Cut into it: Understanding, maximizing and caring for your ventilation tools
We must be well versed in the proper use of chainsaws and our go-to hand tools
One of the most important tactical operations on the fireground is ventilation. It is essential to the success of our mission. Whether horizontal or vertical, hydraulic or pneumatic, or even active or passive, the removal of smoke, gases and other byproducts of combustion must happen to effectively extinguish a fire.
As important as this objective is, we often overlook some of the most important aspects of ventilation: understanding, maximizing and caring for the tools that we rely on to perform these actions.
Although there is an endless list of tools and resources available to perform the varying tasks of ventilation, for the purpose of this article, we will focus on the most common and readily available tools – chainsaws and various hand tools.
Understand your tools
To understand the best approach to ventilation, we must first understand our tools. It is not enough to simply be able to identify a New York hook or know how to start a chainsaw. We must know their designs and their features. We must know the advantages and, in some cases, disadvantages that they present.
Chainsaws: The gasoline-powered chainsaw has been a mainstay in the fire service for both limb removal and ventilation. However, many firefighters know little more than how to start a chainsaw, and do not have a clear understanding of how the chainsaw can be used to the benefit of the sawyer. While it may go without saying that a gas-powered saw performs more quickly and with less effort than a manual-powered axe, the effective operation of a chainsaw involves more than simply pulling the rope and cutting a hole.
First, understand that the saw is an extension of a more important tool, the firefighter. Imagine placing a novice driver behind the wheel of a racecar or a toddler at the keys of a grand piano. While they may be able to operate the equipment, the likelihood of achieving the desired outcome would be low. Without the training and knowledge of correct and effective operation, the saw becomes a 110-decibel paperweight, or worse, a 110-decibel ticket to the emergency room.
Chainsaws are designed to operate under a load. This means that to effectively perform a cut, and to minimize the risk of kickback or binding of the chain, the engine of the saw must be operating a nearly full throttle before the cut is made. It is also important to understand that the chain of the saw is designed to pull the saw into the material it is cutting, and to eject the debris back toward the sawyer. Failure to operate the saw in this manner could result in an ineffective cut at best or a kickback injury at worst.
Halligan, hooks, axes and poles: Let’s now turn to hand tools like the Halligan bar, New York hook, flathead axe and pike pole. While the operation and function of these tools are relatively self-explanatory, there are some general principles that must be understood before we can proceed. For example, while the flathead axe is indeed a cutting tool, when used on a roof, you will be better served to view it as a striking tool, which we’ll address later in the article.
Other hand tools, such as the Halligan bar and the New York hook offer several different uses depending on the situation; their basic use as a prying or pulling tool is only the beginning of their functionality.
Maximize your tools
If knowledge is the gasoline for the brain engine, experience and application are the nitrous oxide. Once we really know our tools, the next step is to amplify that knowledge, taking the theoretical knowledge of our tools and applying practical applications to achieve a better outcome. Each tool offers benefits to the user; however, we must understand how to apply these advantages to our gain.
Chainsaw: Being able to access the roof, cut the needed opening, and then safely exit the roof are tasks that require repetitious training and practice. It is during these training sessions that a firefighter can gain confidence and learn to master the many different tasks that take place when the call to vent the roof is made. It is also during this time that we can learn the best ways to maximize the tool’s abilities and make our jobs easier and safer to accomplish. Each tool used has specific features and functions that can be utilized to make the task easier, safer or both. It is up to us, the user, to learn about these tools and use them to our advantage.
Any gas-powered engine requires three things to run efficiently: fuel, spark and the correct mixture of air to support the combustion of the fuel. Fuel and spark are, in the absence of mechanical failure, guaranteed to be available for the engine; however, clean air can be a bit of a challenge.
When a chainsaw is being used, it is best practice to start the saw on the ground in clean air prior to gaining access to the roof. Once started, the saw should remain running until the task is completed and all cuts are made. To perform this safely, once the saw is started on the ground, the chain brake should be applied to prevent accidental movement of the chain. The saw should also be carried up the ladder by the front handle away from the throttle control and, of course, extra care to divert the bar and chain away from yourself as well as other members of the crew.
