Flanks are the sides of a ground Head is the part of a ground cover Fingers are narrow fast moving
The subject today is concerning forest fires or sometimes called woods fires. Forest fires destroy acres of land, property and lives. Forest fires can be started by lightning strikes to trees, by people, and plane crashes or other transportation that travels through or around the country side. There are things that affect the way a Forest fire will travel. Also to be considered is fire ground safety and the hazardous situations that may occur.
Some things to keep in mind while fighting a forest fire are wind shifts, wind speeds, heat temperature of the day, have an escape plan and route, and remember that loose rock may make travel difficult and dangerous.
You also need to know fire behavior and be able to anticipate fire movement in the area you are in.
You need to wear proper protective clothing and equipment for protection against falling objects.
Always carry tools by your side and not over your head and stay no more than 12 feet apart on the fire line.
Watch for hanging limbs, burning or dead trees, trees leaning against another, rolling rocks and logs,
When driving through smoke turn on lights, sound horn, close windows, and drive slowly.
Avoid driving thought if you don’t have an escape route.
When parking always face vehicle the direction of the escape route.
Remember burned areas are safer than unburned areas.
Watch for power lines and fences that can become energized by a fallen power line.
Always keep in contact with other surrounding fire fighters.
Ground cover is one thing that is considered as fuel. When fighting a forest fire ground cover is considered to be either green fuels, heavy fuels, or flash fuels.
Green fuels are considered growing vegetation. They are not normally flammable but heat from fire can dry the vegetation fast and cause fire to ignite the dried out vegetation.
Heavy fuels are usually slow burning like stumps, logs, matted duff, and heavy limbs. Heavy fuels like these have moisture within and take super heat from a flash fuel fire.
Flash fuels are pine needles, small branches, twigs, dead leaves, or dried grass. These fuels burn quickly and travel rapidly. Flash fuel fires supply the heat to ignite heavy fuels.
Two types of ground cover fires are ordinary fire and blow up fires.
Ordinary fires are brush and grass fires. They have length and width dimensions.
Blow up fires are three dimensional. They have width, length, and height.
Undergrowth or duff fires burn deep into peat or duff from past years under mulch. When I lived in Alaska we had these type fires pop up after the snow would melt .These type fires can smolder for a long time.
Crown fires occur as fire crosses through leaves or needles of trees, dense brush or large bushes.
Spot fires is a result of a spark or ember carried by wind to start another fire else.
Things that can affect the spread of a forest fire are a long dry spell when the ground cover is really dried out.
Relative humidity when the volume of warm air will hold more moisture than cool air. This has a big affect upon the spread of fire because of the daily fluctuations of relative humidity dry air and low humidity. This also has an effect in the spread of a forest fire.
Temperature along with the relative humidity can help slow the spread of forest fires because of the late evening dampness.
The slope of the land will affect the spread of fire.
Fire will usually burn much faster and intense uphill because the heated air draws the flames upward.
The parts of a ground fire will usually form a pattern. Listed below are four of those patterns.
Fingers are narrow fast moving parts of the fire that fork out from the main head of the fire. The name for this was used because it looks like the fingers on your hand when you spread your fingers out.
Flanks are the sides of a ground cover fire meaning to the left or right.
Head is the part of a ground cover fire that is spreading most rapidly.
Rear is the back side of a ground cover fire.
We have ways of attacking a forest fire and one of those is called back firing. This is done by starting a fire to burn ground fuels so the main fire will hopefully run out of fuel to burn.
We also can use track vehicles from the forest service to cut a large fire break to help prevent fire spread.
We also can use planes and helicopters to drop water and fire retardant chemicals on the fire to help stop the fire from spreading.
As you can see my job can be dangerous when we fight forest fires.