In this blog post, I will discuss the importance of using chainsaw chaps while working with an electric chainsaw.
Yes, chainsaw chaps specially designed for use with electric chainsaws exist There is no difference between an electric chainsaw and a gasoline-powered chainsaw in the likelihood of the rotational kickback. But the velocity of the rotation during the kickback is much greater in a gas-powered chainsaw, about twice that of an electric chainsaw.
The ANSI Z133 Safety Requirements for Arboricultural Operations requires that every worker must wear cut retardant chainsaw chaps that meet or exceed ASTM F1897 and ASTM F1414 while chainsawing on the ground operations. The Z does not differentiate between an electric or a gasoline-powered chainsaw. When you are operating a corded or a cordless electric chainsaw on the ground, you must wear chainsaw chaps.
In a study, gyroscopes and accelerometers were mounted to a battery-powered electric chainsaw and to a mid-sized, gasoline-powered chainsaw, and results were observed during normal cutting and kickbacks. These devices measured the accelerations perpendicular to the guide bar and along the guide bar of the chainsaws as well as rotational velocities toward the user’s lower legs. Data collected from the battery-powered electric chainsaw showed that accelerations during normal cutting and kickbacks had peak magnitudes of from ~2 to ~6 g and from ~6 to ~8 g, respectively, and the rotational velocities typically reached over 6007s during a kickback.
The detailed analysis of the results revealed that the gyroscope alone, using a threshold value of 300 degrees, was effective in distinguishing normal cutting from the chainsaw kickback. The results from the gasoline-powered chainsaw revealed the same general trends as those with the battery-powered electric chainsaw, but the rotational velocities during a kickback were greater, typically exceeding 1,0007s. By using machine learning techniques, a very effective method than a simple threshold, distinguishing kickback from normal chainsaw operation was developed.
Using these techniques, kickback was determined very reliably and often when the deviations from the rotational velocities corresponding to normal cutting were small. The use of chainsaw chaps can lead to an improved kickback control system on chainsaws. It is the torque, not the speed, that you must consider.
The speed on an electric chainsaw is 2200 feet per second, while the speed of the chain on a gasoline-powered chainsaw is 5100 feet per second. Gasoline-powered chainsaws differ from electric chainsaws in many ways. For instance, a gasoline-powered chainsaw has a peak torque value for a given revolution per minute (RPM).
An electric chainsaw produces torque in response to load. When the load increases, the revolution per minute (RPM) decreases, the chainsaw draws more power and its torque increases. When the load on a gas-powered chainsaw increases, revolutions per minute and the torque decrease.
In an electric chainsaw, as the load increases the torque increases too, to maintain the speed of the chainsaw.
What are chainsaw chaps and why are they used?
The chainsaw chaps are a piece of safety equipment worn on the legs of an arborist, an arboriculturist, or a tree surgeon, to protect them from any serious injury. Chainsaw chaps are specially designed with extra attention paid to the areas around your lower leg muscles and under your kneecaps to offer more protection than your regular jeans or cotton trousers. Designed to perfectly cover all contact areas on your ankles, calf, knees, shins, thighs, and feet, chainsaw chaps are constructed from slightly rounded high-density impact foam that conforms to your legs.
Chainsaw chaps have a layer of gel that covers your entire foot top for extra strike absorption. They have comfortable straps to secure them to the back of your leg and open fully to allow you to easily slip the pair on and off. These straps keep the chaps secure to your feet, including a larger strap on the ball of the foot with rubber dots for extra traction on the ground.
You must prefer the chainsaw chaps that have a mesh window constructed in its back that allows the flow of fresh air for ventilation. The chainsaw chaps made out of synthetic leather will offer an improvement of anti-odor technology if you clean them once a week. You should prefer the chainsaw chaps that have dual hook and loop strap and silicone grip to minimize shifting.
How to measure your legs properly to buy a pair of chainsaw chaps?
You must measure the length of your legs, your waist, thighs, shins, calves, and ankles before buying a pair of chainsaw chaps. You should measure from your belt loop to your bottom.
You must know your outseam length because some manufacturers provide their electric chainsaw chaps with varied outseam lengths ranging from thirty-two inches to forty inches. Sit down with your feet flat on the floor, now measure around the widest part of your calf using a measuring tape. To measure the height of your chainsaw chaps you must start measuring from your ankle to your kneecaps.
Measure around the area about 2 inches to 4 inches below where your thigh bends. After the measurement of both of your thighs, you must add 2 inches to 4 inches to these figures. Select the electric chainsaw chaps an inch longer and a couple of inches looser than the figures.
