Monday, February 8, 2010

Barberchairs Revisited

Barber chairs have a bad reputation for killing people. People who are going to be falling trees need to understand what causes a barber chair, and how to avoid creating them. A barber chair occurs when the tree goes into motion and the hinge wood cannot bend to let the tree fall over. This can occur with a forward leaning tree when the faller makes the front cuts correctly, but then saws from the back, which allows the tree to begin tipping before the hinge wood has been cut to the right thickness. This situation can be prevented by using the Bore Cut to sever the tree from the stump, except for the hinge, and a backstrap which holds the tree motionless until you cut it, releasing the tree to fall.

A front cut that closes too quickly allows the tree to gain momentum, then shuts it down; and this will also cause a barber chair. The old methods of cutting trees opened the front up to a 45 degree angle, and that is enough to prevent a barber chair if the tree stands still until the hinge is completed. The two cuts that make the front opening should meet up as closely as possible. If one cut bypasses the other, the narrow gap will close when the tree begins to tip, creating a similar situation to the stump pictured above. The closing of the gap in a bypass is very likely to cause a barber chair, so clean up your cuts before you turn a tree loose.




This video from YouTube clearly illustrates the making of a barber chair, and the results. Luckily, no-one was hurt. The cutter has made an open face in the direction he wants the tree to fall, but he has not accounted for the back lean of the tree. As the video begins he is cutting straight in from the back, and you can hear the saw bog down as the back lean causes the tree to sit on his saw. He must have heard fibers popping, because he ran, so he did do one thing right. This is a classic "Too-Thick-Hinge" barber chair, and the altitude the trunk gains is very impressive right before it drops next to the stump. There is some annoying whining going on by a spectator, so after the guy runs, you may want to turn down the volume.



Review the safety rules in the left sidebar and watch the video to see how to set up a tree while keeping it motionless. Click on the "Chainsaw" label to see all of the chainsaw related videos posted on True Blue Sam. Be sure to click on "Older Posts" at the bottom of each page to go to the next page.

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