User:Davidjanoschek/Felling

Goals for 3/27/23


 * 1) 1. Create a list of every type of hand-felling.
 * 2) 2. Add an image/some kind of visual to distinguish.
 * 3) 3. Add between 3-5 sentences about the different kinds to make sure to explain the technique to the public.

There are three types of directional felling notches that are most commonly used the the logging and arborculture industries by chainsaw operators. They are the conventional, the Humbolt, and the open-face. Each has different advantages and disadvantages based on the type of tree, the condition of the tree, the environment surrounding the tree, and the region in which the tree is being felled.

The conventional face cut is perhaps the most commonly used and most well recognized face cut used in the world today. It has an open upwards angle of plus or minus 35 degrees, and is the easiest undercut to learn. Lining up the cuts is fairly easy and quick, and it gives the operator the most directional control of the tree as it falls since the top of the tree will always hit the ground first due to the prolonged time the tree spends on the stump. Some downsides of the conventional face cut are that the two flat faces of the angle can come into contact prior to the tree actually hitting the ground, which can cause stump pull, log fiber pull, or a barber chair effect where the tree splits in half and snaps back in the direction of the operator. All of the above scenarios are extremely dangerous and negatively effect the monetary value quality of the tree in a lumber production scenario.

The Humbolt face cut is a less well-known felling undercut, and is commonly used in the pacific northwest and pacific coast of Canada and Alaska. A Humbolt face cut has a downward 45 degree angle, and allows the directional face cut to be made out of the stump rather than the log. Additionally, the downward open angle of the Humbolt allows the tree to jump off of the stump when it falls, making the tree always land butt first and lay out, which is not only safer for the operator b ut also smashes up less wood in a timber production scenario. Some downsides of the Humbolt are that it takes significantly more skill to quickly and efficiently line up your cuts, nd you cannot cut your stumps as low to the ground due to the downward-facing open angle.

The Open-Face undercut is essentially a mixture of the conventional and the Humbolt, with a wide open angle of 70 to 90 degrees. This face cut is most commonly used in extreme scenarios where the tree in question has a severe back lean. The wide open angle of the cut allows the tree time to become upright, and then close as it falls without the two flat ends of the angle prematurely closing. The open face is fairly easy to master and line up correctly. A couple big disadvantages are that it takes quite a bit more time to cut compared to a conventional or Humbolt, and there is waste left on both the stump and the log due to the angle being so open. It is not a common practice in the logging community and is much more frequently used in commercial tree work.

A good rule of thumb for all felling scenarios is to make the depth of the face cut or undercut roughly equal to 1/3 the diameter of the tree and leave about 10% for your holding wood or hinge wood to direct the tree on its way to the ground. The remaining 2/3 of the tree is for the back cut, which acts as the final piece of the puzzle to get the tree on the ground.

My chosen article is going to detail a "hand-felling" section within the broader "felling" page on Wikipedia. There are currently only two sentences in the hand-felling section and there is a specific request on the page to add more good information into that section. My plan is to write about hand-felling techniques specifically relating to safety aspects of general tree work, as well as making the most out of "sustainable" lumber production and harvesting by wasting less wood in the process of hand-felling.

Kawahara, D., Urabe, Y., Maeda, N., Sasadai, J., Fujii, E., Moriyama, N., ... & Iwata, S. (2015). The effect of different working postures while felling a tree with a chain-saw on trunk muscles' activity. Sangyo Eiseigaku Zasshi= Journal of Occupational Health, 57(4), 111-116.

-       This source is about proper working posture while felling a tree using a chainsaw. Low back pain due to poor posture is a common problem that affects the safety and mood of the operator, and this article clarifies the relationship between working postures and trunk muscle activation as measured by surface electromyography.

-       I plan to use this paper to explain how proper posture when felling can help to alleviate back pain and increase longevity.

Grzywinski, W., T. Jelonek, A. Tomczak, M. Jakubowski, M. Bembenek. (2017). Does body posture during tree felling influence the physiological load of a chainsaw operator? Annals of Agricultural and Environmental Medicine 2017, 24(3): 401-405. www.aaem.pl

-       This source talks about working posture related to tree felling. In the study, a group of 10 experienced fellers were studied. Their heart rates were recorded while performing 4 different working postures; back bent forward with straight legs (stoop), back bent forward with bent legs, squat, and kneeling on one knee. The study concluded that the squatting and half-kneeling positions took the operators significantly less effort as measured by heart rate than the two standing positions, measured in significant by heart rate in beats per minute (bpm).

-       I plan to use this paper to talk about proper working posture, similar to the source above.

Suhartana, S. (2019, October). The Economic and Environmentally Friendly Tree Felling Techniques in Natural Forest. In IOP Conference Series: Earth and Environmental Science (Vol. 359, No. 1, p. 012007). IOP Publishing.

-       This source talks about how improper tree-felling techniques may reduce productivity and log supply, leading to increases in production costs. This study was carried out in 2015 and investigated how the implementation of proper felling techniques in Indonesia impacted Timber Utilization Efficiency (TUE), felling productivity, production costs, and residential stand damage.

-       I plan to use this paper to explain why it is important to implement proper felling techniques to utilize as much of the tree as possible.

Garland, John J. (1983). Felling and Bucking Techniques for Woodland Owners. Oregon State University, Extension Service. https://ir.library.oregonstate.edu/concern/administrative_report_or_publications/sx61dm430

-       This source outlines everything you need to know about felling and bucking. It goes into great detail about proper positioning and safety equipment, what type of face cut to use and why, compression and tension while in the back cut, conditions of the tree and the surrounding area, and the proper percentages of face cut, back cut, and hinge wood.

-       I plan to use this paper to explain the different kinds of cuts and when/why to use them. I also plan to use this paper to talk about examining your work site for hazards before you start cutting and making a good escape route to mitigate accidents on the job site.

Gülci, N., Gülci, S., Akay, A. E., & Sessions, J. (2023). A Comparison of Two Felling Techniques Considering Stump-Height-Related Timber Value Loss. Croatian Journal of Forest Engineering: Journal for Theory and Application of Forestry Engineering, 44(1), 103-110.

-       This source is about felling techniques in relation to stump height and timber value loss, and the study that was done compared hand felling with a chainsaw to using a feller buncher machine. Four ground slope classes: high, medium, low, and flat, were all compared relating to the economic value loss of three wood products – sawlogs, pulpwood, and fiber-chip wood.

-       I plan to use this article to talk about wood product loss due to poor cuts on the stump.