Training Notebook | BY TIM FRANKENBERG AND BRIAN S. GETTEMEIER
LIKE IT OR NOT, if our company arrives at the scene of a working fire in a structure with an active sprinkler system, we are second due. One of the primary tasks of a second-due engine company is to support the initial fire suppression efforts, primarily establishing a water supply.
The basic fire attack model is to accomplish three tasks:
- Locate the fire.
- Confine the fire.
- Extinguish the fire.
The sprinkler system discovered the fire, the alarm system activated, and containment operations began—all before we were even alerted about a potential fire. If the sprinkler system gets overrun by fire, the chances of the fire department saving the structure through manual efforts is significantly reduced.
- Firefighter Training Drill: Locate the FDC
- Fireground Operations Using Fire Department Connections (FDC)
- Firefighter Training Drill: Fire Department Connection Identifications
Establishing a Water Supply
One reason initial companies should consider connecting to the fire department connection (FDC) is because the FDC typically enters the sprinkler system above the mainshutoff valve (photo 1). In the event the sprinkler is shut down initially, due to an impairment, water supply issues, an underground partially closed, or maliciously through an arson event, the fire department will be able to bypass the closed valve and begin suppression efforts prior to entering the building.
Depending on the size of the structure, it can take companies several minutes to locate the fire and identify the best access routes for the hoselines—and even more time to get firefighting efforts into place. The sprinkler system knows where the fire is and can begin operations right away. Statistically, the number one reason for sprinkler system failure is a shut valve. The National Fire Protection Association (NFPA) report “U.S. Experience with Sprinklers” indicates that as much as 64% of the sprinkler failure rate is due to a closed valve.1
Firefighters must know how the sprinkler systems are fed to a structure. In the event a sprinkler system has a fire pump, you must use caution to avoid stealing the water intended to supply the fire pump. For example, a crew should understand whether they are connectingto a municipal fire hydrant vs. a private fire hydrant owned and maintained by the property owner. If a company inadvertently connects to a fire loop that is feeding the sprinkler system, that water is no longer being supplied to the sprinklers.
Thorough engine company inspections and preplanning efforts are necessary. This is how you can identify what structures in the area have fire pumps. You’ll need to make sure you have answers to the following questions:
- Where is the pump located?
- Is the water supply on a municipal system or a fire protection water tank?
- If there is a water tank, how much water is available?
- When you arrive on scene, will someone need to confirm the fire pump is running?
- If it is not running, do you know how to manually start it?
One way to quickly identify whether a building has a fire pump is to look for a test header. The test header will usually be just on the other side of the wall of the fire pump (photo 2). It is important to ensure crews recognize the difference between a pump test header and the FDC inlet.
In most cases, a municipal system supplies a wet pipe system. Your apparatus will serve as the fire pump that takes over the sprinkler supply. The pressure boost will enhance the sprinkler discharge pressure and gallons per minute (gpm) at the open sprinklers. Think of the typical sprinkler as a half-inch smooth-bore nozzle. As you apply more pressure to that nozzle, the sprinkler discharges more gallons per minute to help confine the fire.
You must supply all the available inlets to the system involved. Your supply lines should be as short as possible to maximize the pressure and gpm entering the building. Crews must consider the structure’s collapse and radiant heat zones when positioning the apparatus. A hydrant should be located within 100 feet of the FDC, with the pumper as close to the source as possible (photo 3). For systems equipped with 2 1/2-inch inlets, the water will be better supplied through a 3-inch supply line vs. a 2 1/2-inch attack line. The 3-inch line provides greater gpm with less friction loss. When supplyingan FDC system, the industry practice is setting the discharge pressure at 150 pounds per square inch (psi) unless otherwise indicated by the sprinkler system design. A placard above the FDC should be provided to indicate the design inlet pressure, in the event another pressure is called for (photo 4).
NFPA 13, Standard for the Installation of Sprinkler Systems, requires a minimum pressure of 7 psi to operate the most remote or farthest sprinkler from the supply.2 When more pressure is supplied to the system, the flow rate for the open sprinklers increases. Sprinklers follow the same trends as the construction math vs. mass theory. Engineers are designing systems for maximum performance while also minimizing material usage, which equals greater cost savings to the building owner. This math vs. mass theory eliminates some of the overbuilt factors of the older systems that provided us with additional margins of error.
Locating the Fire Department Connection
Companies must identify where the FDC is located. Once again, preplans to assist in locating the FDC are imperative for efficient operations. Proactive planning by code officials helps with quickly identifying the FDC location beyond the code required sign. For example, in Washington, Missouri, we have the following requirements:
- FDCs are required to be on the address side of the structure.
- A water gong or bell is required to indicate water flow.
