ENSURING A CONTINUOUS WATER SUPPLY

BY BILL GUSTIN

One of the first objectives of an engine company is to secure a continuous and adequate water supply. Yet, fire departments technically violate this rule every time they begin firefighting operations with just the water carried in their apparatus booster tanks. Why the difference between “textbook” theory and firefighting in the real world?

LARGER TANKS, SMALLER CREWS
Reliance on tank water is a result of two trends in the modern fire service: (1) Apparatus are being specified with larger booster tanks, and (2) many departments are experiencing a reduction in staffing.

Photo 1. Photo by Eileen Kimball.

An engine with a 750- or 1,000-gallon booster tank carries sufficient water to achieve a quick knockdown of our most common structure fire—the single-family dwelling. Given their average size, fire load, and compartmentation, most fires in private residences can be controlled with one or two 1¾-inch handlines and less than 1,000 gallons of water. This makes it tempting for an understaffed engine company to initiate an attack with its booster tank and to count on the second-due engine to lay in a supply line.

Many departments today consider themselves lucky if they can turn out with a crew of three—an officer, a driver/engineer, and one firefighter. The officer of a three-firefighter engine company can be forced into making a difficult decision: Should we stop at a hydrant and lay in our own supply line or just roll straight in, attack the fire with our booster tank, and hope that we don’t run out of water before the second engine arrives?

Laying your own supply line will secure a continuous supply of water—but at the expense of your only firefighter, if you drop him off at the hydrant to connect and charge the supply line.

Attacking a fire with only tank water is fast and impressive if it is successful. An officer who gambles on his booster tank has a lot to lose if he underestimates the potential size of a fire or the arrival time of his second engine. Running out of water can result in the fire’s spreading out of control and an apparatus’ being sent to the repair shop with melted lights and scorched paint. To ensure against this, some departments require a first-arriving engine company to lay in its own supply line whenever there is an indication of a working fire. This means that a company will begin its attack with one less firefighter if he gets off at the hydrant to connect and charge the supply line.

SPEEDING UP THE HYDRANT FIREFIGHTER
Naturally, the sooner the hydrant person can make the connection and “send the water,” the faster he can rejoin his company and assist in firefighting. One way to hasten a hydrant person’s duties is to apply a hose clamp to the supply line as soon as the engine stops at the fire. This allows the firefighter to charge the supply line without waiting for it to be connected into the pump (see photo 1). Attack hoselines are initially charged with water from the booster tank. The engineer then can take the time needed to disconnect the supply line from the hosebed, connect to an intake, and open the hose clamp.

Photo 2. Photo by Raul Torres.

A hose clamp is not recommended for use on many brands of large-diameter hose (LDH). In its place, a portable manifold can be connected into the last coupling in the hoselay. The manifold serves the same purpose as a hose clamp—it allows the hydrant person to charge the supply line without waiting for it to be connected to an intake. Then, after charging the attack hoselines with tank water, the engineer can connect a 15-, 25-, or 50-foot “pony” section of LDH from the manifold to the pump’s intake (see photo 2).

It is a sad fact that many suburban engines respond with just two people, an officer and a driver/engineer, and must combine with another engine or ambulance crew to form a working “company.” When staffing levels are critically low, an engine officer may choose to lay a supply line without committing a hydrant person. This option, called “lassoing” a hydrant, is performed by stopping an engine at a hydrant, pulling a supply hose, and securing it to the hydrant with a loop of rope or nylon webbing (see photo 3). The engine then proceeds to the fire with its entire crew and initiates an attack with tank water. The supply line can be connected to the hydrant and charged by later arriving personnel or by the engineer, who runs back to the hydrant.

Photo 3. Photo by Eileen Kimball.

Some departments use a hydrant valve that will automatically charge a supply line (without need for a hydrant firefighter) once it is connected to an engine (see photo 4). The valve allows a small amount of water to flow into the supply hose while it is being laid to the fire. The valve can be adjusted to give a company time to lay its line, depending on its length, and connect to an intake, which remains closed at this time.

Once the flow of water reaches the engine’s closed intake connection, it will start to completely fill the hose and create a backpressure at the hydrant valve. The valve senses this backpressure in the supply line and fully opens without a firefighter’s having to stay at the hydrant.

HAND-STRETCHING SUPPLY LINES
In areas with good hydrant distribution, the first-arriving engine may choose to begin an attack on a fire with tank water and then stretch its own supply line to a nearby hydrant. For example, in Chicago, hydrants are generally spaced every 300 feet. This means an engine should never be more than 150 feet from its closest hydrant.

Photo 4. Photo by Eileen Kimball.

