG Φ) + C YS a sway sinθ.6 Ch 6, Sec 1, [.7.4] As the interpretation of the cases where n >10 and/or n 3 >5 are added to the renumbered paragraph [.7.3], the paragraph [.7.4] is deeted..7 Ch 6, Sec, [.5.1] The nd and the 3 rd sentences are deeted..8 Ch 6, Sec, [.5.] and [.5.3] The formuae for a oad cases are provided as simiar to the revision of the scanting formua for pating in Ch 6 Sec 1..9 Ch 6, Sec, [.5.4] As the interpretation of the cases where n >10 and/or n 3 >5 are added to the paragraph [.5.3], this paragraph is deeted. h PAGE 54 OF 171

55 COMMON STRUCTURAL RULES FOR BULK CARRIERS TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO Scanting impact due to modifications For scanting of inner bottom pating and ordinary stiffeners there is ess impact due to this modification. For thickness of bige hopper soping pate and inner hu pate and section moduus of ordinary stiffeners, the conservative scanting required by the current requirement is improved by this modification. Detais of the cacuation for scanting impact due to these modifications are described in Annex. PAGE 55 OF 171

56 TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-3 COMMON STRUCTURAL RULES FOR BULK CARRIERS Annex 1: Background of the formuae for stee coi oading Ch 6, Sec 1.7 Inner bottom oaded by stee cois on a wooden support.7.1 Genera.7.1a In dimensioning the pating and ordinary stiffeners, static and dynamic oads due to dry buk cargoes and iquid acting on the pating and ordinary stiffeners are considered as uniformy distributed oads. On the other hand, as stee cois are oaded on a wooden support (dunnage) provided on the inner bottom pating and bige hopper pating, the concentrated oads due to stee cois act on the pating through the dunnage. However, as the ocation of concentrated oads and the distance between concentrated oads depend on the oading pattern and size of dunnage, it is assumed that the concentrated oad is transformed to a ine oad with a sma breadth (hereinafter referred to as rectanguar oad ) which acts on the most severe conditions (oad point and distance between oad points). Based on this assumption, the specific formuae for dimensioning the pating and ordinary stiffeners under stee coi oading are introduced in the Rues separatey from those based on uniformy distributed oads..7.1b The specific requirements for pating are specified in Ch 6 Sec 1 [.7.] and [.7.3], and those for ordinary stiffeners are specified in Ch 6 Sec [.5.] and [.5.4]..7.1c The technica background of oads due to stee cois is common for pating and ordinary stiffeners..7.1d These requirements are based on the assumption that stee cois are oaded on a wooden support and secured in the standard manner. These assumptions are given in Figure in Ch 6 Sec Inner bottom pating.7.a Load mode Stee cois are usuay secured to each other by means of stee wires. Heavier stee cois are oaded with one or two tiers, and ighter ones are oaded with two or more tiers. Exampes of stee coi oading are shown in Figs.1 and. key coi Bige hopper Bige hopper soping pating soping pating Inner bottom pating Inner bottom pating (A) with key coi (B) without key coi Fig.1 Loading conditions of one tier Bige hopper soping pating Inner bottom pating Fig. Loading conditions of two tiers PAGE 56 OF 171

57 COMMON STRUCTURAL RULES FOR BULK CARRIERS TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-3 The oad due to stee cois acts on an eementary pate pane as a concentrated oad through dunnages. However, it is difficut to treat concentrated oads directy because the ocation of concentrated oads and the distance between concentrated oads depend on the oading pattern and size of dunnage. Then, the foowing assumptions regarding the oads due to stee cois are considered. (1) Loads due to stee cois act aong a centreine of a pate pane. () A rectanguar oad instead of concentrated oads is used in order to be on the safer side considering the interaction between concentrated oads. Stee coi z Inner bottom pating x Foor Foor dunnage y s x Eementary pate pane ' Fig.3 Convert concentrated oads to rectanguar oads As it is the most severe when oads act on the inner bottom verticay, the vertica acceeration is considered for the scanting formua of inner bottom structures. The position of the centre of gravity is given by the foowing. x direction: (i) for the hod of which the mid position is ocated forward of 0.45L from A.E.: X G_SC = 0.75 H forward of aft bukhead, and (ii) for the hod of which the mid position is ocated afterward of 0.45L from A.E.: X G_SC = 0.75 H afterward of fore bukhead, where H is a cargo hod ength y direction: ε 4, measured from the centreine B h z direction: h + + ( n 1) DB ( 3 ) d 1 SC Where, d SC : The diameter, in m, of stee coi h DB : The height, in m, of doube bottom B h : breadth, in m, at the mid of the hod PAGE 57 OF 171

58 TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-3 COMMON STRUCTURAL RULES FOR BULK CARRIERS d SC h DB 3 dsc d SC Inner bottom pating h DB 3 dsc Bottom pating Fig.4 The height of stee cois.7.b Structura mode As mentioned in.7.a, the rectanguar oad acts aong the centreine of the pane. Its ength ' is determined by the pane ength, the ength of a stee coi S, the number of oad points n and the number of dunnages supporting one stee coi n 3, and its width 0.3s is derived from dunnage width based on the actua oading data. Of course, the axia stress due to hu girder bending is considered in addition to the atera rectanguar oad due to the stee cois. An eementary pate pane is coapsed ike Fig.5. The boundary conditions of an eementary pate pane are that a sides are considered fixed. s ' 0.3s Fig.5 Rectanguar oad and coapsed mode.7.c Number of oad points and distances between oad points in ship ength direction per eementary pate pane Tabes 3 and 4 in Ch 6, Sec 1 of the Rues give the standard number of oad points and distances between oad points in ship ength direction for the case of n 10 and/or n 3 5. For other cases, the current treatment as noted in Ch 6, Sec 1, [.7.4] stipuates that oads due to stee cois are considered as a uniform distribution oad and the scanting of pating is obtained according to Ch 6, Sec 1, [3..1]. However, it is considered that the scantings of pating and ordinary stiffeners under stee coi oads are treated separatey from those for distributed oads. Therefore, the instruction in Ch 6, Sec 1, [.7.4] is not appropriate and it has been deeted. Instead a ine oad at pane centreine is assumed throughout the pane ength. PAGE 58 OF 171

