Defensive Outside Firefighting Tactics

Defensive outside operations could be just as dangerous as inside in possible collapse situations. The collapse zone must be defined. Here, members operate outside the vertical zone from the street and from the tower ladder. The firefighters are also beyond the horizontal zone operating in a corner safe area from a flanking position. Should this structure collapse, planning, tactics, and control are in effect to prevent surprises and assure safety.

Photo by Warren Fuchs, Jr.

Defensive Outside Firefighting Tactics


Fireground dangers are just as deadly outside burning buildings as they are inside.

Communications to Battalion 1. Go ahead with your message.”

“Battalion 1 to Communications at Box 214. We are going to use an outside attack on a fire in threestory, 20by 60-foot wood-frame vacant building at 2147 Webster Avenue. The structure is fully involved. We have fire on all three floors. We need an aerial platform to respond to this box.”

“Communications to Battalion 1. You are getting Ladder 6, which is an aerial platform.”

“Battalion 1 to Communications. Inform Ladder 6 while enroute that the battalion wants them to set up in front of the fire building, and that they should approach the fire from Fordham Street, against traffic. Traffic has the street blocked.”

“Communications to Battalion 1. Message received. The time is 1330 hours.”

“Ladder 6 to Communications. We receive and acknowledge Battalion 1 message.”

Ladder 6’s chauffeur slowly moves the vehicle into the smokefilled street. In the afternoon sunlight, smoke banks down into the street, reducing visibility. The chief runs over to the cab of the incoming aerial platform and steps up onto the running board on the officer’s side.

“Captain, we have supply lines being stretched to the front of the fire building. I want your aerial stream in operation right in front of the building.”

“OK, Chief. Will do.”

Flames are blowing out of every opening on every floor of the vacant building’s front. The asphalt siding on the building has caught fire. Flames travel vertically up the siding while flaming droplets of melting asphalt rain down the building’s face. The concrete sidewalk is a pool of burning, black liquid.

A wooden decorative cornice near the roof line is in flames. It suddenly collapses at one end and swings down across the front of the structure like a pendulum. When the falling cornice hangs straight down, the other end breaks loose and the flaming wooden structure crashes on the sidewalk.

As the turntable is centered in front of the building, the chauffeur stops the vehicle, sets the brakes, engages power takeoff, and jumps out of the cab. At the aerial platform control panel on the side of the apparatus, the firefighter pulls a handle down to activate the corner jacks. The jack plates hit the pavement and the truck is lifted up into the air. Another firefighter places lock pins in each jack.

Now on the turntable, the chauffeur waits for the go-ahead signal from the captain and firefighter who are climbing into the basket, fastening their safety belts. The chauffeur raises and rotates the boom from the trailer toward the burning building. He speaks into the two-way intercom between tLirntable and basket.

“Captain, take over the controls in the basket whenever you are ready.”

“We are ready. I’m taking over the controls,” replies the captain.

The men in the basket can feel the heat from the flames on their faces.

“We are going to start on the lower floors and work up,” the captain says to his firefighter.

“10-4, Captain.”

As the boom is extended toward the fire, they shield their faces from the heat waves, turning away from the burning building and pulling up the collars of their turnout coats.

“Start up the water,” the captain calls over his walkie-talkie.

“Here comes the water, Captain!” the firefighter on the turntable shouts into the intercom.

The firefighter in the aerial platform basket readies the deluge nozzle affixed to the front of the basket as the captain operates the controls. The stream of water spurts out of the 1 5/8-inch nozzle tip. Slowly, it pours down into the street without pressure, then straightens out suddenly and violently, smashing into the front wall of the burning building and cascading into the street. The firefighter gains control of the stream’s direction and aims it into a ground-floor window, instantly driving the flames back into the structure.

“We are going to the second floor!” the captain shouts over the roar of the accelerating diesel engine, over the sound of the master stream hammering the front wall of the building.

