Getting cats out of trees remains a simple task for firefighters compared to what will be discussed today. The fire service industry faces multiple challenges from day to day and from call to call. Firefighting remains a great deal more than hanging out and resting at the firehouse. Firefighting has a broad spectrum, for example, responding to motor vehicle incidents all the way to responding to large gasoline truck fires. In the scenario I will to provide, in greater detail, when it comes to fighting different types of flammable liquid fires and the appropriate approach that should be taken to effectively extinguish gasoline fires.
Gasoline fires remain extremely different to each other, similar to various incidents in which firefighters respond to day to day. The scenario exists in the town of Yonkers New York. The scenario contains an 8,900-gallon gasoline tanker overturned on a New York Thruway right after midnight. The first arriving unit found the gasoline burning with another vehicle involved. The other vehicle crashed into the gasoline tanker causing the gasoline to ignite. The tanker remained beneath a bridge bringing difficulties for responding units.
Prior to this call the YFD had placed new master streams that were capable of flowing large amounts of water/foam for situations such as this. The new master streams were capable of flowing 400 gallons per minute with a 150-foot reach. Also, the exposures involved in this scenario caused multiple roads to be shut down for safety of the commuters and other traveling the thruway. When dealing with Aqueous foams agents a special class to enhance the water must be chosen (Gann & Friedman, 2015). When one is adding certain types of additives into water, it is important to distinguish the additives.
The correct chemistry should be used to adequately suffocate or extinguish the burning liquid (Gann & Friedman, 2015). The nozzle needs to be aerated to ensure that the agent will create the foam needed (Gann & Friedman, 2015). The agent should be the correct mixture to ensure that a foam blanket can be formed over the flammable liquid to suffocate or smolder the flammable liquid that has been ignited (Gann & Friedman, 2015). The Large pool or spillway of the flammable liquid must be considered a Class B fire.
Numerous 2-dimensional fires or spills can be measured by the length and the width of the spill or pool (Gann & Friedman, 2015). Considerations when applying the foam on the fire should be kept in mind, as the wind speed can affect the application just as blowing the layer of foam off of the pool or spill. Numerous additives that will affect the foaming operation can be the chemicals involved and break down the foam resulting in foam structure break down (Gann & Friedman, 2015). Elevated heat can affect the foam as it can vaporize the water when applications onto the spill (Gann & Friedman, 2015).
When using foam application always create a thick layer to ensure the burned area will not ignite the foamed area that has been confined already (Gann & Friedman, 2015). The scenario that YFD encountered that day was extremely effective in the process of applying the foam early on into the scenario. The scenario did not describe which type of foam the used, AR-AFFF or AFFF would be my guess though. With the magnitude of the spill that existed, it would be a decent suggestion to start with. The AFFF remains perfect foam for flammable liquid fires with the exception of alcohol based liquid.
The fuel vaporization on the spill seemed to be contained quickly for containment to be achieved quickly before a major malfunction occurred. With the vaporization cut off by the application of foam it basically suffocated the fire. Based on the scenario the YFD has no choice, the fire had to be to extinguished. The fire remained underneath a major thruway, beneath a bridge, which could cause the structural integrity of the bridge to become compromised if any flammable liquid remained during the burn off process.
The new nozzle used, put into tactical usage on the trucks remained a tremendous benefit for the department. Supplying the flammable liquid fire with multiple master streams greatly benefitted the department. The application gave the first arriving unit a quick attack and to apply foam on the spill in a timely manner for extinguishment and confinement. The rate of 12 gallons a minute per master stream the application used nearly 650 gallons of concentrate to contain the tanker fire. The master stream nozzle and the reach stayed a plus for containment.
The fog application of the master stream created a blanket for extinguishment. The aerated fog pattern gave the foam the correct mixture to form a blanket over the spill for extinguishment. The gasoline industry has changed over the years. Present time a person will encounter alcohol based fire where the need of AR-AFFF foam will be used in the event of a tanker fire or flammable liquid spill. The AFFF foam will not serve the purpose for burning fuel spilled due to the alcohol content used in the mixture. The AR-AFFF foam will provide a longer resistance in the event of vapor suppression of non-ignited fuels.
The ethanol blended gasoline used in today’s vehicles will be seen increasingly on the roadways and precautionary measures should be taken by firefighters to ensure the apparatus stays equipped to the correct foam. The AR-AFFF would be the choice of foam for ethanol based fuel due to the resistance of alcohol based foam. The AFFF application will cause reaction and could cause the fire to burn throughout the spill. The YFD did a tremendous job with the tactical side of the scenario. YFD extinguished the fire tactic fully and caused no injuries while on the scene.
The only other option that may have been a consideration would be let the flammable liquid burns itself off. The consideration did not exist as a choice due to the exposure of the bridge. The bridge may have collapsed and caused further issues during the scene. The option of flammable liquid burn off could become an option would be, if the area has nearby streams or lakes when the contamination of runoff remains an issue. Often time this option must be used to prevent contamination of surrounding water systems or other situations. Consideration of this tactic should be thought through carefully and handled accordingly.