Re: Stone Shifting | Forum — The Modern Antiquarian

Stonehenge 181

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Stone Shifting

nigelswift Aug 25, 2003 08:59:49

Replying to Steve Gray

Sunday afternoon. Rocks, logs, holes in the lawn….

Gordon, hope you don’t mind all the questions. This time it’s about putting the uprights into the holes. Small scale, I had a problem with the stone not pivoting cleanly into the hole but sometimes sliding down on the pivot point, so the arc it goes through is elongated. I could design for that OK but it’s an intermittent effect, depending on how rough or uneven the stone is. As such, I was getting an unpredictable degree of inaccuracy. Any thoughts? Steve, do you have a lawn?

The only way I found to cure it on the small-scale model was to have the stone tilted upwards instead of horizontal. That way, it seems to build up a bit more rotational speed when it drops –it’s already built up a bit of speed when it reaches horizontal, and after that it seems to pivot round more cleanly and not to start sliding down the pivot point. So that might be something worth thinking about.

I suppose, if you did find tilting the stone was good, you could change your means of elevating it by building a sloping track and rowing it up until the end was supported on the A frame. At that point you could remove much of the track and end up with the stone supported in much the same way as you’re proposing, but tilted instead of level.

(If it did turn out to work that way it would have a lot of advantages apart from the pivoting aspect: you could set the whole thing up before the stone was brought to it, it would involve less mechanical effort and time, and you wouldn’t be needing the stone to be raised so high. Also, it would be sweet if your Big Idea, stone rowing, was not only the key to transporting the stones but also to erecting them.)

I tried this and it seemed to work, but I’m acutely aware that small-scale experiments may be quite different to what you’re proposing.

GordonP Aug 25, 2003 10:15:13

Replying to nigelswift

Mind? No I live to talk about it, ******* obsessed.

What we are doing on this forum is known in the business world as "Brainstorming" and it can be very useful.

For instance, you have identified something I was doing, either accidentally, or subconsciously. (I prefer to think it was the latter) I now realise the importantance of this one small detail. The stone must be tilted.

I too was getting erratic results with the test model (I was using a capping stone from the garden wall) at the time I was only concerned with getting the stone to drop in the hole, I varied the height of the towers in relation to the bottom of the hole, with some success. However on the 4 ton stone (which is much more predictable in its movements) I used a piece of 4 by 3 across the balance piont which in effect tilted the stone, this tilt was increased as I placed the "A" frame under the stone. I now reckon both these facts are vital. The height from which the stone is dropped, in relation to its length and the depth of the hole, and the amount of tilt on the stone. On the plus side a stone of 10 ton should be even more predictable and so on.

I've only given it a quick thought be feel instinctively that raising the stone on a tower will be much quicker and more stable than building a ramp perhaps I'm just anti ramp. I will think on and am open persuasion.