FIRE OPERATIONS AT STORAGE BUILDINGS
BY GERARD J. NAYLIS
A fire department`s ability to combat fires in warehouses, distribution centers, and storage buildings is strongly influenced by the nature and makeup of the commodities in the building and the storage arrangement of those commodities. Changes in business practices have resulted in larger and larger operations coming under a single roof while the products and commodities have been pushed higher and higher.
More and more businesses are realizing the need to contain costs to maximize their bottom line. One of the avenues they have taken to achieve this is to consolidate their operations from many small facilities to a few very large warehouses. Where we once had a grocery store of 10,000 square feet and warehouses of 80,000 square feet, we now have retail stores of 100,000 square feet and distribution centers of one million square feet or more. Storage heights that peaked at 12 feet around the 1950s have been rising steadily to the point where storage heights of 40 feet are now commonplace. Automation has also compounded the firefighter`s problem by introducing pick racks, flow-through racks, multirow racks, and conveyor feeds.
Older warehouse buildings are still in use in many of our nation`s cities. These buildings are usually multistoried and have freight elevators that move the storage up and down. New warehouses and distribution centers found in suburban and rural areas are typically spread out on a single level. But these two very different types of buildings have two things in common: a large concentration of combustibles on a single, wide-open area.
Further complicating the fireground attack have been changes in construction materials and methodologies. The widespread use of plastics as construction material and the expansion of lightweight construction present firefighters with significant challenges.
AUTOMATIC AND FIXED FIRE PROTECTION
Automatic and fixed fire protection includes all systems designed to control the spread of the fire and, in some cases, effect extinguishment. It would include automatic sprinkler protection (both ceiling and in-rack systems), deluge systems, preaction systems, and chemical agent extinguishing systems (both gaseous and liquid). Among other components of fixed fire protection are the following: fire doors, fire shutters, curbing and diking, ramps, draining systems, blowout panels, ventilation systems, and process shutdown de-vices that include power interlocks.
Interestingly, all of these systems and their components were installed to make the job of attacking and controlling these fires easier and safer. Unfortunately, human error and lack of proper maintenance cause many of these system components to fail. That is the reason preincident planning is one of the most critical, but usually the most often overlooked, function of a fire department.
Some of the largest warehouse and distribution center fires that have occurred were helped along by improperly shut sprinkler control valves; inoperable deluge or preaction valves; fire doors and fire shutters that couldn`t close because they were blocked open and couldn`t close properly; or missing curbing, diking, and ramps, which allowed flammable liquids to spread on the surface and throughout the building un-checked.
FIRE ATTACK CONSIDERATIONS
Because storage buildings tend to be large, open structures–whether spread out on a single level, as may be found in suburbia or rural areas, or stacked in multistoried buildings in the older cities–fires in these buildings will spread quickly. While there is hope that the automatic sprinklers will control the fire, you must realize that you could be faced with a significant-size incident on arrival. The fire service must recognize that automatic sprinkler protection can do its job only if the design parameters are adhered to. Unfortunately, that all too often is not the case.
Water Supply
Since this is the case, the first-in companies need to decide which method of attack to employ. The first control consideration, therefore, must be the water supply: Is it adequate and reliable? Ask yourself, How much water will I need, and how quickly will I be able to deliver it to the fire? At these large fires, water and time are your two most valuable commodities. The improper allocation of either one usually results in the total loss of the building and its contents.
Of course, the quickest method of putting water on the fire is to use the existing distribution piping of the automatic sprinkler system. An assignment that should be performed at one of these buildings is to have one of the first-in engine companies reinforce the sprinkler system. This single action could literally spell the difference between saving and losing the building. Do not be lulled into the mistaken belief that you should abandon this practice and instead lead with an attack hoseline before the sprinkler system is reinforced. The delay in deploying the hand-line likely will be enough to give the fire the head start it needs to win the battle and the war. In the end, the building will be a total loss.
How much water is enough? You need to have a water supply that will meet the design requirements of the sprinkler system, provided, of course, that the sprinkler system is designed for the fire challenge of the occupancy. This would include the added supply needed for any in-rack sprinklers. In addition, you should have water to feed fire department hose streams. Code requirements normally call for 500 gpm. In some cases, that figure is lowered to 250 gpm, as is the case with Early Suppression Fast Response (ESFR) sprinklers.
For these types of buildings, it is not uncommon to find water supply requirements of 2,000 gpm or more. Although this may sound like a lot of water, remember that if the sprinkler system does not contain the fire, you will find yourself needing as much as triple this volume just to perform exposure control. Ask yourself where you would get a water supply of 6,000 gallons per minute or more and enough water to sustain that supply for several hours. Perhaps this is a good time to have your water supply officer do some preplanning just in case.
Sprinkler System
The second action is to make sure that all of the building`s sprinkler control valves are wide open. Why? you may ask. For any number of reasons. A well-intentioned but misinformed or misguided employee may have turned the valve off, thinking he was doing the right thing. Or the system could have been down for maintenance or testing. Or maybe the valve was turned off by the person who set the fire to make sure that the results of his efforts are realized. Regardless of the reason, if the valve is closed, all that water you thought you were pumping and putting on the fire may be slamming into a closed valve and doing nothing. Hopefully, these valves will be accessible from the exterior of the building and can be checked without endangering firefighters. However, if the valves are located inside the building, take adequate precautions to perform this task safely.
Building Construction
The third fire attack consideration is the building`s construction. If the warehouse is multistoried and located in an inner city, the construction could be of heavy reinforced concrete or of ordinary construction. Prior knowledge of the building`s construction type is essential and is paramount to firefighter safety.
