Ignition Techniques & Control Flashcards

What is the most common diesel-to-gasoline ratio range used in drip torches?

Answer: 2:1 to 4:1 diesel to gasoline

Drip torch fuel is typically mixed at about 2:1 to 4:1 diesel to gasoline, with 3:1 common.

In cold, damp conditions, how might igniters adjust the drip torch fuel mix?

Answer: Increase the proportion of gasoline slightly

More gasoline makes the mixture more volatile and easier to ignite in cool, moist fuels.

Ring firing is most useful for which objective?

Answer: Creating a strong central convection column that draws fire inward

Ring firing ignites the perimeter so fire draws toward the center, often used for slash or debris piles and units requiring strong indrafts.

What is a key hazard of center firing combined with ring ignition?

Answer: High-intensity convection can loft firebrands and cause spotting

Strong central convection can produce intense columns and long-range spotting.

Chevron (V-pattern) ignition is typically used in what terrain situation?

Answer: Ridge points or nose of a ridge

Chevron burning is used on ridge points by igniting lines from the apex downslope on both sides.

When igniting on slopes, where is backing fire typically started to establish a secure black line?

Answer: At the top of the slope along the control line

Igniting from the ridgetop control line lets fire back downslope at low intensity, building black.

Why must ignition begin from an anchor point?

Answer: To reduce the chance of fire outflanking control resources

Anchoring prevents the fire from getting around holding forces at the start of operations.