May the Force be with you

[neksmerj]

Can't get my head around this one, despite a couple of glasses of medicine to ease an aching back.

Just suppose I need to pull out a tree stump sideways and I have a 1.5T chain block and a 500kg lever hoist, and there's a tree nearby to anchor from.

In order to get the benefit of both, do I couple up both pulling devices in series, or in parallel?

Ken

[Stustoys]

parallel

series, would limit your pull to 500kgs

[.RC.]

If you hook in series won't the 1.5t block overload the 500kg one?

[neksmerj]

RC, I didn't think of that, you are right. That means the pull from each has to be in parallel, and there's probably no gain, or is there?

May be some more medicine might help!

Ken

[malb]

I would be reluctant to operate them in parallel also because you cannot guarantee that the load would be divided appropriately between the two units. For example, if you apply X force between the anchor tree and the stump to be moved, you cannot guarantee that the chain hoist is providing .75X and the lever block .25X, particularly since you cannot realistically activate both units simultaneously and in proportion to their capabilities.

Also if one unit or its attachment mechanism to fixed and moving tree parts were to fail, the transfer of shock load to the remaining unit would quite likely destroy it as well.

Just the thoughts and ramblings of a retired engineer.

[neksmerj]

malb, both the pulling units are new, so I doubt there would be a failure there. I'm also using two lengths of 6mm load chain, again new.

Is there any safe way of using both units to increase the pull?

I should add that this tree stump is hard up against my weather board house. So far I have severed four lateral roots about the size of my arm. There's every chance that there are roots under the house.

Up against the house means I can't dig up every root.

Ken

[BobL]

I agree with Malb.

However, my feeling is that even those two units together are not going to move much in a sideways direction especially if the laterals are arm size. Pulling sideways means you will be pulling directly against the laterals under the house, breaking those under tension is going to be in the 10+ ton range.

[neksmerj]

Bugger, I have left about 600mm of stump still standing, in fact, the stump is actually four stumps, each about 75mm in dia.

Let's leave it at that, some how, I'll get this bugger out.

Ken

[RayG]

Get a shovel.

In answer to the mechanical problem, I think the maximum pulling force would be when they are in parallel, but since the force is applied by the tension in the chain of the block and tackle if the lever hoist reduces the tension in the chain it would reduce the force applied by the block and tackle, so how effective it is will depend on the details. You could make them independant but still get more force by arranging them to pull at right angles to each other, that way the combined force will always be applied, just use pythagorus to resolve the vectors. Potentially you would get sqrt( 0.52 + 1.52 ) = 1.6 tonnes total.

Ray

[BaronJ]

Hi Ken,

I'm inclined to agree with Ray !

A couple of years back I had need to get rid of a 40 ft long row of leylandi trees.

Having hired a mini JCB to dig them out and having cut the tops off leaving around an 8 ft length of 8 or 9 inch diameter trunk to use to pull them over and out It was a dismal failure. The JCB just couldn't get enough traction to pull them over.

We ended up using the JCB to dig a trench along one side of the row cutting the roots with a Sthill saw which allowed them to be pulled to one side. Then we just cut them off with a chain saw so that the tops were below ground level. After drilling some 1" holes into the remaining trunks and filling with caustic soda to kill the roots off, we put the soil back over them. The whole area was block paved afterwards. So far no sign of any regrowth or damage to the paving.

We couldn't pull them out from the other side because of a public footpath that runs along that boundary edge. :no:

Sorry about your back.

[.RC.]

Bugger, I have left about 600mm of stump still standing, in fact, the stump is actually four stumps, each about 75mm in dia.

Let's leave it at that, some how, I'll get this bugger out.

Ken

Well there is always.... Well maybe I better not say that in this day of extreme terrorist hysteria... :D

[bollie7]

I had a bloke pull some palm trees out for me at one point. He had a backhoe and he had a ripper tyne from a dozer attached to a quick release plate for the hoe. He used that like a giant finger to rip down around the tree to break the roots. That was very effective.

bollie7

[Theberylbloke]

Get a shovel.

In answer to the mechanical problem, I think the maximum pulling force would be when they are in parallel, but since the force is applied by the tension in the chain of the block and tackle if the lever hoist reduces the tension in the chain it would reduce the force applied by the block and tackle, so how effective it is will depend on the details. You could make them independant but still get more force by arranging them to pull at right angles to each other, that way the combined force will always be applied, just use pythagorus to resolve the vectors. Potentially you would get sqrt( 0.52 + 1.52 ) = 1.6 tonnes total.

Ray

Hi Ken,

I can't quite follow Ray's idea, although while drawing it up, I was reminded of another idea. Attach your chain to the stump and to your anchor, fairly tightly. Find another anchor point about half way down the chain and off to one side. attach your 1.5t pulling equipment to that and the chain so that it attempts to pull the chain sideways. A small amount of sideways travel will create a huge amount of tension in the chain and by default against the stump.

Word of warning - before you begin check the load rating of your chain If I recall correctly the lifting limit for grade 80 chain is the diameter squared mutiplied by 32 = 1152kG? Using both chains and attempting to spreading the load equally across both chains is possibly not recommended.

Cheers

The Beryl Bloke

[Stustoys]

A small amount of sideways travel will create a huge amount of tension in the chain and by default against the stump.

I'd thought of that google said his chains arent up to it.

I think a set up with good old fashion rope might work(i.e. something with some give in it).........put 1.5 on one rope, tie it off. put 1.5 ton on a second rope, tie it off. Move back to the first.. repeat...... seems like a waste of time and rope though

Stuart

[Theberylbloke]

I'd thought of that google said his chains arent up to it.