Most single-story warehouses and distribution centers are lightweight all-metal building systems. These structures may have several courses of concrete block on top of which are metal sandwich panels that rise up to a metal roof deck. Most of these buildings employ lightweight open-web bar joists that fail rapidly when exposed to fire. Although economical from a building construction cost standpoint, these building systems almost certainly dictate an exterior and defensive attack in a developed fire. When dealing with a building that has exposed structural steel, direct one or two hose streams at the roof from inside the building to cool the steel members. This action may forestall the failure of the steel and the collapse of the roof if the fire is still in the early stages of development.
Size of Fire vs. Resources
The fourth consideration is the size of the fire on arrival vs. the resources available to you. If the fire is relatively small and is being controlled by the sprinkler system, and you have sufficient staffing on scene, you may elect to work the fire by removing the storage and attacking the seat of the fire while leaving the sprinklers operating. However, if the fire has progressed to a point where the sprinklers have been overwhelmed and the fire is spreading rapidly, you need to draw the line in the sand and determine then and there where you are going to make your stand. Essentially, you go on defense and identify the exposures you are going to protect.
Collapse Potential
The high ceilings found in these buildings may allow for fire department personnel to enter the building and venture deep within, not realizing that the open-web bar joists and steel deck roof typically found in newer buildings have been subjected to high temperatures. These building components were never intended to withstand the extremely high temperatures of a fire and will lose their strength quickly. So, size-up becomes even more critical to ensure firefighter safety. Ascertain how long the fire has been burning and whether the sprinkler system is controlling the fire. Look for indications of the roof`s stability and whether you have an imminent collapse potential.
Breathing Air
A fire in one of these buildings, even a contained and controlled fire, will generate a tremendous amount of smoke. Be sure to consider breathing air and SCBA cylinders. Expect this to be an extended operation that will require the use of numerous air cylinders.
A generation ago, leading fire service texts identified time of day as a major consideration. Today, that is not as significant because many warehouses and distribution centers operate around the clock to meet just-in-time (JIT) requirements of suppliers, wholesalers, and retailers. What this does mean, though, is that there may be life hazards present that we would not have expected previously.
The ability of fire streams to penetrate the fire and attack the seat is another consideration that the incident commander must take into account. Unless the streams are able to penetrate to the seat of the fire, you are wasting your water. Remember the rule from consideration number one: The improper allocation of water will usually lead to the total loss of the building and its contents. You may need to write off a portion of a building or complex to save another–as an example, you may need to use large-caliber streams to protect an uninvolved portion of the complex while permitting the fire to rage in the involved section. While this may seem ludicrous to the casual observer, learned fire tacticians will readily recognize the wisdom of this action.
Weather Conditions
Always consider weather conditions, especially at large-scale operations such as these. Wind speed and direction are perhaps the two most important weather factors to consider. Very often, warehouses and distribution centers will have numerous doors on multiple sides to facilitate the shipping and receiving of goods. These doors could be open at any time of year, allowing a clear path for air to enter or smoke to be vented. Depending on the conditions at the time of the fire, this may prove to be a help or a hindrance. If, for example, the wind is such that it pushes the smoke away from the unburned section of the building and allows you to set up the proper exposure protection lines, then the wind is a beneficial factor in the firefight. If, however, the wind is blowing into the building and helping to spread the fire, then the wind condition will hinder your ability to control the fire.
Ventilation
As in all fires, ventilation is a key consideration. The question to address is, How and where do you commit firefighting personnel to effect this operation, particularly roof ventilation? The answer to this question depends largely on two factors–building construction and the extent of the fire. A review of the structural stability of newer lightweight all-metal building systems under fire conditions reveals a substantial potential for collapse, often without warning. Simply stated, these building systems were never designed to withstand their structural loads under extreme fire conditions. Tremendous reliance has been placed on the successful operation of the automatic sprinkler systems to keep ceiling temperatures at a safe level to prevent the building from collapsing. This strategy works so long as the occupancy`s fire load does not exceed the design of the sprinkler protection.
Resources
The last factor is resources, namely personnel and apparatus. The availability or lack of personnel or apparatus will most certainly impact the strategy and tactics employed. Therefore, it is critical to perform an adequate size-up immediately on arrival. Although time of day is no longer a critical factor from the standpoint of hours of operation and the ability to gain access to the building, the time of day will have an impact on volunteer departments and their ability to turn out large reserves of personnel. Staffing levels in most career departments have already been reduced to a point that many consider dangerously low, so in either case a well-involved fire will dictate an immediate call for additional assistance.
We would like to think that mutual-aid companies can be on scene in just a couple of minutes. Unfortunately, you need them now, and they have to travel to get to you. In reality, it can take 10 minutes or longer for even the first mutual-aid company to make it to your scene. This time lapse will allow the fire to grow. Therefore, you must allocate your resources to contain the fire as best you can, using the resources available at the time. However, history has shown that if the fire is overwhelming the automatic sprinkler system, the fire department will at best be able to contain the fire to the four main walls of the building. So exposure control and protection may in fact be the primary objective. This, of course, should be considered in conjunction with other available building protection such as fire doors and shutters, construction features, and site layout.
Fires in warehouses, distribution centers, and storage buildings present the fire service with serious challenges not really seen in other occupancies. Firefighters must educate themselves about the construction, occupancy, protection, and exposures these buildings represent. A preincident plan is of vital importance to fire suppression activities. Adequate resources must be contemplated well in advance of the incident if the fire service is to have any success in combating a fire in one of these buildings.
GERARD J. NAYLIS has been a volunteer in the Bergenfield (NJ) Fire Department for 26 years and previously had been a career firefighter in the Atlantic City (NJ) Fire Department for 10 years. He is the second vice president of the International Association of Arson Investigators, a member of the Arson Conference Planning Committee at Rutgers University in New Jersey, and a member of the Bergen County Juvenile Fire Prevention Program Advisory Board.
