The term barber chair or barber chairing in tree work refers to the slabbing up of timber when doing the back cut (when felling a tree) resulting in a very dangerous out of control situation.
It can also occur on large limbs in trees.
i've attached a tree felling power point file, ppt, which is around 3mb with felling techniques and it shows what goes on although I disagree a little that a "dutchman" is the cause. The predominant cause is forward leaner, species and too narrow a gob on the scarf.
http://www.treeworld.info/manualuplo...arberchair.ppt
The guys down Victoria Australia fell huge eucs called Mountain Ash (eucalyptus regnans) which is prone to barber chairing.
Some methods to overcome barber chairing is strapping the timber above the cut, bore cutting your back cut setting up the hinge then coming out the back of the tree opposite to the normal back cut ... sometime done with a strap release.
Of course there's the
"fish cut" which I've never tried which is also supposed to help prevent the barber chair.
