Alders are notoriously bad. The wood is so clear and splits so darn easy. You maybe should have bound that tree, Jed. But in any case if deciding to use the coos bay you need to get the side cuts more than a third the way in, or just figure the more the better. Ideally until the strap left holding the tree,,,, fails to hold it.
People tend to be very nervous using the coos bay on a heavy head leaner for the first time. Rightfully so too. And I think it makes them feel overly anxious to release the tree prematurely. As long as the tree is standing,,,, keep cutting the sides. And..... in trees of size be sure to use a wedge to keep the cuts open. You really do not want the tree to shift over to any side. Because it can cause the tree to twist off the stump rather than break off of it.
Believe me, there is no single and sure solution to tripping all the head leaners a sawyer is going to encounter. Because of the high pressure and tension forces involved the stumps are always going to be more prone to failing in some manner or form before we can execute any cut the way we want. Either by twisting, splitting or pulling the roots. It is the nature of a head leaner to do so.
There are alternative methods to dealing with head leaners. As some members here have pointed out.
As for myself, I've reamed through the pressure side of some head leaners up to three quarters the way through and tripped them by severing the remaining tension wood. Just like the tree were a big limb. No opening cut about it. Pops the tree right off the stump very clean. However,, this is a risky method to use in anything but a hard leaner because there is no stump shot.
In other cases I have worked a face cut deep enough into the tree until the remaining tension wood folded and eased the tree down quite easily. No release cut about it. On good ground the method is a little bit safer, but it does take more time because you have to whittle the face in a little at a time and keep cleaning it out.
With either of these alternatives the method puts a sawyer beside the tree to execute the cuts. And on steep ground with a head leaner that could be very unsafe. And too, with either alternative the chance of getting the saw stuck is much higher,,, if you're not quick on the draw with your reaming or whittling . The CB on the other hand puts a sawyer on the high side to execute the cut and the chance of getting the saw stuck is much less.
You have to remember too that the conventional method of using a face and boring the back cut increases the amount of pressure and tension forces in the wood left holding a head leaner, and that in itself can bring on its own additional problems and risks.
In any case, more than anything else, our safety and success comes down to understanding the forces of leverage, tension and pressure and how it bears on the stems of a tree. With a thorough understanding of this we should be able to figure the appropriate action to take. Which at times means not doing anything at all.
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