9.2 Protection of accommodation spaces, service spaces and control stations
Clasification Society 2024 - Version 9.40
Statutory Documents - IMO Publications and Documents - International Codes - 1989 MODU Code – Code for the Construction and Equipment of Mobile Offshore Drilling Units, 1989 – Resolution A.649(16) - Chapter 9 – Fire Safety - 9.2 Protection of accommodation spaces, service spaces and control stations

9.2 Protection of accommodation spaces, service spaces and control stations

  9.2.1 All bulkheads required to be "B" class divisions should extend from deck to deck and to the deckhouse side or other boundaries, unless continuous "B" class ceilings or linings are fitted on both sides of the bulkhead, in which case the bulkhead may terminate at the continuous ceiling or lining. In corridor bulkheads, ventilation openings may be permitted only in and under the doors of cabins, public spaces, offices and sanitary spaces. The openings should be provided only in the lower half of the door. Where such an opening is in or under a door, the total net area of any such opening or openings should not exceed 0.05 m2 . When such an opening is cut in a door it should be fitted with a grille made of non-combustible material. Such openings should not be provided in a door in a division forming a stairway enclosure.

  9.2.2 Stairs should be constructed of steel or equivalent material.

  9.2.3 Stairways which penetrate only a single deck should be protected at least at one level by "A" or "B" class divisions and self-closing doors so as to limit the rapid spread of fire from one deck to another. Personnel lift trunks should be protected by "A" class divisions. Stairways and lift trunks which penetrate more than a single deck should be surrounded by "A" class divisions and protected by self-closing doors at all levels. Self-closing doors should not be fitted with hold-back hooks. However, hold-back arrangements incorporating remote release fittings of the fail-safe type may be utilized.

  9.2.4 Air spaces enclosed behind ceilings, panellings or linings should be divided by close fitting draught stops spaced not more than 14 m apart.

  9.2.5 Except for insulation in refrigerated compartments, insulation material, pipe and vent duct lagging, ceilings, linings and bulkheads should be of non-combustible material. Insulation of pipe fittings for cold service systems and vapour barriers and adhesives used in conjunction with insulation need not be non-combustible but they should be kept to a minimum and their exposed surfaces should have low flame spread characteristicsfootnote. In spaces where penetration of oil products is possible, the surfaces of the insulation should be impervious to oil or oil vapours.

  9.2.6 The framing, including grounds and the joint pieces of bulkheads, linings, ceilings and draught stops, should be of non-combustible material.

  9.2.7 All exposed surfaces in corridors and stairway enclosures and surfaces in concealed or inaccessible spaces in accommodation and service spaces and control stations should have low flame spread characteristics. Exposed surfaces of ceilings in accommodation and service spaces and control stations should have low flame spread characteristicsfootnote.

  9.2.8 Bulkheads. linings and ceilings may have combustible veneers provided that the thickness of such veneers should not exceed 2 mm within any space other than corridors, stairway enclosures and control stations where the thickness should not exceed 1.5 mm. Alternatively. veneers which have a calorific value not exceeding 45 mJ/m2 of the area for the thickness used may be accepted by the Administration, irrespective of the thickness of those veneers.

  9.2.9 Primary deck coverings, if applied, should be of approved material which will not readily ignite, or give rise to toxic or explosive hazards at elevated temperaturesfootnote.

  9.2.10 Paints. varnishes and other finishes used on exposed interior surfaces should not offer an undue fire hazard in the judgement of the Administration and should not be capable of producing excessive quantities of smoke.

  9.2.11 Ventilation ducts should be of non-combustible material. Short ducts, however, not generally exceeding 2 m in length and with a cross-sectional area not exceeding 0.02 m2 need not be non-combustible. subject to the following conditions:

  • .1 these ducts should be of a material which, in the opinion of the Administration, has a low fire risk;

  • .2 they may only be used at the end of the ventilation device;

  • .3 they should not be situated less than 600 mm, measured along the duct, from where it penetrates any "A" or "B" class division including continuous "B" class ceilings.

