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Friday 18th and a grey overcast again. I have spent the morning shoring up the north side of the raised observatory, self-compacting gravel pad with rocks. This is prior to adding more gravel. This material is remarkably firm but can be locally disturbed by heavy rain or repeated drips from the veranda. A covering of pea gravel solves this problem nicely, once the surface is levelled.
A flat area in the back garden/parking area has had the new dome circle roughly marked out with small stones. Just to check exactly how much room I really need. A surprisingly large footprint! There is a long wait for it to become warm enough for outdoor fibreglass work. So the dome could be sitting there for some months. Fortunately there is plenty of room to turn the car around despite the dome "workshop" circle. The trailer will happily sit on the opposite side of the dome "roundabout" until needed.
My plans for a low, mobile, dome carrying trolley, with trailer jockey, wheel jacks, will allow the dome to be moved about at will. The last dome sat on fixed stands while I built it from scratch. It seemed considerably smaller. Being able to move the dome about will make it easy to change its location at a whim if it proves necessary. Perhaps to place it in bright sunshine to harden the GRP?
Not to mention easy rotation to point the "doorway" out of the wind. Or into the sun for more working light. The dome will provide its own weather protection as I work. Unless I cut the observation slit away before I have the shutters ready. That would be rather silly. Even though I do have plenty of tarpaulins.
Once the observatory building, wood work is completed I could lift and finish off the dome "upstairs" in its final position. This would mean working on reinforcing the slit from stepladders resting on the upstairs observatory floor. The observatory's wall height would be added to the dome height. Instead of standing more safely down on the ground with the dome only slightly raised and adjustable. The semicircular doorway is already 1.4 meters high. So jacking it up will make entry even easier.
Not a huge deal to do GRP work "upstairs." Because I have numerous and sturdy, builder's stepladders. Though my memory is still sharp on the difficulties of fitting the bi-parting shutters on the dome when it was up high! Access to fit the holding screws to heavy duty drawer slides was a nightmare. Worth keeping firmly in mind with an even bigger dome and even heavier shutters.
The hinged, folding, builder's stepladders, with stabilizer bars across both sets of feet are heavy but very solid. Not the usual, flimsy things intended for indoor use and absolutely lethal outside on soft ground. I even use paired stepladders with my chain hoist for heavy lifts like the mounting.
The crossbars at the feet are superb for stability on smooth surfaces. I just lash a pair of crossbars together with the stepladder straightened out. Then hang the hoist from the paired top bars. Four splayed guy lines, using trailer ratchet straps around the dome support roller brackets, provide all the stability one could wish for.
If I leave the dome intact the area around the [supplied] top lifting ring remains at full strength. It is intended to be repeatedly lifted that way by farmers using front loaders and tractors fitted with front buckets. If I cut the observation slit away, when the dome is still on the ground, then I would have to rely on strops for the big lift. Major decisions to be taken in the future. Lifting the fully completed dome would [probably] be far wiser.
This afternoon was spent shovelling yet more self-compacting gravel into the wheelbarrow. Then trundling off to dump it around the edges of the observatory building pad. To be stamped down to firm it well. It had rained hard on the steeply sloping heap at the gravel stockist. So it weighed a ton and was very difficult to shovel it out of the trailer. It has been quite a hard day altogether!
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