Rate My Hinge.

[skyhuck]

It must be a combination of both bending moment and weak point of the object (tree in this instance) . If you pick up a stick and bend it , it wont break at the greatest leverage point ie your hand , but somewhere along its length .

 

Yes, but not if you put a gob and back cut in near your hand

[Reddog]

Sorry but that makes no sense, the longer a lever the more force it has, so the more tree above the cut the greater the "force/stress".

 

So the longer the stem the more pressure the crown weight can place on the root zone acting like a lever. So if you were to measure the stress placed on the stem/trunk it would be highest at just above the stump to a meter or two up. So were ever you place the notch that becomes the fulcrum point for tensioning the back/holding wood. The higher you place it above the stump the more stress and chance of barber chair.

 

May be fulcrum isn't right and it is more a stress riser in a loaded spar. I am open to any rewording that makes it better understood.

[finchyo]

It is true that most stem failures in trees occur at that sort of 2-3m height (depends on height of tree) but I think with felling it doesn't really matter that much depending on the type of fell plus crown weight/distribution. You was fine cutting that gob where you was on that tree tom but it is something to think about, will have to ask paul about it. Its true, not a great position to be cutting in too but your are tall! lol.

[Peter]

ok guys and gals here is my effort be kind only been doing this 3 months,

 

dead lime tree about 25" diameter rotten in base hence the high fell

 

Looks pretty rotten at the height you felled at, how much sound hinge wood would you say you had there?

 

If possible I use the buttresses as the hinge on those pulpy lombardies, only works if they are lined up right for the intended direction of fell, but very often you get the most sound hinge wood that way.

[Tom Hall]

right guys, for a start it was a lime tree not a lombardy. and the way i cut it was to bore in and cut away from my hinge and left a third of the stem intact then bored in from the other side but followed round to complete the cut so i avoided the barbers chair making sure my head was well out the way as i finished it off, just so you all know my cutting method, thats not me being defensive i'm just explaining.

 

i had about 3" off sound wood either side.

 

i understand what you mean about when you say about bending the stick, but what i don't get is, when you put the sink in you are creating a weak point any way be it 90' up in the canopy or 1" above the ground so surely a barbers chair can occur at any point you choose to fell at?????

 

by the way guys this is great stuff, you are really making me think, i like it

[RobRainford]

If that decay column was the same relative size to the base I would have felled it just at the top of the buttresses. That 3" at head height could have been 4 or 5 at the bottom and you could use the buttresses as hinges. Plus the saw is at a safer height. Without filling your face with sawdust.

[Spruce Pirate]

so surely a barbers chair can occur at any point you choose to fell at?????

 

It can, had it happen (or start to go) about 40' up once taking a top out. Scarry biscuits:w00t: Should have used a double v or a dog tooth as top was leaning, but didn't have thinking head on at the time. I was lucky, I was far enough through to be able to keep cutting and it came out alright, but yeah, trees can jack-knife at any point. Never had one do it (yet) on a high fell though.

[AlvinD]

As its been said before each tree has its own different characteristics. The snapping point on a trunk takes into variables such as canopy dimensions, leaning degree of tree, centre of gravity etc. I personally think that it is a lot safer to fell at the base of the load rather than at some point along the angle of curvature (if there is a lean). No one can say you done it wrong Tom because it worked to plan

[Tom Hall]

bloody hell spruce pirate that does sound scary:scared1:, i thought it could happen at any point hopefully i won't ever experience it though up the top of a tree, or at all for that matter!!!! thank you alvind it did go as planned:party:, but in future i will look closely at the buttresses to see if i can use them to aid the fell by giving me more sound wood to hinge off. hopefully soon have some more pics for you to dissect!!!

[Tom Cook]

Topping out an oak!

 

 

 

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