Chapter 10 - Mechanical Ventilation in the Cargo Area
Clasification Society 2024 - Version 9.40
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Chapter 10 - Mechanical Ventilation in the Cargo Area

 To ensure that arrangements are provided for enclosed spaces in the cargo area to control the accumulation of flammable and/or toxic vapours.

10.1 Application

10.1.1 For vessels to which the present Code applies, the provisions of this chapter replace the requirements of SOLAS regulations II-2/ and

10.1.2 However, for products addressed under 9.1.3, except acids and products for which 15.12 and/or 15.17 of the IBC Code applies, SOLAS regulations II-2/ and may apply in lieu of the provision of 10.2 of this chapter.

10.1.3 For non-flammable products addressed under 9.1.2, except acids and products for which 15.12 and/or 15.17 of the IBC Code applies, the provisions for permanent installations in 10.3 may apply for spaces required to be entered during normal cargo handling operations.

10.2 Spaces normally entered during normal cargo handling operations

10.2.1 Cargo pump-rooms, spaces containing cargo handling equipment and other enclosed spaces where cargo vapours may accumulate should be fitted with fixed mechanical ventilation systems, capable of being controlled from outside such spaces. The ventilation should be run continuously to prevent the accumulation of toxic vapours. A warning notice requiring the use of such ventilation prior to entering should be placed outside the compartment.

10.2.2 Mechanical ventilation inlets and outlets should be arranged to ensure sufficient air movement through the space to avoid accumulation of toxic or asphyxiant vapours, and to ensure a safe working environment.

10.2.3 The ventilation system should have a capacity of not less than 30 changes of air per hour, based upon the total volume of the space.

10.2.4 Where a space has an opening into an adjacent more hazardous space or area, it should be maintained at an overpressure. It may be made into a less hazardous space or non-hazardous space by overpressure protection in accordance with standards acceptable to the Organization.footnote

10.2.5 Ventilation systems should be permanent and should normally be of extraction type. Extraction from above and below the floor plates should be possible.

10.2.6 Ventilation intakes should be so arranged as to minimize the possibility of recycling hazardous vapours from any ventilation discharge opening.

10.2.7 Ventilation ducts serving hazardous areas should not be led through accommodation, service or machinery spaces or control stations.

10.2.8 Electric motors driving fans should be placed outside the ventilation ducts that may contain flammable vapours. Ventilation fans should not produce a source of ignition in either the ventilated space or the ventilation system associated with the space. For hazardous areas, ventilation fans and ducts adjacent to the fans should be of non-sparking construction, as defined below:

  • .1 impellers or housing of non-metallic construction, with due regard being paid to the elimination of static electricity;

  • .2 impellers and housing of non-ferrous materials;

  • .3 impellers and housing of austenitic stainless steel; and

  • .4 ferrous impellers and housing with not less than 13 mm design tip clearance.

10.2.9 Any combination of an aluminium or magnesium alloy fixed or rotating component and a ferrous fixed or rotating component, regardless of tip clearance, is considered a sparking hazard and should not be used in these places.

10.2.10 Where fans are required by this chapter, full required ventilation capacity for each space should be available after failure of any single fan or spare parts should be provided comprising a motor, starter spares and complete rotating element, including bearings of each type.

10.2.11 Protection screens of not more than 13 mm square mesh should be fitted to outside openings of ventilation ducts.

10.2.12 Where spaces are protected by overpressure the ventilation should be designed and installed in accordance with standards acceptable to the Organization.footnote

10.3 Spaces not normally entered

Enclosed spaces where cargo vapours may accumulate should be capable of being ventilated to ensure a safe environment when entry into them is necessary. This should be capable of being achieved without the need for prior entry. For permanent installations, the capacity of 8 air changes per hour should be provided and for portable systems, the capacity of 16 air changes per hour. Fans or blowers should be clear of personnel access openings, and should comply with 10.2.8.

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