The Nozzleman part 2

the thermal balance which most fire situations establish will not be upset if the correct nozzle pattern is used if you cool the whole room evenly the resulting air currents will ventilate the area it's easy to continue the application of fog too long what happens is that the cool water begins to condense the steam which has formed the time to shut down is just as soon as the fire has been blacked out this should happen within 30 seconds if your rate of flow and your distribution of water has been proper you should move in as soon as possible if you don't spot fires will intensify heat will accumulate and in about four minutes after shut down the fire will be back to its original intensity however if you have used a penetrant foam for knocked down it will stick to and penetrate the fuel and your spot fires will not build so rapidly special equipment such as a bypass eductor is needed to introduce the penetrate foam liquid into the hose line an adductor is designed to operate with a certain flow of water if the flow is not correct the adductor will not pick up the additive consequently the adductor and a carefully matched constant flow nozzle must be used if the adductor is marked 95 gallons per minute a 95 GPM nozzle must be used when you arrive at the scene of a fire your officer is going to be calling the signals he's the quarterback he'll figure out how to attack the fire / to attack it and make assignments for getting the job done coordinating good equipment manpower and know-how in fighting a fire sounds simple but firefighting isn't simple it's complex that's why you need to observe actual firefighting attacks if you arrive at the fire in the early stage with a low heat level a direct attack should be used keep your stream just wide enough to cover the flame area that type of fire is easy but here's a hotter situation where the indirect attack has been chosen direct your stream into the heated overhead narrow or vary the pattern to a point where it will reach the entire overhead but still keep the water which strikes the walls at a minimum with the indirect approach you want to cool only the heated fire guesses hang on to the nozzle keep your hands where you can control and adjust the pattern at all times as heat radiates from the walls and fuels steam production will continue every fire department should be equipped with self-contained breathing apparatus men who are to work with masks should not have been over exerted beforehand with the combination approach your intent is to cool and blanket with a minimum amount of water water is applied to the area of major involvement your knockdown should take 20 to 30 seconds if the fire stream is of proper size and the distribution is good shut off the nozzle to avoid over cooling which will condense part of the steam and stagnate the atmosphere if the building is safe move in as soon as possible for overhauling spot fires if it's still too hot short bursts will reduce the temperature if you can just endure the heat and steam while standing the temperature is ideal for holding the steam blanket and lifting the atmosphere in the area always keep the opening through which you entered clear this will usually give you a good supply of air you've knocked down the fire but it's not out with a good steam blanket temperatures will continue to drop for about 2 minutes at this time your steam will begin to break up or lift and spot fires will pick up to maintain the thermal balance you should use short straight stream bursts to quench those spot fires a fog stream would circulate bad air and block vision when you go in for overhaul do not spend too much time with small fires near your point of entry get as deeply as you can into the area and overhaul on your way out rather than on the way in many times a small flame which is not doing any damage will help ventilate the area remember hot air goes up and out and cool air comes in at the bottom to replace it when overhaul crews have entered the building other lines should be operated with extreme caution if not the men inside will take unnecessary punishment or may be driven out of the area here's a situation in which your approach to the fire must be through another room avoid using fog in the first room choose the correct pattern and direct your stream into the involved room this will control the fire reduce the temperature in the two rooms and maintain the thermal balance visibility and your air channel penetrant phone can be helpful in most fire situations penetrant foam offers these advantages less water fewer spot fires cleaner atmosphere as the size of the fire increases your rate of flow for control must increase whether the fire involves a residence a small structure or a larger building one basic principle remains the same a sufficient volume of water must be properly distributed larger fires require more and larger lines and their coordination becomes increasingly complex this complexity may be the chief consideration for choosing the attack to be used efficient firefighting requires both knowledge and skill the degree of efficiency is dependent on the individuals ability to apply basic principles to the situation he encounters you you