EDER Titan 80 Ratchet Felling Wedge

[drinksloe]

3 hours ago, Khriss said:

@drinksloe thats the thing in Arb, that doubt in yr head-had a 35m Syc' heavily weighted over a brand new house,  put guy rope on it with JCB loader with tines stuck in ground, an other rope on tirfor to tug it over with High lifts in backcut. Site manager was shitting it. K

 

Done a few like that right behind my own house,  minus the machines.

Just a solo effort on tirfor and another winch.

Was laying them along the house within 4m or so, surrounded by other targets too.

No matter how often u've done it before still squeaky bum time on a few.

Think I gave myself false confidence with that 1, had doubts 1st thing but rest went over so easily despite gusting wind, but when gusting wind got stronger and more constant I should never have tried to put it where I did.

Every day's a school day, and no one was hurt

 

To me I'm sure they will be brilliant for 70% of trees in forestry work but u still need a jack to do the other 15% and the last 5 prob need a hurricane in right direction or a real winch.

 

Yes a jacks heavy and takes time but if I've walked 1 mile into a wood I should be able to handle most trees I need to do.

[Khriss]

Mate of mine misjudged wind factor. The video is quite popular  😉K

[josharb87]

On 05/12/2020 at 03:44, drinksloe said:

How rough a tree will it push over thou??

 

I currently work with a 20t bottle ( and got a proper 30T Treeman's on order which was not cheap but should last a long time) and had it struggling a few times.

But seen me at full extension and tree still sitting balanced as so much wieght on the wrong side.

 

From wot I was told there only good for medium sized trees with not too much back lean/wieght on them. So u still need something bigger Incan for the real hairy outside monsters.

But can see it saving a lot of time not cutting the pocket at back and getting the stumps that bit lower

 

 

Have you read the first post?

 

 

 

lifts 2 wedges high. Theres no magic involved, so its not miraculously going to tip over something that requires more.

 

 

 

What it does do, is tip trees over that need 2 wedges (maybe 3-4 if theres space in the backcut for a reposition) and it does that very well, much more civilised, easier and safer than whacking wedges in

[Marc Lewis]

@drinksloe when you are using the jack on a big back leaner, outside tree with all the heavy branches adding to the back weight, do you ever get the hinge failing from the stress that the jack puts on it?
 
I can remember jacking over a big oak on a field edge, it all seemed to be going right, back into the wood, when suddenly the  hinge just let go and it went down 45 degrees into the field, a lot of clearing up. I felt that had I used the winch there would have been far less strain on the hinge.

I've often wondered this because the force used to get the tree over is from a different direction i.e. upwards not sideways and i worry that with alot of force you could pop the hinge off.

[dumper]

1 hour ago, Marc Lewis said:

On 05/12/2020 at 11:21, openspaceman said:

@drinksloe when you are using the jack on a big back leaner, outside tree with all the heavy branches adding to the back weight, do you ever get the hinge failing from the stress that the jack puts on it?
 
I can remember jacking over a big oak on a field edge, it all seemed to be going right, back into the wood, when suddenly the  hinge just let go and it went down 45 degrees into the field, a lot of clearing up. I felt that had I used the winch there would have been far less strain on the hinge.

Read more  

I've often wondered this because the force used to get the tree over is from a different direction i.e. upwards not sideways and i worry that with alot of force you could pop the hinge off.

The cause of the only major accident I have had felling used a 20 tonne bottle jack on a leaning sycamore popped hinge before pushing tree over only took out telephone wires could have been a lot worse, 

Edited December 6, 2020 by dumper
Speeling

[openspaceman]

1 hour ago, Marc Lewis said:

On 05/12/2020 at 11:21, openspaceman said:

@drinksloe when you are using the jack on a big back leaner, outside tree with all the heavy branches adding to the back weight, do you ever get the hinge failing from the stress that the jack puts on it?
 
I can remember jacking over a big oak on a field edge, it all seemed to be going right, back into the wood, when suddenly the  hinge just let go and it went down 45 degrees into the field, a lot of clearing up. I felt that had I used the winch there would have been far less strain on the hinge.

Read more  

I've often wondered this because the force used to get the tree over is from a different direction i.e. upwards not sideways and i worry that with alot of force you could pop the hinge off.

It's fairly easy to see what's happening with simple  applied physics and levers. We only need to consider the cases where the tree is not leaning  into the direction of fell and heavy branches are moving the centre of gravity of the tree away from the stump to opposite the direction of felling. To topple the tree you just need to move the line of action of the centre of gravity to  past the hinge and over the gob or beyond.

 

Say the line of action of the centre of gravity is 1 metre from the hinge and the  jack is 30cms from the hinge. To rotate the tree about the hinge the jack  has to counter the weight Mkg times gravity  of the tree times its distance, 9.81 M Newton metre but the jack is nearer to the hinge so it has to apply this torque from 1/3 metre so it has to supply 3 times this upward force and this is resisted by the weight of the tree and the tension in the hinge. This upward force on the fibres of the hinge is the opposite from which the fibres are normally stressed and worse as the tree moved the hinge is bent and the fibres at the back of the hinge fail in tension earlier than normal as they are pre stressed. Normally the point at which the strain on the fibres exceed their tensile strength is when the tree has moved around 10 degrees but because of this pre stress they must fail somewhat earlier. With a rope the tension in the rope counters the moment of the weight of the tree without altering the stress on the hinge until the tree moves.