The captain has both hands on the controls to insure smooth movement of the rising basket. With the back pressure of the large caliber stream, any erratic motion of the basket controls is magnified tenfold. Flames are visible through the top-floor windows. The captain looks over the basket railing to check for flames that could reignite below them. As he moves in toward the building, the nozzle of the aerial stream is placed into the top-floor window near the sill and is directed upward. The stream bounces off the ceiling. It extinguishes the flames.

He notices flames at the rear of the top floor. The basket is moved in closer for deeper penetration. Suddenly, without warning, the building collapses.

“Hold on!” the captain shouts.

The firefighter shouts back, “Captain, the nozzle is caught in the window, it’s pulling the basket down!”

In an instant, the basket of the aerial platform and the extended boom is pulled down with the collapsing building. The nozzle unsnags from the window and whips violently back upwards. The basket springs back up and the firefighters hold on to the railing; but as the basket reverses direction and vibrates downward again they are both thrown upward above the railing. The safety belts around their waists snag them, pulling them back to the basket. They are slammed down onto the diamondplate steel deck of the basket. The basket of the aerial platform continues to vibrate up and down, and the aerial stream shoots around uncontrollably.

The building lays in a smoldering pile beneath the aerial platform boom.

Officer and firefighter scramble up off the basket floor. The firefighter grabs the controls of the aerial stream and directs it downward into the smoldering, collapsed building. The captain grabs the operating controls.

“Are you OK?” the officer asks the firefighter.

“Yes, I think so. My hand hurts.

I might have broken something.”

The captain looks down to the street.

“I guess they forgot about us up here. Ladder 6 to turntable control. Shut down the supply line to the aerial stream. The ground handlines can take over now.”

“10-4, Captain,” turntable control returns. “Boy, that was some collapse—are you guys OK up there?”

Question #1

Which one of the following is not a defensive outside fireground tactic when there is danger of a wall collapse?

  1. Use the reach of a hose stream to withdraw firefighters away from a dangerous wall.
  2. Use an aerial stream inside a collapse zone instead of a ground stream.
  3. Use an aerial stream above the dangerous wall.
  4. Flank the dangerous wall with ground or aerial streams.

Question #2

Which one of the following is an untrue statement regarding a collapse zone?

  1. A collapse danger zone must be calculated for the vertical (outward) and horizontal distance a wall may collapse.
  2. A collapse danger zone for an aerial stream and ground stream are the same.
  3. A collapse danger zone is the distance away from an unstable wall equal to the height of the wall for a ground stream.
  4. Bricks and timbers may bounce and roll out further than the collapse danger zone.
90-degree-angle wall collapseCurtain-fall wall collapseInward-outward wall collapse

Answers to questions

  1. The answer to Question 1 is (B). Using an aerial stream inside a collapse danger zone is an unsafe act when there is danger of wall collapse.
  2. The answer to Question 2 is (B). A collapse danger zone is not the same for an aerial and ground stream.

Firefighters operating outside of burning buildings must know A how to protect themselves against injury’ from the collapse of burning buildings.

Most firefighters killed by falling walls are outside the burning building. Firefighters must be trained in defensive outside fireground tactics. For example:

  • Firefighters must understand the concept of the collapse zone.
  • Firefighters must know how to use the reach of a hose stream as a safety device.
  • Firefighters must know the safety
  • advantages of using an aerial stream.
  • Firefighters must know how to calculate the collapse danger zone for an aerial stream.
  • Firefighters must know how to outflank a wall in danger of collapse.
  • Firefighters must know how to safely position an aerial ladder or elevated platform truck when there is danger of wall collapse.
  • Fireground dangers are just as deadly outside burning buildings as they are inside.

Collapse danger zone

A wall of a burning building can collapse in one of three ways: a 90degree-angle collapse, an inwardoutward collapse, and a curtainfall collapse.

The 90-degree-angle wall collapse is the most dangerous because it creates the largest collapse danger zone. In such a case, the wall falls out from the building a further distance than both the inward-outward collapse and the curtain-fall collapse. A wall collapsing at a 90-degree angle will fall straight outward in a manner similar to a falling tree cut by a woodsman. It will cover the ground area with deadly bricks and timber for a distance equal to at least the height of the falling wall section.