59 COMMON STRUCTURAL RULES FOR BULK CARRIERS TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-3 The cacuation resuts are shown in Tabe 1. In this cacuation, the coefficient n 3 is changed from 3 to 6, the coefficient n is derived from the same procedure gotten from Tabes 3 and 4 in Ch 6, Sec 1 of the Rues. The cacuation resuts according to the generic formua for pating and ordinary stiffener specified in Ch 6, Sec 1, [3..1] and Sec, [3..3] of the Rues are cacuated by assuming that the oads due to stee cois are treated as uniformy distributed oads defined as (W/s). It is found from this resut that the required net thickness and net section moduus for uniform oad is greater than those for oad mode specified in the Rues. In order to eiminate this difference between the case of n >10 and/or n 3 >5 and the case of n <=10 and n 3 <=5, the treatment of the case n >10 and/or n 3 >5 is added to the Rues and current paragraphs [.7.4] of Ch 6 Sec 1 and [.5.4] of Ch 6, Sec are deeted. Tabe 1 Comparison of required scantings Line oad according to Ch 6, Sec 1, [.7.] and Sec, [.5.] Uniform oad according to Ch 6, Sec 1, [3..1] (m) s (m) n 1 - n n s (m) (m) W (kg) F (kg) (n =6) t net_req (mm) w net_req (cm 3 ) d Coefficient K S When stee cois are ined up in one tier with a key coi as shown in Fig.1 (A), two cois support a key coi. However, it is known that haf of the weight of a key coi does not act on the supporting coi due to the frictiona resistance between stee cois. In order to investigate the effect of the frictiona resistance between stee cois, parametric experiments were carried out by the Shipbuiding Research Association of Japan. If the force due to stee cois is expressed by the foowing formua, the effect of frictiona resistance ( K S ) is given in Tabe. Wn1n F = K S n3 Where, W : Mass of one stee coi, in kg n 1 : Number of tier of stee cois n : Number of oad points per eementary pane n : Number of dunnages supporting stee coi PAGE 59 OF 171

60 TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-3 COMMON STRUCTURAL RULES FOR BULK CARRIERS Tabe Coefficient K S derived from experiments resuts Position of a/d key coi (m-n) 1/ 1/3 1/ This resut shows that the effect of the frictiona resistance depends on the diameter of stee cois and distance between the centres of cois. The average vaue is 1.38, and therefore K is taken to equa to 1.4 to be on the safe side. S.7.e Coefficient K 1 and K The coefficients K 1 and K are derived from the principe of virtua work based on materia physics..7.f Formua for required thickness of inner bottom pating Finay, the scanting formua for inner bottom pating is given as foows. { g( cos( CZPΦ) cos( CZRθ )) + az} F t = K1 λ R P Y Where, For n <=10 and n 3 <=5, For n >10 or n 3 >5 F = K S F = K S n1 Wn1n n 3 W S.7.3 Bige hopper soping pate and inner hu pate.7.3a Load mode The oad mode for hopper soping and inner hu pating is very compex because the oads are supported by the inner bottom directy or by other stee cois as shown in Fig.6. Bige hopper soping pating Inner hu pating Inner bottom pating Inner bottom pating Fig.6 The exampes of stee coi oading conditions The force due to stee cois for bige hopper soping pate and inner hu pate is expressed by the foowing formua considering the effect of frictiona resistance between stee cois and the support by the inner bottom. WnCk F' = n3 Where, W, n and n 3 are specified in.7.d. C : The coefficient specified in.7.3c. k PAGE 60 OF 171

61 COMMON STRUCTURAL RULES FOR BULK CARRIERS TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-3 This oad mode is the same for the inner bottom. Athough the vertica component of the oad is supported by the inner bottom directy or by other cois, ony C k is considered to derive the oads acting on the side wa. As specified in.7.3c, the coefficient C k is introduced based on the experiments. This coefficient C k is based on the component of the oad in the transverse direction. Therefore, the component of the oad in transverse direction is ony considered in the scanting formua for bige hopper pate and inner hu pate. In the origina formua specified in the current Rue text, it was considered that the equivaent design wave (EDW) R was dominant in the bige hopper soping pate or inner hu pate. However, as the acceeration in transverse direction specified in Ch 4 Sec, [3..1] incudes the static component due to ro ange, the static component due to gravity acceeration is counted in dupicate. Therefore, the term reated to the transverse acceeration in scanting formua for oad case R is revised. In addition, in order to cover a oad cases, the term reated to the acceeration in the scanting formua is revised as foows, considering the oad combination factors. yg _ SC 1 ahopper = CYRaR sin tan θ h + g cos( θ h CYGθ )cos( C XGΦ) + CYSasway sinθ h R Where: a ro y sway a : Acceeration due to ro and sway, in m/s, defined in Ch.4 Sec. [3.] a R : Tangentia ro acceeration, in m/s. (See Fig. 7) π π ar = θ yg sc + R 180 T R yg sc : Centre of gravity of stee cois in transverse direction, in m. (see Fig, 7) R : Coefficient defined in Ch. 4 Sec. [3..1]. (see Fig.7) T R : Ro period, in s, defined in Ch 4, Sec, [.1] g : Gravity acceeration, in m/s θ h : Ange, in degrees, between inner bottom pating and bige hopper soping pate or inner hu pate. (see Fig. 7) θ : Singe ro ampitude, in degrees, defined in Ch 4, Sec, [.1] C YG, C YR, C YS, C XG : Load combination factors defined in Ch 4, Sec 4, [.] PAGE 61 OF 171

62 TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-3 COMMON STRUCTURAL RULES FOR BULK CARRIERS y G-sc θ h R a R θ h CL Centre of gravity Fig.7 Definition of the acceeration a R.7.3b Structura mode The structura mode for bige hopper soping pating and inner hu pating is the same for inner bottom pating..7.3c Coefficient Ck In order to determine the coefficient C k specified in.7.3a, experiments were performed by the Shipbuiding Research Association of Japan. According to the report, the experiments were carried out under the foowing conditions specified in (a) to (d) and as shown in Fig.8. m Key coi n Dunnage Side she Strain gauge a D Note: m and n is the number of cois counted from the key coi. Fig.8 Experiment device and oading condition of stee cois (a) Stee cois were oaded with one tier with key coi (b) Ro ange was 0 degree (c) Ro period was 60 seconds (d) Position of key coi was changed ( m in Fig.8 was changed from 1 to 8) In addition, a theoretica anaysis was tried and the resuts are shown in Fig. 9. According to the resuts shown in Fig. 9, the foowing outcomes were obtained. PAGE 6 OF 171

