What Is a Wildfire Mobile Attack? Pump-and-Roll Firefighting Explained
Updated: Aug 28
Learn the basics of a Wildland Fire Mobile Attack.
The Quick Answer: A wildfire mobile attack, also known as pump-and-roll firefighting, is a wildland fire suppression tactic where a fire apparatus moves along or near the fire perimeter while supplying water to firefighters working the fire edge. It is commonly used during initial attack on accessible grass and light-vegetation fires when conditions allow safe vehicle operation.
Now, lets get into the details. A wildfire mobile attack, often called pump-and-roll firefighting, is a wildland fire suppression tactic in which a fire engine or equipped vehicle moves along or near the fire perimeter while water is applied to burning vegetation.
Mobile attack can be particularly effective during initial attack on grass fires and other fires burning in light fuels, where terrain allows vehicle access and the fire can be safely approached.
Unlike a stationary fire engine supplying a long hose lay, a properly equipped mobile attack apparatus can move with the firefighters as they work along the fire's edge. This provides crews with a mobile water supply and can allow them to suppress a fire perimeter more efficiently under appropriate conditions.
Mobile attack, however, is a professional wildland firefighting tactic that requires training, situational awareness, communication, appropriate equipment, and continuous assessment of fire behavior. Conditions can change rapidly, and no firefighting tactic is appropriate in every situation.
This guide explains how wildfire mobile attack works, what pump-and-roll means, the terminology associated with wildland fire attack, the equipment commonly used, and why water management and firefighter safety are critical.
What Does Pump-and-Roll Mean in Firefighting?
Pump-and-roll describes the ability of a fire apparatus to pump water while the vehicle is moving.
Instead of parking the apparatus and extending hose away from it, the vehicle can slowly move with the suppression operation while supplying water through a hose or other discharge.
This capability is particularly useful in wildland firefighting because a fire perimeter may extend across a large area.
Depending on the apparatus and operation, firefighters may work from a hose line alongside the vehicle while another crew member operates the apparatus.
Pump-and-roll capability is commonly associated with wildland fire engines, brush trucks, slip-on units, and skid-mounted firefighting systems designed to carry both water and pumping equipment.
When Is a Mobile Attack Used?
Mobile attack is most useful when the fire behavior, terrain, vegetation, vehicle access, and available resources make it safe and practical.
It can be especially effective on fires burning through lighter fuels such as:
Dry grass
Weeds
Light brush
Agricultural vegetation
Roadside vegetation
Other accessible surface fuels
Grass fires are a good example of why mobile attack can be valuable.
Dry or cured grass can ignite easily and allow fire to spread rapidly, particularly under hot, dry, and windy conditions. Although the individual vegetation may be relatively small, a fast-moving grass fire can cover significant acreage.
When conditions allow safe apparatus access, the ability to move along the fire perimeter while applying water can provide an efficient method of initial suppression.
However, mobile attack is not appropriate simply because a vehicle can physically reach the fire. Terrain, fire intensity, wind, fuel conditions, escape routes, vehicle capabilities, visibility, and many other factors must be evaluated by trained personnel.
Understanding the Parts of a Wildfire
To understand mobile attack, it helps to understand several basic terms used to describe a wildfire.
Head of the Fire
The head is generally the portion of the fire perimeter spreading most rapidly.
It often produces greater fire intensity and faster rates of spread than other portions of the perimeter.
The location and behavior of the head can change as wind, terrain, and fuel conditions change.
Flanks
The flanks are the sides of the fire between the head and the rear.
They are commonly described as the left flank and right flank when viewed from the rear of the fire toward the head.
Firefighters may work along a flank as part of a suppression operation.
Rear or Heel
The rear, sometimes called the heel, is generally the portion of the fire opposite the head.
Fire behavior at the rear may be less intense than at the head, depending on conditions.
The Black
In wildland firefighting, the black refers to an area that has already burned.
Under appropriate circumstances, burned areas may contain less available fuel than the unburned vegetation surrounding the fire.
