By FRANK VISCUSO and MICHAEL TERPAK
There are various reasons to change strategy from offensive to defensive (photo 1). Threat of collapse, rapid fire growth, truss roof involvement, and explosive contents within a structure are just some of the reasons you may elect to go defensive. All circumstances revolve around conditions becoming worse and resources not being sufficient enough to get the job done. When the water supply, resources, and on-scene personnel are not enough to keep up with a growing fire and interior operations present great unnecessary risks for firefighters, the incident commander (IC) should be prepared to retreat and switch tactics. Any time a decision is made to change from an offensive to a defensive operation, the announcement must be clearly communicated to all fire personnel operating at and responding to the scene.
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| (1) Firefighters engage in a defensive operation. (Photo by Robert Osborn.) |
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| (2) After personnel withdrawal, the priority will shift to protecting exposure buildings. (Photo by Michael Terpak.) |
OPERATIONAL GUIDE
The following operational guide provides ICs with the necessary steps to take when changing from an offensive to a defensive strategy. Always remember, it is better to shift too soon rather than too late. When it comes to firefighter safety and fireground survival, there is no room for hesitation.
1. Announce a move to defensive operation by radio.
- Have your dispatcher announce a change in tactics from offensive to defensive, and order all personnel operating within the structure to evacuate and meet at the command post (or another designated location).
2. Sound the evacuation tones and air horn.
- Have your dispatcher send a designated evacuation tone over the radio.
- Have apparatus drivers activate their air horns four times to signify evacuation of the structure.
3. Request additional alarms.
- Request an additional alarm and necessary resources if you do not have enough on scene or in staging to handle the change in tactics.
4. Conduct a personnel accountability report (PAR).
- Along with your accountability and safety officers, account for all personnel to ensure they have made it out of the structure. Have your dispatcher call the officer of each company to confirm all personnel are accounted for.
Following is an example:
- – Dispatcher: “Engine 1.”
- – Engine 1 officer: “E-1 officer, ALL members are accounted for.”
- – Dispatcher: “Engine 2 officer.”
- – Continue calling units until all companies/members are accounted for.
- If members do not respond, activate the rapid intervention crew (RIC).
- – The RIC should follow the “Operational Guide for the RIC.”
5. Readjust your incident management system to reflect the new defensive operation.
- Establish divisions on all four sides (A, B, C, and D). Do this after you conduct a PAR and account for all members.
6. Establish your collapse zone.
Walls collapse in three general manners, which follow:
- 90° angle collapse: This is most common and is similar to a falling tree. The wall falls straight out, and the top hits the ground at a distance equal to the height of the wall.
- Curtain-fall collapse: This generally occurs with a masonry wall. It collapses like a curtain dropping from the top, creating a pile of debris at the base of the wall.
- Inward/outward collapse: A wall leaning inward may not necessarily fall inward.
The lower or upper portion may slide or “kick” outward. The collapse zone itself should be as wide as the structure and 1.5 times the height. Take construction materials into consideration.
- Ordinary and heavy-timber buildings are two times the height of the structure.
- – Use caution/barricade tape to clearly mark the edges of the collapse zone.
- – When established, collapse zones must be maintained during and after the incident, during the investigation, and until the structure is examined by an engineer.
- – Assign additional safety officers to cover all four sides.
- – Call for the response of the utility companies to shut off the gas, electric, and water to the building from exterior locations, away from the structure.
7. Monitor for signs of collapse.
- Depending on the height of the structure and its building features, set up a number of surveyor transits to detect an early structural movement from walls, church steeples and bell towers, water tanks, and so on.
- Consider the following when determining collapse potential:
- – Fire size and location.
- – Heavy fire for an extended period of time.
- – Pieces of the building falling off.
- – Cracks in walls.
- – Leaning or bowing walls.
- – Building age and condition.
- – Faulty/poor construction.
- – Foundation failure.
- – Extraordinary loads.
- – Lack of water runoff.
- – Sagging floors or beams.
- – Spongy roof or floors.
- – Previous fires at this location.
- – Explosions, flashovers, or backdrafts.
- – Water and/or smoke pushing through solid masonry wall.
- – Smoke through mortar joints.
- – Accidental cutting of structural support members.
- – Lightweight construction components.
- – Extreme weather conditions.
- – Fire reaches the truss roof.
- – Unusual noises (creaking).
- – Any combination of causes.
- Firefighters should be mindful of the condition of the parapet, canopy, marquee, cornice, floors, and roof.
- Constantly monitor for secondary collapse from the existing structure or collapse and failure of any surrounding exposure buildings.
- Note: If collapse occurs, follow the “Operational Guide for Structural Collapse.”
8. Set up master streams (ground monitors, deluge guns, large-diameter hoselines, and so on).
- If the roof is still intact, aim the streams up and through the windows into involved ceilings.
- If the roof has burned away, use elevated streams and aim down onto the fire.
- If possible, position and secure unstaffed master streams outside the collapse zone.
9. Secure an additional water supply (from another source or water main).
- Whenever possible, do not use the same water main when additional water is needed.
10. Protect nearby exposures.
- Do everything in your power to protect exposures from collapse, radiant heat, water runoff, and so on.
- Evacuate exposures, if necessary.
11. Assign a brand patrol. (This will depend on the building’s contents, height, and construction.)
- Use a minimum of one engine and one ladder company.
- Position downwind to track and extinguish flying brands.
12. Rotate personnel frequently.
- Establish emergency incident rehabilitation.
- – Follow the “Operational Guide for Emergency Incident Rehabilitation.”
FRANK VISCUSO is a 20-year veteran of the fire service and a tour commander in Kearny, New Jersey. He is a level 2 New Jersey fire instructor, co-creator of FireOpsOnline, and the author of three books including Fireground Operational Guides (Fire Engineering, 2011). He has developed more than 50 standard operating procedures and has served seven years as his department’s training officer.
MIKE TERPAK is a 35-year veteran of the fire service and a deputy chief and citywide tour commander in the Jersey City (NJ) Fire Department. Throughout his career, he has worked in the city’s Lafayette and Greenville areas with Engines 10 and 17, Ladder 12, and Rescue 1; as chief of the city’s 2nd Battalion; and as former chief in charge of the city’s Training Division. He lectures nationally on fire/rescue topics and is the founder of Promotional Prep, a New Jersey-based consulting firm that prepares firefighters and fire officers studying for promotional exams. He has a BS degree in fire safety administration from the City University of New Jersey and is the author of Fireground Size-Up, Assessment Center Strategy and Tactics, and Fireground Operational Guides (Fire Engineering, 2011).
