Layout Pt.4 Backfill and be damned!

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After endless measurements with spacing rods I finally decided to use cord to run a line across the center from each footing. This proved that my center rod was off-center by a couple of inches but that all the strings/lines crossed nicely together. Enough was enough! I scraped all the excess gravel from all the excavations back down the holes around the concrete footings. Note how removal of the steel brackets on the footings returns the site to bare gravel for car parking, or whatever.

All the rocks I have removed has left an empty space for more gravel on the right. [East] So I shall have to fetch a couple more trailers full to bring the gravel up to the shed base level. The pier pipe needs back filling too, once the concrete anchors/footings and 4"x 4" timbers are in place. I'm not sure I want the pier timbers sticking right up in the air. At least, not before I have proper access at observatory floor level.

The pier can be centralized in the observatory floor aperture, as needed, by gently sliding the timbers against each other before fastening them firmly together. The height adjustment brackets on the footings can also be used for this purpose.

That does not mean the concrete pier anchors can't be placed in the big concrete pipe then the pipe back-filled and well rammed with gravel to that level. The gravel can go on further consolidating while I get on with the rest of the build.

See image left of partial back-fill of the big concrete pier pipe. I packed out the anchor blocks to the inner edge of the pipe at top and bottom with old bricks to maximize the size of the pier base footprint. Trying to move the blocks after back filling the pipe proved impossible. Which is promising for stability.

The images do not convey the weeks of backbreaking work required to reach this stage. I have lost count of the number of times the heavy [75lb] anchor blocks have had to be repeatedly lifted out of the ground! Nor the number of wheelbarrows full of sand & gravel to be filled with a shovel, rolled the forty yards to the site and dumped.

Click on any image for an enlargement.

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