The Nozzleman

If fires are to be controlled or extinguished the department must pre-plan and be capable of skillful execution trained officers are essential Modern equipment is necessary But in most cases the person who actually controls the fire is a key man the nozzle Minh In firefighting know-how is vital there is no substitute for an understanding of fire behavior And an understanding of your equipment You must be able to focus this know-how on fire conditions as you find them. If you are to be a top-notch nozzle Let's start with your chief weapon the nozzle It's important to use the right tools for the job the smoothbore of the solid stream nozzle delivers a solid high velocity stream This gives you a long reach and delivers a large volume of water Both the solid stream nozzle and newer adjustable nozzles have a ball type shutoff It has nothing to do with the shape or pattern of the stream. The pattern is controlled by the forward part of the nozzle Today the most versatile nozzle is the adjustable type It can deliver patterns ranging from a wide angle stream with low velocity to a straight stream with a high velocity As a nozzle, man, you should have an idea of the mechanics of its operation With new constant gallonage nozzles your flow and gallons per minute is the same in all positions These nozzles are designed to operate at about 100 pounds nozzle pressure Most nozzles have marks or notches which serve as a guide to indicate the degree of fog? These are helpful But when you're fighting a fire the important thing is not which mark you are on But whether the fog pattern you are using is correct for the job To choose the right pattern in each situation. You must be familiar with fire behavior. This fire could go through several phases Most fires start with a small flame which may continue to spread over the fuel surface as The heat builds up there will be a flashover and if air is available through windows doors or other openings The fire will assume a steady state in Most cases this steady state will expand only if more air is made available Additional doors may be opened or the fire may go on to burn through the walls or ceilings and eventually will no longer be confined Because so many structure fires are of necessity attacked during the steady-state we're going to deal primarily with fires of this nature The temperature of the fire we have described will be in the neighborhood of 1,400 degrees at ceiling level You'll need as much protection from that heat as you can get When your line is charged, you will adjust your fog pattern to protect you from the heat But you can and should improve the effectiveness of your protective clothing by wetting down Protective clothing does an excellent job of shielding you from falling debris and heat As the nozzle none you should know the three methods of attack if The fire is small and heat accumulation is low. You will probably make a direct attack with a relatively straight stream Intense heat may force you to use either the indirect or the combination attack With the indirect attack you spray only the heated overhead The combination attack a Combination of the direct and indirect methods is accomplished by rapidly rotating the nozzle in a clockwise direction following the perimeter of the room How do you choose between the combination attack and the indirect attack on the fire ground If only one or two rooms are involved and one line will give sufficient flow The combination method will give the fastest results with the minimum amount of water This method cools the atmosphere and the heated materials at the same time consequently large volumes of steam are generated and the fire is blacked out quickly as compared with the combination method the indirect attack continues steam production over a somewhat longer period of time This can be used to advantage in a complex situation where several lines are necessary and their coordination is a problem In any attack, the maximum heat absorption of water is utilized only when the water is converted to steam Don't confuse an indirect attack on a fire with indirect results Fire may follow various channels in spreading from one room to another area Steam generated by either an indirect or a combination attack may follow the same channels and control the fire This is a valuable indirect result As a nozzle, man, you need to know something about thermal balance what it is and how it can help you Almost every fireman has approached a fire which he could see clearly But just as soon as his fog pattern hit the interior of the room smoke and steam swirled down and his visibility was gone What happened? The hot air smoke and gases are lighter than cold air in an undisturbed Situation these products of combustion will be evenly distributed at the top and the cooler fresher air will be at the bottom The atmosphere in this room is in thermal balance Just as soon as your fog hits the heated gases near you they cool the cooled gases drop and Thermal balance is upset this causes circulation of fire gases and smoke which limits both visibility and entry 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 to 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 shutdown. The fire will be back to its original intensity However if you have used a penetrant foam for knockdown 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 or 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 its complex That's why you need to observe actual firefighting attacks If You arrived 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 gases? 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 fuel 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 twenty to thirty 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 two 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 spotfires 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