Base Construction

Once my wife was (finally) satisfied with the house extension, I was allowed to commence phase 2 of the observatory. I extended an armoured electricity cable from the fuse box in the garage under the lawn to the observatory. I needed to build the floor such that vibrations would not be transmitted to the telescope pier. I cast six short concrete piles into the ground, 3 along where each of two opposite side walls where planned to be and made sure they where all at exactly the same level. I had six 3 metre lengths of 80mm x 80mm mild steel angle welded back-to-back to make a grillage to support approx. 1.4m long 100mm x 50mm timber joists. I drilled the pile tops and placed 10mm threaded bar in resin anchor grout to hold down the steelwork. The timber joists were cut and fitted including trimming round the telescope pier. Before the floor of 18mm board was screwed to the joists, I positioned an electric cable clipped to the joists to supply power to the telescope pier to avoid trailing cables across the floor. The wall structure was built from 100x50 and 75x50 studding framed and angle braced at the corners and cladded with roofing felt to help keep out damp and faced with shiplap. A strong door was made and fitted with security hinges and a 5 lever mortise lock.

With no roof and winter upon us, I built a simple temporary timber structure off the telescope pier with timbers sloping down to the walls and fitted a waterproof tarpaulin staple gunned in place. Inside the back wall I fitted a large extraction fan which gives about 15 air changes an hour to help with equalising air temperatures inside and out.

With lots of bad weather there was not much to do except fit a weatherproof fuse box inside and continue planning the top section.

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