Angled back cut| backcut| tree felling| back cuts

Ekka · 11th January 2008, 11:11 PM

Often you will see an angled back cut. You will never see it taught or printed as an acceptable method of felling.

The practice has continued and stumps like the one in the picture below is seen too often.

This thread is to sort the shit from the clay regarding this technique.

In page 2 of this thread the discussion came up, and there were some reasons given for it. Those posters may want to add their information to this thread now.

conventional figure-8

Ekka · 12th January 2008, 12:05 AM

Well, to get the ball rolling I'll import a couple of posts from that other thread.

Quote:

Originally Posted by Ekka

Hang on, what difference does the angle back cut make then if it still has to pivot?

Are you saying that some how it prevents the saw bar getting jammed from the tree sitting on it?

Quote:

Originally Posted by quercus

I'd have to agree with newguy on this. We do this all the time and it does work. It's just a case of simple mathematics. Whe the surface of the cut is angled, it is bigger and has more square inches. So the pressure per square inch is less then if the cut was horizontal. We also use it on tops, ekka, because indeed, like newguy says, it keeps the top from sliding away on the back side where the climber is. Tests have shown that 1200 kg per square centimeter is needed to pull a hinge on a oak tree apart in the vertical direction. So if the cut is angled the pulling force on the wood is much less then if it where horizontal and will therefore less easily break apart in the wrong direction. If a top of a pine gets hung up when falling down, you actually could saw through the hinge and the top would still slide off of the cut in the right direction. When using this on hung up tops, you do have to realize that sometimes the upper branches of the top come back to the tree you're working on when falling down.We've been using this technique hundreds of times, it does work, but one has the know the math and the mechanics of it before using it.

Ekka · 12th January 2008, 12:32 AM

In verification and response of what Quercus is saying I present a diagram. He says it's tough pulling wood apart, it's also tough compressing it to fail. The wood is strongest upon it's own axis.

In felling trees at ground level we are trying to get maximum strength, especially if we have hollow or decayed wood. Keeping in mind the model above you would agree then that a level hinge as displayed in the diagram below does 2 critical things.

1/ It carries the weight of the tree on the strongest axis.

2/ any force applied by wedging or even jacking is lifting the tree working the strongest axis.

There is less probability of failure this way, if the wind blows and it "sets back" then you have the force acting upon the fibres in the strongest way you can.

Now lets take a look at the angled back cut in the same situation.

What you'll see in the diagram is both the weight of the tree is now acting toward the weaker direction of the fibres and same when wedging. It could happen the fibre break and the tree slides down a bit pivots backward toward the cutter.

Also if the wind blows and you get sit back then it's also going to get force or leverage toward it's weaker axis.

There's also one other key point, it's difficult to get that cut right, level, even and the step height correct.

Now both Newguy18 and Quercus mention the use of this angled back cut for felling tops out of trees. The idea being, as he posted above, is that you get some barrier or ramp to prevent the butt coming back at you especially if it gets caught up in another tree. Now the step is supposed to do that anyway on a conventional back cut.

But hang on, he wants the hinge to break easier, the angled back cut is going to break sooner right?

Maybe, but why wouldn't you just have a thinner hinge from a conventional cut?

What about if it does get stuck with the traditional scarf (notch) and back cut if you do cut through the hinge then there's no ramp for the thing to slide off butt first (like a spear cut sort of).

So I present next diagram, and one that if you performed it on the ground felling it would be called a Humboldt. Perhaps have a slightly higher step too but this way you have a little better control and accuracy of your back cut.

Now I've felled a few tops and hollow trees and decayed trees etc and I can say that I dont do the angled thing. There's one thing I do with the angled thing though ... spear cuts, that's mainly on smaller stuff, mainly on branches not the verticle leader.

If there was a chance of the top getting caught in other vegetation whilst going over and getting stuck ... I'd go for the humboldt technique but seriously, haven't really had it happen and I dread it ever happening.

