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Wednesday 22nd. What needs to be done before the larger dome can be lifted into place?
In no particular order:
1. Remove and safeguard the stored timber inside the new dome to provide safe access. Remove and cover with tarpaulins. To a site well away from the immediate working/lifting area. The greenhouse?
2. Fit the eye bolts, which I have already purchased, to the upper dome in place of existing 10mm clamping bolts. Internal reinforcement will be required to spread the loads. The seam is a double layer of GRP but local loading, during the lift, might cause damage. Even with existing, large, round washers inside. I can implement large, square, galvanized, roofing washers instead. The eye bolts can be left in place for the life of the observatory. Which will aid lowering the dome when desired. They will need to be sealed, with tap washers, like all the other bolts, to avoid rain leakage.
3. Remove and shelter the telescopes, mounting, electronics and furniture from the old dome.
4. Remove the old 3m/10'dome from the obs. building. To make room for work on the top ring. Cover the top of the larger building with lightweight, white tarpaulins. Some form of support will avoid a hideously heavy, raised pond! Pairs of builders stepladders lashed together at the top? I have safely used these as a support for my chain hoist. For lifting the heavy mounting. These reach almost as high as the old dome. Stable and strong enough for windy conditions.
5. Cut and fit circular plywood arcs to the top of the larger building. To lie perfectly level. In a complete ring on top of the existing, 2"x6", 14 sided, timber ring. The plywood ring will provide a much better wind seal with the inside of the dome. Rather than a multi-sided ring. Which would be open at the straight sections.
6. Fit the extra rotation rollers to the new, plywood top ring of the larger building. The rollers are already purchased and stored ready for use.
7. Trim and fit GRP panels to close the triangular holes on either side of the shutters. These are non-structural components. So may be omitted until the dome is in place. The arched doorway, steel reinforcing arc, has been refitted for dome safety during the lift.
There are lots of further steps once the dome is safely in place. The new dome will provide the vital shelter from the weather for the interior work. Tasks which cannot be carried out while the building is wide open to the sky. The shutters can be opened to let the daylight in. Or LED exterior floodlights used in inclement weather.
The existing dome provides some shelter but only over its much smaller footprint. It is also leaking badly at the seams. Fortunately the rain mostly runs down inside the dome's interior surface. Rather than dripping onto the observatory floor. The larger building is open to the sky over a crescent shaped arc.
No imaging can take place while this work is in progress. It would be best to carry out this work before the arrival of bad weather next autumn/winter.
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