2. 9
Learning Objectives (1 of 9)
• Compare and contrast a defensive
versus offensive fire attack, explaining
the key differences.
• Explain why an offensive attack is
preferred over a defensive attack.
• Enumerate conditions that would lead to
a defensive attack.
3. 9
Learning Objectives (2 of 9)
• Describe how collapse zone dimensions are
determined.
• Evaluate the effectiveness of master streams
operated from distances required to maintain
a safe collapse zone.
• Discuss the positive and negative effects of
operating a hose stream into a window or roof
opening.
4. 9
Learning Objectives (3 of 9)
• Describe conditions when a direct
defensive attack is preferred as
compared to an indirect defensive
attack (i.e., covering exposures).
• Describe how water should be applied
when protecting an exposure from
radiant heat.
5. 9
Learning Objectives (4 of 9)
• Compare and contrast the use of
handheld hose streams versus master
stream appliances during defensive
operations.
• List two ways the water utility may be
able to increase the total water supply
at the incident scene.
6. 9
Learning Objectives (5 of 9)
• Compare and contrast the use of fog
versus solid streams during a defensive
attack.
• Estimate staffing and apparatus needs
when operating master streams.
• Define conflagrations and group fires.
7. 9
Learning Objectives (6 of 9)
• List common problems leading to
conflagrations.
• Explain tactics used to control a
conflagration.
• Discuss why conflagrations are likely to
occur immediately after a natural
disaster.
8. 9
Learning Objectives (7 of 9)
• List reasons for a non-attack strategy.
• Given a scenario, calculate the
dimensions of the collapse zone.
• Prioritize exposures based on fire
conditions, occupancy, and weather
factors.
9. 9
Learning Objectives (8 of 9)
• Develop an incident action plan for a
defensive fire.
• Develop an incident action plan for a
conflagration.
• Apply defensive tactics to a defensive
fire attack.
10. 9
Learning Objectives (9 of 9)
• Apply defensive tactics to a conflagration.
• Evaluate staffing, water supply, and
apparatus needs for a large-scale defensive
fire.
• Apply NIMS to a defensive fire scenario.
• Determine the probability of a conflagration
for a specified response area.
11. 9
Overview (1 of 2)
• Offensive fire attack
– Preferred strategy
• Defensive fire attack
– Limits operations to the exterior
– Results in larger property loss
– Limits rescue options
12. 9
Overview (2 of 2)
• Offensive/defensive decision based on:
– Risk-versus-benefit analysis
• Solid fire-ground information
• Training and experience
• Staffing available to accomplish interior
attack, water supply, ventilation
13. 9
Defensive Attack (1 of 2)
• Objective: save property and/or protect
the environment
• Easier to handle
• Pose fewer risks if the proper
precautions are taken
14. 9
Defensive Attack (2 of 2)
• Situations:
– Structural integrity concerns, fire
conditions, or other hazards prohibit entry
– Resource needs outweigh resource
capabilities.
– Risk-versus-benefit analysis indicates that
the risk is too great.
15. 9
Collapse Zone (1 of 2)
• Equal to the height of the building plus
an allowance for debris to scatter
– Anything less = calculated risk
• Distance equal to 1½ times the height of
the building
• Can be pre-planned
– Estimated floor height = 12′ per floor
16. 9
Collapse Zone (2 of 2)
• Non-attack strategy: tall buildings
– Water application distance for master
streams
• Width of street = limiting factor
– Building evaluated to determine safest
position
• IC must consider expected benefits.
– Risk-versus-benefit analysis
17. 9
Evaluating Exposures
• Two types: internal and external
• Internal
– Fire extends from one area to another
within a structure.
• External
– Surrounding buildings/property
18. 9
Defensive Streams
• May spread the fire inside the building
• Fog streams may push fire.
– May also fill an area with steam, helping
the suppression effort
• Exterior streams may push fire into
concealed spaces.
• Elevated streams may push vented fires
back into the building.
19. 9
External Exposures
• Protecting external exposures is critical.
• Should be evaluated in terms of:
– Life safety
– Extinguishment
– Property conservation
20. 9
Prioritizing Exposures
• Based on:
– Distance between exposed structures
– Volume and location of fire
• Radiant heat increases as flame front
increases.
– Extinguish main volume of fire
21. 9
Radiant Heat
• Inversely proportional to the square of
the distance between the heat source
and the exposure
– Closer the buildings = greater radiant heat
– Exposures higher than the fire are also at
greater risk.
22. 9
Protecting Exposures
• Options depend on:
– Available staffing
– Apparatus resources
• Wetting the exposure is most effective way.
• Directing a stream between buildings is less
effective.