Sean Freeman · 12th January 2008, 02:58 AM

I think Eric has effectively covered all the important points relating to this angled back cut sometimes (incorrectly) called a sloven. Critical in all the negatives is the increased difficulty in making the backcut correctly meet the scarf, and the very real dangers in not doing so...and by meet I mean set up your hinge correctly. The angled backcut increases the risk of placing your back cut below the bottom cut of the scarf....not recommended. Yes in times past and with some loggers today still the arguement is put that it reduces the likelyhood of the stem coming back at you once the hinge breaks, but honestly controlled directional felling carried out by qualified experienced fellers makes this type of back cut outdated and unnecessary.

newguy18 · 12th January 2008, 06:54 AM

I started useing it after having a rotten tree set back and shoot over backwards at me[thank god it was in the middle of the woods].i never had a problem lining up the cuts and when i use it aloft I make two opposing diagnols to the under cut to get a wide deep notch then I finish with an angled back cut at the same angle and cut it to about 3/8s of an inch for a hinge.if it would try and set back it"ll slide down into the rigging or ground however your doing it.in effect it works similar to a slice cut.I don't use it exclusivly only when the need arises.

JohN Dee · 12th January 2008, 03:52 PM

If you cut your scarf correctly, the branch/leader should not go anywhere - hence the use of a pull rope and in some cases wedges.

When I'm heading out a leader, I like to be on a 90* angle from the face and backcut. Again if you've cut your scarf correctly it's only going to go 1 of 2 ways back or forth.

newguy18 · 12th January 2008, 03:58 PM

notch and back cut were perfect.It was completely hollow on the inside and the sapwood was really soft.It happened and I found something that i use on occasion and it works.

JohN Dee · 12th January 2008, 04:06 PM

Quote:

Originally Posted by newguy18

notch and back cut were perfect.It was completely hollow on the inside and the sapwood was really soft.It happened and I found something that i use on occasion and it works.

Perhaps you should have compensated on the hinge then?

newguy18 · 12th January 2008, 05:41 PM

I left about an inch of hinge wood[40"diameter].No wind and after I got the hinge down to the 1" mark it started to move so I thought good its going then it set back and I ran out of there real quick.After that I turned around and it was on the ground backwards.it was well balanced as far as I can tell[no lean].

Sean Freeman · 12th January 2008, 06:44 PM

Its always a good sensible practice when felling larger trees with adverse leans, weight distribution etc...even when there is no external evidence of hollows, rot etc... to put in a line as high as you can and have a control line as back up, should anything be found when cutting the scarf (front cut) or even during the back cut. On all our larger fells we always use wedges, very often have control lines and always go through a written risk assessment.

I'm sure you do but it bears repeating....always take tree felling seriously, always properly assess the job and go through the steps slowly and clearly in your head no skipping elements, ensure the fell zone is clear and will remain so, double check all your cuts....never NEVER stay at the stump plan for and use your escape route on every fell......Oh yes enjoy your tree felling!

bigshea13 · 12th January 2008, 06:53 PM

ive felled all sorts of trees in all sorts of situations. at the top or the base, gravity is the same. what ive seen is that if the tree happens to come back on you and it hollow, that angle created by the angled cut acts like a teeter and can flip the butt end into the air maybe even to the side vreating a potential hazard. as eric said the conventional and the humbolt done correctly will prevent kickback. another problem is that if for some crazy reasonthe feller needs to swing the cut {remove one half of hinge to cause it to tip to other side} they are unable to do so. if your using the angle cut to prevent kickback your going about felling all wrong. if your in the tree , cut higher and shorter to prevent the piece from lodging into another tree. dont rely on that angled piece thats withe the grain to prevent the top you cut from blasting back at you. on the ground an properly executed conventional will allow you the appropriate time to remove yourself from the danger area. if your still worried about kick back take the 5 min and tie off thebutt to the stump. i dont agree with the angle cut idea.

newguy18 · 12th January 2008, 07:03 PM

i only use it seldomly in fact I've only used it3 times in 2 years only when I'm not sure if a conventional cut will hold.[like in rotten tops you can here every time you punch gaffs into to or critical situations you can't afford mistakes].i know many people don't agree with it but I like to leave without damage to a piece of property or myself.

bigshea13 · 12th January 2008, 07:28 PM

thats why you need to slow down and do it correctly. cut smaller pieces{even if it means snap cutting 12" pices} and use a tag line.

newguy18 · 12th January 2008, 07:34 PM

You obviously get paid by the hour.I get paid when the job is done.Unless the tree has several targets I can't afford to go really small and slow.Just slow enough to be safe.I don't try and take the biggest pieces possible but I also don't take the smallest unless nessecary.I appreciate your input but when the need arises I use it.

