Section 4 Shell envelope plating
Clasification Society 2024 - Version 9.40
Clasifications Register Rules and Regulations - Rules and Regulations for the Classification of Inland Waterways Ships, July 2022 - Part 4 Ship Structures (Ship Types) - Chapter 9 Passenger Ships - Section 4 Shell envelope plating

Section 4 Shell envelope plating

Parent topic: Chapter 9 Passenger Ships

4.1 General

4.1.1 This Section covers the requirements for the shell envelope plating, viz., keel, bottom, bilge and side shell plating and sheerstrake plating.

4.1.2 The thickness of the shell envelope plating is to be not less than required in Table 9.4.1 Shell envelope plating, but for ships over 65 m in length the thickness of the bottom plating may require to be increased to meet the requirements of Pt 4, Ch 9, 3 Longitudinal strength.

Table 9.4.1 Shell envelope plating

Item and parameter Requirements
(1) Plate keel  
Breadth The greater of:
  0,1B m
  0,75 m
Thickness As bottom plating tb
  When there is a rise of floor, the thickness is to be increased by 1 mm
(2) Bottom plating The greater of:
Thickness
  tb = 10s mm
(3) Bilge plating  
Thickness t = tb + 2 mm
(4) Bilge chine bars  
(a) Round bars  
Diameter 3tb mm, but not less than 30 mm
(b) Square bars  
Side 3tb mm, but not less than 30 mm
(c) Angle bars  
Flange thickness t = 2tb mm
(5) Side shell plating The greater of:
Thickness
  tb = 10s mm
(6) Sheerstrake
(only to be fitted in absence of efficient steel fender around the ship at deck height) 		 
Minimum width W sh = 0,1D m
Thickness t = side shell thickness as required in (5) + 5 mm
Symbols
L, B, D, S, s, k and t are as defined in Pt 4, Ch 9, 1.14 Symbols and definitions 1.14.1
tb = thickness of bottom plating, in mm
C1 = , where is the ratio of the unstiffened bottom panel under consideration

4.1.3 For requirements in respect of structural details, see Pt 3, Ch 10 Welding and Structural Details.

4.2 Keel

4.2.1 The breadth and thickness of the keel plate is to comply with the requirements of Table 9.4.1 Shell envelope plating and is to be maintained over the full length of the ship.

4.3 Bottom plating

4.3.1 The thickness of bottom plating is to comply with the requirements of Table 9.4.1 Shell envelope plating and is to be maintained over the midship region and may be tapered to the end thickness in the forward and aft region (see Pt 3, Ch 5 Fore End and Aft End Structure), according to the requirements for taper given in Pt 3, Ch 3, 2.5 Principles for taper.

4.4 Bilge plating

4.4.1 The thickness of the bilge plating is to be maintained from amidships to well beyond the forward and aft shoulder of the bilge, but at least over the midship region. For definition of shoulder, see Pt 3, Ch 5, 2.4 Shell plating 2.4.2.

4.4.2 The bilge radius is to be at least 10 times the thickness of the bilge plating and the bilge strake is to extend at least 100 mm on either side of the radius.

4.4.3 Square bilges, constructed by solid round, square or externally fitted angle bars (see Figure 9.4.1 Square bilge arrangements), are to comply with Table 9.4.1 Shell envelope plating. The bottom plating and side shell plating adjacent to the round, square or angle bars need not be increased above that of the bottom plating or side shell plating in way.

Figure 9.4.1 Square bilge arrangements

4.5 Side shell plating

4.5.1 The thickness of the side shell plating is to comply with the requirements of Table 9.4.1 Shell envelope plating, which is to be maintained over 0,5L amidships and may be tapered to the end thickness in the forward and aft region (see Pt 3, Ch 5 Fore End and Aft End Structure), according to the requirements for taper given in Pt 3, Ch 3, 2.5 Principles for taper.

4.6 Sheerstrake

4.6.1 The width and the thickness of the sheerstrake is to comply with the requirements of Table 9.4.1 Shell envelope plating.

4.7 Shell openings

4.7.1 Openings in the shell plating are to have well rounded corners, compensation is generally only required for openings having a width greater than 250 mm. The edges of openings in the shell for side scuttles and windows are to be reinforced on the inside by angle bars of at least 75 mm in height to which the frames of the side scuttles and windows are to be fastened and thus protected. Compensation for the shell plating cut out is only required in the case of large windows. Openings in way of or near the bilge radius are to be circular or elliptical.

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