If a 25-foot-high wall collapses at a 90-degree angle, it will fall straight outward for 25 feet. No one within 25 feet of the building will survive. They will be buried beneath the collapsed wall.

Whenever there is a danger of wall collapse, plan for the worst — a 90-degree-angle collapse.

Establish a collapse danger-zone area equal to the height of the wall. Withdraw all firefighters away from the burning building a distance equal to at least the height of the wall. This is the so-called “vertical” or “outward collapse” danger zone.

Next, estimate how much horizontal area of the wall may collapse. This is the so-called “horizontal” collapse danger zone. For example, a 25-foot-high wall is 100 feet long, with a parapet wall over a row of stores, and it has a 10-footlong bulge at the center. The horizontal collapse danger zone may be a horizontal area 10 feet directly in front of the bulge. However, a firefighter or fire officer must know whether or not the walls are tied together by steel reinforcement rods. If they are tied together, a small portion of unstable wall could pull down an entire horizontal length of a wall. In this instance, it may be required to establish a horizontal collapse danger zone equal to the entire wall frontage or building width.

Reach of hose stream

When a collapse danger zone is established, the fire officer is trading off the advantage of close-up hose stream penetration through a door opening or window of a burning building for the greater advantage of firefighters’ safety. This is conforming to the commandments of firefighting: life safety first—and this includes life safety of firefighters as well as civilians; fire containment second; and property protection third.

A danger zone must be established when potential for collapse exists. This area is composed of two dimensions. The vertical zone is equal to at least the height of the burning structure. The horizontal dimension is the width of the building expected to be affected. Because of construction techniques, the horizontal danger zone may be defined as the entire width of the burning building.

The reach of a hose stream is used as a safety measure. It allows firefighters to withdraw away from a dangerous wall and still discharge water on the fire. The typical reach of a hand-held hose stream is 50 feet; the typical reach of a master stream is 100 feet. By utilizing this as a safety tool, a 50foot hose stream could allow firefighters to operate outside a collapse danger zone. The officer could withdraw firefighters 25 feet away from a dangerous wall and still discharge water into a burning building a distance of 25 feet. In increasing foreground safety, maximum hose stream effectiveness is sacrificed. Yet, another hose stream could be positioned at another side or at the rear of the burning building to regain fire stream effectiveness. Such a fireground strategy increases fireground safety.

Master streams often must be located to operate from a flanking position outside the collapse zone. Defensive strategies are still supported but are in corner safe areas of the fireground.

Aerial stream use

The most effective use of an aerial stream from a ladder, aerial platform, or snorkel is from below the roof through a window or other wall opening in a close-up approach to the burning building. Even when fighting a fire in a onestory building, an aerial platform may be used at a low angle close to the ground. When large, plateglass windows have been removed by flames or by firefighters for ventilation purposes, and when there are not interior partitions or walls, a powerful stream from an aerial platform can sometimes sweep the open space and quickly extinguish a large fire. However, when there is danger of wall collapse or where interior partitions or stock subdivide a row of small stores, and when fire burns through the roof, it’s safer and necessary to operate the stream from above. It is less effective, but becomes a great advantage in maintaining the safety of firefighters operating in the basket or at the tip of the aerial when there is danger of collapse. Moreover, when interior partitions and/ or stock block stream penetration during an outside attack, there is no alternative but to operate from above. When operating an aerial stream from above a dangerous wall —directing the stream downward at a fire burning through a roof—the safety device is the height of the aerial. The wall may collapse outward at a 90-degree angle, but the firefighters in the basket or at the tip of the aerial are out of the collapse danger zone. They are above it.