63 COMMON STRUCTURAL RULES FOR BULK CARRIERS TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-3 i) The Ck vaue is obtained from the oads on side wa based on the force in transverse direction. ii) The C k vaue strongy depends on the ocation of the key coi. iii) The effect of the diameter of stee cois and the ength between the gravity centre of stee cois is reativey sma compared to the effect of the ocation of the key coi. iv) The cacuation resuts match the experimenta resuts we. v) In order to be on the safe side, C k = 3. is an appropriate vaue when the key coi is ocated second or third from the side she and C =. 0 is appropriate in other cases. C k : Coefficient taken to equa: C k = 3. when stee cois are ined up in two or more tiers, or stee cois are ined up in one tier and the key coi is ocated second or third from the bige hopper soping pating or inner hu pating C =.0 for other cases k 3. k Ro ange = 0 (deg) Ck Cacuation a The current text is deeted. m-n Fig.9 Experimenta resuts Ch 6, Sec.5 Ordinary stiffeners of inner bottom oaded with stee cois on a wooden support.5.1 Genera.5.1a Same as specified in.7 for pating..5. Ordinary stiffeners ocated on inner bottom pating.5.a Load mode As the structura mode for pating is based on the pastic theory, it is too compex to treat the concentrated oad. Therefore, a rectanguar oad is considered in the requirement for pating mentioned in Ch 6, Sec 1, [.7.]. On the other hand, the structura mode for ordinary stiffeners is based on the simpe eastic beam theory. Therefore, the oad mode for ordinary stiffeners is based on concentrated oads due to stee cois acting through the dunnage. PAGE 63 OF 171

64 TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-3 COMMON STRUCTURAL RULES FOR BULK CARRIERS The cacuation of acceeration is based on the same assumption for pating. The parameter and coefficients are aso the same for pating. According to the simiar reason specified in.7.c, Ch 6, Sec, [.5.4] has been deeted..5.b Structura mode Structura mode of ordinary stiffeners is based on the simpe beam theory with the boundary condition that both ends of beams are fixed..5.c Coefficient K 3 The coefficient K 3 is derived from the ratios of moments at ends of ordinary stiffeners against n = 1 when oad points of the concentrated oads are ocated eveny between ' as shown in Fig.10 When n is over 10, the coefficient K 3 is /3. P P/ P/ ' n=1 P/3 P/3 P/3 n= P/4 P/4 P/4 P/4 ' ' n=3 n=4 Fig.10 Load points on an ordinary stiffener.5.3 Ordinary stiffeners ocated on hopper soping pate or inner hu pating.5.3a Load mode The concentrated oad is considered as specified in.5.a and the acceeration due to ro motion is considered as specified in.7.3a of Ch 6, Sec b Structura mode Structura mode of an ordinary stiffener is specified in.5.b a This item is deeted. PAGE 64 OF 171

65 COMMON STRUCTURAL RULES FOR BULK CARRIERS TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-3 Annex : Scanting impact due to modifications Ramification studies In order to quantify the impact due to the modification of the scanting formua for pating and ordinary stiffeners, ramification studies were performed using the foowing 6 ships isted in Tabe -1. The data of the stee cois isted in Tabe - taken from the oading manuas of the considered ships was used for the ramification study. Tabe -1 Principa dimensions of subject ships Pre-CSR ship CSR ship Ship 1 Ship Ship 3 Ship 4 Ship 5 Ship 6 Handy max Sma Sma Handymax Handymax Handy Tabe - Data of stee cois Ship 1 Ship Ship 3 Ship 4 Ship 5 Ship 6 W (kg) S (m) Number of tiers 1 1 Key coi not used used used Not used Not used Not used 1. Scanting changes at inner bottom structures Where the number of oad points is not greater than 10 and/or number of dunnages is not greater than 5, the scanting formuae for inner bottom pating and ordinary stiffeners are not changed by the Rue Change proposa 3. However, as the cacuation point of acceeration is modified and the defaut vaue of GM and k r are newy added, the scanting impact cacuations were carried out in order to grasp the changes. Cacuation resuts are shown in Figs.-1 to -3. These resuts show that the required scantings are not that different between the current CSR and the modification because the vertica acceeration in EDW H which is dominant for the scantings of inner bottom pating and ongitudinas is not affected by the y- and z- coordinate of the gravity centre. For reference, the required thickness of inner bottom pating was increased by 3 to 4mm compared to that of pre-csr designs because the corrosion additions specified in CSR are arger by 3 to 4 mm than those used in Pre-CSR designs. Regarding inner bottom ongitudinas, the difference between the required section moduus and the actua one of pre-csr designs varies argey depending on the design. The required shear area is smaer than the actua one of pre-csr designs. On the other hand, as the offered scantings of inner bottom structure for CSR design ships are greater than those determined by the requirement for stee coi oading, they may be determined by the requirement other than that for stee coi oading. Therefore, there is no scanting impact for inner bottom pate and ongitudinas due to his change.. Scanting changes at bige hopper and inner hu structures.1 Scantings of pating Required gross thicknesses of bige hopper soping pating are shown in Fig.-4. This figure shows that the modification improves the formua by providing the appropriate thickness compared to that of inner bottom pating. PAGE 65 OF 171

