C^S SAFETY OF LIFE AT SEA 



be at least two pipes, one of which shall be fitted in the forward part and oi 

 in the after part; the pipes shall be led well down in the space as remote 

 possible from the shell. 



(c) (i) When carbon dioxide is used as the extinguishing medium in cargo 

 spaces, the quantity of gas available shall be sufficient to give a minimum 

 volume of free gas equal to 30 per cent, of the gross volume of the largest 

 cargo compartment in the ship which is capable of being sealed. 



(ii) When carbon dioxide is used as an extinguishing medium for spaces 

 containing boilers or internal combustion type machinery, the quantity of gas 

 carried shall be sufficient to give a minimimi quantity of free gas equal to the 

 larger of the following quantities, either 



(1) 40 per cent, of the gross volume of the largest space, the volume to 



include the casing up to the level at which the horizontal area of 

 the casing is 40 per cent, or less of that of the space concerned; or 



(2) 35 per cent, of the entire volume of the largest space including the 



casing; 

 provided that the above mentioned percentages may be reduced to 35 per 

 cent, and 30 per cent, respectively for cargo ships of less than 2,000 tons 

 gross tonnage; provided also that if two or more spaces containing boilers or 

 internal combustion type machinery are not entirely separate they shall be 

 considered as forming one compartment. 



(iii) When carbon dioxide is used as an extinguishing medium both for 

 cargo spaces and for spaces containing boilers or internal combustion type 

 machinery the quantity of gas need not be more than the maximum required 

 either for the largest cargo compartment or machinery space. 



(iv) For the purpose of this paragraph the volume of gas shall be calculated 

 at 9 cubic feet to the pound (or 0-56 cubic metres to the kilogramme). 



(v) When carbon dioxide is used as the extinguishing mediima for spaces 

 containing boilers or internal combustion type machinery the fixed piping 

 system shall be such that 85 per cent, of the gas can be discharged into the 

 space within 2 minutes. 



{d) Where a generator producing inert gas is used to provide smothering 

 gas in a fixed fire smothering installation for cargo spaces, it shall be capable 

 of producing hourly a volume of free gas at least equal to 25 per cent, of 

 the gross volume of the largest compartment protected in this way for a 

 period of 72 hours. 



{e) When steam is used as the extinguishing medium in cargo spaces the 

 boiler or boilers available for supplying steam shall have an evaporation of 

 at least 1 pound of steam per hour for each 12 cubic feet (or 1 kilogramme for 

 each • 75 cubic metres) of the gross volume of the largest cargo compartment 

 in the ship. Moreover the Administration shall be satisfied that steam will 



Ch. 2 



