Descripción del tratamiento de la información

General

1.1 Application

1.1.1 This Chapter applies to all types of ship covered by Part 4 except where specifically stated otherwise.

1.1.2 The requirements given are those specific to fore ends and relate to structure situated in the region forward of 0,3L from the forward perpendicular.

1.1.3 Requirements for cargo space structure within this region not dealt with in this Chapter are to be as detailed in the relevant Chapter of Part 4 for the particular ship type.

1.2 Structural configuration

1.2.1 The Rules provide for both longitudinal and trans- verse framing systems.

1.2.2 In the case of container ships and open type ships, additional requirements may apply as detailed in Pt 4, Ch 8.

1.2.3 In the case of fast cargo ships, the additional requirements given in Pt 4, Ch 1,3 are to be complied with where applicable.

1.2.4 The requirements regarding minimum bow height given in Ch 3,6 are to be complied with where applicable.

1.3 Structural continuity

1.3.1 Suitable scarfing arrangements are to be made to ensure continuity of strength and the avoidance of abrupt structural changes.

1.3.2 Where longitudinal framing terminates and is replaced by a transverse system, adequate arrangements are to be made to avoid an abrupt changeover. Where a fore- castle is fitted extending aft of 0,15L from the F.P., longitudinal framing at the upper deck and topsides is generally to be continued forward of the end bulkhead of this superstructure.

In bulk carriers and oil tankers the longitudinal framing at the upper deck is to be maintained over the cargo space region and continued over the fore peak region.

1.3.3 In container or similar ships having continuous side tanks or double skin construction in way of the cargo spaces, the longitudinal bulkheads are to be continued as far forward as is practicable and are to be suitably tapered at their ends. Where, due to the ship’s form, such bulkheads are stepped, suitable scarfing is to be arranged.

1.3.4 In bulk carriers the topside tank and double bottom hopper tank structures are to be maintained over the cargo space region, and suitable taper brackets are to be arranged in line with the end of these tank structures in the fore peak region. In addition, in way of the cargo space forward bulk- head, a girder or intercostal bulb plate stiffeners (fitted between and connected to the bulkhead vertical stiffeners), are to be arranged on the forward side in line with the sloped bulkheads of the topside and hopper tanks clear of the taper brackets.

1.4 Symbols and definitions

1.4.1 The following symbols and definitions are applicable to this Chapter unless otherwise stated:

L, B, D, T, C_bas defined in Ch 1,6.1

k_L, k = higher tensile steel factor, see Ch 2,1.2

l = overall length of stiffening member, in metres, see Ch 3,3.3

le = effective length of stiffening member, in metres, see

Ch 3,3.3

s = spacing of secondary stiffeners, in mm t = thickness of plating, in mm

I = inertia of stiffening member, in cm4_{, see Ch 3,3.2} S = spacing, or mean spacing, of primary members, in

metres

Z = section modulus of stiffening member, in cm3_{, see}

Ch 3,3.2

rÿ = relative density (specific gravity) of liquid carried in a tank and is to be taken not less than 1,025.

1.4.2 For the purpose of this Chapter the forward perpendicular, F.P., is defined as the forward limit of the Rule length L.

1.5 Strengthening of bottom forward

1.5.1 The bottom forward of a sea-going ship is to be additionally strengthened, except where the ship is so designed that a minimum draught forward, T_FB, of 0,045L can be achieved for any ballast or part loaded condition. This draught is to be indicated on the shell expansion plan, the plan showing the internal strengthening, the Loading Manual and loading instrument, where fitted, see Ch 4,8.

1.5.2 The requirements for the additional strengthening apply to ships where L is greater than 65 m. Where a ship is classed for service in protected waters or extended protected waters, compliance with the requirements of this Section may be modified or waived altogether.

RULES ANDREGULATIONS FOR THECLASSIFICATION OFSHIPS, July 2000

Part 3, Chapter 5

Section 1

LLOYD’SREGISTER OFSHIPPING 1

Section

1 General

2 Deck structure

3 Shell envelope plating

4 Shell envelope framing

5 Single and double bottom structure

6 Fore peak structure

Fore End Structure

1.5.3 The additional strengthening is to extend forward of 0,3L from the F.P. over the flat of bottom and adjacent plating with attached stiffeners up to a height of 0,002L above the base line or 300 mm whichever is the lesser.

1.5.4 The scantling requirements outside the areas defined in 1.5.3 are to be suitably tapered to maintain adequate continuity of strength in both longitudinal and transverse directions.

1.5.5 The requirements for the additional strengthening within the region defined 1.5.3 are given in Table 5.1.1, or may be obtained by direct calculation. Where T_FBis less than 0,01L, the additional strengthening is to be specially considered.

