Water is the most readily available and commonly used extinguishing agent and it is also the cheapest to acquire by all measures. In any emergency, there should be enough supply of water to meet the demands of firefighters. You may wonder where exactly firefighters get water from?
Firefighters get water from the following sources:
- Fire engine water tanks
- Wet fire hydrants
- Dry fire hydrants
- Tanker trucks (water tenders)
- Lakes and rivers (less common)
- Brush trucks
The rest of this article will cover all of these water sources in-depth. We’ll also discuss the instances in which each source would be used, as well as how water is extracted from them. To learn more, read on.
Also read: 8 Ways To Find The Nearest Fire Hydrant
Water Sources for Firefighters
Sources of water will vary in every community, so a fire engine driver /operator needs to be familiar with what is readily available within the area. It’s one of the reasons why fire departments have independent training programs. These programs aim to orient their recruits on different sources of water, together with the process that it takes to get water into the fire.
As mentioned in the intro, there are five primary sources of water that firefighters use. Let’s take a look at each of them below.
The primary purpose of a fire engine or fire truck is to transport firefighters and firefighting equipment to the emergency scene as quickly as possible. It carries all the essentials for a fire-ground operation such as hoses, ground ladders, hand tools, specialized equipment, PPE (Personal Protective Equipment), breathing apparatus (SCBA), and medical supplies.
To learn about the difference between a fire engine and fire truck, read: What’s the Difference Between a Fire Engine and a Fire Truck?
All fire engines are required to have on-board water tanks, but the size can depend on the type of fire engine (there are 7 types). The NFPA (National Fire Protection Association) has guidelines (1901 and 1906) that classify the requirements for each type of engine. NFPA 1901 is the Standard for Automotive Fire Apparatus and NFPA 1906 is the Standard for Wildland Fire Apparatus.
Here is a table that shows the minimum water tank and pump capacity requirements of each type of fire engine:
|Engine Type||Primary Use||Minimum Water Tank||Minimum Pump Performance|
|Type 1||Structural||300 gallons||1000 gallons per minute|
|Type 2||Structural||300 gallons||500 gallons per minute|
|Type 3||Wildland||500 gallons||150 gallons per minute|
|Type 4||Wildland||750 gallons||50 gallons per minute|
|Type 5||Wildland||400 gallons||50 gallons per minute|
|Type 6||Wildland||150 gallons||50 gallons per minute|
|Type 7||Wildland||50 gallons||10 gallons per minute|
These are the minimum requirements, however, many engines exceed these standards. Most structural (type 1 and 2) fire engines have tanks that can carry at least 500 gallons and frequently as much as 1,000 gallons of water.
In some states, the use of fire trucks with bigger capacity is more practical. They deploy a fleet of fire engines that can hold up to 3,000 gallons of water to spearhead the fire-ground operation.
Some communities use several smaller, more agile fire engines that can only carry 300 gallons of water or less. This strategy aims to improve the average response time during emergencies and to get all firefighting equipment to the scene as fast as possible.
Tankers or water tenders follow shortly, carrying up to 5,000 gallons of water to provide firefighters with more reliable water sources.
Fact: On a Type 1 engine, a 500-gallon tank can be emptied in as little as 20 seconds, depending on the hose-line that is flowing.
Every fire engine has an impeller water pump that operates through a dedicated diesel engine. It’s a rotor-like device that spins at high speed to create a centrifugal force that slings the water outward. When an engineer opens the valve, the water hits the center of the impeller, which creates extreme pressure.
To learn more about centrifugal pumps, watch this video:
All hose lines that firefighters use are independent of each other, and the operator controls it through a panel of manual valves and gauges or through a built-in electronic device called a mastermind.
This device handles most of the discharge control and maintains even distribution of water in different lines. It also has a built-in relief valve, which acts as a stabilizer. It maintains stable pressure on all outlets, so even in an event where one line gets cut off, the force doesn’t get fed to other outlets.
Operators may still need to calculate correct pressures and operate valves to open and close each water discharge. They must also keep an eye on a series of red lights near the mastermind.
It serves as an indicator of how much water is still in the tank. Before it runs out, the operator should already have an alternative source of water to keep it stable and reliable for the firefighters. Running out of water can be a serious issue and it is the driver/engineer of the fire engine’s job to make sure that does not happen.
For more information about the different types of fire engines, read: Types of Fire Engines
Fire engines have limited capacity, and if firefighters require high nozzle flows, the tank will dry out quickly. In urban areas, fire hydrants are the most practical solution to provide firefighters with a reliable source of water.
