Section 2 Scantlings of erections
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Clasifications Register Rules and Regulations - Rules and Regulations for the Classification of Inland Waterways Ships, July 2022 - Part 3 Ship Structures (General) - Chapter 8 Superstructures, Deck-houses and Bulwarks - Section 2 Scantlings of erections

Section 2 Scantlings of erections

Parent topic: Chapter 8 Superstructures, Deck-houses and Bulwarks

2.1 Superstructures

2.1.1 The scantlings of plating and framing and the type of end connections of the side structure are to be the same as for the shell in way.

2.1.2 The scantlings of plating and stiffening and the type of end connections of the end bulkheads are to be the same as for the end bulkheads of deck-houses, see Table 8.2.1 Deckhouse scantlings (and further references as per Pt 3, Ch 8, 2.2 Deck-houses and exposed machinery casings bulkhead plating 2.2.1, Pt 3, Ch 8, 2.3 Stiffeners and their end connections 2.3.2, Pt 3, Ch 8, 2.4 Deck plating 2.4.1 and Pt 3, Ch 8, 2.6 Deck supporting structure 2.6.2).

Table 8.2.1 Deckhouse scantlings

Item Parameter Requirements
Side and end bulkheads of lower tier Plating:
t = 7,5s + 0,010L mm
Stiffeners:
Z = 14fs + 4 cm3
wherein
f = 1,25 – 0,005L
See Notes 1 and 2
Side and end bulkheads of 2nd and 3rd tiers Plating:The greater of:
t = 7,5s + 0,010L – 0,75 mm
t = 3 mm
Stiffeners:
Z = 14fs + 4 cm3
wherein
f = 1,25 – 0,005L
See Notes 1 and 3
Decks (all tiers) Plating:
t = 8,0s + 0,013L mm
Beams and longitudinals:
Z = 4s h ilb 2 + 4 cm3
See Note 4
Non-exposed decks and top decks:
t = 8,0s mm
Girders and transverses:
Z = 4,5h i Sle 2 + 4 cm3
I = 2,3le Z cm4
Pillars, see Note 5 Cross-sectional area
A p = 4,5 + 0,875P cm2
Minimum wall thickness of hollow pillars The greater of:
  1. t = 0,033d b mm
    for tubular pillars
    = 0,056b mm
    for square pillars
  2. t = 5 mm
Symbols
b = breadth of side of hollow square pillars, in mm
b d = breadth or length of the deck panel supported, in metres
d b = mean diameter of tubular pillars, in mm
f = factor
h i = design head and is to be taken as 0,45 m for no load-bearing weather and accommodation decks and 0,30 m for top decks and the relevant values for h i from Table 3.4.1 Design heads and permissible cargo loading (SI units) for load-bearing decks
lb = span, in metres, of deck beam or longitudinals and is to be taken not less than 1,5 m
le = effective span, in metres, of girder or transverse as defined in Pt 3, Ch 3, 3.3 Determination of span point
s = spacing of stiffeners, beams or longitudinals, in metres
A p = cross-sectional area of tubular or hollow square pillar, in cm2
L = length of ship, in metres, as defined in Pt 3, Ch 1, 6.1 Principal particulars
P = load, in tonne-f, supported by the pillar and is to be taken as P = 0,72Sb d h i tonne-f, to which the load exerted by superposed pillars is to be added
S = spacing or mean spacing of girders, transverses or pillars supporting them, in metres
t = thickness of plating, in mm
Z = section modulus of stiffening member, in cm3, see Pt 3, Ch 3, 3.2 Geometric properties of section

Note 1. If the unsupported length of a stiffener exceeds 2,5 m the section modulus is to be suitably increased.

Note 2. The section modulus of the stiffeners is to be increased by 15 per cent where a second tier house is fitted and by 30 per cent where also a third tier is fitted.

Note 3. The section modulus of the stiffeners of the second tier is to be increased by 15 per cent if a third tier house is fitted.

Note 4. The depth of beams and longitudinals is to be not less than 45 mm.

Note 5. The minimum diameter of hollow pillars is 50 mm. The minimum dimensions of hollow square pillars is 45 x 45 mm. Solid and fabricated pillars are to be of equivalent strength.

2.1.3 The scantlings of plating and stiffening and the type of end connections of the deck structure are to be the same as for the main deck in the respective position.

2.2 Deck-houses and exposed machinery casings bulkhead plating

2.2.1 The thickness, t, of exposed end and side bulkheads is to comply with the requirements of Table 8.2.1 Deckhouse scantlings.

2.2.2 The thickness of load-bearing internal bulkheads is to be not less than 3 mm in conjunction with suitable stiffening.

2.3 Stiffeners and their end connections

2.3.1 Stiffeners are to be fitted in line with deck beams or longitudinals.

2.3.2 The section modulus of stiffeners of end and side bulkheads is to be in accordance with Table 8.2.1 Deckhouse scantlings.

2.3.3 The lower end of stiffeners of single tier deckhouses may be unattached. The upper end of stiffeners of all tiers is to be connected to the deck beams or longitudinals.

2.3.4 When a multiple tier erection is fitted, the lower end of the side bulkhead stiffeners is to be attached to the deck, except in the case of the uppermost tier.

2.4 Deck plating

2.4.1 The thickness of exposed and unexposed deck plating is to be in accordance with Table 8.2.1 Deckhouse scantlings.

2.5 Deck stiffening

2.5.1 Deck beams and longitudinals are to have a section modulus in accordance with the requirements of Table 8.2.1 Deckhouse scantlings.

2.5.2 The beams and longitudinals are to be connected to the bulkhead stiffeners.

2.6 Deck supporting structure

2.6.1 Decks are to be supported by suitably spaced girders or transverses and pillars.

2.6.2 The scantlings of girders, transverses and pillars are to comply with Table 8.2.1 Deckhouse scantlings.

2.6.3 Effective support is to be fitted under the heel of pillars.

2.6.4 The girders and transverses are to be suitably connected to the bulkhead stiffening. The modulus of the bulkhead stiffeners bearing transverses is to be increased by 40 per cent. End connections are generally to comply with Pt 3, Ch 10, 4.7 End connections.

2.7 Strengthening at sides and ends of erections

2.7.1 Web stiffeners or equivalent strengthening is to be arranged to support the sides of large erections.

2.7.2 Web stiffeners should be spaced about 10 m apart and are to be arranged in line with bulkheads or webs below.

2.7.3 Web stiffeners or equivalent strengthening is also to be fitted within erections that have erections above exceeding 5 m in length or, 0,1L, whichever is the greater.

2.7.4 Adequate support under the ends of erections is to be provided.

2.8 Erections in way of machinery spaces

2.8.1 If engines of high horsepower in relation to the size or type of ship are fitted, measures are to be taken to prevent undue vibration of the structure.

2.9 Erections contributing to hull strength

2.9.1 Where an effective superstructure, see Pt 3, Ch 3, 3.4 Calculation of hull section modulus 3.4.2 or a deck-house with a length of more than 0,2L is fitted and which is situated within the midship 0,5L region, the scantlings of deck plating and longitudinals of these erections may require to be increased.

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