Section 1 General
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 11 Closing Arrangements to Openings in Shell and Deck, Ventilators, Air Pipes, Sounding Pipes and Discharges - Section 1 General

Section 1 General

Parent topic: Chapter 11 Closing Arrangements to Openings in Shell and Deck, Ventilators, Air Pipes, Sounding Pipes and Discharges

1.1 Application

1.1.1 This Chapter applies to all ship types detailed in Pt 4 Ship Structures (Ship Types). In addition to this Chapter, additional requirements for dry cargo ships carrying dangerous goods are given in Pt 4, Ch 1 Dry Cargo Ships. Additional requirements for tankers carring dangerous liquids in bulk are given in Pt 4, Ch 4 General Requirements For Tankers Carrying Dangerous Liquids in Bulk.

1.1.2 Requirements are given for:

  1. Steel, aluminium or wooden hatch covers, self-supporting and portable, securing arrangements, tarpaulins and closing arrangements for miscellaneous openings.

  2. Hatchways less than 3 m in length and breadth (requirements for larger hatchways are given in the relevant ship type Chapter, see Pt 4 Ship Structures (Ship Types)), cargo tank hatches, ventilators, air pipes, sounding pipes and discharges.

Hatch covers of other materials will be specially considered.

1.1.3 Hatch covers are to be fitted on holds intended for the carriage of perishable cargoes. Means are to be provided for making hatch covers weathertight by fitting tarpaulins or by sealing arrangements to the hatch cover and/or hatch coaming.

1.1.4 The requirements for scantlings and arrangements of the following types of hatch covers are defined in this Chapter:

  1. Self-supporting steel or aluminium, single plate hatch covers stiffened by webs, stiffeners or corrugations.

  2. Self-supporting steel or aluminium, double plate hatch covers having interior webs and stiffeners.

  3. Portable wood, steel or aluminium hatch covers used in conjunction with portable beams, fore and afters and crossbeams if necessary.

  4. Hatch covers on small openings to dry spaces.

  5. Hatch covers and coamings for cargo tanks and similar spaces.

1.1.5 The scantlings specified in the following Sections apply basically to uniformly loaded rectangular hatch covers, being simply supported and with stiffening members arranged primarily in one direction. When covers are stiffened otherwise or concentrated loads are applied, the scantlings are to be determined by direct calculations based on the permissible stresses and deflections given in Table 11.2.2 Parameters for direct calculation and are to be submitted for approval.

1.2 Symbols

1.2.1 The following symbols and definitions are applicable to this Chapter, unless otherwise stated:

h H = hatch cover design head, see Pt 3, Ch 3, 4 Design loading
lo = unsupported span of stiffening member, in metres
s = spacing of stiffeners, in metres
d w = depth of stiffener, in mm
w = width of effective plating included in the section modulus, 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
I = moment of inertia of stiffening member, in cm4, see Pt 3, Ch 3, 3.2 Geometric properties of section.
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