Steve Gray
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Re: Hole Profiles
Sep 17, 2003, 08:27
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Interesting. I presume that the dating methods involve samples taken from the holes, which would fit with one being removed for access.
With only one sarsen removed it would be quite difficult to "row" the trilithon stones through the gap.
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nigelswift
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Re: Hole Profiles
Sep 17, 2003, 08:36
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Naah, Pickfords could do it!
It only means you have a gap between rowers of a metre or two and I suppose you could angle the oars and sort of fiddle it through.
You had me worried for a moment, I thought you'd disproved stone rowing right there and then!
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Steve Gray
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Re: Do we need ropes?
Sep 17, 2003, 08:38
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Using the weight of the lintel involves either getting it up there and bringing it back down (while we raise the second upright) or else we need guy ropes capable of withstanding the 7 ton strain.
I'm concerned that such a load being taken up by the guy ropes as the levers are operated will produce enough stretch that the levers will never achieve their full pressure on the stone before they run out of movement. We need a method that can absorb the stretch in the rope first and then continue to apply movement to the stone.
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nigelswift
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Re: Do we need ropes?
Sep 17, 2003, 08:41
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I can’t follow the current discussion very well, but can you explain why the 100 ft pole idea isn’t being pursued, as it seems to involve the least effort of all in my garden.
Although, for a stone lying at a shallow angle, the pole needs to stick very high in the air, it would seem we could achieve this fairly easily:
Raise the pole Horizontally on towers under each end. Build a third “pivot” tower underneath it, just right of centre. Remove the Left tower, and allow the pole to pivot downwards until it rests at right angles against the base of the stone. Attach a rope to complete the triangle. Remove the remaining towers.
This seems to involve little or no stone-raising towers, just pole-raising towers so has got to be worth thinking about.
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Steve Gray
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Re: Hole Profiles
Sep 17, 2003, 08:46
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I said difficult, not impossible. Given that the rowers have to move their levers fore and aft as well as up and down, the gap in the rowers needs to be quite large. We have a 32 foot stone being rowed by 40 people (20 each side). So for normal rowing each person will have 1.6 feet in which to operate. Leaving a sizeable gap may produce some congestion. I suppose we could always use only 10 levers per side and 2 people per lever to solve the congestion problem. Or alternatively set the fulcrum logs closer so that fewer people are needed, and accept a slower rate of progress for a short while.
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GordonP
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Re: Do we need ropes?
Sep 17, 2003, 08:52
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leave the lintel on the ground at the other side of the hole. Use it as an anchor for the bracing strutts on the tower. (ropes tightened with a windlass)
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GordonP
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Re: Do we need ropes?
Sep 17, 2003, 08:57
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I,ve not given this idea much thought, before I do, 1, are there any 100ft trees left? 2, Is it quicker to raise a 30ft stone, or an 100ft tree trunk?
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Steve Gray
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Re: Do we need ropes?
Sep 17, 2003, 08:59
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We may need to have small guy ropes either side to prevent the pole from pivoting sideways, but that's a minor issue. Although the pole seems like it's acting as a big lever, it's actuallyh the rope that pulls the stone up. The pole merely acts like an A-frame keeping the rope in the correct place. It's the angle between the rope and the load that gives the mechanical advantage. All the load on the pole is compressive, so it doesn't need to be especially stout.
It's also possible to reset the angle of the pole as follows:
Suppose the pole is set initially quite low and we only manage to pull the stone from 70 to 80 degrees before the pole reaches the ground. If the back of the stone is then rammed with rubble to retain it, the end of the pole can be raise back up and the rope retensioned ready for a second go. This is not a big deal because we are only talking of a 2-3 ton load at the end of the pole.
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Steve Gray
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Re: Do we need ropes?
Sep 17, 2003, 09:05
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The bracing struts are not a problem; they can be anchored into sockets in the ground. I thought you were intending to use the lintel as an anchor for the ropes.
But anyway, if you are relying on ropes to take the strain of the levers, then you are using ropes. So yes, we do need ropes.
Why go to all the trouble with the tower when ropes can be used directly to raise the stone?
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Wotan
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Re: Eh?
Sep 17, 2003, 09:05
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I can follow this even less well than Nige - but i'm immensley impressed at you guys being able to work all this out - is it all done behind the eyes or has any of this been tested on a pc? and Steve - have you any tech drawings for the process ?
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