There are very few bodies of water that firefighters can draft from in an urban area, so city engineering ensures that there are enough fire hydrants spread throughout the area.
A fire hydrant is an important part of the public pipeline systems and fireline construction. Before a fire engine’s water tank dries out, an operator will connect to a fire hydrant to serve as a reliable, continuous source.
There are two main types of fire hydrants that city planning departments can install, but in most urban areas, they prefer to use “wet barrel fire hydrants.”
Wet Barrel Hydrants
Wet barrel hydrants are the ones we see on the sidewalks and are capable of releasing large quantities of pressurized water.
Highly urbanized areas can have these outlets installed every 200 feet from each other. Some city planning departments even have these hydrants closer to ensure that there is enough supply to support massive firefighting operations.
Wet barrel hydrants are pressurized up to the barrels to reduce the time needed to source water in case of emergencies. These outlets have three to four valves, with varying sizes from 2 ½ inches to 4 ½ inches in diameter. When fire engines dry out (or preferably well before), the operator can establish a supply hose connection to support continued firefighting efforts.
Wet barrel hydrants, however, have one significant disadvantage; it doesn’t have an independent shutdown valve. The pressure in these hydrants is so powerful that it can shoot water up to 70 feet in the air, and can flood an area when struck.
We respond to calls all the time where a car or truck hits a fire hydrant and knocks it off the supply piping. We arrive to find water spraying high in the air.
Even so, it’s still the most efficient hydrant for emergencies because it’s always ready to discharge pressurized water. Firefighters don’t have to locate a central valve and wait to get the pressure on all lines. The water release is instantaneous, which can mean the difference between life and death when an emergency arises.
Dry Barrel Hydrants
The major reason to use a dry barrel over a wet barrel hydrant is temperature. In areas where the climate can get very cold, the dry barrel is preferred. This is because the water in the wet barrel hydrant can freeze, rendering the hydrant un-useable (until it thaws).
Unlike a wet barrel, a dry barrel hydrant doesn’t have pressurized water up to the valves. The water is drained from the hydrant after use.
Since there is no water in the hydrant, it won’t freeze. Instead, an operator can control it through an internal shut off valve, that is located underground when water is needed
Here is a video that better illustrates the different types of fire hydrants:
Water Tankers and Tenders
In rural areas, installing a fire hydrant isn’t practical. That’s why some departments use a fleet of large fire engines supported by a handful of drop tanks and water tenders or tanker trucks.
It serves as a support for the fire engines, in an event where firefighters need more water than what the fire engines can carry, or when fire hydrants aren’t enough to support the firefighting efforts.
A water tender is a specialized firefighting vehicle that is capable of drafting water from any accessible source of water, then transporting it to the fire scene. Most water tenders can carry 1,000 gallons of water, while larger departments use water tenders that can load up to 5,000 gallons at a time.
Water tenders don’t have the pumping capacity similar to a fire engine. Instead, it utilizes a smaller pump to draft water from sources that are inaccessible to fire engines. They can not be used for attacking or extinguishing fire directly, as they are not equipped to do so.
Once the water tender reaches the fire scene, the crew will discharge the water into a drop tank. It’s similar to an above-ground swimming pool — only much bigger.
Drop tanks can hold as much as 2,000 gallons of water, to which the fire engine operator will connect, using a 6-inch pump to keep the water supply stable.
With enough water tenders at the scene, firefighters will be able to refill drop tanks as often as needed. In some cases, fire departments use a fleet of brush trucks to ensure that there is enough water supply to support the fire-ground operation.
Firefighters call this strategy of sourcing water “Water Shuttle.” Although it requires massive staffing and smooth coordination between different teams, it’s the most efficient way of ensuring that there is enough water supply.
However, a Tanker Shuttle Service is not as simple as collecting water then discharging it into the drop tank. There’s a process that firefighters need to follow to ensure that the water they draft will be useful for the operation.
It’s all well and good if your community has a fire hydrant. But it becomes a bit more challenging when firefighters need to draft water from other bodies of water. In some cases, the fires get too big that even fire hydrants cannot support the amount of water that firefighters need.
Drafting is the process of pulling water from a non-pressurized source like a lake or pool. This is done using hard suction hoses and a special priming motor that can pump air. The negative pressure created by pulling the air out of the hose will cause the water to be pulled into the pump. Once water is in the pump, it can be pressurized and used to fight fires.
