Section 9 Hopper side tank structure

9.1.1 Provision is made in this Section for longitudinal framing of the hopper side tank, but proposals for transverse framing will be specially considered.

9.1.2 Where oil cargoes are carried the scantlings of the sloped bulkhead are to comply with the requirements of Pt 4, Ch 7, 10.2 Bulkheads supported by stools.

9.1.3 For ships to be classed ‘100A1 bulk carrier, strengthened for heavy cargoes, any hold may be empty, ESP’, the requirements of Pt 4, Ch 7, 9.2 Sloped bulkhead plating, Pt 4, Ch 7, 9.3 Sloped bulkhead stiffeners and Pt 4, Ch 7, 9.6 Primary supporting structure are to be complied with. In addition the value for C, the stowage rate in m³/tonne, as defined in Table 7.8.1 Strengthening for heavy cargo requirements, is not be taken greater than 0,60 for each hold.

9.1.4 The buckling requirements of Pt 3, Ch 4, 7 Hull buckling strength are also to be satisfied.

9.1.5 The ShipRight FDA Procedure, Structural Detail Design Guide (SDDG), indicates recommended details of structural design configurations around the transverse ring web of the hopper tank.

9.2.1 The thickness of the sloped bulkhead plating is to be as required by Pt 4, Ch 1, 8.4 Inner bottom plating and stiffening 8.4.1 but based on actual spacing of sloped bulkhead stiffeners.

9.2.2 Where the ship is regularly discharged by grabs and the optional notation for heavy grabs is not desired (see Pt 3, Ch 9, 7 Bottom strengthening for loading and unloading aground), the increase in thickness, as required by Pt 4, Ch 1, 2.2 Protection of steelwork, is to be tapered from the inner bottom knuckle to nil at the top corner of the tank.

9.2.3 Where a `strengthened for heavy cargo notation' is desired, in addition to Pt 4, Ch 7, 9.2 Sloped bulkhead plating 9.2.2 the thickness of the sloped bulkhead plating is also to comply with the requirements of Table 7.8.1 Strengthening for heavy cargo requirements (3)(b) using the actual spacing of stiffeners and with H, in metres, measured vertically from a point one third of each plate width from its lower edge to the upper deck at side.

9.2.4 Where the hopper tanks are interconnected with the topside tanks, or in way of ballast holds, the plating is also to comply with the requirements of Table 7.8.1 Strengthening for heavy cargo requirements (3)(c) and (3)(d), whichever is appropriate.

9.3.1 The scantlings of sloped bulkhead stiffeners are to be as required for inner bottom longitudinals, see Pt 4, Ch 7, 8 Double bottom structure. In ships strengthened for heavy cargoes, the scantlings of the stiffeners are to be derived from Table 7.8.1 Strengthening for heavy cargo requirements using a head for heavy cargo measured vertically from the mid-point of the effective length to the underside of the topside tank sloped bulkhead. Where the hopper tanks are interconnected with the topside tanks, or in way of ballast holds, the scantlings of the stiffeners are also to comply with the requirements of Table 7.8.1 Strengthening for heavy cargo requirements (4)(c) and (4)(d), whichever is appropriate. For higher tensile steel longitudinals the requirements of Pt 4, Ch 1, 6.2 Longitudinal stiffening 6.2.3 are to be complied with where applicable, see also Pt 4, Ch 7, 9.7 Structural details 9.7.1.

9.4.1 The scantlings of the shell and bilge longitudinals are to comply with the requirements of Pt 4, Ch 1, 6 Shell envelope framing.

9.5.1 The scantlings of tank end bulkheads are to comply with the requirements for deep tanks in Table 1.9.1 Watertight and deep tank bulkhead scantlings. Where the hopper tanks are interconnected with the topside tanks, the scantlings are to be derived, using the load head h ₄, in metres, from Table 7.8.1 Strengthening for heavy cargo requirements (3)(c) and (4)(c), as appropriate.

9.6.1 Transverses supporting longitudinal stiffening are to comply with the requirements of Table 7.9.1 Hopper tank primary structure, and are to be in line with the double bottom floors.

9.7.1 Bracket/diaphragms at the top of the hopper tank are to be of sufficient size and thickness to provide effective rigidity, and care is to be taken to ensure alignment with brackets at the bottom of the side frames in the holds. The shell and sloped bulkhead longitudinals supporting the diaphragms are to be derived using the span taken between transverses, see also Pt 4, Ch 7, 6.2 Transverse stiffening 6.2.11.

Table 7.9.1 Hopper tank primary structure

Item		Modulus, in cm3		Inertia, in cm4
(1)	Bottom and side shell transverses	Z = 11,71ρkShl e 2
(2)	Sloped bulkhead transverses	The greater of:
		(a)	Z = 11,71ρkSh 1le 2
		(b)	Z =
Symbols
S, k, l e, Z, , ρ = as defined in Pt 4, Ch 7, 1.7 Information required for non-CSR bulk carriers 1.7.1 h = distance, in metres, from the mid-point of the effective length to the upper deck at side h 1 = the greater of the distance, in metres, from the midpoint of the effective length to the top of the tank or half the distance, in metres, to the top of the overflow, or in way of cargo oil or ballast holds: the distance from the tank top to the deck at centre, or where the hopper tank is interconnected with the topside tank: the load head h 4, as derived from Table 7.8.1 Strengthening for heavy cargo requirements(4)(c), whichever is the greatest C = stowage rate, in m3/tonne, as defined in Table 7.8.1 Strengthening for heavy cargo requirements. For bulk carriers without the notation `strengthened for heavy cargoes', the value to be used is 1,39 m3/tonne. For bulk carriers with the notation `strengthened for heavy cargoes', the actual stowage rate is to be used, but the value is not to be taken greater than 0,865 m3/tonne. H H = distance, in metres, measured vertically from the mid-point of the effective length to the underside of the topside tank sloped bulkhead