The rotary saw is one of the best tools on the fireground, beneficial for forcible entry operations as well as ventilation operations and providing a powerful option for both. The rotary saw can be a scary tool to use for some firefighters, but when you get familiar with using it, it becomes a standard tool like any other.
- Truck Company Operations: Using the Rotary Saw, Part 1 | Part 2
- Training Minutes: Body Positioning While Making Horizontal Cuts
- Training Minutes: All About Saws: Doggy Door Cut
- Training Minutes Revisited: Rotary Saws
When using the rotary saw, there are some basic items to consider and deal with that are the same for any type of saw that is manufactured. Listed below are some of these basic points to remember when using the saw.
Full Throttle
Power saws are a great asset on the fireground. They allow firefighters to complete many functions quickly and easily as opposed to using hand tools and brute force. No matter what type of power saw you use, it needs to be operated at full throttle. Two-stroke engines, the type used in power saws, deliver a high-performance output when operated properly. When the throttle is wide open, the two-stroke engine will deliver maximum performance. When it is only opened halfway or at quarter, it will not perform optimally and will lead to other mechanical problems with the power saw. Remember–all the way open or idle.
When going to plunge the saw blade into the material, the blade needs to be spinning at full rpms to be effective. To accomplish this requires the rotary saw to be running at full throttle, then introduce the blade into the material to be cut. If the saw blade is resting against the material and then you try to throttle up the saw, you will hear the saw trying to ramp up, working against itself because of the friction being created by the blade against the material at idle speed while trying to achieve full rotational spinning. This can cause the saw’s belt to burn out and potentially damage the engine.
Blade First?
Whenever using a rotary saw, the blade of the saw is the dangerous part. The rotary saw does not have an engine break on it to stop the blade from spinning once the throttle has been brought back to idle. The blade will spin freely on its own until it comes to a complete stop due to a loss of momentum or because it was buried into the material to make it stop quickly. When passing a rotary saw between two people on a ladder, a roof, or even on the ground, avoid passing the saw with the blade first. This way if the blade is still spinning, it will not be presented first to the other firefighter.
Stop the Blade
We mentioned how we do not want to pass a rotary saw between two people with the blade first just in case the blade is still spinning. It is important for us to stop the blade once we have finished using it to make our cuts. The rotary blade spins at a high rate of speed, between 4,500 -5,500 rpms for certain models and makes. The combination of a high rate of speed and a thin kerf of a blade provides for a disastrous outcome in terms of personal injury. Stopping the blade needs to be done manually by pressing it against a piece of material so that the blade stops. Make sure to stop the blade.
Use Gravity to Your Advantage
When using a rotary saw on a roof, wall, garage door, or any vertical surface, remember to use gravity to your advantage. Too many firefighters rely upon using their own muscle and power to work the saw. Let the saw do the work and let gravity pull the saw down towards the ground. This can be accomplished by walking the saw down the roof or down the wall. By doing this the fatigue factor will not be as high and the saw will work perfectly–as it is intended to.
Use Your Body to Hold the Saw
When using a rotary power saw, you may have to conduct your cuts in different positions. The cuts may have to be made high above the shoulder, middle around the waist area, and low around the feet area. Whenever making these types of cuts, fatigue will set in quickly; holding a rotary power saw with just your muscle is only going to last so long. Using your body to help hold the saw will extend the endurance of your muscles. The saw may have to rest on your shoulder or in the cradle of your arms so that you use your whole upper body as opposed to just your arms.
Using the Peak
When vertical ventilation is required and the use of power saws are needed to cut the opening, starting the saw is sometimes the hard part. When on a sloped roof, this can prove to be difficult. Even though we start the saw on the ground, we cannot carry it up the ladder with it running – we want to start the saw on the roof. Using the peak of the roof can help with this. A technique developed by the Milwaukee (WI) Fire Department has the power saw rested on the peak of the roof with the firefighter holding it place while pulling on the pull chord. It’s a great technique for starting a saw.
Limited Visibility
When working on the roof of a building, the visibility of the roof area can become limited. With billowing smoke exiting from the building, the roof area can become a dangerous place due to not being able to see. Teams working together on a roof must rely on other means of accountability such as voice communication when visibility is limited. The team members need to know where each other are so that they will not be caught in the cutting path of the roof opening. Stay out of the cutting path.
Mark van der Feyst has been in the fire service since 1999 and is a firefighter with the Fort Gratiot (MI) Fire Department. He is an international instructor teaching in Canada, the United States, and India, and at FDIC. He is also the lead author of Residential Fire Rescue (Fire Engineering Books & Video). He can be contacted at Mark@FireStarTraining.com.