– Radiant heat travels through transparent materials
such as water.
23. 9
Master Streams (1 of 2)
• Defensive operations
– Can apply more water from a greater
distance with fewer personnel
25. 9
Elevated Master Streams
• May hinder upward and outward
movement of heat and smoke
– Usually detrimental to the operation
• May push fire back into the building
– Spreads fire into uninvolved areas.
– Reverses positive effects of ventilation
26. 9
Water Supply Needs
• Defensive operations may be more
challenging than offensive attacks.
• Master streams can require total pump
capacity of apparatus.
– Even reliable water systems can be
exhausted.
– Large-diameter hose is effective.
– Water relay remains a possibility.
27. 9
Exterior Stream Position
• Considerations:
– Safety
– Ability to apply water to exposures and
interior of the building
• Preferably will not push fire into uninvolved
areas
28. 9
Nozzle Type
• IC should know the
advantages/disadvantages of nozzles.
• Solid-stream nozzle
– Greatest reach and penetrating ability
– Best suited for attack on main body of the fire
• Variable-stream nozzle
– Fog pattern
– Straight stream
29. 9
Staffing/Apparatus Needs
• Offensive attack: personnel intense
– More fire fighters for hand lines
• Defensive attack: apparatus intense
– Master streams handled by one person
– Pumpers for water supply or drafting
– Tankers for water shuttle operation
30. 9
Conflagrations (1 of 3)
• A fire with major building-to-building
flame spread over some distance
• Departments should recognize the
challenge.
– Determine the probability in their area.
• Special tactics needed
31. 9
Conflagrations (2 of 3)
• Historical
– Rome, London, Constantinople
– Jamestown, Virginia
– Plymouth, Massachusetts
– Boston
32. 9
Conflagrations (3 of 3)
• Recent
– Oakland/Berkeley, California
– San Jose, California
33. 9
Wildland/Urban Interface
• Fires spreading from wildlands into an
urban area, destroying large numbers of
buildings
– Peshtigo, Wisconsin
• October 7, 1871
• Same day as The Great Chicago Fire
• Killed 1200 people (some estimate as many as
2000 fatalities) and destroyed 17 towns.
34. 9
Contributing Factors (1 of 2)
• Closely built structures
• Wood shingle roofs (most often cited
cause)
• Poor water supplies
• Dilapidated structures
35. 9
Contributing Factors (2 of 2)
• Large-scale, combustible construction
projects
• Developments near wildlands
• Built-up areas near high-hazard
locations
36. 9
Group Fires
• Similar to conflagrations
– Fire is confined within a complex or among
adjacent buildings.
– Potential to become conflagrations
– Smaller in scale
37. 9
Strategies and Tactics
• Important to understand how fires
spread
– High convected heat
– Flying brands
– High radiant heat
• Primary means of fire extension
38. 9
Priorities
• Life safety
• Extinguishment
• Evacuating people before they are
threatened is key to success
– Proactive measure
39. 9
Evacuation
• Area must be beyond the secondary
line of defense
– Wide-perimeter should be maintained
• Evacuation should be handled by police
department.
– A police branch in the IMS is a good
organizational tactic at large-scale fires.
40. 9
Water Supply
• Will be challenged by large-fire tactics
• Priorities:
– Water conservation
– Maintaining fire break
– Protecting exposures
41. 9
Tactical Elements (1 of 2)
• Evacuate and rescue people in
imminent danger
• Evacuate people in the endangered
area beyond the secondary line of
defense
• Set up a line of defense with natural or
artificial fire breaks
42. 9
Tactical Elements (2 of 2)
• Establish a secondary line of defense
• Narrow the flame front
• Maintain brand patrol
43. 9
Non-Attack
• Seldom used strategy
• ICs fail to recognize a total loss.
• Used when:
– Environmental concerns are paramount.
– Safe offensive attack is not possible.
– Defensive attack is not practical.
44. 9
Summary (1 of 4)
• Three possible operations at a structure
fire:
– Offensive
– Defensive
– Non-attack
• A proper size-up will indicate which
operation is appropriate.
45. 9
Summary (2 of 4)
• Offensive attack
– Best chance of saving lives and property
– Operation of choice when justified by
proper size-up
46. 9
Summary (3 of 4)
• Defensive attack
– Rarely an effective means of saving lives in
the building of origin.
– May be the IC’s only reasonable option
– Indicated by proper size-up
– Strategic objectives:
• To protect internal and external exposures
while extinguishing the fire
47. 9
Summary (4 of 4)
• Non-attack posture
– May be best option when:
• Offensive attack is not possible
• Building and surroundings are a total loss
