Once the centre slab was completed, I leveled some strings across it and out beyond the dimensions of the sawmill using my line level. This increased the accuracy of my levels, and also overcame the very real problem of having nothing to drive stakes into, as we had dug down between 15 and 60 centimetres to get to solid rock.
Using the oversize tube that our window coverings had been shipped in, I was able to roughly cut four pillars of the varied lengths we needed. Of course, two of them had to be cut at large bevels to accommodate the unevenness of the rock below. Grandpa assisted me by holding the tubes steady as I poured concrete into them up to their brim, packing them with rocks and tamping the concrete down with a scrap piece of lumber. We leveled the tubes up decently, and left them to dry for a few days.
With the obstacles out of the way and the pillars ready to offer their support, it was time to actually move the mill. Grandpa and I had discussed a number of times the easiest way to accomplish this. He preferred to dismantle as much of it as possible, whereas I leaned towards dismantling nothing, and simply dragging it onto the new supports. In the end, we met in the middle. I agreed that it wasn't worth the risk to try to drag it with the mast still on, in spite of my profound misgivings about being able to restore the mast to the track after it was moved. Mounting it onto the track the first time around had been responsible for my tractor tipping fear, and this time around I saw that I would have to do it under much more difficult circumstances. In any case, I decided to cross that bridge when we actually came to it.
Grandpa and I threw caution to the wind about our mutual weaknesses, and decided to remove the mast by hand - after dismounting all the items we realistically could. The engine, water supply and blade were all placed carefully in my nearby trailer, and then we eased the mast off the end of the track, and onto a scrap piece of OSB that has been doing various duties ever since the yurt floor was completed.
We then hooked up the comealong to the track after reinforcing it in various locations to reduce bending and twisting. Lowering it to the ground was more challenging than I expected. It was hard to lift the entire track by hand (that is to say, nearly impossible) while Grandpa removed the supports we had put in place under it.
moai (giant heads) of Easter Island, managed to get the mast onto the track, and positioned correctly.
And the next morning...
I was confident that my fresh mix had not froze as it was still against the rock and in a small area of still-warm soil (or so I convinced myself).
No cracks have appeared yet.
After an unbelievably hair-raising tractor trip through some virgin forest to obtain new skidway logs, all that remains is to assemble a new skidway and to redistribute the soil we had dug out for the tractor to have a smoother approach to the skidway.