38 SAFETY OF LIFE FROM FIRE AT SEA. 



Upon the discovery of fire efforts are first made to close the openings to the 

 compartment involved and then open the valve on the steam-pipe to it, the smother- 

 ing effort of the steam being depended on to extinguish the fire. Experience has 

 demonstrated, however, that it is frequently impracticable or impossible to close the 

 compartment, as instanced in the burning of the Volturno aforementioned, under 

 which condition the steam has practically no extinguishing effect, and even when 

 confined the steam is not a very effective extinguishing agent, especially if used 

 after the fire has gained considerable headway. In fact, tests have befen made on 

 shore where combustible materials were completely burned, although enclosed in 

 an atmosphere of steam. Steam pipes were commonly provided in the picker rooms 

 of cotton and woolen mills for fire-extinguishing purposes about thirty years ago, 

 but their practical utility has over and over again been found so small that their use 

 has been abandoned. The effect of steam blown into a closed compartment, like 

 the hold of a ship, would doubtless be greater than in a picker room, but we believe 

 that its real efficiency is greatly overestimated in the popular view. 



Steam will damage a valuable cargo as much as water and, besides, it is very 

 wasteful. In one case of fire on an Atlantic liner, in which cotton was burned in 

 the holds, so much steam was used that the engine nearly stopped, thus preventing 

 the vessel from rushing to the nearest port for assistance. Furthermore, since the 

 steam is applied only to the holds, it forms at best only a partial protection. 



Gases. — Several gases which are non-supporters of combustion have been used 

 to a limited extent to replace steam, and these have proven to be good fire-ex- 

 tinguishing agents when the fire is confined. The gases are not as effective as 

 water, however, in absorbing heat and have but little cooling effect on the fire. 



Carbon dioxide gas (CO2) is compressed to liquid form in steel tubes containing 

 about 40 pounds, and these are connected to the pipe distribution system. While 

 it can be made on shipboard, the process would be too complicated for quick use and 

 also quite expensive. 



The use of the gas is objectionable since it causes asphyxiation, although a 

 person could live a limited time in an atmosphere containing 15 per cent of gas, while 

 40 per cent is necessary to extinguish fire. A 40-pound tube is required for each 

 1,000 cubic feet of air space. This objection is not serious, however, as the gas is 

 proposed for use in the holds only, and there is small possibility of any of the 

 crew being in there when on fire. The gas is non-injurious to merchandise. 



The arrangement of the pipe distribution system is similar to that for steam 

 previously described. Since the gas is heavier than air the outlets are placed at the 

 ceiling, and in operation the gas will descend through the cargo, filling crevices and 

 interstices which could not be reached by water except by flooding. When the neces- 

 sary amount of gas has entered the compartment the fire is extinguished, and the 

 gas can then be removed by an air pump piped to the bottom of the hold. 



Another gas is sulphur dioxide (SO2), and this is being exploited to-day for 

 this use. It is said to have been in use for years and to have successfully ex- 

 tinguished fires at sea. An apparatus is on the market for making the gas on 



