Weight of a stem...

[openspaceman]

A 20m length of diameter 1m will have a volume of 15.7m3 and at a density of 0.55T/m3 will weigh 8.6 tonnes

 

What about the water? scots pine is about 1tonne/m3 green but abies less.

[Ty Korrigan]

The weather was very poor yesterday.

The tree on the left is the one estimated at around 45m.

It is growing in a well sheltered hollow, you can make out the lake behind.

[Ty Korrigan]

Plan is to either zipline branches to the top of the bank or just free fall them and have 2 guys make up bundles of branches and winch them (cone on front) to the top of the bank.

It is hidden by the 2 beech trees but the top has sustained some damage since I last worked on the site, maybe even reducing the height a little.

The top is a bit of a tangled mess and this could be free falled for the winch or digger to lift up the bank.

Now, my pto winch is a 3.5t Uniforest normally attached to a 26hp tractor but I can borrow/rent a 35hp tractor for the job.

It's evacuating the stem in useable sections which might require the large 360.

The only reason the client wants the tree out is that 'should' it fail one day it will either crush the roof of the farmhouse and 3 phase lines or land slap across the fishing lake. Either way prove to be a far more expensive job than a preempted removal.

All advice welcome.

When the weather has improvedr I'll return to take some better images.

Ty

[Daniël Bos]

If that is 45m, and 1m dbh, it's got enough taper to make me stand by my guess.

Weights are for wood only, measurements are (presumably) over bark.

[NFG]

Volume = pi x radius squared x length

Volume = 3.142×0.5x.5×20 = 15.71m metres cubed

weight = 15.71 x 550 = 8640 Kg

 

Take a bit off for the bark, plus water content - not sure what to allow.

Edited February 21, 2017 by NFG

[Daniël Bos]

Volume = pi x radius squared x length

Volume = 3.142×0.5x.5×20 = 15.71m metres cubed

weight = 15.71 x 550 = 8640 Kg

 

Take a bit off for the bark, plus water content - not sure what to allow.

That would be correct for a solid cylinder.

This isn't that, it tapers and the 1m includes bark, hence my calculations based on 75cm average dia

[daltontrees]

What about the water? scots pine is about 1tonne/m3 green but abies less.

Fair enough, the FC has published figures somewhere indicating a wet/dry ratio of about 50%. 550kg/m3 must be air dry density, so double that. And i suppose an overbark diameter could be misleading as Douglas Fir can be quite corky barked.

[daltontrees]

PO needs to clarify, is it the volume of teh 20m lower half that's needed or the whole stem? Stem taper requires a bit of juggery pokery to estimate volume, I have seen papers explaining that it's not as simple as taking average diameter, and involves measuring or estimating the diameter at several points up the stem. This graph is for the famous 'General Sherman' redwood. Height is in m along the bottom axis, radius up the side axis.

 

 

If it's just the first 20m here that matters and as the OP says it's fairly constant at 1m diameter, a cylinder calculation would maybe suffice.

 

So wet weight 17.2 T.

 

Maybe the question is how does it need to be cut so that each piece does not exceed the available 3.5T PTO winch?

 

17.2/3.5 = approx 5 pieces of 3.5T each. Over 20 meteres that's 20/5 = 4m. MAybe near enough to 3.6m standard length to make that a useful target?

[Mark Bolam]

I think we're getting in too deep here (and the MC is always going to be a big guess).

 

The answer is, yes Ty, a 20T 360 will handle that stick easily.

 

Id be more worried about getting out of the way of the butt when you fell it up that bank!

[Ty Korrigan]

Hah! Plan is to leave a healthy hinge.

It's got a slight lean away from direction of fell.

So once it's ready to be pulled over, I'll be beating a well planned retreat further away than it's height.

I have now thought, if we leave it as long as possible, a neighbouring farmer may be able to drag it up the slope in one...

Certainly it will be one to film!

I could set up a GoPro in a neighbouring tree...

Ty