Felling Rotten / Hollow trees

[ABtrees]

9 hours ago, Moose McAlpine said:

Oooh! What part?

Morning Moose.  Perhaps I should have said, in the rural middle of France.  We are due south of Paris and due East of La Rochelle, in the Indre.  The nearest town of any significance is La Chatre. 

 

Someone asked me on the phone the other day if I was self-isolating to which my response was yes since 2006 !

[ABtrees]

22 hours ago, lux said:

All dead wood is far less forgiving to fell or cut, being hollow with rot exaggerates this no end. Learn a little about the different types of rot and how they affect the structure of the timber. That might help you with how you go about cutting.
As previously mention use mechanical advantage to help. A portable winch or just setting up a double / triple purchase can really help.
A lot of it will come down to simply how it feels as you begin making cuts. Watch the crown as well as the cut , it will tell you a lot about what’s happening as you are cutting.
I don’t think there is a real problem solving answer for you. Just keep safety top of the list when dealing with these sorts of trees and if it goes wrong at least you shouldn’t get hurt

Thanks for this Lux.  Safety is always top of my list.  Can you (or anyone else) suggest some reading on the rot and their effects (or is it Google search - again !)?  My v. limited knowledge is 'dry' and 'wet' rot but I'm sure there is more to it than that.  I'm fortunate to live surrounded by trees (maybe 70% Oak) of all different ages and states of decay (in most of the older ones).  I generally just leave them be if they're out of the way as I really enjoy the whole nature/habitat/ecosystem bit, so I'm certainly not complaining.  It really is a case of trying to deal with those that I have to competently (which I view as being less reliant on a tractor to determine the direction of fall !!!!!).  So as ever any guidance much appreciated. 

[David Cropper]

1 hour ago, ABtrees said:

Was trying not to get involved in the derail (as I'm genuinely keen to learn) but ……..  Stubby, if you're going to be the fashion police I feel it's important you know your wellies before you start flinging them !  So those are NOT B&Q's - they are Noras (here we go !) - the staple footwear of any self respecting dairy farmer (not that I am one!) - they're plastic not rubber, very hard wearing and as, wellies go I highly recommend them ( but not for chainsawing !).  For the record, I also have a pair of bright orange ones (yes, you know the make) and a pair of Chameau - both of which I find uncomfortable after a couple of hours - I have odd feet !

 

So as not to offend I'll try and keep my footwear out of future pics but I had to get up there to illustrate my point !!!!!

Oh dear! I think you may receive the "Footwear you are allowed to display on ArbTalk" equivalent of a yellow card from Mr Stubbs. How dare you!

[Treeation]

Sounds like your on the right tracks with using tractors and ratchet straps,

Presuming you know your 3 basic felling cuts to for back leaners, fwd leaners and straight fells.....

As said before leave buttressess to your advantage to add strength when needed,

You can leave adequate hingewood %by leaving wider hinges to make up for loss of rotten/hollow central wood.

You can use a sounding mallet to build up a picture of what's going on inside the wood as part of your planning and prep work....

The suggestion of learning rot types is a good one, although I know characteristics of the different types must admit I treat a felling situation with them in the same way (with extra caution and extra planning) would be intrigued to hear how others plan their work with this in mind, which also leads to suggesting if you are mainly dealing with oak you could learn to identify the main decay fungi that affect the trunks/roots etc...Ganoderma, honey fungus, beefsteak, psuedoinnotus, chicken of woods etc...and some basic Claus Mattheck Body language of trees will help you to decypher a bit more about where the strength in the wood lies and all helps to build up the bigger picture.

 

[drinksloe]

It sounds like ur doing ok as it is.

To be fair dead oak tends to hold its strength and branches more than other dead trees, but not done masses of it.

 

In ur 1st post i think u talked about those back protector things, if it's wot I'm thinking about, only seen photos, looks like a space rocket strapped to ur back.

