Module 15: Ignition tools

Resources

Module Objective: To know what ignition tools are available, how to use them correctly and safely, and the different circumstances in which to use them.

Types of ignition tools

A wide range of ignition tools is available to the land manager. Careful selection of the most appropriate ignition tool will increase the probability of achieving the prescribed burning objectives.

Selection of ignition tool

The selection of the most appropriate method will depend on the fuel, weather, topography, machine and equipment availability, human and financial resources and the management objectives of the prescribed burn.

In planning a low intensity prescribed burn, choice of ignition tools will be largely determined by the size of the area and the dryness of the fuels.

• If fuels are likely to be quite dry (FMCs less than 12—13%) then wind proof/water proof matches may be suitable for ignition.
• If FMCs are higher, drip torches may be better to ensure fuels are well ignited at each spot.
• Ground ignition is suitable for smaller sized areas and where there is good access.
• Aerial ignition is of greatest value where large areas or a large number of areas have to be burned in a day, where access is difficult or unsafe, or where there is a narrow window of opportunity for burning within the prescription limits.

Matches

• Matches are cheap and easy to use but need to be kept very dry.
• However, matches only suit small burn areas and fuels which are quite dry and will ignite easily.
• Matches can be difficult to keep lit in windy situations
• Consider using windproof and waterproof matches. Typically, these are longer than a normal match, and have a wax-coated match-head that extends two-thirds the way down the length of the stick. (or you can dip the match head in nail polish to make it waterproof).
• For safety reasons, do not carry the box in your pockets.

Hand-held drip torches

• Drip torches have a simple design with low maintenance requirements and come in a variety of shapes and sizes.
• Hand-held drip torches can effectively ignite relatively damp fuels.
• They are relatively light weight and cheap, very durable, highly dependable, easily lit and extinguished, and simple to refuel.
• However, drip torches are a relatively slow method of ignition, they will require multiple refills on long ignition lines which may be logistically awkward, and they can be heavy and tiring to use, particularly in thick vegetation.
• Sometimes when using drip torches with multiple staff, there is a temptation to over-light an area. Monitor your staff and reinforce the burn plan if things are getting out of control.
• Give the vegetation a chance to catch, promoting low and slow burning.

Activity: Proper techniques to adjust and utilize a drip torch on a prescribed burn: - - {% include youtube id=”DWbXQgrYS2M” width=”60” %} ` ->

Fuel mix

• Hand-held drip torches are usually fuelled by a 3:1 or 4:1 or 5:1 mix of diesel and petrol.

• More diesel than petrol is the cardinal rule when it comes to mix ratio, with somewhere between 3:1 and 4:1 being the most common.

• The most volatile mixture, according to the U.S. Forest Service, is 3:1, and is recommended for use only in appropriate fuel types (such as grass) during periods of high humidity.
• Where longevity of combustion is more important than temperature, as in pile burning or broadcast burning for reduction of larger diameter fuels, a higher percentage of diesel may be desired.
• 3:1 is very petrol rich, so is easier to ignite, but does not burn as long and is ‘flashier’, more volatile (use a 5L can of petrol then 15L of diesel to fill a 20L container)
• More diesel provides more sustained burning, but more diesel makes the torch difficult to light. More petrol provides better ignition but is more volatile.
• The diesel provides a longer burning material that “sticks” to the material intended to be burned, providing the heat to keep the fire lit until the fuel begins to burn, while the petrol provides the rapid combustion to help the diesel fuel burn.
• Fuel delivery rate is adjusted with an air supply valve screw, which can be turned slightly to increase or decrease the drip rate.

Activity: read the short article (Who Mixed the Fuel) Think about suitable torch mix ratios for your burn.

Fuelling/refuelling

• Never fuel/refuel around someone who is smoking
• Refuel well away from fire or embers
• Visually ensure that there are no flames on or near the torch when opening or refilling the torch
• Avoid fuel spills on body or clothing (preferably carry a second pair of gloves)
• Re-ignite away from re-fuelling area (at least 3m)

Lighting the drip torch

1. Tighten all connections before using the torch and DO NOT use the torch if there is evidence of any leaks.
2. Select a safe, clear area and open the fuel valve (where fitted).
3. Tip the torch just enough to wet the wick and wet the small pile of grass with the fuel.
4. Place the torch upright.
5. Light the small pile with a match and dip the wick of the torch into this small fire to light the wick.
6. Place the torch upright and the wick should continue to burn, until the fuel mix is exhausted.

Using the drip torch

1. Hold the torch slightly away from the body, tip the torch downward so that the fuel flows out the end and is ignited when it passes through the mesh. The desired flow rate is usually a slow steady drip which maximizes the length of line that can be ignited before refilling.
2. The operator must keep the burner head close to the ground when lighting up to ensure a continuous line of fire.
3. If ground fuels are damp or green, progress may be relatively slow. If a spot is difficult to reach, swing the torch forward and terminate with a snapping motion of the wrist.
4. Use cleared tracks when lighting in rough terrain. (don’t stand in unburnt vegetation)
5. Carry a lit torch in the middle of the firebreak/track
6. Keep the torch upright when not using it for burning
7. To extinguish the torch, place the torch upright, close the valve and blow out the wick or allow it to burn out or smother the wick (with a leather glove).
8. Allow all parts to cool sufficiently prior to handling, refuelling or disassembling.
9. Wipe off the torch and store well away from heat when finished.