If you end up with too big a pair of chainsaw chaps they will disrupt your freedom of motion during training and cutting. They will not fit well and slip off forcing you to realign your chaps after each step.
And if you ignore your sizing and end up with too-small a pair of chainsaw chaps, they may fit too tight and will not offer enough protection. When you purchase a pair of electric chainsaw chaps with accurate size, they will provide you with maximum protection and comfort.
What material are the chainsaw chaps made up of?
Modern-day chainsaw chaps are made of many different synthetic materials, including, but not limited to:
- Fiberglass – Stiff, sturdy, and lightweight which offers maximum protection in case of a kickback.
- Foam rubber – Very lightweight, but not as sturdy and solid as fiberglass which offers enough safety and protection.
- Polyurethane – Heavy and sturdy, which offers almost complete protection from most impacts.
- Plastic – Less protective than any of the other synthetic chainsaw chaps.
- Metal – Highly protective, but very heavy and uncomfortable while moving or climbing up a high tree.
- Hand-made pair of chainsaw chaps are the most durable and worthy of investment.
The weight of the early chainsaw chaps used to be about 15 pounds or more. The weight used to discourage its use in the tree care industry. In the late 1960s, the US Forest Service began providing chainsaw chaps to the crew.
In January 1975, Mr. Robert Felix, Executive Secretary of the National Arborist Association which was the forerunner of Tree Care Industry Association wrote a brief in the Journal of Arboriculture on a recent Occupational Safety and Health Administration (OSHA) citation to Asplundh Tree Expert for not providing the chainsaw workers with chainsaw chaps. National Arborist Association and Asplundh Tree Expert considered that the chainsaw chaps provided a false sense of security and trip hazard.
The material of the chainsaw chaps has nowadays become lightweight and very comfortable to wear. Many manufacturers sell chainsaw chaps ranging from summer material to winter material, comfortable and suitable for every reason and every season you cut. The protective material used in the manufacturing of chainsaw chaps is reliable.
The outermost layer of the chainsaw chaps is made up of regular fabric that will protect your legs against hitting by flying sawdust, stones, wood chips, snow, rain, etc. It is not cut-retardant, it is only waterproof. It is the innermost loose layer that is responsible for stopping the movement of the chain and the sprocket of your electric chainsaw.
The innermost layer of the chainsaw chap is made up of ballistic-nylon, polyester or Kevlar that has very strong, cut-retardant fiber. The fibers can spread or straggle by the cutters of your electric chainsaw, holding, stopping and locking the chain of your electric chainsaw by pulling into its drive sprocket. The four layers of ballistic nylon in electric chainsaw chaps can stop a chain speed of 2750 feet per minute.
The Forest Service has an even higher requirement for protection at 3200 feet per minute. When you are out to purchase a pair of chainsaw chaps, make sure that it meets the specifications in ASTM F1897-98. The pair of chainsaw chaps that meet ASTM F1414 are puncture and cut resistant.
Some chainsaw chaps may carry a warning that it will not control the movement of the chain on an electric chainsaw. Before ordering one, make sure that you have read the product description twice. Ask the manufacturer about its use with an electric chainsaw if you can’t find any details in the product description section.
What do experts say about the importance of using chainsaw chaps while using an electric chainsaw?
Tsioras in 2014 and Kenyon in 1989 stated that proper chainsaw chaps and user training are really effective in reducing the number of avoidable deaths, kickback occurring, and the severity of the subsequent injuries. Pratt in 1979, Smith in 2000 and Koehler in 2004 stated that the electric chainsaw kickback injuries consist of the removal of a wide swath of flesh, often resulting in the wounds filled with dust, oil, and wood debris. Hamming and Jones in 2015 stated that the most common cuts caused by electric chainsaw use are 40 percent to the user’s leg with half of these to the user’s knee.
In 1999, Cullman stated that the chainsaw chaps have proven to be effective. According to some studies they have caused a three-fold reduction in leg lacerations due to electric chainsaws. Petrilli and Messenger in 2004 stated that the four layers of ballistic nylon in the early chainsaw chaps were manufactured to resist a chain speed of one thousand and eight hundred feet per minute without cutting across.
Are electric chainsaw accidents really common?
Data collected from the National Electronic Injury Surveillance System for the years from 2009 to 2013. A total of 115,895 emergency room (ED) or Intensive Care Unit (ICU) visits for injuries related to the use of a chainsaw occurred during the survey period. Ninety-five percent, injury visits occurred among the male users and persons aged between thirty years and fifty-nine years.
