Ignition Techniques & Control Flashcards

Which ignition technique is best for reducing fire intensity in heavy fuel loads?

Answer: Strip-head firing

Strip-head firing involves igniting a series of parallel strips into the wind, allowing each strip to burn a short distance before the next is ignited. This technique is effective for reducing fire intensity in heavy fuel loads by creating a wider, less intense fire front, which helps manage heat output and control fire behavior more effectively than a single head fire.

What is the primary purpose of a 'backfire'?

Answer: To create a fuel-free buffer zone

A backfire is intentionally set to burn against the wind, creating a wide, fuel-free buffer zone that an approaching head fire cannot cross. This technique is critical for establishing secure control lines, particularly in situations where a head fire might otherwise become unmanageable, thereby enhancing safety and containment.

When is 'spot ignition' most effective?

Answer: In areas with patchy fuels or ecological sensitivity

Spot ignition involves igniting individual points, allowing the fire to spread outward from each spot. This technique is most effective in areas with patchy fuels or ecological sensitivity because it allows for more precise control over fire intensity and spread, minimizing impact on specific areas and achieving desired burn objectives with greater nuance.

What safety precaution is critical during aerial ignition?

Answer: Ensuring ground crew communication and escape routes

During aerial ignition, maintaining clear communication between the aircraft and ground crews is paramount, along with established escape routes for all personnel. This ensures that ground crews are aware of ignition patterns, can respond to unexpected fire behavior, and have safe egress in case of emergencies, mitigating risks associated with rapid fire spread.

Which factor determines the choice between 'head firing' and 'flanking firing'?

Answer: Wind direction and desired fire spread rate

The choice between head firing (burning with the wind) and flanking firing (burning perpendicular to the wind) is primarily determined by wind direction and the desired fire spread rate. Head fires spread rapidly and intensely, while flanking fires offer more control and a slower spread, allowing managers to select the technique best suited for specific fuel types and burn objectives.

Why is 'cold trailing' used after ignition?

Answer: To extinguish residual heat along fire edges

Cold trailing is a mop-up technique performed after a fire, involving carefully feeling the fire edge with bare hands or gloved hands to detect any remaining heat. Its purpose is to ensure all residual heat, embers, and smoldering materials along the fire perimeter are extinguished, preventing rekindles and ensuring the fire is completely out.

What is a key advantage of 'pulsed firing'?

Answer: It minimizes smoke production and allows fuel moisture equilibration

Pulsed firing involves igniting small sections of the burn unit sequentially with periods of rest in between. This technique helps minimize smoke production by allowing smoke to disperse between ignitions and allows fuel moisture to equilibrate, leading to a more controlled and often less intense burn, which is beneficial for air quality and achieving specific ecological objectives.

Which tool is typically used for precise spot ignition?

Answer: Drip torch

A drip torch is a specialized tool commonly used for precise spot ignition in prescribed burning. It allows operators to control the placement and amount of ignited fuel, making it ideal for creating individual ignition points or for more controlled firing patterns in specific areas.

How does 'blacklining' enhance fire control?

Answer: By creating a firebreak of burned fuel adjacent to control lines

Blacklining is a technique where a narrow strip of fuel adjacent to a control line is intentionally burned prior to the main ignition. This creates a "black" or fuel-free buffer zone, effectively widening the control line and preventing the main fire from crossing it, thereby significantly enhancing fire control and containment.