NFSI Firefighting Knowledge 5 — Questions and Answers
Question 1: What is 'water hammer,' and why is it a concern during fireground operations?
- A technique for breaking padlocks using a flat-head axe and hammer
- A pressure surge in hose lines caused by rapidly opening or closing valves, potentially rupturing equipment (Correct answer)
- The noise produced when suppression water contacts superheated steel
- A collapse pattern caused by water weight accumulating on weakened floors
Correct answer: A pressure surge in hose lines caused by rapidly opening or closing valves, potentially rupturing equipment
Water hammer is a destructive pressure wave created by sudden changes in water flow velocity, capable of damaging pumps, couplings, and hose lines.
Question 2: What is the purpose of the 'cool, cover, and call' approach for burn victims at a fire scene?
- Cool the burn with ice, cover with a sterile dressing, and call the fire investigator
- Cool with cool (not cold) water, cover to prevent hypothermia, and call for advanced medical care (Correct answer)
- Cool the environment to prevent re-ignition, cover the victim from smoke, and call for evacuation
- Cool burns with foam agent, cover with a fire blanket, and call poison control
Correct answer: Cool with cool (not cold) water, cover to prevent hypothermia, and call for advanced medical care
Cool water stops the burning process, covering prevents hypothermia and contamination, and calling for ALS ensures the victim receives definitive care for serious burns.
Question 3: What is the primary purpose of salvage operations during and after a fire?
- To collect evidence for fire investigators before it is destroyed by suppression water
- To protect property from further damage by fire, water, and smoke through covering and removing items (Correct answer)
- To ventilate the structure to speed drying and prevent mold growth
- To document the fire's spread pattern for training purposes
Correct answer: To protect property from further damage by fire, water, and smoke through covering and removing items
Salvage operations use covers, squeegees, and water removal techniques to minimize property damage from suppression activities, reducing overall loss.
Question 4: In wildland firefighting, what does the acronym LCES stand for?
- Lookouts, Communications, Escape routes, Safety zones (Correct answer)
- Location, Command, Entry point, Suppression resources
- Lookouts, Crew size, Equipment status, Safety briefing
- Lines of control, Communication, Escape, Staging
Correct answer: Lookouts, Communications, Escape routes, Safety zones
LCES (Lookouts, Communications, Escape routes, Safety zones) is the foundational safety system for wildland firefighters to prevent entrapment.
Question 5: Which type of building construction is most susceptible to rapid structural failure during a fire due to lightweight engineered components?
- Type I (fire-resistive)
- Type II (non-combustible)
- Type V (wood frame) with lightweight truss construction (Correct answer)
- Type III (ordinary masonry)
Correct answer: Type V (wood frame) with lightweight truss construction
Lightweight wood trusses and I-joists used in modern Type V construction can fail in as little as 5–7 minutes of fire exposure, far faster than older solid-wood construction.
Question 6: What is the correct sequence of actions when a firefighter's PASS device activates during interior operations?
- Reset the device, report to command, and continue the search
- Immediately transmit a mayday, activate emergency traffic on radio, and attempt to exit or go to a safe area (Correct answer)
- Signal teammates with a light, stay in place, and wait for RIT arrival
- Deactivate the PASS alarm to avoid distracting other crews, then self-rescue
Correct answer: Immediately transmit a mayday, activate emergency traffic on radio, and attempt to exit or go to a safe area
An activating PASS device indicates a firefighter may be down; the immediate actions are to declare a mayday, switch to emergency traffic, and attempt self-rescue or reach a defendable position.
Question 7: What is the purpose of a fire department connection (FDC) on a sprinkler system?
- To allow firefighters to drain the system after a fire is controlled
- To enable the fire department to supplement or boost water supply to the sprinkler system from a pumper (Correct answer)
- To connect building standpipe hose cabinets to a municipal water main
- To provide a test connection for annual sprinkler flow testing
Correct answer: To enable the fire department to supplement or boost water supply to the sprinkler system from a pumper
The FDC allows engine companies to connect a supply line and pump water into the sprinkler or standpipe system to augment pressure and flow during firefighting operations.
NFSI Firefighting Knowledge 5
What is 'water hammer,' and why is it a concern during fireground operations?