Section 10 Single side shell and deck supporting structure
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 1 Dry Cargo Ships - Section 10 Single side shell and deck supporting structure

Section 10 Single side shell and deck supporting structure

Parent topic: Chapter 1 Dry Cargo Ships

10.1 General

10.1.1 This Section covers the arrangements and requirements for one of the following transverse framing systems:

  1. Support of the side shell and deck by framing of equal profile depth only.

  2. Support of the side shell and deck by a combination of frames and web frames or bulkheads.

10.1.2 The scantlings of the side shell structural parts, viz. frames, web frames and the brackets under deck from frame to coaming are to comply with Table 1.10.1 Single skin construction.

10.1.3 Where a longitudinal framing system is adopted, the scantlings and arrangements will be specially considered.

10.2 Frames

10.2.1 In ships with a single bottom, the lower end of the frames is to overlap the floors. In ships with a double bottom, the lower end of the frame is to be efficiently connected to the double bottom structure.

10.3 Web frames

10.3.1 If web frames are fitted, they are to be spaced not more than 5 m apart. The thickness, stiffening arrangement and end connections of web frames are to be in accordance with the requirements of Pt 3, Ch 10, 4 Construction details for primary members.

10.4 Brackets under deck

10.4.1 At the head of frames and web frames, brackets are to be fitted supporting deck and hatch coaming. The arrangements of the brackets is shown in Figure 1.10.1 Frame arrangement. The scantlings of the brackets at the frames and web frames are to have equal dimensions, it being assumed that the load from coaming and deck is evenly distributed over each bracket. Proposals for other structural arrangements resulting in a different distribution of loads will be specially considered. Where a travelling crane for the lifting of hatch covers or cargo is used, the load from the crane is also to be taken into account when calculating the bracket scantlings.

Figure 1.10.1 Frame arrangement

Table 1.10.1 Single skin construction

Item Parameter Requirement
(1) Frames Modulus cm3
(2) Web frames Modulus
(3) Brackets under deck Depth d b = as shown in Figure 1.10.1 Frame arrangement
Thickness
Flange width b f = 70 mm minimum
Minimum required modulus Zb = 29k x k 2 x b x s (b x h 1 + b 1 x h h) cm3
Symbols

D, T, S, s, t, k and z are as defined in Pt 4, Ch 1, 1.5 Symbols and definitions 1.5.1

b = width of bracket, in metres, as shown in Figure 1.10.1 Frame arrangement
bf = width of bracket flange, in mm
b1 = width of hatchway, in metres
hh = head, in metres, on the hatch covers (if fitted) as defined in Pt 3, Ch 3, 4 Design loading
h1 = head on deck, in metres, as defined in Pt 3, Ch 3, 4 Design loading
k1 = 1 + (u – 15) x 0,078, but this factor is to be not less than 1, nor greater than 3,33, where
u = distance between transverse bulkheads, web frames or other efficient transverse supports, in metres
k2 = L co/12d co – 1, but this factor is to be taken not less than 0, nor greater than 1, where
Lco = length of hatch coaming between transverse bulkheads, or other efficient vertical supports, in metres
dco = depth of hatch coaming, in metres, as shown in Figure 1.10.1 Frame arrangement
q = height of single or double bottom, in metres, as shown in Figure 1.10.1 Frame arrangement
H1 = vertical framing depth, in metres, as shown in Figure 1.10.1 Frame arrangement
T1 = D – q but need not be taken greater than T + 0,4 – q for Zone 3, T + 0,7 – q for Zone 2, T + 1,0 – q for Zone 1, in metres
Zb = modulus, in cm3, of brackets under deck at the intersection with the frame as indicated in Figure 1.10.1 Frame arrangement
Zf = modulus of the frame, in cm3

Note 1. Where frames do not support cantilever brackets under deck, a minimum value of 15 cm3 for Zb is to be applied.

Note 2. Zb is to be obtained from (3) taking k2= 1 and s as the spacing between web frames

Note 3. If the factor k2 is 0, the frame bracket may also be replaced by a deck beam with a section modulus not less than half the section modulus of a frame and suitably connected to the frame.

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