1.5.6 Bottom longitudinals are to pass through and be supported by the webs of primary members. The vertical web stiffeners are to be connected to the bottom longitudinals. The cross-sectional area of the connections is to comply with the requirements given in Table 5.1.1.

1.5.7 The scantlings required by this Section must in no case be less than those required by the remaining Sections in Chapter 5.

1.5.8 For minimum draught forward, T_FBbetween 0,01L and 0,045L, the equivalent slamming pressure expressed as a head of water, h_s, is to be obtained from Fig. 5.1.1, where

h_maxis calculated from the following expressions: 65 < L £ 169 m, h_max = 10 L F m 169 < L £ 180 m, h_max = 130 F m L > 180 m, h_max = 130 Fe– 0,0125(L – 180)0,705 m where F = 5,95 – 10,5

( )

0,2 and

e = base of natural logarithm, 2,7183

(a) The application of the maximum pressure for forward of 0,3L from the F.P. is as indicated in Fig. 5.1.1. For C_b between 0,70 and 0,80 its position may be obtained by linear interpolation.

(b) Where the bottom plating forms the boundary of a double bottom tank, deep tank or double skin tank which is full in all ballast conditions, then for such condi- tions the head, h_s, may be reduced by 1,25 times the head, in metres, of ballast water to top of tank. (c) For bulk carriers the reduction to the head, h_s, is not to

exceed the head, in metres, of ballast water to the top of the hopper tank or 1,25 times the depth, in metres, of the double bottom tank, whichever is the greater. (d) For ballast and part loaded conditions where the draught

forward is less than 0,045L and the reduction to the head, h_s, has been applied, the ballast tanks are to be filled and a note added to the loading booklet to this effect, see Ch 4,8.2.4(d).

T_FB L

1.6 Strengthening against bow flare slamming

1.6.1 The side structure in the area forward of 0,075L from the F.P. and above the summer load waterline is to be strengthened against bow flare impact pressure. The strengthening is to extend vertically to the uppermost deck level, including the forecastle deck, if fitted, but need not exceed the level of

T + 1,65H_b above the base line, where H_bis the minimum bow height, in metres, as derived in Ch 3,6.1.

1.6.2 The flare angle, a, is the angle between the vertical axis and the tangent of the outer shell measured normal to the shell in a vertical plane, at the point under consideration. The entry angle, b, is the angle between the longitudinal axis and the waterplane tangent measured on the outer shell, at the point under consideration. The flare angle may normally be derived in accordance with Fig. 5.1.2.

1.6.3 The equivalent bow flare slamming head, h_S, is to be taken as:

h_S = 0,8

(

0,2 + 1,5 tana

) (

0,51V sinb cosa +

d

)

2 _m

where

V = maximum service speed, in knots, with the ship at maximum summer draught

aÿ = flare angle, in degrees, at the point under consideration

bÿ = entry angle, in degrees, at the point under consideration

dÿ =

(

L e–0,0033L_{– 0,5d}

)

_{and is not to be taken less}

than zero

e = base of natural logarithms 2,7183

d = vertical distance, in metres, between the waterline at draught T and the point under consideration

p 30 p L

Part 3, Chapter 5

Section 1 h max 0,5 h max 0,4 L 0,3 L 0,2 L 0,1 L 0,05 L 0,05L 0,175 L 0,125 L Cb > 0,8 F.P. Cb < 0,7

Fore End Structure

RULES ANDREGULATIONS FOR THECLASSIFICATION OFSHIPS, July 2000

Part 3, Chapter 5

Section 1

LLOYD’SREGISTER OFSHIPPING 3

(a) Ships having one or more longitudinal bulkheads:

(i) Centre girder

Scantlings as required by item (4) in Table 5.5.1 and (iii)

(ii) Bottom transverses Maximum spacing As for midships region

Scantlings as required by Pt 4, Ch 9,9 or Pt 4, Ch 10,2

(iii) For horizontally stiffened longitudinal bulkheads and girders the depth to thickness ratio of the panel attached to the bottom shell plate is not to exceed 55 k

(iv) Where T_FB, < 0,025L₂the scantlings and arrangements will receive individual consideration

(b) Other ship arrangements will receive individ- ual consideration

Transverse framing Longitudinal framing Will be specially considered

Requirements

Table 5.1.1 Additional strengthening of bottom forward (see continuation)

(a) Centre Girder:

Scantlings as required by item (1) in Table 5.5.1,except that in determining Z in way of a deep tank forward of 0,2L from the F.P. the value of h₅is to be increased by the following percentages:

where T_FB£ 0,03L₂, 30 per cent where T_FB³ 0,04L₂, 0 per cent

The increase in h₅for intermediate values of

T_FBto be obtained by interpolation (b) Floors:

Scantlings as required by item (2) in Table 5.5.1, except that in way of dry cargo spaces the minimum face area is to be increased by the following percentages: where T_FB£ 0,03L₂, 50 per cent where T_FB³ 0,04L₂, 0 per cent