Most of these accidents took place during the months of September through November. The main body sites injured were the legs and knee. Eighty percent of injuries were deep lacerations.
In the United States, an average annual frequency of 23,179 injuries occurs while using an electric chainsaw without using proper chainsaw chaps. The results depict the frequency and percentage estimates of injuries. Fifty-seven percent of which are adults aged thirty to fifty-nine accounted for the majority of emergency room visits for injuries, with ninety-five percent males representing the visits for an injury related to an electric chainsaw.
Most of these injury visits occurred during the spring months, summer months, and fall months, while fifty-eight percent of these injuries occurred at the patient’s house. The results showed that lacerations were the primary diagnosis for eighty-one percent of the ED visits. Among body parts injured, twenty-nine percent of the injuries occurred to the hand or fingers, eighteen percent to the knee, twelve percent to the lower leg or ankle, and eleven percent to the upper leg.
Closer analysis of injuries to these body parts showed that these lacerations were the predominant injury diagnosis, presenting for eighty-seven percent of hand and finger injuries; eighty-nine percent of the lower leg and ankle injuries; ninety-eight percent of knee injuries; and ninety-eight of upper leg injuries.
Verbatim results of a survey conducted in the USA revealed that three patients were hospitalized every year while ninety-four percent of the electric chainsaw victims were treated and released. There were on average, annual 139 amputations and 983 injuries to the head and neck, with sixty-nine percent of head and neck injuries diagnosed as lacerations. Death is also common with death before arrival to the emergency room or death in the emergency room.
How do electric chainsaw accidents happen?
An electric chainsaw is a portable machine used for multi-purpose forest operations. It is commonly used by professionals and non-professionals. Forestry and related tree operations are one of the most hazardous working sectors of human activity.
At the moment, operations with electric chainsaws are conducted by all persons and are not solely restricted to professional lumberjacks. Serious or lethal lesions, due to the use of electric chainsaws, are often encountered by emergency or forensic doctors. Such serious accidents often occur during electric chainsaw activities and are essentially due to kickback, uncorrected use of an electric chainsaw and in case of lost implement control due to falling or slipping of the user.
Developed countries have agencies responsible for the collection and analysis of electric chainsaw accidents. In the majority, one accident reporting form is used for all types of accidents. Whereas, this represents a solid basis for comparison between the different production sectors in the same country, and also allows for comparison between different countries, this approach needs improvements with regard to the forest sector.
The driving factor behind this need, is a large number of variables that should be analyzed and correlated in electric chainsaw accidents, which outnumber those of other production sectors. When this kind of information is missing (e.g. weather conditions during the time of the incident, slope, tree species, wage system) the following analysis may result in misleading conclusions. Electric chainsaw accidents happen when the chain is spinning after you release your finger from the throttle and the chain brake is not engaged. When a gasoline-powered chainsaw touches your chainsaw chaps while its chain is still spinning, it will cut into the outermost layer and into the protective fibers as well. The chain of a cordless electric chainsaw will stop spinning the moment your finger comes off its trigger.
A cordless electric chainsaw will make only a slight nick in the outermost layer of your chainsaw chaps when it touches them. The fact is that the chain of your electric chainsaw will not spin once your finger is off the trigger which reduces the probability of an accident. There are 6 major reasons for electric chainsaw accidents:
- Felling trees that overhang electric wires, water bodies, bridges, and buildings.
- Felling trees on uneven surfaces or on a steep slope.
- Felling the species of such a tree that is able to split or has a stem rot.
- Felling trees that have a heavy lean.
- Felling trees in large shelterbelts.
- Removing storm-thrown trees in storm-prone areas.
How to prevent electric chainsaw accidents?
Researchers have developed and adopted an innovative safety device able to stop an electric chainsaw when needed. The device is based on a Wiimote controller (Nintendo™) which includes two accelerometers and two gyroscopes for detection of rotation and inclination. Bluetooth wireless technology is used to transfer data to a portable computer.
Collected data about linear and angular acceleration are filtered by an algorithm based on the Euclid norm which differentiates between normal and dangerous electric chainsaw movements. The results showed a good response to the safety device which sent an alarm signal when a dangerous situation occurred in order to stop the cutting chain. The device demonstrated correct behavior in all tested dangerous situations.