12th January 2008, 02:58 AM	#4 (permalink)
Sean Freeman PDF King & Arborist Extrodinaire Join Date: Feb 2007 Location: Townsville Nth Queensland & Gold Coast Sth Queensland Posts: 1,671	Re: Angled back cut\| backcut\| tree felling I think Eric has effectively covered all the important points relating to this angled back cut sometimes (incorrectly) called a sloven. Critical in all the negatives is the increased difficulty in making the backcut correctly meet the scarf, and the very real dangers in not doing so...and by meet I mean set up your hinge correctly. The angled backcut increases the risk of placing your back cut below the bottom cut of the scarf....not recommended. Yes in times past and with some loggers today still the arguement is put that it reduces the likelyhood of the stem coming back at you once the hinge breaks, but honestly controlled directional felling carried out by qualified experienced fellers makes this type of back cut outdated and unnecessary. __________________ Sean Trees are poems that earth writes upon the sky, We fell them down and turn them into paper, That we may record our emptiness. - Kahlil Gibran

12th January 2008, 06:54 AM	#5 (permalink)
newguy18 Part of the Furniture Join Date: Jun 2007 Location: Live Oak Florida home of the crapiest trees you will ever see. Posts: 2,679	Re: Angled back cut\| backcut\| tree felling I started useing it after having a rotten tree set back and shoot over backwards at me[thank god it was in the middle of the woods].i never had a problem lining up the cuts and when i use it aloft I make two opposing diagnols to the under cut to get a wide deep notch then I finish with an angled back cut at the same angle and cut it to about 3/8s of an inch for a hinge.if it would try and set back it"ll slide down into the rigging or ground however your doing it.in effect it works similar to a slice cut.I don't use it exclusivly only when the need arises. __________________ Have your say join us today. http://www.youtube.com/watch?v=Xzkd_m4ivmc http://www.youtube.com/watch?v=Xzfzb...eature=related http://www.youtube.com/watch?v=x-OqK...eature=related

12th January 2008, 03:52 PM	#6 (permalink)
JohN Dee Over mature heritage tree Join Date: Feb 2007 Location: Sydney, Australia Posts: 750	Re: Angled back cut\| backcut\| tree felling If you cut your scarf correctly, the branch/leader should not go anywhere - hence the use of a pull rope and in some cases wedges. When I'm heading out a leader, I like to be on a 90* angle from the face and backcut. Again if you've cut your scarf correctly it's only going to go 1 of 2 ways back or forth. __________________ Climber with slow climbing speed, must make up with mighty chainsaw roar. Free Tree and Green Industry Link Directory Red : Green : Blue

12th January 2008, 03:58 PM	#7 (permalink)
newguy18 Part of the Furniture Join Date: Jun 2007 Location: Live Oak Florida home of the crapiest trees you will ever see. Posts: 2,679	Re: Angled back cut\| backcut\| tree felling notch and back cut were perfect.It was completely hollow on the inside and the sapwood was really soft.It happened and I found something that i use on occasion and it works. __________________ Have your say join us today. http://www.youtube.com/watch?v=Xzkd_m4ivmc http://www.youtube.com/watch?v=Xzfzb...eature=related http://www.youtube.com/watch?v=x-OqK...eature=related

12th January 2008, 05:41 PM	#9 (permalink)
newguy18 Part of the Furniture Join Date: Jun 2007 Location: Live Oak Florida home of the crapiest trees you will ever see. Posts: 2,679	Re: Angled back cut\| backcut\| tree felling I left about an inch of hinge wood[40"diameter].No wind and after I got the hinge down to the 1" mark it started to move so I thought good its going then it set back and I ran out of there real quick.After that I turned around and it was on the ground backwards.it was well balanced as far as I can tell[no lean]. __________________ Have your say join us today. http://www.youtube.com/watch?v=Xzkd_m4ivmc http://www.youtube.com/watch?v=Xzfzb...eature=related http://www.youtube.com/watch?v=x-OqK...eature=related