Chicago’s pumpers are equipped with 150 feet of four-inch supply hose preconnected to an intake on the front bumper (see photo 5). This facilitates stretching to a hydrant in front of the apparatus. In Chicago, hydrants behind the pumper are reached by stretching from the main hosebed.

Unlike Chicago, most departments do not configure supply hose on a front bumper and must stretch all their supply lines from the main hosebed. In this case, it is usually easier to stretch hose to a hydrant behind the apparatus even if there is a closer one in front of the pumper, especially when the engineer has to do all the hand-stretching himself.

But, what if the only hydrant is in front of the pumper? It is still possible for an engineer to hand-stretch as much as 300 feet of three- or four-inch hose using the following technique:

• After charging the attack line(s) with tank water, estimate the amount of hose needed to reach the hydrant; then take the end of the hose out of the hosebed and lay it down at the side of the pumper, even with the back step (see photo 6).
• Now, pull the hose, hand over hand, from the hosebed as you walk 25 feet toward the rear and slightly to the side of the apparatus (see photo 7). Pulling hose hand over hand yields loops 25 feet long, each consisting of 50 feet of hose. It is somewhat easier to judge the length of the loops when the hose is in 50-foot sections. Stop when the couplings come out of the hose-bed and strike the rear step.
• Return to the hose-bed, and repeat this process until you have pulled sufficient hose to reach the hydrant. Now, break the hose from the hosebed (see photo 8) Note: All couplings are laid out at the apparatus back step. Connect the hose to a gated inlet; use a double male adapter, if necessary (see photo 9).
• Return to the back step of the pumper, and place your arms through the loops of hose, with the couplings resting on your chest. Take a hydrant wrench, double female (if necessary), and a gate valve to facilitate connecting a second supply line (see photo 10) to the hydrant without shutting it down; drag the hose toward the hydrant. Drop the loops and couplings to the street as the slack is pulled from the hose.

It is important to realize that the flow limitations of a single three-inch supply line fed directly from hy-drant pressure. Al-though the exact gpm available varies with hydrant flow pressure and the length of the supply line, three-inch hose can usually de-liver 300 to 400 gpm, which is sufficient for most house fires. This flow, however, can be dangerously inadequate for large residential and commercial occupancy fires. When larger flows are desired, they are most effectively achieved by using four- or five-inch large-diameter hose and positioning an engine directly at the hydrant to boost pressure in the supply line(s).

CHANGING FROM TANK TO LDH SUPPLY LINE
For many fire departments, the task of laying supply hoseline(s) usually rests with the second-arriving engine company. It is not within the scope of this article to examine the merits of forward (hydrant to fire) vs. reverse (fire to hydrant) hoselays, but I believe that most of us would agree that departments using LDH generally stretch from hydrant to fire, a forward lay. This means that the second-arriving pumper will stop at a hydrant and lay LDH to the first-arriving pumper. LDH is capable of much higher flows than conventional 2½-inch or three-inch hose, but it takes longer to connect and flow water. The reason for the delay is that most LDH comes in 100-foot sections, which can require pulling as much as 90 feet of excess hose to reach the next coupling in the hosebed or connecting a short pony section of LDH between the last coupling in the street and the pump’s intake. Getting water will be further delayed if the hydrant person follows the cardinal rule of charging LDH: It must be done S-L-O-W-L-Y. As a result, the first-arriving engine may run out of tank water before it receives water from the LDH supply line.

There is, however, a temporary supply of water available almost immediately—the water carried in the booster tank of the second-arriving engine. The engineer of the first-arriving engine can rapidly tap into this supply by rolling out a section of 2½ – or three-inch hose and connecting it to an intake and then connecting this line to a discharge of the second-arriving engine as soon as it pulls up to the fire scene. Now, the second engine can pump its tank water to the first engine while the LDH supply line is being connected and charged (see photo 11).

MAINTAINING THE PROPER PRESSURE
Once a supply line is connected and flowing, it can significantly raise the pump discharge pressure of the engine receiving the water—how much depends on the flow pressure of hydrants in the area. This sudden increase in pressure can be passed directly to firefighters operating handlines and can catch them off guard, knocking them off a ladder or down a flight of stairs. An engineer must smoothly compensate for the increase in pressure by “throttling down,” reducing engine rpm as he slowly opens his intake. Additionally, a competent engineer will correctly set his relief valves or governor to guard against a sudden, unexpected increase in pressure.

Automatic pressure control governors are becoming increasingly common on pumpers with electronically controlled diesel engines. Governors automatically maintain the proper pump pressure by sensing an increase in intake pressure from the supply line and automatically reducing engine rpm. Governors work great if they are set in the proper operating mode.

