BLITZING How to Make It Work for the Rural Fire
STRATEGY AND TACTICS
OF the many strategic decisions that the fire officer must face, the rural structure fire certainly involves significant ones. Large general stores, rambling farm complexes, and stately churches— these are the traditional images associated with rural America. When we add the large “district” school buildings and condominiums of modern rural living, we find that large fire flow demand is not uncommon to the rural firefighter.
When we combine these fuel loads with the delays caused by long response distances, we can understand why many rural fire departments develop a blitz attack capability. But when is blitz right and when is another strategy—such as protecting exposures—more appropriate?
Let us begin by agreeing that “blitz attack” means the immediate application of a flow that will unquestionably overpower the fire. This will usually mean a flow of at least 200 gpm for a dwelling fire, and up to 1,000 gpm or more for a larger structure, applied through a single fire stream. (See “Blitz Attack Really Works, Test Fires in Buildings Show,” FIRE ENGINEERING, April 1977, for a discussion of single-stream advantages.)
The procedures of developing blitz fire streams will be the subject of a future article. For now, let us agree that pre-connected master stream appliances and pre-connected hoselines of 1 ¾ inches to 2 1/2 inches can be easily arranged to provide flows of these magnitudes in a speedy format.
Perhaps we should ask: What is the difference between the rural versus the urban fire? It is obvious that the gases, flame temperatures, and physical properties of a fire have no relation to whether their setting is rural or urban. A “toosmall” attack line is just as ineffective for a rural attack crew as it wpuld be for their downtown colleagues. Fire is a rate type of problem—it demands a rate type of solution. The utilized fire stream must absorb heat at a faster rate than the fire is releasing it.
So, we must agree that the difference between the rural and urban fire is in our resources, not in fire behavior. The water supply resource must be even more effectively managed, if that is possible, in the rural setting. In some departments, this has led to the use of small lines as a well-intentioned attempt at conserving water supply. Running out of water during a fire may not be the greatest firefighting sin, but it certainly ranks among the more obvious to the public we serve.
Managing resources effectively, however, is not the same as hoarding resources. For the rural firefighter (as for the urban), the most efficient fire stream is that which extinguishes the fire with the fewest total gallons of water (not to be confused with the fewest gallons per minute).
During the period of 1978 to 1980, I became involved in a series of training evaluations to determine the water supply requirements for structural fire attack at various flow rates. During early 1978, work with the Milo, ME, Fire Department proved that an attack on a fire in a fully involved four-room cottage with a 1 1/2-inch handline required 300 gallons for knockdown when applied at a rate of 100 gpm. The same knockdown, when applied by a 2 1/2-inch handline delivering 250 gpm, required a total of only 150 gallons.
Further work at a training exercise in Levant, ME, during that year showed that a fire in a fully involved farm house was darkened down twice with 400 gallons of water from a 2 1/2-inch handline at 250 gpm, allowing smaller handlines to be stretched and interior firefighting begun.
This work culminated in a training exercise at Hampden, ME, in April 1979, when photographic slides were taken to document the progress of a 250-gpm master stream on a fully involved house fire. The 250-gpm rate was selected because it was the specified minimum tank-to-pump flow rate capability for a pumper, according to NFPA 1901, Automotive Fire Apparatus. Hampden’s test proved to be the most dramatic because we had recorded photographic evidence of the effectiveness of the blitz method in managing a limited water resource.
Further work during 1980 provided the finishing touches to the method, with some associated guidelines for managing the initial attack fire stream:
- Choose a position that will place the handline (nozzle) between the fire and most of the exposed portions of the structure (given no life hazard). Try to gain the position that offers most access points from a single spotting. Avoid pushing the fire into uninvolved areas, vertical arteries (stairways, etc.), or into suspected life areas.
- When multiple level access points are available, start by directing the stream at the lowest level of fire and move first to the sides, then upward, taking advantage of steam expansion and convection currents to assist in attacking above as you advance.
- Be constantly aware of your progress. If you are succeeding, it will begin to be obvious within 15-20 seconds. If no change in fire volume is seen at this point, shut down and revise your position or perhaps even the strategy. Note that at 500 gpm a 20-second burst will have “wasted” less than 200 gallons of water, should you decide that the blitz is not working at that point and switch to protecting exposures with small lines.
- Provide supply lines for continuous flow duration. Your rural water supply method should be flexible enough to permit immediate blitz capability with subsequent smooth transition into a reliable and sustained attack. (See “Rural Hitch,” FIRE ENGINEERING, December 1984.)
- Manage any fire stream with an eye to thermal balance. After
- darkening down, ventilation will continue because of interior heated surfaces and convective movement of steam or heated water vapor. However, continued deluging of the space at this point will often make interior work more difficult because of slowed ventilation currents as you over cool the interior environment.
- After knockdown and steam generation comes water damage control. Nozzle handling is a skill enhanced by well-directed training. Such training is the true route to conserving water resources—not use of smaller lines. High-rate/ short-duration applications achieve earlier knockdown, resulting in reduced water usage.
- After using the blitz for a knockdown, prepare to move in. Recall the adage: “You’ve gotta’ get in to win!” Assess the structural integrity and, if safe, move in for mop up.
- Usually, a line should be advanced with the nozzle shut, but readied. This conserves water, increases safety on slippery surfaces, and affords a chance to assess one’s progress toward extinguishment. (One exception would be when a protective spray is needed, such as in fighting flammable liquid fires.)
So, now you have it—a blitz attack methodology based on nearly three years of training fires, accompanied by fireground successes. Your own success or failure will depend largely on your ability to assess when blitz is appropriate. Training ground experience, combined with general fireground experience, will help the fire officer to select the optimum fire stream size and access point for almost any fire.
Meaningful training fires must be taken beyond the level of water-squirting sessions. Try various methods, and compare them objectively. Training fires provide an opportunity to measure and assess results objectively under unhurried conditions—a situation seldom found during a real-life fire response.
In a future article, we will look at some methods of arranging apparatus in a manner that enhances high flow-rate attack capability.