66 TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-3 COMMON STRUCTURAL RULES FOR BULK CARRIERS For reference, the required thicknesses of bige hopper soping pating was increased by 3 to 4mm compared to those of pre-csr designs because the corrosion additions specified in CSR are arger by 3 to 4mm than those used in the pre-csr designs. For CSR ships, the thicknesses of bige hopper pating are determined by the requirement for stee coi oading, but, the scanting of ongitudina attached to the hopper soping pate may be determined by the requirement other than that for stee coi oading. As a resut, ony thickness of hopper soping pate according to the proposed formua becomes that simiar to inner bottom pating and decreased about 4mm for these exampe cases. If the thicknesses of hopper soping pate woud be determined by the proposed requirement for stee coi oading, the tota stee weight is decreased about 0 tons for ship 5 and 15 tons for ship 6 by this change.. Scantings of ordinary stiffeners..1 Section moduus Required net section modui of ordinary stiffeners attached to bige hopper soping pating are shown in Fig. -5. This figure shows that the modification improves the formua by providing the appropriate section moduus compared to that of inner bottom ongitudinas. Regarding the bige hopper ongitudina, the difference between the required section moduus and actua one of Pre-CSR designs varies argey depending on the design. For CSR ships, the scantings of ongitudina attached to hopper soping pate become about 60% of those required current rues in terms of section moduus by this change. Therefore, the fina scantings of the ongitudina may be determined by other requirements. If the scanting of ongitudinas woud be determined by the proposed formua, the stee weight wi be decreased about 4 tons for ship 5 and tons for ship 6 by this change... Section area Required net section areas of ordinary stiffeners fitted to the bige hopper soping pating are shown in Fig.-6. The required section area according to modified formuae is arger than those of current CSR. This increase is caused by the correction of a mistake in the formua. For reference, the required shear area according to the modified formua is smaer than the actua one of both pre-csr designs and CSR ships. PAGE 66 OF 171

67 COMMON STRUCTURAL RULES FOR BULK CARRIERS TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO Actua CSR Modification Gross Thickness (mm) Ship 1 Ship Ship 3 Ship 4 Ship 5 Ship 6 Fig.-1 Comparison of gross thickness of inner bottom pate Actua CSR Modification Net Section Moduus (cm 3 ) Ship 1 Ship Ship 3 Ship 4 Ship 5 Ship 6 Fig. - Comparison of net section modui of inner bottom ongitudinas PAGE 67 OF 171

68 TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-3 COMMON STRUCTURAL RULES FOR BULK CARRIERS Actua CSR Modification Net Section Area (cm ) Ship 1 Ship Ship 3 Ship 4 Ship 5 Ship 6 Fig.-3 Comparison of net section area of inner bottom ongitudinas Actua CSR Modification 30 Gross Thickness (mm) Ship 1 Ship Ship 3 Ship 4 Ship 5 Ship 6 Fig. -4 Comparison of gross thickness of bige hopper soping pate PAGE 68 OF 171

69 COMMON STRUCTURAL RULES FOR BULK CARRIERS TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO Actua CSR Modification Net Section Moduus (cm 3 ) Ship 1 Ship Ship 3 Ship 4 Ship 5 Ship 6 Fig.-5 Comparison of net section modui of ongitudinas attached to bige hopper soping pate Actua CSR Modification Net Section Area (cm ) Ship 1 Ship Ship 3 Ship 4 Ship 5 Ship 6 Fig.-6 Comparison of net section area of ongitudinas attached to bige hopper soping pate PAGE 69 OF 171

70 TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-3 COMMON STRUCTURAL RULES FOR BULK CARRIERS PAGE 70 OF 171

71 COMMON STRUCTURAL RULES FOR BULK CARRIERS TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-4 Common Structura Rues for Buk Carriers, Juy 008 Rue Change Notice No.1-4 (Minimum Scanting, Side Frame and Grab) Notes: (1) These Rue Changes enter into force on 1 Juy 009. Copyright in these Common Structura Rues for Buk Carriers is owned by: American Bureau of Shipping Bureau Veritas China Cassification Society Det Norske Veritas Germanischer Loyd Korean Register of Shipping Loyd's Register Nippon Kaiji Kyokai Registro Itaiano Navae Russian Maritime Register of Shipping Copyright 006 The IACS members, their affiiates and subsidiaries and their respective officers, empoyees or agents are, individuay and coectivey, referred to in this cause as the IACS Members. The IACS Members, individuay and coectivey, assume no responsibiity and sha not be iabe to any person for any oss, damage or expense caused by reiance on the information or advice in this document or howsoever provided, uness that person has signed a contract with the reevant IACS Member entity for the provision of this information or advice and in that case any responsibiity or iabiity is excusivey on the terms and conditions set out in that contract. PAGE 71 OF 171

72 TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-4 COMMON STRUCTURAL RULES FOR BULK CARRIERS For technica background for Rue Changes in this present document, reference is made to separate document Technica Background for Rue Change Notice No.1-4. Chapter 6 HULL SCANTLING Section ORDINARY STIFFENERS. Genera requirements. Minimum nnet thicknesses of webs of ordinary stiffeners..1 Minimum net thicknesses of webs of oordinary stiffeners other than side frames of singe side buk carriers The net thickness of the web of ordinary stiffeners, in mm, is to be not ess than the greater of: t = L 40% of the net required offered thickness of the attached pating, to be determined according to Ch.6, Sec.1. and is to be ess than times the net offered thickness of the attached pating.. Minimum net thicknesses of sside frames of singe side buk carriers The net thickness of side frame webs within the cargo area, in mm, is to be not ess than the vaue obtained from the foowing formua: tmin = 0.75α ( L) where: α : Coefficient taken equa to: α = 1.15 for the frame webs in way of the foremost hod α = 1.00 for the frame webs in way of other hods...3 Maximum net thickness of web of ordinary stiffener The net thickness of the web of ordinary stiffeners, in mm, is to be ess than times the net offered thickness of the attached pating. 3. Yieding check 3.3 Strength criteria for side frames of singe side buk carriers Net section moduus and net shear sectiona area of side frames The net section moduus w, in cm 3, and the net shear sectiona area A sh, in cm, of side frames subjected to atera pressure are to be not ess, in the mid-span area, than the vaues obtained from the foowing formuae: w = 1.15α m ( p + p ) s 3 S S W mλ R Y 10 PAGE 7 OF 171