Two of the most common electronic governor controls must be switched from “throttle control” to “pressure control” before advancing the throttle. Failing to push a button or move a toggle switch to the pressure control mode leaves an engine without the overpressure protection of the governor. Once an engine receives water from a supply line, the pump operator should immediately refill his booster tank. The water in the tank is an insurance policy, giving a company enough water to back out if its supply line is cut, disconnected, or accidentally shut down.

Modern pumpers are required by National Fire Protection Association (NFPA) 1901, Automotive Fire Apparatus—1999, to have a one-way check valve installed in the tank suction line to prevent a reverse flow of water (from a supply line) from backfilling through the tank suction line and bursting the tank. As such, the tank suction valve can remain open on newer engines after a supply line is connected and flowing. Older engines without this check valve in the tank-to-pump piping will require the extra step of closing the tank suction valve once it is receiving water from a supply line.

SHUTTLING WATER
Even a department with an excellent municipal water supply can occasionally find itself at a fire without a hydrant in sight—for example, for fires in railyards and junkyards and on expressways, engines may have to shuttle water to the fire scene in booster tanks. Unfortunately, urban fire departments that rely so heavily on hydrants can be ill-prepared when one isn’t nearby. This is because these departments generally do not have large-capacity tankers or folding tanks. Additionally, big city engines usually carry no more than 500 gallons. Experience is also a factor; urban firefighters are generally not as proficient as their rural counterparts in setting up an efficient tanker shuttle operation.

The keys to an efficient water tank shuttle are the following:

• Rapidly dump tank water into the engine pumping at the fire.
• Quickly return to a hydrant or other water source.
• Refill booster tanks at an expedient rate.
• Respond back to the fire scene.

An engine company can expedite the process of receiving tanks of water by laying a supply hoseline from a main road to the fireground. This builds the foundation of an efficient shuttle operation because it allows engines to remain on the main road and dump their tank into the supply line. This will take significantly less time than having engines maneuver down a long, narrow driveway and will eliminate the need to back up and turn apparatus around at a congested fire scene. At the main road, place a clappered or gated siamese on the end of the supply line to facilitate connecting two pumpers.

The faster an engine can dump its tank, the sooner it can return to a water source to refill. Engines shuttling water should pump out their tanks at 60 to 100 psi. At that pump discharge pressure, the rate of flow from the booster tank could exceed the flow being pumped on the fire, such as when small handlines are being flowed intermittently. In this case, the engine pumping at the fire scene should divert any extra water it receives into its booster tank by opening its “tank fill” valve.

Refilling booster tanks at the water source can be hastened by doing the following:

• Lay hose between the drafting site or hydrant and the main road to reduce backing up and maneuvering apparatus.
• When using a hydrant to refill tanks, connect a gate valve to its outlet. This allows the hydrant to remain open throughout the operation. The flow of water will be controlled by the gate instead of your having to open and close the hydrant with each tank of water (see photo 12).
• When refilling a booster tank, put the pump in gear and pump 100 psi discharge pressure through the tank fill valve. If you’ve never filled a tank with the help of pump pressure, you’ll be amazed at how fast it is. Caution: Do not exceed 100 psi. Some tanks can’t handle this excess pressure.

A booster tank allows an engine company to rapidly attack a fire before securing a continuous supply of water. Since the majority of fires occur in private residences and involve only room and contents, firefighters can control and often extinguish a substantial number of fires with just the water carried in their apparatus booster tank.

Firefighters, however, must not be lulled into a sense of complacency and rely too heavily on tank water alone. They must recognize fires, however infrequently they may occur, that have the potential to grow beyond the suppression capabilities of tank water and never commit personnel to fire operations where their lives could depend on a supply of water that could run out.

Thanks to Chief (Ret.) John Mittendorf, Los Angeles City Fire Department; Chief Paul Martin, Chicago (IL) Fire Department; Driver/Engineer Guy Lindauer, Cooper City (FL) Fire-Rescue; and William C. Peters, apparatus supervisor, Jersey City (NJ) Fire Department, for their technical assistance.

BILL GUSTIN is a captain with the Miami-Dade (FL) Fire Department (formerly Metro-Dade) and lead instructor in his department’s officer training program. He began his 28-year fire service career in the Chicago area and teaches fire training programs in Florida and other states. He is a marine firefighting instructor and has taught fire tactics to ship crews and firefighters in the Caribbean countries. He also teaches forcible entry tactics to fire departments and SWAT teams of local and federal law enforcement agencies. He is an editorial advisory board member of Fire Engineering.