This document outlines learning objectives and provides an overview of defensive firefighting operations. It discusses when a defensive attack is preferable to an offensive attack, such as when structural integrity is compromised or risks outweigh capabilities. Defensive tactics include operating master streams from a collapse zone distance and protecting external exposures. Conflagrations can rapidly spread between buildings and require special tactics due to their large scale. Contributing factors and strategies for controlling conflagrations are described.

1. 9
Defensive
Operations

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

24. 9
Master Streams (2 of 2)

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