Section 2 Panel scantling requirements – bulkheads

2.1.1 The requirements of this Section cover watertight and deep tank transverse and longitudinal bulkheads.

2.1.2 The buckling requirements of Ch 3, 7 Buckling are also to be satisfied.

2.2.1 The top and bottom plate thickness of the steel sandwich panel are to be determined in accordance with Ch 3, 2.2 Watertight and deep tank bulkheads 2.2.2. For a deep tank bulkhead an allowance of 2,5 mm is to be added to the face plate thicknesses of the sandwich plate determined in Ch 3, 2.2 Watertight and deep tank bulkheads 2.2.2. The allowance is to be apportioned according to the location of the bulkhead and type of cargo on either side of the bulkhead. The allowance may be increased depending on the nature of the cargo.

2.2.2 The steel sandwich panel for watertight and deep tank bulkheads is to be dimensioned such that the requirement below is satisfied:

1. watertight bulkhead

   

2. deep tank bulkhead

   

   where

   dT	=	total thickness of the sandwich panel, in mm
   	=	tc + t n1+ t n2
   σo	=	specified minimum yield stress in N/mm2 of the face plates
   α	=	see Table 3.2.1 Coefficient α
   ρ	=	relative density (specific gravity) of liquid carried in a tank but is not to be taken less than 1,025
   h4	=	see Table 1.9.1 Watertight and deep tank bulkhead scantlings in Pt 4, Ch 1 General Cargo Ships of the Rules and Regulations for the Classification of Ships, July 2022.
   tn1	=	net thickness of the top plate, in mm
   tn2	=	net thickness of the bottom plate, in mm
   	=	a, b as defined in Ch 1, 7.2 Symbols.

2.2.3 The bond shear capacity of a panel is to satisfy the following criteria:

where

q	=	in N/mm2 where the bulkhead is a deep tank
	=	0,01h 4 in N/mm2, where the bulkhead is a watertight bulkhead
β	=
γ	=	see Table 3.2.2 Coefficient γ
τc	=	6 MPa.
	=	a, b as defined in Ch 1, 7.2 Symbols.

2.2.4 The ultimate bending capacity of the sandwich panel is to be assessed by the method in Ch 3, 2.2 Watertight and deep tank bulkheads 2.2.5. This is only applicable for sandwich panels subjected to lateral pressure.

2.2.5 The ultimate bending capacity, q _u, is to be taken as:

2.2.6 The ultimate bending capacity, q _u, calculated in Ch 3, 2.2 Watertight and deep tank bulkheads 2.2.5 is to satisfy the following criteria:

where

2.2.7 The thicknesses of the core, top and bottom plates are not to be less than:

1. Deep tank bulkheads

   t c

   =

   20 mm

   t n1, t n2	=	4,5 mm where L < 90 m
   	=	5,0 mm where L > 90 m

2. Watertight bulkheads

   t c

   =

   20 mm

   t n1, t n2

   =

   3,0 mm.

2.2.8 Stiffeners, stringers or webs supporting vertical or horizontal stiffening are to be in accordance with the requirements in Pt 4, Ch 9, 9 Primary members supporting longitudinal framing of the Rules and Regulations for the Classification of Ships, July 2022.

2.2.9 Where tanks are intended for liquid cargoes of a special nature the scantlings and arrangements will be considered in relation to the nature of the cargo.