I think a set up with good old fashion rope might work(i.e. something with some give in it).........put 1.5 on one rope, tie it off. put 1.5 ton on a second rope, tie it off. Move back to the first.. repeat...... seems like a waste of time and rope though

Stuart

Hi Stuart,

That would be pretty big rope I think. for natural fibre rope SWL is diameter squared so in this case, diameter is the square root of the load so about 40mm. Would be slow, however given that the chain is not up to the 1.5 tonne chain block, it could be safer.

Ken,

Is there a particular reason for wanting the stump & roots removed rather than say just cutting the stump back to ground level and letting the rest slowly rot away?


Cheers

The Beryl Bloke

[neksmerj]

My experience with just cutting the trunk at ground level is the tree will spring up again. It's happened to three trees I've cut down. I suppose I could do as you say and hit the stump with round up, but where's the fun in that.

I assembled a tripod with 40 NB water pipe, and using the 500KG lever hoist hung from the apex, attempted to jack the stump out. Trying a vertical lift proved fruitless, hence an attempt at a sideways pull.

There must be some massive roots under the house, these I can't get to. Stustoys, I'm not pulling up floor boards, so don't mention that.

I'll have another go tomorrow and will have to use a combination of two lengths of 6mm G80 chain and 1/2" sisal rope doubled up a few times.

My hitching tree is a bit further away for the chain alone to reach.

You know your an old bugger when you have to carry a chair to the work site. Work 5 minutes, rest 5 minutes, work 5 minutes, rest 10 minutes, and so on.

Ken

[BaronJ]

You know your an old bugger when you have to carry a chair to the work site. Work 5 minutes, rest 5 minutes, work 5 minutes, rest 10 minutes, and so on.

Ken

I know just what you mean :U:U:U

[neksmerj]

I hate to admit it, but I'm beat. This piddly little stump will not budge, I couldn't shift it one millimetre.

There must be quite a few hidden roots under the house that shall remain hidden, and in hard clay.

It looks as though I will have to dig away as much of the soil as I can, and attack the stump with my chain saw.

Attached is a pic of my final effort.

Ken

[wbleeker]

Make a fresh cut across the stump ends and paint with roundup, leave to die, and then pull out one day in the future
Will

[BaronJ]

Yes cut them off, below ground level if possible. Roundup or caustic soda will kill it. Then just put the soil back and forget that its there. It will rot away in time.

[neksmerj]

I'm not going to kill this tree trunk with roundup, it's too bloody dangerous.

I'm digging in under the house with great difficulty, and have just discovered another lateral root about 75mm in dia. Chain saw dispatched.

Try standing in a ditch and swinging a matic sideways, in under the house.

I won't be defeated, when I set my sights on achieving something, I will press on even it it kills me, unless the fags and medicine get me first.

Pictures later.

Ken

[rodm]

Ken,
As much as i hate reformed smokers think about this - are you going to give up the fags before you have been diagnosed with a smoking related illness or give them up now to avoid that decision..

I don't stand on high ground having been a heavy smoker for 45 years but i do know the benefits having given them up over a year ago. Seriously it is worth it Ken so think about the options.
I am not passing judgement on you so do not be offended. I was a 40 to 50 a day bum sucker and at 60 was feeling my life time addiction. I don't have tightness in the chest nor pains down the left arm and have got rid of the dreaded smokers cough. That horrible phlegm regurgitation in the morning. Knowing what i know now I would have given them up years ago and avoided the long term health consequences of smoking. I know I am not out of the woods after a lifetime addiction to the weeds but I can only hope I have improved my chances.

My decision to give up the fags was easy - my son was critically injured 15 months ago in spray booth explosion/fire and while he was in intensive care we made a pact to give up the fags together. While it was an insignificant gesture under those circumstances you do these things because everything else is out of your control so you do something that you can do.

If any of you have knowledge of severe burns you will understand the hideous situation and how maybe a positive might bring you hope.
Anyway I am committed to it and I have given up the fags for over twelve months so I can say to all smokers that it is worth the effort. I pass no judgement on smokers and know the difficulty in giving up but would like to say to you give up while it is voluntarily.

Flame me if you like but do not expect a response. As I have said I an not standing on high ground and it required a major event to change my behaviour.

[bob ward]

Sort of on topic, vegetation clearing among the temples at Siem Reap. These guys are pulling over a tree (top left) using ropes and pulley blocks. It was going to take them all day given the size of the tree vs the gear they had, it was interesting watching them work, they knew exactly what they were doing and how to do it.

http://i237.photobucket.com/albums/ff28/sirrobertthegood/IMG_1130_zpskhufoxjw.jpg (http://s237.photobucket.com/user/sirrobertthegood/media/IMG_1130_zpskhufoxjw.jpg.html)

[BaronJ]

Hi Rod,

I know just what you mean :) I gave up smoking 36 years ago, just before my daughter was born,
I swore that I would never inflict smoke or smoking on my children. Unlike my father who smoked until the day it killed him.

I'm glad that even though the circumstances were difficult, that you have given up and are much better off for it. I hope that your son is doing well.

[simonl]

Hi there,

Do you have vehicular access to the tree?

I used to do a lot of Hilux gardening…… if you know what I mean. :2tsup:

Failing that, perhaps you could set a a mechanical adavantage by attaching the chain block to rope and then to a couple of pulleys. With one pulley you would achieve a 2:1 and with a second pulley, it would be 4:1.

I'd almost guarentee success with the chain block and a 4:1 MA!

Simon

[neksmerj]

After much digging, down on hands and knees, I finally found a three inch dia lateral root under the house that stopped me in my tracks.

With that cut, out came the fantastic Beaver lever hoist and pulled the "bath plug" out, remaining roots and all.

Now I can relax with a nice frothy and a fag.

Here's the proof.

Ken

ps, would some kind member please rotate each image 90 deg CW, I don't have Photoshop or similar