However, burned ground should never automatically be assumed to be safe. The black may still contain burning vegetation, hot material, weakened trees, holes, stumps, or other hazards.
The Green
The green generally refers to unburned vegetation outside the burned area.
Unlike the black, this area still contains available fuel capable of carrying fire.
What Is an Anchor Point in Wildland Firefighting?
An anchor point is an advantageous location from which firefighters can begin constructing fireline or conducting suppression operations.
Its purpose is to help reduce the possibility of firefighters being outflanked by the fire as they work along the perimeter.
Roads, previously burned areas, natural barriers, and other suitable locations may sometimes serve as anchor points depending on the incident.
Establishing a secure starting location is a fundamental concept in wildland fire suppression.
From an anchor point, crews may work along one or both flanks toward other portions of the fire as part of the overall suppression strategy.
Direct Attack vs. Indirect Attack
Mobile attack is generally associated with direct attack, but understanding the distinction is useful.
Direct Attack
During a direct attack, firefighters work at or very close to the active fire edge.
Water, hand tools, equipment, or other suppression methods are used directly against burning material or immediately adjacent fuels.
Mobile attack can support this type of operation when the fire can be safely approached by an apparatus.
Indirect Attack
During an indirect attack, firefighters establish control lines some distance away from the active fire edge rather than working immediately alongside the flames.
Indirect tactics may be selected when fire intensity, terrain, fuel conditions, safety concerns, or other factors make direct attack inappropriate.
The tactic selected depends on the incident. Direct attack is not automatically the safest or most effective option simply because water and a vehicle are available.
How Does a Wildfire Mobile Attack Work?
The exact operation varies based on the incident, apparatus, crew, and agency procedures.
In a typical mobile attack concept, an appropriately equipped apparatus moves slowly along an accessible portion of the fire perimeter while water is supplied to a hose line.
A nozzle operator can then apply water to burning vegetation and the fire edge while the vehicle and water supply progress with the operation.
This allows the crew to continuously advance rather than repeatedly stopping, extending hose, repositioning the apparatus, and beginning again.
Effective mobile attack requires close coordination between the driver/operator and firefighters working from hose lines.
Vehicle movement, hose position, changing fire behavior, terrain, visibility, water supply, and escape routes must all be continuously monitored.
The driver/operator must remain aware of personnel around the apparatus, and firefighters must remain aware of the vehicle and hose movement.
There is no universal "safe distance" between the apparatus and nozzle operator. Appropriate spacing depends on the equipment, terrain, visibility, agency procedures, and conditions.
Flanking and Pincer Attacks
One approach to wildland fire suppression is to begin from a secure anchor point and work progressively along the fire's flank.
If sufficient resources are available and conditions support the tactic, suppression operations may progress along both the left and right flanks.
This is sometimes described as a pincer attack, with resources working from an established area around both sides of the fire.
The objective is to progressively contain the perimeter and prevent additional fire spread.
As crews move toward the head of the fire, however, conditions may become increasingly hazardous because the head is often the fastest-moving and most intense portion of the fire.
Wildland fire behavior can change rapidly due to:
Wind speed and direction
Terrain and slope
Fuel type
Fuel moisture
Temperature
Relative humidity
Spotting and ember activity
Suppression tactics therefore require continuous reassessment rather than following a fixed pattern.
Why Water Management Matters During Mobile Attack
A major limitation of any mobile firefighting unit is its finite water supply.
A 100-, 200-, 300-, or 500-gallon water tank may sound substantial, but firefighting nozzles can discharge water quickly.
The basic calculation is:
Available Water ÷ Flow Rate = Approximate Flow Time
For example:
A 500-gallon tank flowing 20 gallons per minute (GPM) provides approximately:
500 ÷ 20 = 25 minutes
At 30 GPM, the same tank provides only:
500 ÷ 30 = 16.7 minutes
And at 50 GPM:
500 ÷ 50 = 10 minutes
Actual usable time can be different due to plumbing, tank configuration, pump operation, intermittent nozzle use, and other factors.
