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Difficulty: HardFires and Fire Extinguisher Use

Following an emergency stop on an off-ramp shoulder due to an electrical and fuel line fire near the battery box of a flatbed combination vehicle, which procedure must the driver follow when deploying the onboard portable fire extinguisher?

  1. A
    Open all adjacent compartment covers to expose the internal wiring, then aim the extinguisher directly at the top of the flames while moving closer.
  2. B
    Douse the smoldering wiring harness and surrounding fuel tank bracket with pressurized water from the emergency roadside kit.
  3. Stand upwind at a safe distance, aim the extinguisher nozzle directly at the base of the fire, and discharge the dry chemical using a side-to-side sweeping motion.Answer
  4. D
    Position yourself downwind of the burning components and discharge the extinguisher in continuous vertical sweeps across the rising smoke plume.

Answer

Stand upwind at a safe distance, aim the extinguisher nozzle directly at the base of the fire, and discharge the dry chemical using a side-to-side sweeping motion.
The correct response follows official commercial driving fire-fighting safety protocols: the operator stays upwind so wind carries heat and toxic fumes away, maintains a safe distance, aims the nozzle directly at the base/source of the fire rather than the flames, and sweeps the dry chemical agent side to side (the PASS method).

Step-by-Step Solution

1
Assess the wind direction and position yourself relative to the fire.
Driver stands upwind at a safe operating distance.
Standing upwind ensures that wind blows smoke, intense heat, toxic gases, and chemical extinguishing agent away from the driver.
2
Select the proper B:C or A:B:C dry chemical extinguisher and apply the PASS operational protocol.
The extinguisher is prepared and aimed directly at the base or source of the fire rather than into the smoke or upper flames.
Aiming at the base of the fire attacks the fuel source and smothers the combustion process effectively.
3
Squeeze the handle and sweep the discharge nozzle from side to side across the base of the burning material.
The dry chemical agent covers the fuel and extinguishes the fire without unnecessarily feeding oxygen into enclosed compartments.
A side-to-side sweeping motion creates an uninterrupted chemical barrier over the fuel bed, preventing reignition.

Key Concept

Commercial Vehicle Fire Extinguisher Deployment and PASS Containment Protocol
Estimated Time:1m 30s
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Topics

Fires and Fire Extinguisher Use

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