73 COMMON STRUCTURAL RULES FOR BULK CARRIERS TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-4 A sh where: α m 5 = 1.1α S ( p + p ) S W s τ sinφ a B : Coefficient taken equa to: α m = 0.4 for BC-A ships α m = 0.36 for other ships λ S : Coefficient taken equa to 0.9 : Side frame span, in m, defined in Ch 3, Sec 6, Fig 19, to be taken not ess than 0.5D α S : Coefficient taken equa to: α S = 1.1 α S = 1.0 for side frames of hods specified to be empty in BC-A ships for other side frames B : Lower bracket ength, in m, defined in Fig 7 p s, p w : Sti water and wave pressures, in kn/m², in intact conditions cacuated as defined in [1.3] and [1.4.]. Figure 7 Side frame ower bracket ength In addition to the above provision, for side frames of hods intended to carry baast water in heavy baast condition, the net section moduus w, in cm 3, and the net shear sectiona area A sh, in cm, a aong the span of side frames subjected to atera pressure in hods intended to carry baast water are to be in accordance with [3..3], being the span of the side frame as defined in Ch.3 Sec.6 [4.], with consideration to brackets at ends Lower bracket of side frame In addition, aat the eve of ower bracket as shown in Ch 3, Sec 6, Fig 19, the net section moduus of the frame and bracket, or integra bracket, with associated she pating, is to be not ess than twice the net section moduus w required for the frame mid-span area obtained from [3.3.1]. In addition, for hods intended to carry baast water in heavy baast condition, the net section moduus w, in cm 3, at the eve of ower bracket is to be not ess than twice the greater of the net sections modui obtained from [3.3.1] and [3..3]. PAGE 73 OF 171

74 TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-4 COMMON STRUCTURAL RULES FOR BULK CARRIERS The net thickness t LB of the frame ower bracket, in mm, is to be not ess than the net thickness of the side frame web pus 1.5 mm. Moreover, the net thickness t LB of the frame ower bracket is to compy with the foowing formua: hlb for symmetricay fanged frames: 87 k t hlb for asymmetricay fanged frames : 73 k t LB LB The web depth h LB of ower bracket may be measured from the intersection between the soped bukhead of the hopper tank and the side she pate, perpendicuary to the face pate of the ower bracket (see Ch 3, Sec 6, Fig ). For the 3 side frames ocated immediatey abaft the coision bukhead, whose scantings are increased according to [3.3.], when t LB is greater than 1.73t w, the thickness t LB may be taken as the vaue t LB obtained from the foowing formua: t = ' LB 1 ( t t ) 3 LB w where t w is the net thickness of the side frame web, in mm, corresponding to A sh determined in accordance to [3.3.1]. The fange outstand is not to exceed 1k 0.5 times the net fange thickness Upper bracket of side frame In addition, aat the eve of upper bracket as shown in Ch 3, Sec 6, Fig 19, the net section moduus of the frame and bracket, or integra bracket, with associated she pating, is to be not ess than twice the net section moduus w required for the frame mid-span area obtained from [3.3.1]. In addition, for hods intended to carry baast water in heavy baast condition, the net section moduus w, in cm 3, at the eve of upper bracket is not to be ess than twice the greater of the net sections modui obtained from [3..3] and [3.3.1]. The net thickness t UB of the frame upper bracket, in mm, is to be not ess than the net thickness of the side frame web. PAGE 74 OF 171

75 COMMON STRUCTURAL RULES FOR BULK CARRIERS TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-4 CHAPTER 9 OTHER STRUCTURES Section 1 FORE PART 4. Scantings 4.3 Ordinary stiffeners The net thickness of the web of ordinary stiffeners, in mm, is to be not ess than the greater of: t = L 40% of the net offered required thickness of the attached pating, to be determined according to [4.] and [5.]. and is to be ess than twice the net offered thickness of the attached pating. The net dimensions of ordinary stiffeners are to compy with the requirement in Ch 6, Sec, [..] and [.3]. PAGE 75 OF 171

76 TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-4 COMMON STRUCTURAL RULES FOR BULK CARRIERS Section AFT PART 4. Scantings 4. Ordinary stiffeners 4..3 The net thickness of the web of ordinary stiffeners, in mm, is to be not ess than the greater of: t = L 40% of the net offered required thickness of the attached pating, to be determined according to [4.1]. and is to be ess than twice the net offered thickness of the attached pating. The net dimensions of ordinary stiffeners are to compy with the requirement in Ch 6, Sec, [..] and [.3]. PAGE 76 OF 171

77 COMMON STRUCTURAL RULES FOR BULK CARRIERS TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-4 CHAPTER 1 ADDITIONAL CLASS NOTATIONS Section 1 GRAB ADDITIONAL CLASS NOTATION. SCANTLINGS.1. Pating.1.1 The net thickness of pating of inner bottom, ower strake of hopper tank soping pate, and transverse ower stoo pating, transverse bukhead pating and inner hu up to a height of 3.0m above the owest point of the from inner bottom, excuding bige wes, is to be taken as the greater of the foowing vaues: t, as obtained according to requirements in Ch 6 and Ch 7 t GR, as defined in [.1.] and [.1.3]..1. The net thickness t GR, in mm, of the inner bottom pating is to be obtained from the foowing formua: t ( M ) sk GR = 0.8 GR The net thickness t GR, in mm, within the ower 3 m of hopper tank soping pate, and of transverse ower stoo, transverse bukhead pating and inner hu up to a height of 3.0m above the owest point of the inner bottom, excuding bige wes, is to be obtained from the foowing formua: t ( M ) sk GR = 0.8 GR + 4 PAGE 77 OF 171

78 TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-4 COMMON STRUCTURAL RULES FOR BULK CARRIERS PAGE 78 OF 171

79 COMMON STRUCTURAL RULES FOR BULK CARRIERS TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-4 Common Structura Rues for Buk Carriers, Juy 008 Technica Background for Rue Change Notice No.1-4 (Minimum Scanting, Side Frame and Grab) Copyright in these Common Structura Rues for Buk Carriers is owned by: American Bureau of Shipping Bureau Veritas China Cassification Society Det Norske Veritas Germanischer Loyd Korean Register of Shipping Loyd's Register Nippon Kaiji Kyokai Registro Itaiano Navae Russian Maritime Register of Shipping Copyright 006 The IACS members, their affiiates and subsidiaries and their respective officers, empoyees or agents are, individuay and coectivey, referred to in this cause as the IACS Members. The IACS Members, individuay and coectivey, assume no responsibiity and sha not be iabe to any person for any oss, damage or expense caused by reiance on the information or advice in this document or howsoever provided, uness that person has signed a contract with the reevant IACS Member entity for the provision of this information or advice and in that case any responsibiity or iabiity is excusivey on the terms and conditions set out in that contract. PAGE 79 OF 171