Keep a spare burner handy for quick replacement to minimise the delay in maintaining the light-up pattern.

Common operational faults with using hand burners

• Lighting a discontinuous line of fire. This is undesirable especially in the early stages of the burn, as gaps of unburned fuel may provide a bridge for the fire to cross the break and may prevent a rapid build-up of heat, hampering the creation of a draw.
• Failure to keep the burner head as close as possible to the ground. This leads to slow burning and poor, often patchy, lighting up.
• Lack of speed in lighting up. At certain stages of the burn, speed is essential and can be achieves without falling into the errors of the two points above.

Activity: Watch the YouTube video on use of a drip torch by US fire personnel

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• Lower leg injuries can occur due to dripping fuels igniting, mostly from a leaking drip torch.
• Check your clothing for the ‘telltale signs’ of patches on the lower legs of clothing where the oily drips have stained the material.

Refer (Click here)

Home-made hand burners

The standard ignition tool used is a petrol/diesel-soaked rag inside an old tin can on the end of a meter-long wire (like a wand). An old teapot with a ceramic handle and a wick in the spout is an alternate option.

• This is seen as more reliable (and cheaper and less hassle) than using matches to ensure the vegetation will catch and allows the placement of the torch in under areas where fine dry fuel is present.
• It is easier to light up as you walk along this way.
• This tool also does not involve liquid or dripping fuel.

Grassburner gas torch

This is a small handheld gas torch, with spare canisters. The torch has a trigger to ignite, which unlike the tin can allows one to extinguish the lighting tool when not required.

Rake or pitchfork

A heavy rake is an effective ignition device, as it can be used to pull / spread burning materials. A pitchfork can be used to lift burning material and ignite unburnt fuel.

Flame throwers/propane burners

Flamethrowers are less commonly used. They usually have a backpack arrangement with about 20 litres of fuel mix connected to a hand wand and incorporating a hand pump.

CAUTION The knapsack type burner is prone to breakdown and leakages which is a source of danger to the operator

• Serious injury has occurred in New Zealand from using a ‘Solo’ spray units with an adapted flamethrower to burn roots and woody scrub. These units can leak fuel readily and your pants can catch on fire.
• Take special care when using them near people.

Vehicle-mounted flame-throwers: An operator sits in the back of a vehicle tray using the flame thrower while the vehicle drives along the ignition line.

• Vehicle mounted flame-throwers can be a very effective and cheap ignition tool.
• Their use is appropriate when fuels are difficult to light, when a long perimeter burn must be ignited or when the fuels are discontinuous.
• You can cover a large area in a relatively short timeframe.

Propane burners are sometimes used for prescribed burning, but their best application is for burning brush piles and similar concentrated fuels.

• Compared to drip torches, they are heavy, expensive to use per metre ignited, and hold relatively a small amount of fuel. It would take several tanks to light a typical prescribed burn.
• Flame throwers have many of the same disadvantages as propane burners.

Aerial ignition

While aerial ignition is a more expensive option, it reduces the time needed for an area to burn out. Aerial ignition involves dropping burning fuel from a helicopter, and is useful when burning dense vegetation in difficult terrain where walking on foot is unsafe. It is useful as an ignition tool also when trying to cover a large area.

• A common aerial ignition device is a drip torch slung below a helicopter that drops flaming jellied petroleum.
• Flow rates can be adjusted and should be monitored to ensure correct rate. Ignition spacing within and between flight lines can be easily adjusted.
• The rapid firing and burnout utilises a much smaller prescription window.
• Large areas can be safely burned in a single burn period.
• Although roughly the same amount of smoke is produced as hand burning, it is emitted over a shorter period of time.
• Too much heat energy released over a too short a period, will result in a sudden dangerous increase in fire intensity.
• When working with helicopters, ensure all personnel are briefed on ground safety requirements and the danger zones around the aircraft.

General operational and safety considerations when undertaking ignition.

• Have an ignition plan which everyone is aware of
• Use trained skilled operators
• Have a good communication system in place
• Ensure visual contact between parties
• Know where others are and maintain a safe working distance
• Know your escape routes
• Dress appropriately (see Protective clothing training module)
• Check you have sufficient fuel reserves before starting the burn
• Always have more than one ignition source on hand in case one fails to work
• Check ignition tools before & after use for wear & tear, leaks etc. and replace any damaged parts
• It’s a good idea to have a shovel readily available that can be used for beating out un-wanted spot fires, throwing soil on to a fire to smother it, or digging out small hot spots and shielding the face from heat.

Not recommended

Ignition devices that are not recommended include burning tires dragged with a chain and burlap bags held on a pitchfork. Both can be difficult to quickly and easily extinguish, and burning tires release noxious fumes.

Self check

• What ignition device will you use for the prescribed burn you are undertaking?
• Is the ignition device suitable for the type of burn you are undertaking?
• Are you trained in how to use the ignition device?

Activity: Check the condition of your ignition tool, identify any items needing to be replaced or repaired prior to the burn and ensure you have sufficient fuel for the burn

Learning outcome:

Know the factors to consider when selecting and using an appropriate ignition device for a prescribed burn, and how to operate these in a safe manner.