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Chainsaws are a piece of equipment that are priceless in the battle against fire on both fronts, wildland and structure firefighting. In wildland firefighting chainsaws are used to cut fireline, a clearing around the fire that wont burn. Saws lead in fireline construction followed by a number of "scrapes", an assortment of hand tools for digging and scraping the pine needles, leaves, and other litter from the ground leaving only bare mineral soil form a few inches wide or 3 feet or even up to hundreds of feet wide (in that case the line construction is done by bulldozers). The job of the saw teams is to remove the trees, brush, or other obstructions that would get in the way of the rest of the scrapes. A saw team usually consists of two people, a sawyer and a swamper. The job of the sawyer is to run the saw, and the swamper has the task of pulling all the material the sawyer cut and throwing it clear of the line. On larger fires that have many dead trees that pose hazards to the crews around them and may require a higher level of skill that most crews fallers have, professional fallers will occasionally be called in to fall these trees known as "snags". These fallers usually have a great amount of experience falling trees. There are two main types of saws that are used the Swedish made Husqvarna and the German made STIHL. Both are good saws that have unique qualities that make them more or less desirable to each individual sawyer.
Fighting fires in homes also requires the use of chainsaws. When a building burns it naturally fills with smoke, this makes a blinding curtain firefighters cant see through making their job even more difficult. Not only does this thick smoke make it hard to see and navigate, but it is also very dangerous. The thick black smoke often seen in structure fires is very toxic and highly explosive, making it very dangerous to be near. In an effort to reduce these risks firefighters will ventilate a building by cutting holes in the roof of these buildings, this provides a safe passage for the smoke and can also reduce the amount of toxins in the building. This tactic of ventilation is a safe way to avoid the deadly effect know as a backdraft. By removing all of the heat and explosive gasses it reduces the chance of an explosion. The types of cuts made in roofs varies from 4 feet by 4 feet cuts to long "trench cuts" that span many feet. Alterations have been made to the saws that make these cuts. One of the alterations is in the type of chain used. A typical roof is filled with nails or other materials that would break a typical woodcutting chain in no time at all, so to combat this problem these saws have been equipped with "bullet chain". Bullet chain has carbide tipped cutting teeth, this ultra hard and strong material is not unbreakable but it certainly takes more to break it. The carbide chain can cut through nails or metal roofs with little problem. Another modification seen is the use of depth gauges attached to the bar, limiting how deep a cut can be made through the surface of the roof. If a cut is made to deep through the roof top it can cut through the supports that the firefighter counts on to hold his or her weight, so limiting to how deep a cut can be made helps prevent this. Just as in wildland firefighting the two main saw brands used are Husqvarna and STIHL.
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