Once the crew is on the roof, and the location of the ventilation hole has been decided, the sawyer must be able to complete all needed cuts from a safe position – without putting themselves or others in unneeded danger. No matter the type of hole that is being made (traditional 4x4 square, 7-9-8 style or even large trench-style cuts), the sawyer should work from farthest away to closest. The cuts should be made in a strategic manner that allows for the safety of the sawyer and maximizes efficiency of the tool.
The firefighter must become comfortable with operating the saw from both a right- and left-handed position. This will allow them to perform three of the needed four cuts in a traditional opening from one position. Using the saw from a right-handed grip, the sawyer can complete the farthest cut from the peak going downward, followed by the bottom cut coming back toward them. Next, by changing to a left-handed grip, the top cut can be made again from the far vertical cut back toward the firefighter. Finally, after changing position and moving away from the opening, the final vertical cut can be made from well within the safety of the support of the roof ladder.
Halligan, hooks, axes and poles: As mentioned, the chainsaw is designed to operate under load and functions best in a clean air environment. Occasionally, when attempting to throttle the chainsaw up to make the initial cut, the saw may bog down, or even stall due to smoke being taken in through the air intake. Should this occur, the saw may become unusable.
While calling for a new saw may be possible, the crew must have a contingency plan in place prior to beginning their operation. In most cases, that backup plan involves taking a step back in time and utilizing a tool that was the backbone of ventilation for firefighters long before chainsaws came to be – the flathead axe.
Although seeming somewhat counterproductive, the best use of an axe is not as a cutting tool, but rather a striking tool. If a firefighter must use an axe for ventilation, it is most effective to turn the axe around and use the blunt end of tool to punch through the roofing materials as opposed to attempting to cut through the material with the blade end. While a chainsaw allows for some finesse, an axe is more an act of brute force. There is no easy way to accomplish this task, and because of this, this technique should only be used as a last resort.
The pike pole and New York hook are versatile tools, and their functions are both tactical and practical. Using these tools to pull sections of roofing material away, or to punch through the ceiling material below completes the ventilation process, allowing smoke and gases to escape from the structure. However, there are additional uses that can give firefighters more of an advantage in moving toward successful completion of the task.
One of the most difficult tasks to accomplish when operating on the roof of a burning structure is making the first cut. It is during this step that the sawyer can feel the most vulnerable and is furthest away from the safety of the roof ladder. To aid in this step, and to provide a measure of safety, hand tools such as a hook or Halligan bar can be used to provide additional footing.
Using the pick, or spiked, end of a Halligan bar, can provide the sawyer with an additional step to make the far cuts without having to sacrifice balance or stability. The pick end can be driven into the roof and rotated down so that the adz end of the tool runs parallel to the roof line. This method also provides positive feedback to the crew regarding the structural integrity of the roof. By driving the pick into the roofing material, a crewmember can determine, albeit not definitively, if the sheathing under the shingles has been weakened by fire, heat or rot.
In some situations, the sawyer may need more than a simple foothold to extend their reach and make their cuts. In these cases, you might want to call for a New York hook. A hook that’s inserted into the hole of the rung along the beam of the roof ladder can provide as much as 4 feet of additional footing for the firefighter. Firefighters using this method must use caution to ensure that the tool is securely inserted into the rung. Additionally, the method should be used only after first training and ensuring that the equipment your department uses allows the tool to fully insert into the opening of the ladder without slipping or falling out.
Care for your tools: Training and equipment checks
Each day, at the start of your shift, or at your weekly training night, apparatus and tools are checked off and inspected. At least that’s what the check off sheet says. But how often do we find ourselves simply opening the compartment, seeing that the tools are there, and checking them off the list?
Equipment and tools break and get damaged or misplaced. That is the price of doing business in the fire service. It is everyone’s job to not only know how to use every tool carried on the rig, but also know what is needed to keep their equipment in a consistent state of readiness. After all, there is no worse feeling than needing a piece of equipment on a scene only to find out that said equipment is broken, missing or otherwise damaged.
