letterbox cut?

[TimR]

i remember being told by my old man to do this especially if the timber is going to be used for furniture or such like and especially on beech to prevent the centre shattering....

[RPA]

You would cut out the centre of the hinge of a hung up tree? From the opposite side of the sink/gob, yes?

 

Yes.

It’s one method of dealing with a hung tree that is now covered on CS31. If there is or does not appear to be any natural ‘roll out’ direction i.e. hung straight on then this method should be used.

You cut the letter box with the tip of your bar little at a time ensuring that you leave at least 20% of the hinge in tact (10% each side). You then remove the 10% left on one side with vertical cuts little at a time. If there is any chance of the tree rolling out then the first side removed should be opposite to this direction. When the remaining hinge on this side is removed the letter box will close. Repeat this to remove the hinge on the other side and you have a hung tree ready to be levered or winched down.

None of the above should be completed whilst standing directly behind the tree. Before starting you could also ramp down the back side of the stump so the stem will slide back easier.

 

Puwer will be able to explain this better than me but I hope this gives you a rough idea.

[silvafox]

The letterbox cut is ESSENTIAL when harvesting large diameter valuable hardwood sawlogs and also to prevent barber chairing on ash. How can someone go 30 years without knowing this?

[silvafox]

I also use a letterbox cut on willows and big poplars like this one...

[puwer]

Heartwood cutting or face boring is utilised as most have said to relieve tension in the heart of the trunk, removal via heartwood cutting prevents wood fibres being pulled. General rules of thumb (species, grain direction, lean etc etc need to be considered) once a heartwood is used, remaining hinge should be at least 6" either side and approx 50mm wide.

 

Generally heartwood cuts are placed at the same level or just above (25-50mm approx) the sink level, your back cut would also go in at this height so the cuts would all marry up in alignment/levels.

 

Humboldt sinks, use of ears, heartwood cuts etc. all help reduce the chances of "barber chair, splits, shakes" all good techniques for us to know whether it be felling on the deck or limb removal in the tree!

 

Edenarb - spot on.

[High Scale]

The letterbox cut is ESSENTIAL when harvesting large diameter valuable hardwood sawlogs and also to prevent barber chairing on ash. How can someone go 30 years without knowing this?

 

 

I think it's because it has only recently been called a letterbox cut, I know exactly what the cut is as I asked the same question on the Proclimber forum over two years ago as it was always known as a bore cut, around this way at least.

[Andy Collins]

I think it's because it has only recently been called a letterbox cut, I know exactly what the cut is as I asked the same question on the Proclimber forum over two years ago as it was always known as a bore cut, around this way at least.

 

i was going to post exactly the same thing Carl, fancy new names for the old cuts, is this Americanisation? perhaps its to make it more memorable for the new trainees.

[High Scale]

I would rather work with a guy with thirty years experience than a new guy with a grasp of the modern lingo.

 

I am not hating, just pointing out a different point of view.

[rumination]

I'm not sure that's an American name. Like you guys, I have used that type of cutting technique before, but I'd never heard it called a letterbox cut.

[Quickthorn]

No..I've heard it called a fan cut before. As for the boring cut for the hung up tree, I've heard someone call that one a letterbox cut.

 

I knew one guy who failed a unit he was taking retrospectively because he couldn't explain what a dog tooth cut was..even though he had used that cut many times before, but didn't know anyone called it a dog tooth cut; he called it something entirely different. He wasn't happy about that!