Anchor for winching

[Haironyourchest]

39 minutes ago, AHPP said:

Let's not be dicks to the OP. He was being inventive. I've often considered doing similar. Eddie's idea is the closest to the one I'd probably go with. Scaffold boards on the house corners and a length of rope round the whole thing.

That was my first thought, but it presents a major problem: depending on the width of the house, your rope ends would meet (at a shackle and winch) at a very oblique angle, putting massive leverage on the anchor rope. In order to achieve the same WLL as a straight leg to anchor, you'd need the angle to be 120 degrees. Now, given we don't know the dimensions of the house, let's assume it's about 6 meters across. If so, we're looking at the winch being situated somewhere around 5 to 6 meters from the wall of the house. Now, this might be ok, if the grounds are big, and the distance to the tree is far enough. Or not. Also, the rope will be hammered on the house corners. This could be overcome by padding the corners with side-cut pipe, say, 6-8 inch diameter. That new type platic ridged road drain pipe would be ideal. And the pipe will be crushed unless packed out against the wall with something uncompressable as well. All very complicated. Ground anchor would be ideal, but maybe thats not possible, for some reason. Could be the whole place is tarmcked, concrete or landscaped. Could be utilities whereabouts unknown. Who knows? If there is a slab foundation, then I would suggest bolting to that. Anything is possible, if the perameters are known and the physics understood. Pics and specifications would be great.

[s o c]

How about photos or a sketch of job and site?

[Powerfab]

Please, please do not do this, it will be a total and costly disaster. 

As mentioned above brickwork is good in compression, completely rubbish in tension. But that's not why it will fail.

It will fail because all walls, cavity or solid built in the last 50yrs are on a DPC which forms an excellent slip plane for movement. 

 

I've seen complete two storey gable walls moved on the DPC, in one instance due to the expansion of solid wood timber floor installed without any expansion gap on the perimeter. Hard to believe but the Lounge floor pushed the gable 15mm on the DPC. 

If you find a wall where the plinth is rendered over the DPC, 10:1 odds you'll see movement cracking on the render along the DPC line which has been caused by thermal expansion. 

 

Bottom line is avoid at all costs. 

[Haironyourchest]

Good point above - I never thought about the DPC. Anchor into one of the side walls parallel with the direction of pull, and install the anchor as far back as you can, so the load will be compressing the entire wall edgewise. No way the wall will move then. But there will be shear forces on the bolt, and that's not what they're designed for, so use an oversize bolt. There will also be tortional forces on the immediate bricks around the bolt, which will be impossible to counter. A long plate, anchored with a series of bolts, will be the way to go. Something like a length of 10mm channel iron with some holes punched will do. And a hole in one of the side walls, close to the end, to attach your winch to. If you wanted to be really super-safe, you could get something L-shaped welded up that would wrap around the back corner of the house. Where there's a will, there's  a way - let's not hoist the white rag just yet!

[Haironyourchest]

You know, I've just found the solution: you get a bloody strong pole or something, stick it round the back of the house, with just a foot or so sticking out beyond the corner. Attach your winch to the end sticking out (chokered sling) and that's your anchor. Now, as you apply force, the pole will want to pivot on the edge of the corner, so you have made a reverse lever. You must stop this my anchoring the moving end of the pole. You can do this by either: A) sucuring it to the house with bolts. B) Blocking it with something heavy, like a car. Whatever you secure it with had better be strong enough though, cos if it fails under load the butt end will flip away from the house like a Roman trebuchet. The longer the pole, the less force will be needed to make it fast. Think leverage and practice with a mini mock-up first so we're clear about the physics. Honestly, that's what I'd opt for. Assuming the house wall is somewhat in line with the tree.

[LGP Eddie]

I’d be straight down the micro digger and auger route!

 

 

Eddie.

[Wedgebanger]

I’ve been readin, then me thinks ahh. I got a pdf with things in .. so here’s a fews pics for ya ta stew over.? 

 

not sayin it will be easy. But it’s a way

[Haironyourchest]

US Army Field Manual 20-22 Vehicle Recovery Operations!

 

https://www.bits.de/NRANEU/others/amd-us-archive/Fm20-22(62).pdf

 

There's gold in that there manual. Excellently written, and forever relevant - the laws of physics never change. ?

[Con]

Thanks for all the input. I'm not offended by any of the comments,  in fact I take the 'most stupid ever' comment as an acalade, especially when I think back to the 'vesp era'!

Haironyourchest painted a better picture than I did. All the usable area is block paved, there's a bit of grass, but your under the tree virtually.  I did consider lifting blocks and ground spikes. Bit of a faff tho. There's a detached garage. I don't like the idea of a rope around it tho. All the stresses are behind the winch operator,  out of sight. Something could be happening unmoniterd. The wall bracket I thought about is right angled, and I considered putting it on corner of the garage. Don't worry,  I'm not now! I do understand about tensile and compressive strength. I'm not trying to uproot a redwood.

It's a holly, with a slight backward lean. 2 men on a pull rope can recover it. I was just trying to think of a more controlled method, in case they slip. Probably end up climbing it, and getting pricked and scratched to death!

Edited October 22, 2019 by Con
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[carlos]

id be thinking along the lines of potentially damaging and having to repair the clients house vrs donning my harness and sectioning the tree! the later seems easier to me.

we did use the multiple angled stake anchor once for a fell, worked fine