80 TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-4 COMMON STRUCTURAL RULES FOR BULK CARRIERS Technica Background for the Changes Regarding Scanting Requirement for Ordinary stiffener, Side Frame and Grab 1. Reason for the Rue Change: 1.1 Ch 6, Sec, [.] The current CSR requires the minimum thickness of webs of ordinary stiffeners is not to be ess than 40% of the net offered thickness of the attached pating. However, there are some cases where the thickness of pating is increased due to bucking check of the pating and hu girder strength check and so on. In such cases, the thickness of web of ordinary stiffener is determined by the increased offered thickness of the attached pating and sometimes scanting of the ange type stiffener is remarkabe arge in order to satisfy with this requirement. This rue change is made to avoid such cases. (KC ID 13). In addition, the maximum thickness of webs of ordinary stiffeners is mentioned in [..1], athough the tite of this requirement is minimum thickness requirement. This requirement is based on the consideration of the proportion of thickness between the attached pating and webs of ordinary stiffener. Accordingy, [.] wi be modified to be appicabe both on minimum and maximum thickness, as foows: Tite of [.] shoud be Net thicknesses of webs of ordinary stiffeners Tite of [..1] shoud be Minimum net thicknesses of webs of ordinary stiffeners other than side frames of singe side buk carriers Tite of [..] shoud be Minimum net thicknesses of side frames of singe side buk carriers New [..3] with the foowing tite: Maximum net thickness of web of ordinary stiffener. 1. Ch 6 Sec, [3.3.1] This change is made to carify the requirement by specifying the extent of the span to use and the cacuation point for sti water and wave pressures (refer to KC ID 16 and 17). It specifies aso that the requirements of Ch6. Sec [3..3] are to be asserted aong the whoe span of the frames for hods intended to carry baast water in heavy baast condition (KC ID 356). 1.3 Ch 6 Sec, [3.3.3] This change is made to carify the requirement by specifying the requirements to be met for side frame s ower bracket in hods intended to carry baast water in heavy baast condition (KC ID 356). 1.4 Ch 6 Sec, [3.3.4] This change is made to carify the requirement by specifying the requirements to be met for side frame s upper bracket in hods intended to carry baast water in heavy baast condition (KC ID 356). 1.5 Ch 9 Sec 1, [4.3.3] and Sec, [4..3] The requirements in Ch 9 Sec 1, [4.3.3] and Sec [4..3] are same required in Ch 6 Sec, [..1]. PAGE 80 OF 171

81 COMMON STRUCTURAL RULES FOR BULK CARRIERS TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO Ch 1 Sec 1, [.1] This change is made to carify the requirement by specifying the areas concerned by this cacuation (refer to KC ID 313 and 544).. Summary of Rue Changes.1 Ch 6, Sec, [..1], [..3], Ch 9 Sec 1, [4.3.3] and Sec, [4..3] (1) The net offered thickness is changed to net required thickness and the required thickness is determined according to Ch 6 Sec 1. () The maximum net offered thickness is deeted from the requirement in [..1] and the formua with the same meaning are added to new paragraph [..3]. (3) The requirements in Ch 9 Sec 1, [4.3.3] and Sec, [4..3] are revised in order to be same for Ch 6 Sec, [..1].. Ch 6, Sec, [3.3.1] (1) The definition of the pressures for side frames is added. () For side frames in baast hod, the scanting check is carried out as an ordinary stiffener with span defined in Ch 3 Sec 6 [4.]..3 Ch 6, Sec, [3.3.3] and [3.3.4] For ower and upper brackets of side frame in baast hod, the net section moduus at the eve of brackets of side frame is to be not ess than twice of the net section modui obtained by the requirements for both side frames and ordinary stiffeners..4 Ch 1 Sec 1, [.1] Inner hu up to a height of 3.0m from the owest point of inner bottom is appied to this requirement. 3. Impact on Scanting 3.1 Ch 6, Sec, [..1], [..3], Ch 9 Sec 1, [4.3.3] and Sec, [4..3] Regarding the minimum thickness requirement of webs of ordinary stiffeners, the scanting impact depends on the stiffener type used. If the ange type stiffener is used, the scanting is decrease by this change but stee weight decrease is negigibe. 3. Ch 6 Sec [3.3.1], [3.3.3] and [3.3.4] There is no change in terms of the stee weight by comparing that before and after the proposed Rue change. 3.3 Ch 1 Sec 1, [.1] For doube side skin buk carrier having the height of the bige hopper tanks ess than 3.0m or hybrid buk carrier with cargo hod without hopper tank, it is considered that the thickness of inner hu may be increased by this rue change. However, as there is no CSR ships with such design, the scanting impact cannot be compared that before and after the proposed Rue change. PAGE 81 OF 171

82 TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-4 COMMON STRUCTURAL RULES FOR BULK CARRIERS PAGE 8 OF 171

83 COMMON STRUCTURAL RULES FOR BULK CARRIERS RULE CHANGE NOTICE NO.1-5 Common Structura Rues for Buk Carriers, Juy 008 Rue Change Notice No.1-5 (Direct Strength Anaysis) Notes: (1) These Rue Changes enter into force on 1 Juy 009. Copyright in these Common Structura Rues for Buk Carriers is owned by: American Bureau of Shipping Bureau Veritas China Cassification Society Det Norske Veritas Germanischer Loyd Korean Register of Shipping Loyd's Register Nippon Kaiji Kyokai Registro Itaiano Navae Russian Maritime Register of Shipping Copyright 006 The IACS members, their affiiates and subsidiaries and their respective officers, empoyees or agents are, individuay and coectivey, referred to in this cause as the IACS Members. The IACS Members, individuay and coectivey, assume no responsibiity and sha not be iabe to any person for any oss, damage or expense caused by reiance on the information or advice in this document or howsoever provided, uness that person has signed a contract with the reevant IACS Member entity for the provision of this information or advice and in that case any responsibiity or iabiity is excusivey on the terms and conditions set out in that contract. PAGE 83 OF 171

