Introduction

For many years I have dreamed of having my very own observatory. Here in Dublin, Ireland clear nights are not so plentiful, so when a good clear transparent night arrives, it is essential to make the absolute most out of it.  Many times I have spent an hour dragging out telescopes, computers, CCD equipment etc only for it to cloud in just as I was about to begin shooting some frames. Other nights I simply didnt set up because I felt the weather might close in.  Often those nights remain clear.  It was clear to me that the only way around this problem was to build a permanent observatory.  With such a facility in place I could make so much more of the limited clear skies.  Just as importantly I could be doing some real astronomy rather than spending all my time setting up and breaking down equipment. Having a structure around me would also mean I could be doing astronomy on nights that I might have considered too windy otherwise.

In May 2006, I finally decided that with the short summer nights here it was time to make that dream a reality.  The first decision was what sort of structure to build.  That was an easy one.  A shed with a roll off roof was not only going to be inexpensive but also well within my constructional capability.  Luckily I had some good help, my good friends Carl O'Beirnes and Gary Clarke were more than willing to lend a hand Gary is a builder by profession so his help was going to be invaluable. I decided an 8ft x 10ft structure would easily meet my needs.

The Pier

The first step was to construct the pier.  To build this pier I began by digging the father and mother of all holes. around 5 feet deep and four feet wide was a much bigger job than it sounds!  With the hole dug, I placed an 9 foot lenght to 11inch PVC sewer pipe in place.  I then poured about a foot and a half of concrete around the base and let it set.  I then backfilled the hole with earth which had been dug out, compressed it down leaving another two feet on top.  This final two feet was filled with cement as was the sewer pipe itself.  The final part of that job was to insert four 12 inch long M12 bolts into the wet concrete.  This will act as the mounting points for steel plates which will eventually support the mount.

This photo shows the pier structure after cementing.  I laid a border of 2" concrete slabs around where the base of the structure will go and cenented them in place.  I then filled the center with concrete too.  When the structure is almost finished, the plan is to fill fine sand and cement to make a very level floor.  This will then be overlaid with rubber matting to provide the final flooring.

Beginning the Structure.

On Saturday June 10th, 2006 the construction of the main structure began in earnest.  With the help of Gary and Carl the main 'studding was constructed for the four sides. 4 x 2 timber were used for this stage

Here the studding has been built and assembled.  The front stud is slightly lower than the rear.  This is to accomodate 4 x 3 beams to support the rolling roof.

The stud frame is now clad with 6 x 1 timber.  When finished the gaps will be sealed with silicone, covered in sheet plastic and an outer skin of either treated ply or aluminium sheet will be applied (it really depends on whether I can get shiplapped aluminium cladding cost effectively).  You can also see that 4 x 3 beams are now in place on top of the main structure to support the rolling roof.  AT this stage the frame has not been secured into the ground but you would move this now no matter how hard you try.

A wide shot showing progress to date.  The main four walls are in place as are two 20ft long 4 x 3 beams.  The beams are held temporarily by the 6 x 1 at left.  Next job is to build the roof.

The Roof

The roof is a fairly standard job.  Three 4 x 2 lenghts are screwed together to make the main beam up top.  The trusses are screwed in using aluminium 'roof hangars'.  Inset into the base of the roof are recessed roller bearings, each with a load rating of 100lbs.  With 10 roller bearings used that should just about take the weight ;-) The roof is shown here covered with a skin of PVC sheet as the first layer of damp proofing.  The next stage is to cover the roof in treated ply, then apply another layer of PVC and then finish with a double layer of 'torch on' felt. It is, of course, absolutely essential that the observatory is totally damp proof. All of the walls will be double layered with PVC.  The spaces between the studs filled with insulation and a skin of hardboard on the inside will give the inside a finished look.

June 19th:  The four walls are up roof frame is built (and slides along the 4 x 3 beams).  The 4 x 3 beams will be fitted with a layer of formica to make the roof roll a lot smoother. You can see two 4 x 3's under the rails here temporarily.  The next step is to make 'risers' for these supports so the prodruding beams can be levelled initially and also periodically in case of any sagging.