They encourage extending its use to chainsaws with a combustion engine, as well as to other portable equipment used in agriculture and forestry operations. For these applications, the safety device was also patented.
Modern electric chainsaws include advanced characteristics such as lighter weight, increased horsepower, reduced gas emissions and better ergonomic design (anti-vibration handles and kick-back security). In Europe, wood extraction (i.e. moving the wood from the harvesting site to the forest road for further processing or transportation) by means of animals has been replaced, almost exclusively by tractors, and more specialized forest machines such as skidders and forwarders, with emphasis on ergonomic design. The Personal Protective Equipment, especially the chainsaw chaps have also been improved upon and its parts are specially designed and tested during forest work.
The importance of this can be easily understood if we consider that in the 1980s, forest workers, even in developed countries such as Finland, still used construction helmets which were heavier, made of non-durable materials and permitted inadequate ventilation. All the above mentioned technological developments have reduced the risk of fatal accidents. Increased level of mechanization has “removed” direct contact with the trees and the users can be assisted by powerful electric chainsaws.
How to wash your chainsaw chaps?
You can wash your electric chainsaw chaps in four simple steps:
i) Preparations before washing: Turn the chaps inside out and make sure all of its zippers are closed, so that the washer’s agitator may not cause any abrasions or corrosion on its surface.
ii) Washing: if your electric chainsaw chaps are light-colored then you must wash them and rinse them in cool water only. And if it is dark-colored then select the delicate mode in your washer. Use mild detergents only.
iii) Drying: don’t let the spinner rotate for more than a couple of minutes. Never hang the electric chainsaw chaps in direct sunshine otherwise it will shrink and will not fit on your legs anymore. Open all of its zippers and spread the chaps in an open-air smooth surface.
iv) Conditioning: softeners and conditioners will prevent shrinkage, so you can apply a good amount of it (optional).
You must always make sure that you repair any small holes and cuts in the outermost layer of your electric chainsaw chaps immediately. You should use Seam Grip or any other product recommended by the manufacturer of your electric chainsaw chaps to repair any damage caused to the ballistic-nylon shell of your chaps. These products create an oil-proof and corrosion-proof patch that will protect your Kevlar pad against contaminants.
Important safety measures while operating a chainsaw:
- Make sure that there are no animals, birds or other people in your work area.
- Never use an electric chainsaw in extreme weather conditions such as wind, snow, hail, rain, haze, fog, eclipse, etc.
- Make sure your footing is 100 % balanced and stable. Never reach out of your arm’s length or work on an off-balance footing.
- Be very careful while carrying your electric chainsaw over a steep slope, over a water body or on uneven ground. Always shut your electric chainsaw off before carrying it along with you from one place to the other. Make sure you carry it by its front handle only with its bar to the rear, never carry it near your head or on your neck or shoulders.
- You must make sure that people are 2 tree lengths away while you are felling a tree.
- You must always plan a clear and well-leveled escape route or exit route towards your left and right side and rearwards.
- Make sure there are NO electric wires or any telecommunication cables in your workplace.
- Make sure the low hanging limbs of the tree that you are felling cannot dislodge you.
- Always cover the bar of your electric chainsaw for carrying it to and from your work area.
- Secure the fuel container of your electric chainsaw to prevent it from bursting into flames like a missile.
- Never travel with your electric chainsaw in the passenger compartment of your car or truck.
- Never use your electric chainsaw off a rope ladder.
- Never work alone in a far-flung area, make sure somebody can hear when you cry out.
- Never consume alcohol, drugs or sleeping pills before operating your electric chainsaw.
- To stay alert, take short breaks after every half an hour, have a rest when you feel exhausted and sleepy.
- Never use your electric chainsaw bar for digging hard and rocky soil.
- Make sure that your thumb stays firmly wrapped around the front handle of your electric chainsaw to ensure that in the event of a kickback your hand must not slip off its front handle.
- You must make sure that the chain brake of your electric chainsaw is in proper working condition and you have a rigid handguard fitted or a mitt laced to its front handle.
- Make sure that the chain of your electric chainsaw is well-lubricated. You must activate the oiler and wait for the oil to appear.
- Make sure the throttle control lockout is functioning properly.
- Always keep your feet firmly planted close to the cutting position, never try to overreach. Slightly bend both your arms for improved control of your electric chainsaw. Always position yourself to the side of the cut to minimize the risk of injury in the event of a kickback.
To conclude this blog post, I would say that a good pair of electric chainsaw chaps can make a real difference between life and death. So always wear them.