Section 4 Design loading
Clasification Society 2024 - Version 9.40
Clasifications Register Rules and Regulations - Rules and Regulations for the Classification of Inland Waterways Ships, July 2022 - Part 3 Ship Structures (General) - Chapter 3 Structural Design - Section 4 Design loading

Section 4 Design loading

Parent topic: Chapter 3 Structural Design

4.1 General

4.1.1 This Section contains the design heads/pressures to be used in the derivation of scantlings for decks, tank tops and transverse bulkheads. Where scantlings in excess of Rule requirements are fitted, the procedure to be adopted to determine the permissible loading pressure which may be carried by such scantlings is given in Table 3.4.1 Design heads and permissible cargo loading (SI units).

Table 3.4.1 Design heads and permissible cargo loading (SI units)

  Rule Loading
Structural item and position Component Stowage rate,
in m3/tonne 		Design loading
p, in kN/m2 		Design head
h i, in metres 		Permissible cargo
loading, in
kN/m2
Upper deck outside of accommodation spaces       h 1  
Loading for minimum scantlings All structure 1,39 4,59 0,65 4,59
Cargo decks, tank top or hold ceiling       h 2  
General cargo (standard loads) All structure 1,39 7,07H c H c 7,07H c
Machinery space, workshop and stores 1,39 18,37 2,6 18,37
Ship stores 1,39 9,22 1,3 9,22
Accommodation decks All structure 1,39 3,18 h 3 = 0,45 3,18
Watertight bulkheads Plating and stiffeners 1 h 4 h 4 from Figure 3.4.2 Heads for watertight and deep tank bulkheads  
Deep tank bulkheads
Hatch covers (standard loading) see Note All structure 1,39 1,47 h H = 0,21 1,47
  Applied loading
Upper deck outside of accommodation spaces       h 1  
Specified cargo loading All structure C p a
p a
Cargo decks, tank top or hold ceiling       h 2  
Special cargo (specified loads) All structure C p a
p a
Deep tank bulkheads Plating and stiffeners C but ≤ 1
h 4 from Figure 3.4.2 Heads for watertight and deep tank bulkheads  
Hatch covers (specified loading) All structure C p a
p a

Note For ships operating in Zone 3 only, hatch covers may be designed for a minimum design loading of 0,075 tonne-f/m2 plus the selfweight of the covers.

Table 3.4.2 Design heads and permissible cargo loading (metric units)

  Rule Loading
Structural item and position Component Stowage rate,
in m3/tonne 		Design loading
p, in kN/m2 		Design head
h i, in metres 		Permissible cargo
loading, in
kN/m2
Upper deck outside of accommodation spaces       h 1  
Loading for minimum scantlings All structure 1,39 0,468 0,65 0,468
Cargo decks, tank top or hold ceiling       h 2  
General cargo (standard loads) All structure 1,39
h c
Machinery space, workshop and stores 1,39 1,87 2,6 1,87
Ship stores 1,39 0,94 1,3 0,94
Accommodation decks All structure 1,39 0,324 h 3 = 0,45 0,324
Watertight bulkheads Plating and stiffeners 1 h 4 h 4 from Figure 3.4.2 Heads for watertight and deep tank bulkheads  
Deep tank bulkheads
Hatch covers (standard loading) see Note All structure 1,39 0,15 h H = 0,21 0,15
  Applied loading
Upper deck outside of accommodation spaces       h 1  
Specified cargo loading All structure C p a Cp a p a
Cargo decks, tank top or hold ceiling       h 2  
Special cargo (specified loads) All structure C p a Cp a p a
Deep tank bulkheads Plating and stiffeners C but ≤ 1
h 4 from Figure 3.4.2 Heads for watertight and deep tank bulkheads  
Hatch covers (specified loading) All structure C p a h H = Cp a p a

Note For ships operating in Zone 3 only, hatch covers may be designed for a minimum design loading of 0,075 tonne-f/m2 plus the selfweight of the covers.

4.2 Symbols

4.2.1 The symbols used in this Section are defined as follows:

p = design loading which is either the Rule loading as defined in Table 3.4.1 Design heads and permissible cargo loading (SI units) or the applied loading p a, whichever is the greater, in kN/m2 (tonne-f/m2)
p a = applied loading, i.e. the actual loading specified by the builder or the Owner, in kN/m2 (tonne-f/m2)
h i = design head, which is to be used in the Rule formulæ, in metres
= p x C where p has been defined in tonne-f/m2, or
= p x C/9.81 where p has been defined in kN/m2
C = stowage rate, in m3/tonne
= for inner bottom or hold ceiling
= elsewhere
l e = span of stiffener, in metres
H c = height from inner bottom, hold ceiling or cargo deck, to deck at side or underside of hatch covers or height of deck cargo, in metres, as defined in Figure 3.4.1 Design heads for inner bottoms and & 'tweendecks.

Figure 3.4.1 Design heads for inner bottoms and & 'tweendecks

Figure 3.4.2 Heads for watertight and deep tank bulkheads

4.3 Stowage rate and design loads

4.3.1 Unless it is specifically requested otherwise, the following Rule standard stowage rates are to be used:

  1. 1,39 m3/tonne for weather or general cargo loading on deck and inner bottom or hold ceiling.

  2. 1,0 m3/tonne for liquid cargo of density of 1 tonne/m3 or less on watertight and tank divisions. For liquid of density greater than 1 tonne/m3 the corresponding stowage rates are to be adopted.

4.3.2 Proposals to use a stowage rate greater than 1,39 m3/tonne for permanent structure will require special consideration, and will normally be accepted only in the case of special purpose designs.

4.3.3 The design head and permissible cargo loading are shown in Table 3.4.1 Design heads and permissible cargo loading (SI units).

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