[htb]

Only had one Sitka hinge break and go 180 degrees wrong into another plantation. Was 20 t bottle jack felling FC oversize outsiders, wakes you up quickly, cutter was a bit thin on the hinge.

Would have been easier with rope pulled by forwarder/ harvester.

[Dan Maynard]

It's fairly easy to see what's happening with simple  applied physics and levers. We only need to consider the cases where the tree is not leaning  into the direction of fell and heavy branches are moving the centre of gravity of the tree away from the stump to opposite the direction of felling. To topple the tree you just need to move the line of action of the centre of gravity to  past the hinge and over the gob or beyond.
 
Say the line of action of the centre of gravity is 1 metre from the hinge and the  jack is 30cms from the hinge. To rotate the tree about the hinge the jack  has to counter the weight Mkg times gravity  of the tree times its distance, 9.81 M Newton metre but the jack is nearer to the hinge so it has to apply this torque from 1/3 metre so it has to supply 3 times this upward force and this is resisted by the weight of the tree and the tension in the hinge. This upward force on the fibres of the hinge is the opposite from which the fibres are normally stressed and worse as the tree moved the hinge is bent and the fibres at the back of the hinge fail in tension earlier than normal as they are pre stressed. Normally the point at which the strain on the fibres exceed their tensile strength is when the tree has moved around 10 degrees but because of this pre stress they must fail somewhat earlier. With a rope the tension in the rope counters the moment of the weight of the tree without altering the stress on the hinge until the tree moves.

I've thought this before, felling is risky mostly not because the forces are unpredictable but because the material properties are unpredictable. It is weights and levers.

[drinksloe]

4 hours ago, Dan Maynard said:

8 hours ago, openspaceman said:

It's fairly easy to see what's happening with simple  applied physics and levers. We only need to consider the cases where the tree is not leaning  into the direction of fell and heavy branches are moving the centre of gravity of the tree away from the stump to opposite the direction of felling. To topple the tree you just need to move the line of action of the centre of gravity to  past the hinge and over the gob or beyond.
 
Say the line of action of the centre of gravity is 1 metre from the hinge and the  jack is 30cms from the hinge. To rotate the tree about the hinge the jack  has to counter the weight Mkg times gravity  of the tree times its distance, 9.81 M Newton metre but the jack is nearer to the hinge so it has to apply this torque from 1/3 metre so it has to supply 3 times this upward force and this is resisted by the weight of the tree and the tension in the hinge. This upward force on the fibres of the hinge is the opposite from which the fibres are normally stressed and worse as the tree moved the hinge is bent and the fibres at the back of the hinge fail in tension earlier than normal as they are pre stressed. Normally the point at which the strain on the fibres exceed their tensile strength is when the tree has moved around 10 degrees but because of this pre stress they must fail somewhat earlier. With a rope the tension in the rope counters the moment of the weight of the tree without altering the stress on the hinge until the tree moves.

Read more  

I've thought this before, felling is risky mostly not because the forces are unpredictable but because the material properties are unpredictable. It is weights and levers.

 

Like everything every tree is different and even will depend on weather conditions as well at exact time of felling.

I'd far rather fell a tree than climb it, as I feel more control over it, but I'm a rubbish climber and was only average 20yrs ago when I done a bit

 

I wouldn't even think about jacking or even wedging any hard wood with much of a lean on it.

 

I think in soft woods ( esp SS or NS u can get away with murder, not just as much in larch, douglaus and Grandis is quite brittle for a soft wood) hinge is far more predictable, most off the time.

As the timber is generally still in its prime and generally stronger and more flexible anyway.

In ARB ur generally dealing with mature, over aged or diseased/damaged if ur felling them.

Also the numbers of trees ur knocking over compared to ARB boys.

Be doing 10s of big stuff if snedding/crosscutting a day and more if just felling

As well as in most places even if it goes wrong chances are not going to be a lot off major damage, a broken stock fence etc.

 

 

On bigger stuff 3ft+ butts I think ur jack is far enough away from the hinge not to be lifting the hinge.

 

I have had problems on smaller larch around the 20ish inch butts, heavily leaning and wieghted ( possibly leaning back10 Deg and some limbs could be 4 or 5m into field) and had to be felled directly against wieght  as over a gully and was struggling for hieght for the harvester to reach the tips. And into the prevailing wind, althou got lucky a few days with unusual N winds.

Rightly or wrongly I was cutting my pocket above the back cut which made things worse. But was a good bit quickier.

Thought it made it a tidier job with low stumps and all going to chip anyway and didn't want to leave all the small logs lying where I recut stumps.

On the more heavily leaning smaller stuff it was lifting the hinges u had to watch and wedge as well, but would really struggle to wedge them alone.

Possibly the ideal test for the hydraulic wedge, not too big but enough wieght to make wedging hard work, plus the ammount of trees needing knocked over ( about 400m, so guessing 200ish edge trees)

But trees that size are just a pain u havenae got the room to do much and even knocking wedges in at angles or parrellel to hinge as u'll end up against it otherwise, but snookers u for putting a bigger wedge in.

Bloody hate small back leaners

 

 

Edited December 7, 2020 by drinksloe