  9.2.12 Where ventilation ducts with a cross-sectional area exceeding 0.02 m2 pass through class "A" bulkheads or decks, the opening should be lined with a steel sheet sleeve unless the ducts passing through the bulkheads or decks are of steel in the vicinity of penetrations through the deck or bulkhead; the ducts and sleeves at such places should comply with the following:

  • .1 The ducts or sleeves should have a thickness of at least 3 mm and a length of at least 900 mm. When passing through bulkheads, this length should be divided preferably into 450 mm on each side of the bulkhead. These ducts, or sleeves lining such ducts, should be provided with fire insulation. The insulation should have at least the same fire integrity as the bulkhead or deck through which the duct passes. Equivalent penetration protection may be provided to the satisfaction of the Administration.

  • .2 Ducts with a cross-sectional area exceeding 0.075 m2, except those serving hazardous areas, should be fitted with fire dampers in addition to meeting the requirements of 2.1. The fire damper should operate automatically but should also be capable of being closed manually from both sides of the bulkhead or deck. The damper should be provided with an indicator which shows whether the damper is open or closed. Fire dampers are not required, however, where ducts pass through spaces surrounded by "A" class divisions, without serving those spaces, provided those ducts have the same fire integrity as the divisions which they pierce. The Administration may, given special considerations, permit operation from one side of a division only.

  9.2.13 Ducts provided for the ventilation of machinery spaces of category A, galleys and hazardous areas should not pass through accommodation spaces, service spaces or control stations. However, the Administration may permit a relaxation from this requirement, except for the ducts serving hazardous areas passing through accommodation spaces, control stations and galleys, provided that the ducts are:

  • .1 constructed of steel having a thickness of at least 3 mm for ducts of 300 mm in width or less and of at least 5 mm for ducts of 760 mm in width and over; in the case of ducts the width or diameter of which is between 300 mm and 760 mm, the thickness should be obtained by interpolation:

  • .2 fitted with automatic fire dampers close to the boundaries penetrated; and

  • .3 insulated to "A-60" standard from the machinery spaces or galleys to a point at least 5 m beyond each fire damper;

or

  • .4 constructed of steel in accordance with .1; and

  • .5 insulated to "A-60" standard throughout the accommodation spaces, service spaces or control stations.

  9.2.14 Ducts provided for the ventilation of accommodation spaces, service spaces or control stations should not pass through machinery spaces of category A, galleys or hazardous areas. However, the Administration may permit a relaxation from this requirement, except for the ducts passing through hazardous areas, provided that:

  • .1 the ducts where they pass through a machinery space of category A or a galley are constructed of steel in accordance with 9.2.13.1;

  • .2 automatic fire dampers are fitted close to the boundaries penetrated; and

  • .3 the integrity of the machinery space or galley boundaries is maintained at the penetrations;

or

  • .4 the ducts where they pass through a machinery space of category A or a galley are constructed of steel in accordance with 9.2.13.1; and

  • .5 are insulated to "A-60" standard within the machinery space or galley.

  9.2.15 Ventilation ducts with a cross-sectional area exceeding 0.02 m2 passing through "B" class bulkheads should be lined with steel sheet sleeves of 900 mm in length divided preferably into 450 mm on each side of the bulkhead unless the duct is of steel for this length.

  9.2.16 Where they pass through accommodation spaces or spaces containing combustible materials, the exhaust ducts from galley ranges should be of equivalent fire integrity to "A” class divisions. Each such exhaust duct should be fitted with:

  • .1 a grease trap readily removable for cleaning;

  • .2 a fire damper located in the lower end of the duct;

  • .3 arrangements, operable from within the galley, for shutting off the exhaust fans; and

  • .4 fixed means for extinguishing a fire within the duct.

  9.2.17 The main inlets and outlets of all ventilation systems should be capable of being closed from outside the spaces being ventilated.

  9.2.18 Power ventilation of accommodation spaces, service spaces, control stations, machinery spaces and hazardous areas should be capable of being stopped from an easily accessible position outside the space being served. The accessibility of this position in the event of a fire in the spaces served should be specially considered. The means provided for stopping the power ventilation serving machinery spaces or hazardous areas should be entirely separate from the means provided for stopping ventilation of other spaces.

  9.2.19 Windows and sidescuttles in boundaries which are required to meet an "A-60" standard which face the drill floor area should be:

  • .1 constructed to an "A-60" standard; or

  • .2 protected by a water curtain; or

  • .3 fitted with shutters of steel or equivalent material.

  9.2.20 The ventilation of the accommodation spaces and control stations should be arranged in such a way as to prevent the ingress of flammable, toxic or noxious gases, or smoke from surrounding areas.

Parent topic: Chapter 9 – Fire Safety
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