U look a right tool wearing it but worse if a branch hits them it would probably break ur back anyway.

 

Even with a winch If possible I would be trying to fell them with lean as much as possible, even if it means hitting a fence. Fences are easy fixes esp if u stripped it n advance before u dropped tree on it.

 

Also I think I would probably bore from both sides 1st and leave a strap at back, generally back will be safer and u can be looking up a bit more or standing further away from the tree when just severing a strap when not being precise around hinges.

I tend to do the same when cutting a a machine assisting, ur just slightly more aware of wot's going on.

 

But just got to wiegh up every tree as u do anyway but just look a bit harder. 

 

Ur ratchet strap is a good idea, by rights if no middle shouldnae really barbers chair but could still go early if ur cutting from 1 side round back to other.

But for the little time it takes to put on, I'd far rather have it on and not need it than the other way.

[Dan Maynard]

I think with dead or rotten you have to plan as if the hinge could just snap and lose control, because one day it will and you don't want that to be a surprise. Stack everything you can in your favour - side guy lines, remove weight by taking limbs off (polesaw), assess the rot, winch rather than wedge against a lean, use the most sound wood might mean shallow gob or line hinge up with buttresses. Every tree needs a different plan, I don't think there is a special cut or method which will make that hinge secure again.

It actually sounds as if you're well on the way building up experience, which has taught you to be cautious as these are unpredictable.

I've had ash snap and fall 90 degrees to the hinge, but I was 30 metres back on the tirfor handle and there was nothing in the field for it to hit so no worries. Only thing I didn't want was the tree to go backwards into the brook, so the winch had that covered.

[ABtrees]

Thanks to all of you for your advice and encouraging comments (apart from Mr Stubby, of course !!!).  You guys have much more experience than me and the little ideas, when combined, maybe make a big difference to the outcome.  As I said, this one had a reasonable result and I do spend a lot of time thinking about safety issues.  My dilemma is that I obviously need the 'practice' to expand my knowledge and understanding of the issues in play, but equally I don't (generally speaking) cut down trees for the sake of it.  I felt this one was dangerous (lean increasing, v. top heavy, next to public road and likely to fall into/across the river) so it had to go. (Pic below of it standing - its the one in the middle ! ). Thought about climbing it and removing some limbs to redistribute the weight a bit but caution/safety combined with a lack of understanding of the extent of the rot issue kept my feet on the ground (OK - bottled it and took the easier option !!!).

 

Maybe what I need to do is go through some 'theoretical fells' on those in the field (and leave them for the next storm!) - try to improve my 'tree body language' skills at the same time. 

 

Or maybe ….. it might be time to invest in a proper winch.

 

[openspaceman]

19 hours ago, drinksloe said:

Ur ratchet strap is a good idea, by rights if no middle shouldnae really barbers chair but could still go early if ur cutting from 1 side round back to other.

Yes, in fact I think barber chair happens when the wood is at full and high strength but tensioned, it's when the bending moment on the hinge  is higher than the fibres of the wood can hold together.

[openspaceman]

11 hours ago, Dan Maynard said:

I've had ash snap and fall 90 degrees to the hinge, but I was 30 metres back on the tirfor handle and there was nothing in the field for it to hit so no worries.

One of the problems with hand winching is that you get little momentum into the tree, the hinge only holds for a limited amount of travel, then the fibres at the back of the hinge start failing in tension. With a powered winch the tree gains a bit of inertia as it rotates about the hinge to keep it moving in roughly the right direction.

 

Generally you can fell a leaner directly opposite the way it leans but as soon as you try and go against the lean and sideways the tension on the uphill side of the hinge is too great. This is why one leaves a triangular hinge but ultimately you need a holding rope higher in the tree too.

[Moose McAlpine]

57 minutes ago, openspaceman said:

This is why one leaves a triangular hinge but ultimately you need a holding rope higher in the tree too.

 

Is that what they refer to as a "Dutchman"?