Another safety tactic for aerial operations is to operate the aerial ladder without firefighters at the top rungs. The top of an aerial can be extended out from the base, the centerline of the turntable, approximately 30 feet from the structure. When the aerial stream is directed with halyards by a firefighter on the turntable, the ladder extension and height provides an extra 30 feet of reach. This extra 30 feet reach can be added to the 100 foot reach of an aerial master stream. Firefighters could withdraw 65 feet away from a dangerous wall and still penetrate into a burning building 65-feet high.

Collapse danger zone for aerial streams

When a fire occurs in a multistory building and there is danger of wall collapse, the chief and fire officer sometimes overestimate the capabilities of the aerial stream and underestimate the dangers to the firefighters operating at the top of the aerial device. In some instances we withdraw the ground streams away from a potential explosion or wall collapse danger, then we maneuver the top of the aerial platform or aerial ladder close to an unstable wall to extinguish fire. They enter the same collapse danger zone from which the ground forces were withdrawn.

In recent years, an increasing number of building collapses have killed and seriously injured firefighters at the top of aerial devices operating master streams. An officer and two firefighters were crushed in the bucket of an aerial platform when a wall of a threestory New York City building suddenly collapsed. In another incident in that city, an aerial platform had its basket torn from the boom when a building collapsed on it during an outside attack of a fire. Two firefighters in the basket were thrown 30 feet down into the burning collapse rubble and were seriously injured.

Corner safe areas — areas safe from collapse danger that are beyond the vertical and horizontal collapse zones of all sides of the structure.

A collapse danger zone for an aerial stream will vary slightly from the collapse danger zone for a ground stream. An aerial stream operating in front of a wall in danger of collapse can get a little closer to the burning buiding, but not that much closer. The definition of a collapse danger zone for an aerial stream is the distance away from an unstable wall equal to the height of the wall above the nozzle tip of the raised basket.

Flanking a fire

When a tail structure is involved with fire and there is danger of a wall collapsing, establishing a collapse zone could require firefighters to be positioned so far away from the unstable wall that the hose streams do not reach the fire.

During a fire in a church that’s 80 to 100 feet in height, for example, a collapse zone would require ground and aerial streams to be operated 80 to 100 feet away to avoid falling walls. In this instance a fire officer may position ground streams in a “flanking” position. That is, firefighters must outflank the dangerous wall and continue to direct hose streams.

To accomplish this, portable deluge nozzles must be placed in front of adjoining buildings or in corner safe areas of the fireground. The portable deluge stream range and effectiveness will be reduced, but the life safety of the firefighters will be insured even if the unstable wall falls outward beyond the collapse danger zone.

Corner safe areas

The greatest danger of wall collapse occurs during an outside attack on a fully involved church fire. The side walls usually support the truss roof timbers; when the roof collapses it will cause the side walls to collapse outward. The front wall with the tall steeple can collapse at any moment during the fire; the same goes for the rear of the church.

When we look at the fireground around a burning church from a bird’s-eye view, we see there are only four safe areas to park vehicles and operate master streams from: the four corner safe areas. If all the walls collapsed outward simultaneously (which is unlikely), only four areas would be safe from falling brick —the corner area of the square or rectangular burning structure. Master ground streams and vehicles of aerial streams should be positioned at these four corner areas when smoke conditions and radiated heat make it possible.

The most effective method of extinguishing a building fire is by an interior attack. However, at some fires, due to the area of flames upon arrival, the high flammability of contents within a structure, or the combustible nature of the structure itself, an outside attack must be the only strategy. An outside attack at a rapidly spreading fire can be more dangerous to firefighters than an inside firefighting procedure. At these fires, the flames are so large and the radiated heat so intense that the firefighting forces can not even approach the burning structure. Fire apparatus initially positioned at hydrants, or with ladders raised, have to be hastily repositioned to avoid the radiated heat waves and collapsing walls caused by the fire. At these rare fires the strategy may be simply to protect exposed buildings and let the original fire building burn itself out.

Firefighting priorities are: life safety, prevent extension, confine the fire, extinguish the fire, salvage, and overhaul. Remember this at all times, and know how to employ correct defensive outside firefighting tactics. Your life, and the lives of other firefighters, may depend on it.

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