Section 6 Fore peak structure

6.1.1 The requirements in this Section apply to the arrangements of primary structure supporting the peak framing and the scantlings of the collision bulkhead. Furthermore, requirements for wash bulkheads and perforated flats are given.

6.2.1 The bottom of the peak space is generally to be transversely framed with arrangements and scantlings as detailed in Pt 3, Ch 5, 3.3 Single bottom – Transverse framing.

6.2.2 Where a swim end is arranged in the fore ship and the bottom is longitudinally framed, the longitudinal framing may be extended in the fore peak. The arrangements and scantlings are to be as detailed in Pt 3, Ch 5, 3.6 Swim end forward and Pt 3, Ch 5, 4.3 Shell longitudinals, but the draught for calculation of the longitudinals and transverses may be taken as the actual draught in way of the member.

6.3.1 The framing in the fore peak may be either transverse or longitudinal but should generally be the same system as the framing aft of the fore peak bulkhead. The scantlings and arrangements of transverse and longitudinal framing are to be as detailed in Pt 3, Ch 5, 4.2 Shell framing and Pt 3, Ch 5, 4.3 Shell longitudinals respectively.

6.3.2 Transverses supporting side longitudinals are to be fitted not more than 2,5 m apart. Suitable transverses or deep beams are to be arranged at the deck of the fore peak to provide end rigidity to the side transverses.

6.4.1 Wash bulkheads to support deck beams and/or floors may be fitted in the fore peak and in tanks extending from side to side.

6.4.2 Perforated flats may be fitted in lieu of stringers on shell and bulkheads, see Pt 3, Ch 5, 4.5 Stringers.

6.4.3 Wash bulkheads and perforated flats are generally to have an area of perforation between 5 and 10 per cent of their area.

6.4.4 The scantlings of wash bulkheads and perforated flats are to be determined from Table 5.6.1 Fore peak structure.

Table 5.6.1 Fore peak structure

Item	Parameter	Requirement
(1) Collision bulkhead	Plating thickness	The greatest of: t = 4 × s × + 1,5 mm t = 5 mm t = 5,5 mm for water ballast tanks
	Stiffener modulus	Z = 4,3 × k × s × le1 2 × h5 + 4 cm3
(2) Perforated flats in void spaces	Plating thickness	The greater of: t = 7s + 0,5 mm t = 5 mm
	Stiffener modulus	Z = 3,5 × k × s × le1 2 + 3 cm3
(3) Wash bulkheads and perforated flats in tanks	Plating thickness	The greater of: t = 7s + 1 mm t = 5 mm
	Stiffener modulus	Z = 3,5 × k × s × le1 2 + 4 cm3
Symbols
le , s, Z and t are as defined in Pt 3, Ch 5, 1.4 Symbols and definitions 1.4.1 le1 = le but should be taken as not less than 2 m h5 = load height, in metres, measured vertically as follows: (i) for vertically stiffened plating – the distance from a point 0,5 m above the lower edge of the plate to a point 1 m above the top of the bulkhead, or to the top of the overflow, whichever is the greater (ii) for horizontally stiffened plating - the distance from the middle of the first panel above the lower edge of the plate to a point 1m above the top of the bulkhead, or to the top of the overflow, whichever is the greater (iii) for stiffeners – the distance from the middle of the effective length to a point 1 m above the top of the bulkhead, or to the top of the overflow whichever is the greater k = higher tensile steel factor, see Pt 3, Ch 2, 1.3 Steel 1.3.3

6.5.1 The position and height of the collision bulkhead is to be in accordance with the requirements of Pt 3, Ch 7 Bulkheads.

6.5.2 The scantlings are to be determined from Table 5.6.1 Fore peak structure. End connections of stiffeners are to be in accordance with Pt 3, Ch 10, 3 Secondary member end connections.

6.5.3 For requirements regarding openings in the collision bulkhead, see Pt 3, Ch 7, 1.3 Collision bulkhead 1.3.5.