During the North San Francisco Bay fires of October 2017, firefighters worked with hydrants that can only supply 3 million gallons of water to support the firefighting efforts. It was so big that the firefighters had to draft water from almost every source that they can think of; pond, lake, stream, river, and even the ocean!
Drafting isn’t as simple as bringing the water tender to a body of water, laying down the suction hose and filter, then filling the tank with water. It needs to be a coordinated effort between multiple teams. Firefighters need to consider a lot of things before they can start the “Water shuttle,” and these factors include:
- Drafting points for each water tender, other alternative water sources, and the time it’ll take to fill up the tank and get back to the fire scene.
- Equipment that firefighters need to access alternative water supplies and start drafting water.
- The distance and accessibility of the water source from the operation to determine the amount of time they need to draft water.
- Planning and optimizing work distribution to keep a stable supply of water and maintain the highest flow capacity possible.
The impeller pump in fire engines won’t work when the water that it pumps has air in it.
When a fire engine connects to a water tender or a drop tank, it should be filled with water and have the air removed for the centrifugal source to function correctly. This requires a different type of pump, that can pump air, called a priming pump or motor.
Once primed, the impeller pump takes over, and it’ll keep working until the tank dries out. An operator must ensure that before it happens, there’s already another primed water tender to refill the drop tank or connect to fire engines.
Drafting is where the resourcefulness of firefighters are put to the test because not all bodies of water are made equal. Sometimes, the drafting point isn’t deep enough to pull a draft from, such as a creek or a stream.
There are times when drafting creates a small whirlpool that can draw air into the tanker, making it less useful when connected to a fire engine.
Regardless of the situation, firefighters should have problem-solving skills and enough experience to go through these circumstances. Modern fire departments even have specialized vehicles to make drafting more efficient.
Shallow Drafting Point
During emergencies, there’s very little time to look for a reliable source of water, so firefighters make use of what is available for drafting. If the body of water is too shallow, they use whatever tools are available to create a small hole or a temporary dam that is deep enough to draft water.
In some places, there’s no other option but to draft from a shallow creek or stream. In this case, the fire departments may deploy a backhoe to proactively start building temporary dams long before fire engines run out of water.
Attack Fire Truck or Brush Trucks
Aside from the slow, massive water tenders, firefighters also use brush or attack trucks. These vehicles are more agile and versatile when searching for water sources, but they don’t have the same capacity as large pumps.
It requires massive staffing to conduct a smooth operation, and several attack trucks to create a flow capacity of 1,000 gallons per minute.
Someone needs to be skilled in coordinating every brush truck deployed at the scene to make it work. Still, it’s a highly effective method of supporting fire-ground operations, especially in areas where there is a lack of water sources.
Inaccessible Drafting Site
When responding to fire calls, firefighters don’t have the luxury to navigate the terrain to look for the most accessible and ideal drafting site. There are times when they can’t bring the apparatus close enough to the water to start drafting.
When this situation happens, the best thing that firefighters can do is to piece together hard sleeves (because the soft fire hose would collapse with the negative pressure) for additional length.
This technique will work if the terrain is mostly horizontal and doesn’t have much lift to draft. It’ll also take longer to prime the pump to make the water suitable for the fire engine.
When using this strategy, firefighters connect each hard sleeve carefully to ensure that each connection is airtight, and there are no leaks that can make the draft less effective.
Some fire departments, especially the ones that are operating in areas with fewer water sources, always carry a hard suction that is usually 10 feet long. This equipment reduces the connection points and possible leaks when drafting from less accessible bodies of water.
In rare cases where the drafting site is too far or highly inaccessible, firefighters use a piece of equipment called the “fire eductor.” This equipment will require supply from a 1 ½-inch, 1 ¾-inch or 2-inch handline into the unit with an LDH (Large Diameter Hose) supply line out. A fire eductor can draft 600 gallons per minute and can reach up to 61 meters or 200 feet.
Water is an integral part of all firefighting efforts. With the improvement in techniques, equipment that firefighters use, and experience in fire-ground operations, sourcing water has become a lot easier.
To recap, the main water sources that firefighters use are as follows:
- Fire engines water tanks
- Wet fire hydrants
- Dry fire hydrants
- Tanker trucks (water tenders)
- Lakes and rivers (less common)
- Brush trucks
Lack of access to a sufficient amount of water for firefighting efforts can be the difference between saving someone’s home or even their life. We have learned how to source water, making the firefighting capabilities of each department better than ever.