The location of this 100 acre property south of Goulburn has exceptionally dark night skies, making it a perfect location for the construction of this 4 by 4 metre hardwood deck which now houses a mini observation dome for the Client’s telescope.
The primary requirement for this structure was that it could have zero movement or vibration, and that the movements anyone walking around on it, or wind buffets on the structure, also could not be transferred into the pre-installed telescope mount, (which consisted of a more than 2 ton block of concrete set over a meter into the ground, with a 400mm diameter steel reinforced concrete column and integrated tripod telescope mount points – certainly taking things seriously here!), as any movements would ruin the long exposure images of distant galaxies being collected by the high-end telescope to be installed.
With these detailed specifications in mind, a super solid, and over-engineered decking structure was designed and installed. Are you ready for lots of details, because here they come!
Each of the 14 post holes were drilled to a depth of 700mm, and then filled with a cubic metre of concrete, with 600mm steel stirrups set well into the wet mix.
Then 190x45mm treated pine beams were set at 1400mm centres, and notched into the posts, double bolted, then cross braces of 140x45mm timbers were bolted into place, and finally 4 lengths of steel strapping was installed diagonally over the tops of the beams.
It was a super solid base to which the 140x45mm joists were then fixed. The entire surface was made -absolutely- level, with any minor inconsistencies in the timber members being shaved or notched out to provide a perfectly flat and level surface for the decking.
A set of wide stairs were then constructed allowing access to the slightly elevated decking surface, and the whole structure was covered with 140mm wide Merbau decking timbers, with a small gate opening on the lower side to allow access under the deck to run the cabling and power for the remote operations systems back to the house -because who needs to sit, motionless, out in the cold all night, when you can run this system from your tablet, in the comfort of your lounge room by the fire with a tumbler of your favorite, and not disturb the equipment if you sneeze 🙂
This project was a lot of fun, and since this image was taken the dome has been installed, and the full equipment setup has been completed.
The client was consulted at a number of points during construction to ensure that his strict requirements were being met, and he is super happy with the result.