The increase of minimum face area for inter- mediate values of T_FBto be obtained by interpolation

(c) Side girders:

Arrangement and scantlings as required by 5.2.2 and 5.2.3, with the addition of interme- diate half-height girders or equivalent fore and aft stiffening

Item

(1) Longitudinally framed bottom shell plating (including keel),

see Notes 1 and 2

(2) Bottom longitudinals – other than flat bars

(3) Bottom longitudinals – flat bars

(4) Primary structure in way of single bottoms

(5) Primary structure in way of double bottoms, see Note 3

(a) Plate floors:

Maximum spacing, every frame Scantlings as required by Pt 4, Ch 1,8 (b) Centre and side girders:

Maximum spacing, 0,003s_F m Scantlings as required by Pt 4, Ch 1,8 (c) Intermediate half-height girders to be

arranged midway between side girders: Scantlings as required for non watertight side girders by Pt 4, Ch 1,8

(a) Plate floors: Maximum spacing:

0,002s_F m for T_FB< 0,04L₂ 0,003s_F m for T_{FB³ 0,04L2}

but not to exceed that required by item (2) in Table 5.5.2

Scantlings as required by Pt 4, Ch 1,8 (b) Centre and side girders:

Maximum spacing:

0,003s_L m for T_FB< 0,04L₂ 0,004s_L m for T_FB> 0,04L₂

but not to exceed that required by item (4) in Table 5.5.2

Scantlings as required by Pt 4, Ch 1,8 (6) Primary structure in way of double

bottoms supported by longitudinal bulkheads

–– The scantlings and arrangements will receive individual consideration on the basis of direct calculations using, if necessary, a suitably defined two-dimensional grillage model,

see Ch 1,3 t = 0,003s f h_sk £ 55 k ³ 0,00033 k hss c

(

S –

)

cm2 Z_{³ 6,8 x 10}–6_h ss k

[(

17,5ls

)

2–

(

0,01s

)

2+ dwc

(

S –

)]

cm3 x 10–1_{³ 1} (A₁t + a) p s 2000 s 2000 d_w t_w 100 d_w t_w

Fore End Structure

1.6.4 The thickness of the side shell is to be not less than:

t = 3,2s_C kh_s C_Rx 10–2 _mm

where

s_C = spacing of secondary stiffeners, in mm, measured along a chord between parallel adjacent members or equivalent supports, as shown in Fig. 5.1.3

h_S = bow flare slamming head, in metres, as defined in 1.6.3

C_R = panel ratio factor

=

( )

0,41 but is not to be taken less than 0,06 or greater than 0,1

l = overall panel length, in metres, measured along a chord between the primary members.

1.6.5 The scantlings of secondary stiffeners are not to be less than:

(a) Section modulus of secondary stiffeners

Z = 3,6s_CMk h_Sl_e2_{x 10}–3 _cm3

(b) Web area of secondary stiffeners

A = 3,7s_CMk h_S ( l_e– s_CM/2000) x 10–4 _cm2

where

s_CM = mean spacing of secondary stiffeners, in mm, measured along a chord between parallel adjacent members or equivalent supports, as shown in Fig. 5.1.3

h_S = bow flare slamming head, in metres, as defined in 1.6.3

l s_c

Other symbols are as defined in 1.4.1.

1.6.6 The scantlings of primary members are not to be less than:

(a) Section modulus of primary members

Z = 2S_CMk h_Sle2 cm3

(b) Web area of primary members

A = 0,2S_CMk h_Sle cm2

where

S_CM = mean spacing of primary members, in metres, measured along a chord between parallel adjacent members or equivalent supports, as shown in Fig. 5.1.4

h_S = bow flare slamming head, in metres, as defined in 1.6.3

Other symbols are as defined in 1.4.1.

1.6.7 For primary members with cut-outs for the passage of secondary stiffeners, and which may have web stiffeners connected to the secondary stiffener, buckling checks are to be carried out to ensure that the primary member web plating and web stiffener will not buckle under the design load. The buckling procedure to be followed is given in Table 5.1.3. Where the web stiffener is fitted with a bracket, the buckling capability of the web stiffener in way of the cut-out is to take account of the bracket. Where no web stiffener is fitted, the buckling capability of the primary member web plating is to be checked for the total load transmitted to the connection.