84 RULE CHANGE NOTICE NO.1-5 COMMON STRUCTURAL RULES FOR BULK CARIIERS For technica background for Rue Changes in this present document, reference is made to separate document Technica Background for Rue Change Notice No.1-5. CHAPTER 7 DIRECT STRENGTH ANALYSIS Section GLOBAL STRENGTH FE ANALYSIS OF CARGO HOLD STRUCTURES. Anaysis mode. Finite eement modeing..4 When orthotropic eements are not used in FE mode: mesh size is to be equa to or ess than the representative spacing of ongitudina stiffeners or transverse side frames stiffeners are to be modeed by using rod and/or beam/bar eements where a doube hu is fitted, webs of primary supporting members are to be divided by at east three eements height-wise. However, for transverse primary supporting members inside hopper tank and top side tank, which are ess in height than the space between ordinary ongitudina stiffeners, two eements on the height of primary supporting members are accepted. where no doube hu construction is fitted, side she frames and their end brackets are to be modeed by using she eements for web and she/beam/rod eements for face pate. Webs of side she frames need not be divided aong the direction of depth aspect ratio of eements is not to exceed 1:4. An exampe of typica mesh is given in App 1..3 Boundary conditions.3.1 Both ends of the mode are to be simpy supported according to Tab 1 and Tab. The nodes on the ongitudina members at both end sections are to be rigidy inked to independent points at the neutra axis on the centreine as shown in Tab 1. The independent points of both ends are to be fixed as shown in Tab. Tabe 1: Rigid-ink of both ends Nodes on ongitudina members Transationa Rotationa at both ends of the mode Dx Dy Dz Rx Ry Rz A ongitudina members RL RL RL RL means rigidy inked to the reevant degrees of freedom of the independent point PAGE 84 OF 171

85 COMMON STRUCTURAL RULES FOR BULK CARRIERS RULE CHANGE NOTICE NO.1-5 Tabe : Support condition of the independent point Location of the independent point Transationa Rotationa Dx Dy Dz Rx Ry Rz Independent point on aft end of mode - Fix Fix - Fix - - Independent point on fore end of mode Fix Fix Fix Fix Anaysis criteria 3. Yieding strength assessment 3..1 Reference stresses Reference stress is Von Mises equivaent stress at the centre of a pane eement (she or membrane) or axia stress of a ine eement (bar, beam or rod) obtained by FE anaysis through considering hu girder oads according to [.5.4] or [.5.5]. Where the effects of openings are not considered in the FE mode, the reference stresses in way of the openings are to be propery modified with adjusting shear stresses in proportion to the ratio of web height and opening height. Where eements under assessment are smaer than the standard mesh size specified in [..4] or [..5], the reference stress may be obtained from the averaged stress over the eements within the standard mesh size. 3.4 Defection of primary supporting members The reative defection, δ max in mm, in the outer bottom pate obtained by FEA is not to exceed the foowing criteria: The maximum reative defection between the doube bottom and the forward (or afterward) transverse bukhead obtained from the FE anaysis is not to exceed the foowing criteria: δ max where: i 150 δ max : Maximum reative defection, in mm, obtained by the foowing formua, and not incuding secondary defection between the doube bottom and the forward (or afterward) transverse bukhead, in mm δ max = max( δ B 1, δ B ) where, δ B1 and δ B are shown in Fig 3. i : Length or breadth of the fat part of the doube bottom, in mm, whichever is the shorter. PAGE 85 OF 171

86 RULE CHANGE NOTICE NO.1-5 COMMON STRUCTURAL RULES FOR BULK CARIIERS i δ B1 δ B i δ B δ B1 Figure 3: Definition of reative defection PAGE 86 OF 171

87 COMMON STRUCTURAL RULES FOR BULK CARRIERS RULE CHANGE NOTICE NO.1-5 Section 3 DETAILED STRESS ASSESSMENT 1. Genera 1.1 Appication This Section describes the procedure for the detaied stress assessment with refined meshes to evauate highy stressed areas of primary supporting members. Where the goba cargo hod anaysis of Sec is carried out using a mode compying with the modeing criteria of Sec, [..4], the areas isted in Tab 1 are to be refined at the ocations whose cacuated stresses exceed 95% for non-orthotropic eements or 85 % for orthotropic eement but do not exceed 100% of the aowabe stress as specified in Sec, [3..3]. PAGE 87 OF 171

88 RULE CHANGE NOTICE NO.1-5 COMMON STRUCTURAL RULES FOR BULK CARIIERS PAGE 88 OF 171

89 COMMON STRUCTURAL RULES FOR BULK CARRIERS TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-5 Common Structura Rues for Buk Carriers, Juy 008 Technica Background for Rue Change Notice No.1-5 (Direct Strength Anaysis) Copyright in these Common Structura Rues for Buk Carriers is owned by: American Bureau of Shipping Bureau Veritas China Cassification Society Det Norske Veritas Germanischer Loyd Korean Register of Shipping Loyd's Register Nippon Kaiji Kyokai Registro Itaiano Navae Russian Maritime Register of Shipping Copyright 006 The IACS members, their affiiates and subsidiaries and their respective officers, empoyees or agents are, individuay and coectivey, referred to in this cause as the IACS Members. The IACS Members, individuay and coectivey, assume no responsibiity and sha not be iabe to any person for any oss, damage or expense caused by reiance on the information or advice in this document or howsoever provided, uness that person has signed a contract with the reevant IACS Member entity for the provision of this information or advice and in that case any responsibiity or iabiity is excusivey on the terms and conditions set out in that contract. PAGE 89 OF 171