12th January 2008, 06:44 PM	#10 (permalink)
Sean Freeman PDF King & Arborist Extrodinaire Join Date: Feb 2007 Location: Townsville Nth Queensland & Gold Coast Sth Queensland Posts: 1,671	Re: Angled back cut\| backcut\| tree felling Its always a good sensible practice when felling larger trees with adverse leans, weight distribution etc...even when there is no external evidence of hollows, rot etc... to put in a line as high as you can and have a control line as back up, should anything be found when cutting the scarf (front cut) or even during the back cut. On all our larger fells we always use wedges, very often have control lines and always go through a written risk assessment. I'm sure you do but it bears repeating....always take tree felling seriously, always properly assess the job and go through the steps slowly and clearly in your head no skipping elements, ensure the fell zone is clear and will remain so, double check all your cuts....never NEVER stay at the stump plan for and use your escape route on every fell......Oh yes enjoy your tree felling! __________________ Sean Trees are poems that earth writes upon the sky, We fell them down and turn them into paper, That we may record our emptiness. - Kahlil Gibran

12th January 2008, 06:53 PM	#11 (permalink)
bigshea13 Mature tree Join Date: Nov 2007 Location: hiding Posts: 378	Re: Angled back cut\| backcut\| tree felling ive felled all sorts of trees in all sorts of situations. at the top or the base, gravity is the same. what ive seen is that if the tree happens to come back on you and it hollow, that angle created by the angled cut acts like a teeter and can flip the butt end into the air maybe even to the side vreating a potential hazard. as eric said the conventional and the humbolt done correctly will prevent kickback. another problem is that if for some crazy reasonthe feller needs to swing the cut {remove one half of hinge to cause it to tip to other side} they are unable to do so. if your using the angle cut to prevent kickback your going about felling all wrong. if your in the tree , cut higher and shorter to prevent the piece from lodging into another tree. dont rely on that angled piece thats withe the grain to prevent the top you cut from blasting back at you. on the ground an properly executed conventional will allow you the appropriate time to remove yourself from the danger area. if your still worried about kick back take the 5 min and tie off thebutt to the stump. i dont agree with the angle cut idea.

12th January 2008, 07:03 PM	#12 (permalink)
newguy18 Part of the Furniture Join Date: Jun 2007 Location: Live Oak Florida home of the crapiest trees you will ever see. Posts: 2,679	Re: Angled back cut\| backcut\| tree felling i only use it seldomly in fact I've only used it3 times in 2 years only when I'm not sure if a conventional cut will hold.[like in rotten tops you can here every time you punch gaffs into to or critical situations you can't afford mistakes].i know many people don't agree with it but I like to leave without damage to a piece of property or myself. __________________ Have your say join us today. http://www.youtube.com/watch?v=Xzkd_m4ivmc http://www.youtube.com/watch?v=Xzfzb...eature=related http://www.youtube.com/watch?v=x-OqK...eature=related

12th January 2008, 07:28 PM	#13 (permalink)
bigshea13 Mature tree Join Date: Nov 2007 Location: hiding Posts: 378	Re: Angled back cut\| backcut\| tree felling thats why you need to slow down and do it correctly. cut smaller pieces{even if it means snap cutting 12" pices} and use a tag line.

12th January 2008, 07:34 PM	#14 (permalink)
newguy18 Part of the Furniture Join Date: Jun 2007 Location: Live Oak Florida home of the crapiest trees you will ever see. Posts: 2,679	Re: Angled back cut\| backcut\| tree felling You obviously get paid by the hour.I get paid when the job is done.Unless the tree has several targets I can't afford to go really small and slow.Just slow enough to be safe.I don't try and take the biggest pieces possible but I also don't take the smallest unless nessecary.I appreciate your input but when the need arises I use it. __________________ Have your say join us today. http://www.youtube.com/watch?v=Xzkd_m4ivmc http://www.youtube.com/watch?v=Xzfzb...eature=related http://www.youtube.com/watch?v=x-OqK...eature=related