Re: Do we need ropes? | Forum — The Modern Antiquarian

nigelswift Sep 17, 2003 08:41:11

Replying to GordonP

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.

GordonP Sep 17, 2003 08:57:27

Replying to nigelswift

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?

Steve Gray Sep 17, 2003 08:59:27

Replying to nigelswift

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.

Stone shifting 5