This demonstrates why water conservation and refill planning are critical during mobile attack operations.
A crew that runs out of water at the wrong time can lose an important suppression capability.
Hose & Nozzle Selection for Wildland Firefighting
More water is not always the same as more effective firefighting.
Hose diameter, nozzle selection, pressure, flow rate, pump performance, and available tank capacity all need to work together.
Wildland apparatus may use smaller-diameter hose and nozzles capable of operating at relatively controlled flow rates because conserving a limited onboard water supply can be important.
For example, a nozzle flowing 20 GPM can theoretically operate much longer from a 300-gallon tank than a nozzle flowing 60 GPM.
The appropriate equipment depends on the intended application and operational requirements.
This is one reason a wildland fire skid or slip-on unit should be designed as a complete system rather than simply pairing the largest available pump with a water tank.
Planning for Water Resupply
Mobile attack operations need to consider what happens before the onboard tank runs dry.
Potential water sources can include:
Additional water tenders or engines
Stationary water tanks
Portable water tanks
Approved hydrants
Ponds or other suitable static water sources
Dedicated refill locations
The available source, accessibility, water quality, equipment, and authority to use that source all need to be considered.
Multiple mobile units can provide additional flexibility because one unit may be able to refill while other resources remain engaged in suppression operations.
The objective is to minimize interruption while maintaining an adequate safety margin.
Mop-Up, Hot Spots & Spot Fires
Stopping visible flames does not necessarily mean a wildfire is completely extinguished.
After the primary fire perimeter has been controlled, firefighters conduct mop-up operations to identify and extinguish remaining heat and burning material that could threaten containment.
Potential hot spots can include:
Smoldering vegetation
Logs and stumps
Roots
Heavy fuels
Burning debris
Material near the fire perimeter
Crews must also remain alert for spot fires.
Spot fires occur when burning embers or other firebrands are transported beyond the main fire perimeter and ignite receptive fuels elsewhere.
Wind can carry embers away from the visible flame front, which means firefighters cannot focus exclusively on the fire directly in front of them.
What Equipment Is Used for a Mobile Fire Attack?
A mobile wildland firefighting system needs more than a water tank.
Depending on the apparatus and application, equipment can include:
Water storage tank
Firefighting or water pump
Engine
Suction plumbing
Discharge plumbing
Fire hose
Hose reel
Fire nozzle
Valves and fittings
Tank fill connections
Suction hose
Strainers
Mounting or skid frame
The complete system must also account for vehicle payload capacity and secure mounting.
Water is heavy.
One U.S. gallon of water weighs approximately 8.34 pounds.
That means the water alone weighs approximately:
100 gallons = 834 lb.
200 gallons = 1,668 lb.
300 gallons = 2,502 lb.
500 gallons = 4,170 lb.
That does not include the weight of the tank, skid frame, pump, engine, hose, reel, plumbing, equipment, occupants, fuel, or anything else carried by the vehicle.
Vehicle payload and weight limits therefore need to be considered carefully when selecting a mobile water tank or firefighting skid.
What Is a Wildland Fire Skid or Slip-On Unit?
A wildland fire skid, also commonly called a slip-on firefighting unit, combines a water tank, pump, hose, plumbing, and other firefighting equipment onto a common skid or frame.
Depending on size and configuration, these systems can be installed in:
Pickup trucks
UTVs
Brush trucks
Trailers
Flatbed vehicles
Other suitable utility vehicles
The advantage is portability. The vehicle carries its water supply and pumping equipment together, allowing the system to be transported where it is needed.
For agencies and trained operators, properly configured skid units may support mobile attack, patrol, mop-up, water supply, and other wildland fire operations.
For private landowners, farms, ranches, and rural properties, water skid systems can also provide a portable water source for appropriate property protection, water transfer, vegetation watering, washdown, and emergency preparedness applications.
Can Property Owners Use a Fire Skid During a Wildfire?
Property owners should understand the difference between owning wildfire-preparedness equipment and conducting professional wildland firefighting operations.