Chainsaws: I understand that sitting in a classroom or gathering around a saw in the apparatus bay may not be everyone’s idea of a fun training event, but it is this type of training that can make or break a successful ventilation operation.
Consider the following scenario: While attempting to cut a standard ventilation hole, the sawyer throttles up the chainsaw to one-third power and begins to make the cut. Unfortunately, instead of biting into the roofing materials and cutting the hole, the saw skips off of the shingles and “walks” all over the roof. The operator tries again, but with the same result. With visibility growing to near zero and fire conditions below changing rapidly, the order is given to evacuate the roof. The fire progresses and the structure is lost. What went wrong? How could have time in the classroom or apparatus floor helped to prevent this? Knowing that the chain needs to rotate at a certain speed to operate correctly is much easier to explain in a classroom setting than a hands-on environment.
A bullet chain, for example, needs to move at 74 feet per second. To support this speed, the engine must turn at over 10,000 RPM. How many RPMs does the average vent saw complete at full throttle? Between 10 and 14,000. So, having learned that on the ground, in a calm and controlled environment, and having heard the chainsaw at full speed, we don’t need to see the saw or the chain to know that it is not running at a high enough speed to effectively cut through the material. Even without any visual indications on the roof, a well-trained firefighter can help resolve the issue simply by reminding the sawyer to give the saw more power before beginning their cut.
Beyond the practical training mentioned above, additional training is needed to establish a firm understanding of specific parts and operations that should be checked regularly. For example, when checking a chainsaw, it is not enough to see the saw in the compartment, nor is it sufficient to only check the fuel level and mark the check off as complete. The standard check-off should include ensuring that the bar is secure and that the chain is not overly tight or loose and that it is installed in the correct direction. It is also a good time to ensure that the bar oil reservoir is full. Next, the saw should be started and throttled up and then run at speed for several seconds. This will not only allow the firefighter to check that the saw is running smoothly but also verify that the bar oil is flowing from the reservoir to the bar correctly. Finally, while still running at speed, the chain break should be applied, verifying that the chain stops rotating. These steps may seem tedious and unnecessary, but as previously mentioned, the time to find out the saw is broken is not standing on the roof with a saw that won’t cut.
Halligan, hooks, axes and poles: The care and maintenance of hand tools is not as intensive as that of power tools like a chainsaw, but it is important, nevertheless.
- Pike poles should be inspected regularly for damage and defects. The pike should be securely fastened to the pole and should be free of rust and debris.
- The New York hook is made in one piece and does not need to be checked as a pike pole does, but the tool should be clean and free of debris as well.
- A one-piece, solid-bar style Halligan should be clean of debris, not cracked, bent or otherwise damaged.
- A three-piece style Halligan bar requires a more in-depth inspection. Each piece is connected by welding or rivet pins. These connections should be inspected for cracks, damage or weakened connection points. Additionally, three-piece bars must be inspected for corrosion at the connection points. Remember, the weakest part of these bars is the connection points between the pieces, which means that if failure is going to happen, it will happen at these points, and while under load.
- Flathead axes should be inspected regularly for damage and wear. Like the Halligan bar, the weakest point of a flathead axe is the connection between the handle and the head of the axe. If the axe handle is made of wood, stress from use as well as general wood degradation will eventually lead to failure during use. If the handle is made of a composite material, cracking and breaking is unlikely but not impossible. Composite handles should be inspected for bends and warps. The handle should also be inspected for gouges or damage that would further weaken the strength of the axe. The head of the axe should be kept clean of rust and debris, and the cutting edge should be clean and unbent. Remember that when using a flathead axe, you are not cutting the material as much as you are crushing it. The blade edge should not be razor sharp, but rather have a well-defined, even edge that is not susceptible to bending or deforming when striking the material.
A quick search on the internet or through most fire service magazines will point you in the right direction for additional ways that our hand tools can be maintained, modified and made more effective; however, when in doubt, follow your local policies and guidelines.
Time to practice
I challenge each of you to take this information and do something with it. Get out of the recliner and onto the training ground, the classroom, or the bay floor, and apply the information gained to your own system and department. Knowledge is power, so each of us should strive to be the strongest firefighter on our crew, our shift, our department and beyond.