- In newer buildings, strobes must be above the FDC. This draws firefighters’ attention.
Does the FDC have a single 2 1/2-inch inlet, a typical 2- to 2 1/2-inch Siamese, or possibly a single large-diameter inlet (photo 5)? A typical FDC for a sprinkler system will have Siamese inlets (photo 6). An FDC for a standpipe system can have one to five inlets.
In cases of multiple FDCs on a structure, firefighters must identify which systems these FDCs go to (photos 7 and 8). Is it a sprinkler system or a standpipe system? Or is it a combined system for sprinklers and standpipes? When multiple occupancies are under a single roof, crews need to be able to quickly identify that they are connecting to the proper system. The maximum sprinkler design area is 52,000 square feet. Once this square footage has been exceeded, the owner will need to add a second riser. Piping is required, so the FDC supplies all of the risers in a building.
Many jurisdictions are seeing large distribution facilities that span 1 million square feet with at least 20 sprinkler risers. It is time to identify these risers, what they protect, and where their FDC is located long before a fire occurs.
The authority having jurisdiction can require more than what the standard codes require. For example, if we look at ordinary hazard (group 2), the minimum sprinkler system design is 300 to 600 gpm, plus the hose allowance. The standard firefighting flow of an ordinary group system is going to exceed 500 gpm, which also exceeds the 2- to 2 1/2-inch inlets of the FDC. Code officials can create an ordinance to require additional 2 1/2-inch inlets or large-diameter inlets to meet the flow requirements of a high-hazard facility (photo 9). It is more efficient for a crew to stretch a single large-diameter hose than a 2 1/2-inch hose to three or four inlets. It may be the only opportunity we have to save the structure.
What type of caps will we encounter: twist-off, breakaways, or locking caps (photo 10)? In the event of locking caps, is there a chance a mutual-aid company will be assigned to make the FDC connection? Will it have the proper keys to access the caps?
On arrival at the structure, the crew will need to remove all inlet covers on the system. Any failure of the clapper can result in a buildup of pressure on inlet plugs or could blow caps off dumping water. The back pressure will make it difficult, dangerous, and potentially impossible to remove the cap.
Driver operators must train so they can adapt to challenges. In cases like photo 11, a building’s sprinkler inlet has two double males, and the driver must add two double females to successfully make the connection. Another situation companies may face is inlet swivels that are not moving due to ice or rust conditions. Here are two potential fixes to this issue:
- Add a couple of twists to the hose we connect to the FDC. The procedure for this is to stand with the male coupling in the hand facing the hose and place six clockwise twists into the hose. Then, connect the hose to the FDC, and the twists will come out as the hose is threaded.
- Thread a double male into each inlet and then add a double female to create an operating swivel.
Once the sprinkler system is supplied, crews must begin identifying the location of the fire in the building and begin manual firefighting efforts to extinguish the fire. An interior fire attack in coordination with the fire sprinkler system operating is challenging but will be warranted. Lazy smoke and steam do not want to exit the building and will greatly hamper your interior visibility. Sprinkler systems discharging water will weigh down your gear, make you extremely wet, and create a little misery. It will be the equivalent of fighting a fire with opposing streams.
In many cases, the sprinkler system will require manual firefighting efforts for a successful final extinguishment. According to the NFPA, the second-leading cause of a fire sprinkler system failure is shutting off the system too soon.1 Remember, the premature shutdown of a sprinkler system can have disastrous results.
It’s time for us to prioritize the very thing fire officials advocate for: sprinkler systems. Code officials require sprinkler systems to reduce the loss of people and property—the same job our suppression companies are responsible for. As a suppression company, we need to learn to support—and not hinder—sprinkler operations. Truly supporting the sprinkler system begins with the support of the FDC.
ENDNOTES
TIM FRANKENBERG has been in the fire service for 29 years, serving the past five as chief with the Washington (MO) Fire Department. Frankenberg has a bachelor’s degree in fire protection and safety engineering technology from Oklahoma State University and a master’s degree in management and leadership from Webster University, St. Louis, Missouri. He is a certified safety professional (CSP) and a certified fire protection specialist (CFPS) with numerous state certifications. He is employed by Ameren Services as a fire protection engineer. His duties also include oversight of the facility and training at the Ameren Fire School for energy center fire brigades.
BRIAN S. GETTEMEIER has served the past 29 years of his 32 years in the fire service as a career firefighter with the Cottleville (MO) Fire Protection District, where he serves as an engine company captain. A second-generation firefighter, Gettemeier has a bachelor’s degree in fire service management from Southern Illinois University and has numerous state certifications. He teaches all-hazards classes for municipal and industrial organizations in Missouri and Illinois. He has also presented at FDIC International.
