Provisions applicable to special category spaces whether above or below the bulkhead deck
| (i) | The basic principle underlying the provisions in this Regulation is that as normal main vertical zoning may not be practicable in special category spaces, equivalent protection must be obtained in such spaces on the basis of a horizontal zone concept and the provision of an efficient fixed fire-extinguishing system. Under this concept a horizontal zone for the purpose of this Regulation may include special category spaces on more than one deck provided that the overall height of the zone does not exceed 10 metres (33 feet). |
| (ii) | All requirements laid down in Regulations 23 and 25 of this Chapter for maintaining the integrity of vertical zones shall be applied equally to decks and bulkheads forming the boundaries separating horizontal zones from each other and from the remainder of the ship. |
| (b) | Structural protection. |
| (i) | Boundary bulkheads of special category spaces shall be insulated as required for Category (11) spaces in Table 1 of Regulation 20 of this Chapter and the horizontal boundaries as required for Category (11) spaces in Table 3 of that Regulation. |
| (ii) | Indicators shall be provided on the navigating bridge which shall indicate when any fire door leading to or from the special category spaces is closed. |
(c) Fixed fire-extinguishing system.
Each special category space shall be fitted with an approved fixed pressure water-spraying system for manual operation which shall protect all parts of any deck and vehicle platform, if any, in such space, provided that the Administration may permit the use of any other fixed fire-extinguishing system that has been shown by fullscale test in conditions simulating a flowing petrol fire in a special category space to be not less effective in controlling fires likely to occur in such a space.
| (d) | Patrols and detection. |
| (i) | An efficient patrol system shall be maintained in special category spaces. In any such space in which the patrol is not maintained by a continuous fire watch at all times during the voyage there shall be provided in that space an automatic fire detection system of an approved type. |
| (ii) | Manual fire alarms shall be provided as necessary throughout the special category spaces and one shall be placed close to each exit from such spaces. |
| (e) | Fire-extinguishing equipment. |
There shall be provided in each special category space—
| (i) | a number of hydrants with hoses and dual-purpose nozzles of an approved type so arranged that at least two jets of water each from a single length of hose not emanating from the same hydrant may reach any part of such space; |
| (ii) | at least three water fog applicators; |
| (iii) | one portable applicator unit complying with the provisions of Regulation 7 (d) of this Chapter, provided that at least two such units are available in the ship for use in such spaces; and |
| (iv) | such number of portable fire extinguishers of an approved type as the Administration may deem sufficient. |
| (i) | There shall be provided an effective power ventilation system for the special category spaces sufficient to give at least 10 air changes per hour. The system for such spaces shall be entirely separated from other ventilation systems and shall be operating at all times when vehicles are in such spaces. The Administration may require an increased number of air changes when vehicles are being loaded and unloaded. |
| (ii) | The ventilation shall be such as to prevent air stratification and the formation of air pockets. |
| (iii) | Means shall be provided to indicate on the navigating bridge any loss or reduction of the required ventilating capacity. |
Additional provisions applicable only to special category spaces above the bulkhead deck
In view of the serious loss of stability which could arise due to large quantities of water accumulating on the deck or decks consequent on the operation of the fixed pressure water-spraying system, scuppers shall be fitted so as to ensure that such water is rapidly discharged directly overboard.
| (h) | Precautions against ignition of inflammable vapours. |
| (i) | Equipment which may constitute a source of ignition of inflammable vapours and in particular electrical equipment and wiring, shall be installed at least 450 millimetres (18 inches) above the deck, provided that if the Administration is satisfied that the installation of such electrical equipment and wiring below this level is necessary for the safe operation of the ship, such electrical equipment and wiring shall be of a type approved for use in an explosive petrol and air mixture. Electrical equipment installed at more than 450 millimetres (18 inches) above the deck shall be of a type so enclosed and protected as to prevent the escape of sparks. The reference to a level of 450 millimetres (18 inches) above the deck shall be construed to mean each deck on which vehicles are carried and on which explosive vapours might be expected to accumulate. |
| (ii) | Electrical equipment and wiring, if installed in an exhaust ventilation duct, shall be of a type approved for use in explosive petrol and air mixtures and the outlet from any exhaust duct shall be sited in a safe position, having regard to other possible sources of ignition. |
Additional provisions applicable only to special category spaces below the bulkhead deck.
| (i) | Bilge pumping and drainage. |
In view of the serious loss of stability which could arise due to large quantities of water accumulating on the deck or tank top consequent on the operation of the fixed pressure water-spraying system, the Administration may require pumping and drainage facilities to be provided additional to the requirements of Regulation 18 of Chapter II of the present Convention.
| (j) | Precautions against ignition of inflammable vapours. |
| (i) | Electrical equipment and wiring, if fitted, shall be of a type suitable for use in explosive petrol and air mixtures. Other equipment which may constitute a source of ignition of inflammable vapours shall not be permitted. |
| (ii) | Electrical equipment and wiring, if installed in an exhaust ventilation duct, shall be of a type approved for use in explosive petrol and air mixtures and the outlet from any exhaust duct shall be sited in a safe position, having regard to other possible sources of ignition. |
