Big tree to fall.

[Peter]

I have an interesting job coming up, pics to come on Monday.

Hybrid black poplar, 48"dbh, 45 degree lean on stem, all of the crown is on the side of the lean, so very heavy weighting. I would estimate the whole tree weighs 12-15 tonnes.

Having felled one or two similar trees, I am expecting decay in the buttress roots extending up into the lower part of the stem.

It is in wet ground, and has settled into the lean, but started reactive growth in the crown, so its been in the new position for several years.

I can't fall straight to the weighting, there are no expensive targets but it would be a royal PITA to clean up, and future work depends on getting this one right. The best direction is at 90 degrees to the lean, but the hinge obviously wont hold if I just faced it up and pushed it over.

I can climb and rig to reduce the crown or remove it altogether, and just fall the stick. This is what my client (another contractor) has suggested I do, but the final decision is mine.

What I am thinking is to guy the tree using multiple 16mm DB lines, tensioned with a tirfor, directly against the lean, and then use the tirfor to pull the tree into the lay.

Am I nuts?

 

[pete mctree]

Sounds ok. I would try & keep all my rigging static as opposed to aDB.

How much do you think the stem alone weighs?

 

[Peter]

Thats why I want to tension each line first, then tie off to a base anchor on another tree.

Stem about 6 tonnes.

Some big tenex would be ideal, but I'm not buying new gear just for this tree.

 

[Thor's Hammer]

Sounds good to me. I might core the stem first, try to spot the rot.

 

[Tucker943]

The line pulling the tree against its lean, will cause the tree to make somewhat of a swing back towards that anchor point when it goes over. Just be advised and prepared.

 

[Peter]

Thats what I'm hoping for Tucker, a straight fall to the direction of the hinge is ok, a swing in would be better as then I wont have to winch the stem into place. The lowest 30 feet of trunk is staying in place for the creepy crawlies to eat.

Might just vertical bore the stem and see whats going on in there, havent got a corer.

 

[MasterBlaster]

When in doubt, remove some limbs.

 

[pete mctree]

Perhaps it would be better to "swing" the tree, using the lines as opposed to "fell it" with the lines holding it. Hope thatmakes sense

 

[Peter]

I think I get you, what I want to avoid is reaching a high peak loading. As the tree swings it will describe an arc, at the furthest point the load will be greatest, and if there is too much shock loading something could go pear shaped very quickly.

 

[stig]

Pictures would be good.

It is hard enough to judge a tree from pics, as Burnham's leaner over the historical barn showed us, judging them from pure imagination is WAY harder.

 

[Peter]

I'll get pics, there will be a few days on site before I get onto the big beastie.

 

[High Scale]

Not got enough cable Peter?

I think I would take the crown out like you mentioned.

 

[SouthSoundTree]

What I am thinking is to guy the tree using multiple 16mm DB lines, tensioned with a tirfor, directly against the lean, and then use the tirfor to pull the tree into the lay.

Am I nuts?

Vectors are super important in a case like this. We don't have the height. Is the ground flat, or uphill/ downhill on the side opposite the lean?

If you are uphill opposite the lean, and say you can get your lines horizontal, you are working at a 45 degree angle to the stem.
If you are on flat ground, and have your rope on a 45 degree angle to horizontal, you are working 45 degrees plus half of 45 degrees again, or 67.5 degrees to the stem, which will provide you with a lot of compressional force on the stem, which if bowed, will flex out a lot, IF i'm not mistaken poplars are pretty flexible across the board (seen lombardi and aspen sway considerably).

A part of the equation will be your rope angle. Do you have 200' ropes that you can anchor off at 50' on the stem, giving you a flatter rope angle or would it be 100' or less of rope anchored at 50' up. This will change the angles and vector forces considerably.

I might be inclined to go with a heavy cable or Amsteel, pretensioned as a 90 degree guy, with a light pull over line if I had to do it, but if future work rides on it, and the contractor has his mind made up on what he would do, I might dump off some of the crown, retainer line it, and tip what's left. You're already going up the tree to set the lines.

If it goes as planned with a fell it whole scenario, you'll impress him and maybe yourself. He'll be satisfied (unless wholesale felling makes any harder work for him). If it goes to plan as you both agree is a good way, it might cement the business relationship. All else being equal, I'd probably line up more work with another contractor who thinks as I do, while of course always being ready to learn new tricks.

 

[SouthSoundTree]

Oh yeah, maybe a gap face or whizzy to help the hinge have max flex on the tension side.

 

[Peter]

All good points.

Ground is undulating but flat overall, choices of anchor points for setting rigging are limited, I will know more once I have cleared some ground around it. It may be that there just is no suitable anchor, and the whole tree will have to be pieced out. Sure hope not though!

 

[murphy4trees]

any chance of dropping it to the lean and then picking it out of the hole with a crane?

 

[Peter]

No.

 

[pete mctree]

Just be like Daniel. Pretension with the mighty skid-steer & rip it over

 

[Peter]

Can't see the tree for the wood unfortunately.

 

[Peter]

Here's some other pics of the site. We are clearing a 5 metre path through the wood at the moment.

 

[Burnham]

Quite the jungle.

 

[blue]

We are doing a similar job at the moment but we have a toy coming to play with weds or thurs I'll get some pics.
Lets just say stuff doing it by hand.

 

[Burnham]

I like the sounds of that, Tim.

 

[Peter]

I'm on a day rate, so doing it by hand it quite appealing, especially I am am cutting for two men chipping.

Also doing a little landscraping, bulldozing a levelish path with the mini loader.

 

[blue]

I like the sounds of that, Tim.

Not as much as me