A water tank, pump, hose, or fire skid does not make an unsafe wildfire environment safe.
Wildfire conditions can change extremely quickly, and hazards can include:
Rapid changes in fire direction
Extreme radiant heat
Heavy smoke and reduced visibility
Falling trees and branches
Wind-driven embers
Blocked roads
Equipment failure
Limited water
Entrapment
Loss of escape routes
If authorities issue an evacuation order, follow the evacuation order.
Property owners should never remain behind solely because they have a water pump or firefighting skid.
Wildfire preparedness equipment can be valuable, but it should be considered one part of a larger preparedness plan that includes defensible space, vegetation management, evacuation planning, emergency communication, water availability, and appropriate equipment.
Mobile Attack Safety
Wildland firefighting is inherently dangerous and should be performed by properly trained and equipped personnel.
Professional wildland firefighters use established safety procedures and continuously evaluate fire behavior, weather, terrain, communications, escape routes, safety zones, available resources, and changing conditions.
A tactic that is appropriate at one moment may become unsafe minutes later.
Mobile attack also introduces hazards associated with moving vehicles, hose lines, uneven terrain, limited visibility, heat, smoke, and rapidly changing fire conditions.
No piece of equipment eliminates these hazards.
Life safety always takes priority over property or equipment.
Mobile Attack & Wildland Fire Equipment from Alpine
Alpine manufactures water tank skid units and portable pump systems for wildland fire, property protection, farm, ranch, vineyard, agricultural, and water-transfer applications.
Available configurations range from compact UTV water skid units to larger truck-bed systems incorporating water storage, pumps, hose reels, fire hose, nozzles, and related equipment.
For customers who need a specialized configuration, Alpine can also build custom water pump and tank skid systems around specific applications and vehicle requirements.
Wildfire Mobile Attack: Frequently Asked Questions
What is a mobile attack in wildland firefighting?
A mobile attack is a wildfire suppression tactic in which an appropriately equipped fire apparatus moves along or near the fire perimeter while water is applied to burning vegetation. It is often associated with pump-and-roll firefighting.
What does pump-and-roll mean?
Pump-and-roll means that a firefighting apparatus can pump water while the vehicle is moving, allowing the water supply to move with the suppression operation.
What types of fires are suitable for mobile attack?
Mobile attack can be useful on accessible wildland fires burning in lighter fuels, including grass and some brush fires. Whether the tactic is appropriate depends on fire behavior, terrain, weather, access, equipment, crew capabilities, and other safety considerations.
What is the black in wildland firefighting?
"The black" refers to ground or vegetation that has already burned. Although burned areas may contain less available fuel, they can still contain significant hazards and should not automatically be considered safe.
What is an anchor point?
An anchor point is an advantageous location used as a starting point for fire suppression operations to help minimize the possibility of firefighters being outflanked by the fire.
What is a fire flank?
The flanks are the sides of a wildfire between its rear and head. They are commonly described as the left and right flanks when viewed from the rear toward the head.
How long will a 500-gallon fire skid provide water?
It depends primarily on the flow rate. At a continuous 20 GPM, 500 gallons theoretically provides about 25 minutes of water. At 50 GPM, it provides approximately 10 minutes. Actual operating time varies according to the system and how the nozzle is used.
How much does 500 gallons of water weigh?
Water weighs approximately 8.34 pounds per U.S. gallon, so 500 gallons weighs approximately 4,170 pounds, before adding the weight of the tank, skid, pump, hose, equipment, fuel, and other payload.
Is a wildland fire skid the same as a slip-on unit?
The terms are often used to describe similar self-contained systems consisting of a water tank, pump, hose, and related equipment mounted to a skid or frame that can be installed on a suitable vehicle.
Should a homeowner stay and fight a wildfire with a fire skid?
A fire skid should never be considered a reason to ignore an evacuation order or remain in an unsafe wildfire environment. Property owners should follow instructions from local authorities and prioritize evacuation and life safety.
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