Part 3, Chapter 5

Section 1 L,T, s, k as defined in 1.4.1 c = 1,0 for S_{£ 2,5 m} = (0,87 + 0,16S ) c₁for S > 2,5 m c ₁ = 1,0 for S_{£ 1,0 m} = (1,14 – 0,14S) for 1,0 m < S£ 4,0 m = for S > 4,0 m

d_w = web depth, in mm, which for bulb flats may be taken as 0,9 times the section height

f =

(

1,1 –

)

but not greater than 1,0

h_s = equivalent slamming pressure, in metres obtained from 1.5.8

l_s = l_e, in metres, as defined in 1.4.1 where in way of a double bottom

= S, in metres, where in way of a single bottom

S = spacing of primary members, in metres

p = 9,81 h_ss c₁

[

S –

]

x 10–3 _kN =

(

h_ss c₁

[

S –

]

x 10–3 _tonne-f

)

s_F = spacing of transverse frames, in mm, for longitudinally framed side and bottom construction s_Fmay be taken as s_L

s_L = spacing of bottom longitudinals, in mm

t_w = web thickness, in mm

A_f = cross-sectional area of primary member web stiffener, in cm2

A_fc = effective area of primary member web stiffener in way of butted end connection to the longitudinal, in cm2

A_L = area of weld of lapped connection, in cm2_{, calculated} as total length of weld, in cm xthroat thickness, in cm

A_w = area of weld of lug and web connection to the longitudinal, in cm2_{, calculated as total length of weld} in cm x throat thickness, in cm

A₁ = effective total cross-sectional area of the lug and web connection to the longitudinal, in cm2

L₂ = L but need not be taken greater than 215 m

T_FB = draught, in metres, at the F.P., as defined in 1.5.1 aÿ = Afs¯¯ for the web stiffeners

= A_{fcs¯¯ for a butted connection to the longitudinals} = A_Lt¯¯ for a lapped connection

s¯¯ = permissible direct stress, in N/mm2_(kgf/mm2_{), given in} Table 5.1.2

t¯¯ = permissible shear stress, in N/mm2_(kgf/mm2_{), given in} Table 5.1.2 s 2000 s 2000 s 2500S 2,32 S

Table 5.1.1 Additional strengthening of bottom forward (conclusion)

Symbols

NOTES

1. If intermediate stiffening is fitted the thickness of the bottom shell plating may be 80 per cent of that required by (1) but is to be not less than the normal taper thickness.

2. For transverse framing the bottom shell plating is to be specially considered.

3. Particular care is to be taken to limit the size and number of openings in way of the ends of floors or girders or to fit suitable reinforcement where such openings are essential.

4. The welding requirements of Ch 10, and in cargo oil tanks of tankers, the requirements of Pt 4, Ch 9,10.14 or Pt 4, Ch 10,7.14, are also to be complied with.

1.6.8 The structural scantlings required in areas strengthened against bow flare slamming are to be tapered from 0,075L aft of fore perpendicular to meet the normal requirements at 0,15L aft of the fore perpendicular.

1.6.9 Where the stiffener web is not perpendicular to the plating, tripping brackets may need to be fitted in order to obtain adequate lateral stability.

1.6.10 For stiffeners and primary structure, where the angle between the stiffener web and the plating is less than 70°, the effective section modulus and shear area are to take account of the non-perpendicularity.

1.6.11 The side structure scantlings required by this Section must in no case be taken less than those required by the remaining Sections of Chapter 5.

Fore End Structure

RULES ANDREGULATIONS FOR THECLASSIFICATION OFSHIPS, July 2000

Part 3, Chapter 5

Section 1

LLOYD’SREGISTER OFSHIPPING 5

Item

Primary member web stiffener on area A_f

Direct stress, s¯¯ in N/mm2_(kgf/mm2_{) see Note}

Shear stress, t¯¯ in N/mm2_(kgf/mm2₎ (a) Flat bars,

see Note (b) Bulb plates, see Note (c) Inverted angles –– –– –– ––

Table 5.1.2 Permissible stresses

Primary member web stiffener on area A_fc

Single

Double Primary member web stiffener lapped to secondary member on area A_L

Lug or web connection on area A₁

A_f, A_L, A₁as defined in Table 5.1.1

d = stiffener depth, in mm k = as defined in 1.4.1

t = stiffener web thickness, in mm

––

––

––

––

NOTE

s¯¯ to be taken not greater than

(

22,4

)

k 220 k Symbols ––

[

33 – d

]

t k 10,3 k

( [

33 – d

])

t k 1,05 k

[

40 –

]

d

(

100A_f – t

)

k d 6 8,6 k

( [

40 –

])

d

(

100A_f – t

)

k d 6 0,88 k

( )

22,4 k 220 k

( )

25 k 245 k

( )

17 k 167 k

( )

12,6 k 124 k

( )

14,4 k 141 k

Fore End Structure

Part 3, Chapter 5

In document DIDÁCTICA DE JESÚS, PROPUESTA PEDAGÓGICA PARA LA EDUCACIÓN RELIGIOSA ESCOLAR, EN LA UNIDAD EDUCATIVA PARTICULAR LA PRESENTACIÓN. (página 36-41)