Principles of naval engineering - Historic Naval Ships Association

PRINCIPLES OF NAVAL ENGINEERINGCONTROL OF FIRESFire is a constant potential hazard aboardship. All possible measures must be taken toprevent its occurrence or to bring about itsrapid control and extinguishment. In many cases,fire occurs in conjunction with other damage,as a result of enemy action, weather, or accident.Unless fire is rapidly and effectively extinguished,it may cause more damage than theinitial casualty and it may, in fact, cause theloss of a ship even after other damage has beenrepaired or minimized.Fires are classified according to the natureof the combustible material. Class A fires arethose which involve ordinary combustible materialsuch as wood, paper, mattresses, canvas,etc. Class B fires are those which involve theburning of oils, greases, gasoline, and similarmaterials. Class C fires are those which occurin electrical equipment. Class D fires are thosewhich involve certain metals such as magnesium,potassium, powdered aluminum zinc,sodium, titanium, zirconium and others.Class A fires are extinguished by the useof water. Class B fires are extinguished chieflyby smothering with foam, fog, steam, or purpleK powder dry chemical agent (as appropriatefor the particular fire). Class C fires arepreferably extinguished by the use of carbondioxide. Because of the danger of electric shock,a solid stream of water must never be usedto extinguish a class C fire. Class D fires arepresently extinguished by using large amountsof water. Personnel safety is of prime concernwhen fighting this class fire; toxic gasses,possible hydrogen explosions, splattering ofmolten metal, and intense heat are prime characteristicsof this type of fire. Presently,intensive research is being conducted on bettermethods of attack and more suitable extinguishingagents.The organization of a firefighting party dependson the number of men available. Figure4-1 shows the basic organization of a smallfirefighting party, and figure 4-2 shows thebasic organization of a large firefighting party.At times it is necessary for one person to performmore than one of the indicated duties, andthis fact is taken into consideration in organizingfirefighting parties.One man in the firefighting party must bedesignated as the groupor scene leader (investigator).His first duty is to get to the fire quickly;he investigates the situation, determines the