90 TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-5 COMMON STRUCTURAL RULES FOR BULK CARRIERS Technica Background for the Changes Regarding the Direct Strength Anaysis: 1. Reason for the Rue Change: 1.1 Ch 7, Sec, [..4] and [3..1] In a transverse ring in bige hopper tank, there are some cases where the web height is smaer than the space between ordinary stiffeners. Where the web is divided by three eements, the eement size is reative sma. In addition, the eement sometimes becomes smaer so that the aspect ratio of eement does not exceed 1:4. It is not considered that such smaer eements are appropriate for appying the goba strength anaysis of cargo hod structures. Therefore this rue change is made to carify the requirements according to the interpretation in KC ID Ch 7, Sec, Tabe The boundary condition in FEA, which restricts rotation aong x-axis at fore end of FE mode but aow free rotation at aft end, specified in Tabe. However, this boundary condition may cause unexpected warping deformation under beam sea condition because the one end of FE mode is rotated about x-axis. It has been noticed that the stress eve induced by the warping deformation is sometimes unreasonabe severe, especiay, in case of smaer buk carrier as handy size and Panamax BCs. This rue change is an interim soution made to avoid the unexpected rotation in FEA due to this boundary condition. (Refer to KC ID 340). A definitive agreement on boundary conditions has ater to be made through further studies that wi use same basis in order to make effective comparisons and impact evauations. 1.3 Ch 7, Sec, [3..1] Stress eve of a eements in FE mode shoud be within the aowabe criteria specified in the Rues, in principe. However, the eements having reative sma size are often used in FEA. In this case, the averaged stresses among these eements are normay used where deemed reasonabe by the Society. This change is made to carify the requirements for such a case.(refer to KC ID 340) 1.4 Ch 7, Sec, [3.4] The maximum reative defection is not cear in the current text. In order to carify the reative defection, which does not incude the defection of ordinary stiffeners, the editoria correction is made and new figure which gives a definition of the defection of the outer bottom pate is added. 1.5 Ch 7, Sec 3, [1.1.1] This rue change is made to carify the requirement for the appication of the detaied stress assessment. (Refer to KC ID 341) PAGE 90 OF 171

91 COMMON STRUCTURAL RULES FOR BULK CARRIERS TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-5. Summary of Rue Change.1 Ch 7, Sec, [..4] Considering the actua design for the transverses in bige hopper or topside tank, the height of transverse web is smaer than the spacing between ongitudinas. In order to avoid the smaer mesh size in such structura members as far as practicabe, the rue change is so made that two she eements can be accepted.. Ch 7, Sec, [.3.1] Tabe As an interim soution the rotationa boundary condition R X of independent point on at end of mode is changed to Fix from -..3 Ch 7, Sec, [3..1] Reference stresses Where the cargo hod FE mode incudes the smaer mesh size than the standard mesh size specified in the Rues, the reference stress can be obtained from the averaged stress over the eements within the standard mesh size..4 Ch 7, Sec [3.4] Defection of primary supporting members In order to carify the definition of the reative defection of outer bottom structure, the figure is added in the text and the reevant texts are modified..5 Ch 7, Sec 3, [1.1] Where the stresses cacuated according to the goba strength anaysis of cargo hod structures specified in Ch 7 Sec exceed 95% for non-orthotropic eements or 85% for orthotropic eements but not exceed aowabe stress, detaied stress anaysis specified in Sec 3 is required. 3. Impact on Scanting 3.1 Impact on scanting due to the change in Ch 7, Sec, [..4], [3..1], [3.4] and Sec 3, [1.1] As these rue changes specified in.1,.3,.4 and.5 above are made for the carification, there is no scanting impact due to these changes. 3. Impact on scanting due to the changes in Ch 7, Sec, Tabe regarding the correction of the boundary conditions The cargo hod FEA using the boundary condition specified in the current text gives too unreasonabe stress in cross deck. Due to the unreasonabe stresses, the required thickness for cross deck may be than that for upper deck pating. For exampe, the required thickness for cross deck is.5mm (AH3) and 15mm (AH3) for upper deck according to KC ID 343. From the engineering point of view, this resut caused by the boundary condition which gives unreaistic warping effect in FE mode obviousy. Therefore, the scanting impact due to this change is not carried out. However, the unreasonabe and excessive stresses around the hatch opening and in cross deck are improved drasticay by this modification. The detais of the effect due to the modification of the boundary condition are mentioned in Annex 1. PAGE 91 OF 171

92 TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-5 COMMON STRUCTURAL RULES FOR BULK CARRIERS Annex 1: Detais of the effect due to the modification of the boundary conditions 1. FE Anaysis and resuts In order t to examine the effect due to the modification of the boundary condition regarding the rotationa restriction Rx aong x-axe, the FE anaysis for one Handy max buck carrier is carried out as a typica exampe. Appied boundary condition is given in Tabe 1-1. Tabe 1-1 Appied boundary condition (1) Case-1 Boundary condition as per CSR Independent Point Transationa Rotationa Dx Dy Dz Rx Ry Rz Aft End of Mode - Fx Fix Fore End of Mode Fix Fix Fix Fix - - () Case- Modified boundary condition Independent Point Transationa Rotationa Dx Dy Dz Rx Ry Rz Aft End of Mode - Fx Fix Fix - - Fore End of Mode Fix Fix Fix Fix - - Appied oading condition and oad case are fu oad homogeneous condition and EDW P1. As the effect due to the boundary condition is mainy appeared in the stresses of structures around the hatch opening and cross deck under beam sea condition, the cacuated stresses in cross deck and deformations for fu oad condition under beam sea (P1) as a typica exampe. The samping point of the stress of cross deck is shown in Fig P C.L S Fig. 1-1 Samping Point PAGE 9 OF 171

93 COMMON STRUCTURAL RULES FOR BULK CARRIERS TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-5 The stresses of the samping points for case 1 and case are shown in Tabe 1-. The stress eve in cross deck is given in Figure 1- and the deformation of the FE mode is given in Fig Tabe 1- Stresses at the samping points in Cross Deck in fu oad condition under beam sea (P1) σ aowabe σe (N/mm ) σ aowabe σe (N/mm ) ID (N/mm Case-1 Case- ID ) (N/mm Case-1 Case- ) (CSR) (Modified) (CSR) (Modified) PAGE 93 OF 171

94 TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-5 COMMON STRUCTURAL RULES FOR BULK CARRIERS NG (1) Case -1 (1) Case 1 Fig-5 Deformation (Case- / Boundary Condition of CSR) () Case Fig. 1- Stress eve in the cross deck in fu oad condition under beam sea (P1) PAGE 94 OF 171

95 COMMON STRUCTURAL RULES FOR BULK CARRIERS TECHNICAL BACKGROUND FOR RULE CHANGE NOTICE NO.1-5 (1) Case 1 () Case Fig. 1-3 Deformation for FE mode at the fu oad condition under beam sea (P1) PAGE 95 OF 171