(3) In every ship of Class I engaged in the carriage of dangerous goods there shall be provided a fixed gas fire-extinguishing system complying with the requirements of Schedule 4 in Merchant Shipping Notice MSN 1666 to protect every cargo space, or with a fire-extinguishing system which can be shown to provide equivalent protection for the cargoes carried (other than special category spaces and spaces where a fixed pressure water-spraying system is fitted in accordance with paragraphs (4) and (5)).
(4) In every ship of Class I there shall be provided in each special category space of a fixed pressure water-spraying system complying with the requirements of Schedule 3 in Merchant Shipping Notice MSN 1666. The Secretary of State may permit in lieu of such a system any other fixed fire-extinguishing system provided that it has been shown by full-scale 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.
(5) In every ship of Class I there shall be provided in each cargo space (other than a special category space) intended for the carriage of motor vehicles with fuel in their tanks for their own propulsion a fixed pressure water-spraying system complying with the requirements of Schedule 3, or a fixed gas fire-extinguishing system complying with the requirements of Schedule 4 in Merchant Shipping Notice MSN 1666.
(6) In every ship of Class I there shall be provided in each open ro-ro cargo space having a deck over and in each space deemed to be a closed ro-ro cargo space not capable of being sealed, a fixed pressure water-spraying system complying with Schedule 3 in Merchant Shipping Notice MSN 1666.