Exactly my thoughts FW.
I can’t comment on whether Gordon can make a “collar” strong enough to fix a pivot log to the stone, but using his favourite assessment method – “does it feel right” I’m wondering if we’re ending up with two areas of risk, where we previously had only one (the strength of the edge of the tower). I know this is the opposite of my previous feeling that perfect pivoting produces perfect placement etc but I’m now thinking the practicalities may preclude it.
Looking at the project in terms of risk analysis, and defining failure as “the stone ends up with an irrecoverably severe lean” I’m wondering whether if we dispense with the pivot log, and just tip the stone, slippage and all, we can avoid failure, as defined, whereas the existence of the pivot log could actually introduce the risk of failure.
We’re focussing on an ideal, i.e. that the stone ends up plop, upright in the hole. Hence we’re trying to eliminate any element of variability by avoiding any element of slippage at all. However, maybe we should accept a degree of slippage and variability? We might allow for it perfectly and end up with an ideal result. But the point is, if we can’t be positive of that we can still proceed on the basis that any error won’t be of a disastrous scale. In other words, the worst result is that it’s in the hole but slightly skew and we can pull it straight? This contrasts with the situation where we had a collar and if it failed the stone could end up with an irrecoverable lean.
In terms of authenticity I think this may be the right way to go, as well. I’ve looked at all the inside faces of the sarsen circle and confirm they’re all pretty smooth, certainly smooth enough that slippage would have been pretty predictable. (I haven’t checked this for all the trilithons though). So, whether deliberately or not, I think the ancients could have part pivoted and part slid them pretty predictably.
Also, surely, they would have righted some of them by pulling on ropes? They wouldn’t have got them all perfect first time. And hauling stones upright was in their blood – most stone circles have crazily shaped stones that must have been dealt with that way.
Gordon obviously wants to prove that only a small team was involved, but I think we can maintain that – the lean we’re anticipating will be small, so hopefully it would be easy. Maybe at that point his collar making skills could come into play – attaching a very tall log to the stone and attaching our ropes to the top of that?
