Offensive Versus Defensive Tactics

If we are to reduce the number of injuries and line of duty deaths relating to firefighting, we must take a better look at the total fireground picture and not just focus on the fire. Topic: Offensive Versus Defensive Tactics Time Required: 2...


• Flashover - transition between the growth and fully developed stage and is not a specific event such as ignition; conditions in the area change very rapidly as the fire changes from one that is dominated by the burning of the materials first ignited to one that involves all the exposed combustible surfaces within the area

• Fully Developed - occurs when all combustible materials in the area are involved in fire; maximum heat release based on available oxygen

• Decay - occurs as available fuel is being consumed and the rate of heat release begins to decline; heat level lower and oxygen level very low

• Factors Affecting Fire Development

• Size, number, and arrangement of ventilation openings

• Volume of the area

• Thermal properties of the area enclosures

• Ceiling height of the area

• Size, composition, and location of the fuel package that is first ignited

• Availability and location of the fuel packages (target fuels)

• Effects of Fire on Common Building Materials

• Wood - reaction of wood to fire conditions depends on the size of the wood and the moisture content

• Masonry - minimally affected by fire and exposure to high temperatures although the mortar between bricks, block, and stone may be subject to more deterioration and should be checked for signs of weakening

• Cast Iron - stands up well to fire and intense heat situations but may crack or shatter when rapidly cooled with water

• Steel - structural members elongate when heated and may fail at approximately 1,000oF

• Reinforced Concrete - does not perform well under fire conditions and loses it strength and spalls

• Gypsum - excellent heat resistance and fire retardant properties

• Glass/Fiberglas - wire-reinforced glass may provide some thermal protection as a separation but for the most part conventional glass is not an effective barrier to fire extension; the material used to bind fiberglass may be combustible and can be difficult to extinguish

• Indicators of Building Collapse

• Cracks or separations in walls, floors, ceilings, or roof structures

• Evidence of existing structural instability such as the presence of tie rods and stars that hold walls together

• Loose bricks, blocks, or stones falling from buildings

• Deteriorated mortar between the masonry

• Walls that appear to be leaning

• Structural members that appear to be distorted

• Fires beneath floors that support heavy machinery or other extreme weight loads

• Prolonged fire exposure to the structural members

• Unusual creaks and cracking noises

• Structural members pulling away from walls

• Excessive weight of building contents

II. OPERATIONAL READINESS (EO 1-2)

Before any response can be made to an incident, there are several factors that must be considered and addressed in order to have a safe and effective response

· Training - are the personnel responding on the incident trained to carry out the duties and responsibilities that are expected to be assigned

• Drivers trained to get the apparatus to the scene and back to quarters safely, position it for maximum utilization, and operate the pump or the ladder quickly and efficiently

• Officers trained to perform the size up, develop an overall strategy, devise tactics to implement the strategy, lead an aggressive yet safe suppression, and coordinate any activities assigned

• Firefighters trained to perform the duties to which they will be assigned in a safe and effective manner

• Safety officer to maintain the overall safety of the incident scene

• Staffing - is there adequate staffing to carry out the duties and responsibilities that the unit will be assigned in a safe and efficient manner

• Staffing on the apparatus to make an initial attack or provide support for an engine crew

• Staffing arriving on more than one piece of apparatus to make up necessary minimum staffing for an assignment

• Length of time it will take to have adequate staffing on the scene to initiate an interior attack while maintaining a rapid intervention team in place

• Apparatus

• Adequate apparatus response based on the hazard involved

• Potential for delay in arrival of some of the units due to road conditions, weight and size limitations, travel distances, or units not being staffed immediately