The observatory was built when Jim got tired of setting up his 12 inch (305 mm) Schmidt-Cassegrain telescope.
Taking it down was even worse. So he built a permanent structure.
This is the view from the deck that separates the house from the observatory. This deck doubles as a viewing platform for the secondary telescopes, and is an excellent place to count meteors on those meteor nights of interest.
The Twillingate Astronomical Observatory is located in Gillard's Cove on Twillingate Island.
As you can see from the photo, the scenery is terrific. For us, though, the scenery looking upward is even more important. The relatively clear air and minimal light pollution makes for clear skies.
Gillard's Cove, Twillingate Island is located off the Northeast coast of Newfoundland and is connected by causeways. The coordinates of the observatory are:
49° 37' 02.4" N
54° 45' 28.8" W
Visitors are always welcome. Contact information is here.
Building the Dream
Somewhere in the shadows behind every man’s success, there sits a woman. As is the case this time as well, Audrey helped me lay the cloth and saturate it with resin while working on the dome, the dome wall and surrounding roof. Large amounts of resin had to be mixed at times with hardener and the cloth had to be completely saturated and air bubbles rolled out with an iron roller. Time was very limited in order to prevent a batch from getting hard before it was properly applied. Without her help the work would have been so much more difficult and would have taken much longer to complete.
The dome wall and flat roof on which it sits is completely fiberglassed. The fibreglass turns down over the edge of the flat roof as to prevent water from getting under it. The fibreglass also comes down the wall on the inside all the way to the floor. The entire dome, dome wall and support roof are covered with five layers of material consisting of two cloth, one woven and two cloth in that order. Since the life of fibreglass is about ninety years I should not have any near future maintenance any time soon.
Our two canine family members are yellow Labs whose names are Mira and Mintaka. What a coincidence their names turned out to be star names as well. But at least my two daughters and son feel lucky that they didn’t get named after NGC objects.
After completing this phase of the project you might notice Audrey and I were having refreshments. Noting the colour of the bottle and label, it doesn’t appear to be coffee and I suspect the ingredients in the mug are similar to those in the bottle. Warning! I do not recommend this potion while trying to observe any of Ken Hewitt White’s faint fuzzies.
This photo was taken from part way up the stairway looking through the dome floor opening. This opening would later be the hinged portion of the floor allowing entry into the dome. This was a beautiful warm day as I finished the wood working phase of the dome wall. This wall and the dome floor is completely insulated with rock-wool insulation.
Taken from Emily’s Hill to the west of the observatory. It shows The Twillingate Astronomical Observatory in the little community of Gillard’s Cove. The highest point on Twillingate Island is the large hill in the upper left portion of the photo and is called the Top of Twillingate, so you might say that the observatory is at the bottom of the Top of Twillingate. It may be surprising to note that despite the hills, the view of the night sky is not very restricted.
This photo reminds me that I had a long way to go although at the time I was quite happy to have finally got started. It shows the ten foot diameter ring built on the floor and approximately half of the vertical ribs secured to the ring on the floor and the hub at the top. Spacings on the ring were equally marked where each rib was fastened and corresponding markings were made on the hub showing where the top of each rib was to be fastened. It is surprising how very few ribs I was able to get from a 4 x 8 sheet of plywood. The ribs were later doubled up on the outside edge of the rib to allow for a thicker edge when the sheeting phase started. At least an inch was needed where two pieces of sheeting came together. During the construction of the framework, or the placement of the vertical and the lateral ribs there were no nails used. I used deck screws and pre drilled a portion of each hole.
This is a picture of the completed dome after it came from the shed where it was constructed. The dome had to be tipped up on to its edge in order to insert the shutter on its rail. After the shutter was in place fibreglass blocks were glassed into place to prevent the shutter from coming off at either end. The piece of blue tarpaulin to the right covers the hole I sawed in the shed with a power saw to make enough space to get the dome through the door. Audrey and I put the dome on temporary rollers and made a crude track. With this arrangement the two of us were able to very easily roll the dome out of the shed in a position on the track where the boom truck was able to pick it up and place it on its flat bed for transportation to the observatory. The water to the right is the Atlantic ocean.
This is an image showing all of the vertical and horizontal ribs in place. Part of the sheeting is also under way. The sheeting could only be done in small sections covering one rectangular section at a time. At this phase I must admit I didn’t know how spherical this dome would be when it was completed since I had not done any project of this design before. There were lots of measurements and plenty of angled cuts.
This photo shows the dome on the flat bed in front of the observatory. The two foot wide extension at the bottom of the dome was made larger than the dome itself. This was to allow that portion to pass down outside of the dome wall until the shoe of the dome, the visible ridge, to which the 45 pairs of rollers were attached, came into contact with the top of the dome wall on the observatory. At the bottom of the shutter opening two weather blocks are in place that make contact with the shutter when it is closed, preventing weather from getting into the dome . There are also two similar weather blocks at the top of the shutter opening that make contact with the shutter when it is closed.
A view of the dome securely in place. You may notice a four inch wide rubber band fastened to the extreme bottom edge of the dome. This gently makes contact with the outside of the dome wall and helps prevent any weather from going up under the dome. Before weather can get inside it has to move in a very narrow space over two feet up before it reaches the rollers and then another eight inch weather block that also covers the rollers on the inside, which prevents anything from getting inside the dome. The black box mounted on the roof is Newfoundland's camera #3 of the North American Camera Fireball Network of MIAC (Meteorite Impact Advisory Committee).
Moving the Dream
In the winter of 2008, we decided to motorise the dome as we were getting tired of throwing our weight around. Here's Jim's account of how we (mainly he) did it.
This photo shows all of the drive system except the fluid control valve. The black object to the left is a combination unit consisting of a two hp electric motor (only the top of it is visible) from which a flexible metal tube containing a power cord travels to the power switch. The other feature of the combination unit (again only top portion visible) is the hydraulic fluid reservoir with the filler cap visible. The last feature of this unit is built and placed within the reservoir and this is the hydraulic pump from which two lines come and travel to the control valve (not shown).
Slightly above centre in the photo is the power switch for the electric motor with a plastic pipe containing a wire that connects to the main electrical panel downstairs in the lower part of observatory.
To the right of the power switch box is an assembly made up of the hydraulic motor which is the bottom portion, with two hydraulic lines leading to the control valve. The motor can be seen mounted to an aluminum bracket.
Directly above the bracket is a keyed joiner connecting the motor shaft to the sprocket shaft. This shaft passes through two heavy steady bearings.
Above the bearings is the sprocket from a 16hp ski-doo.
Also visible in the photo is a 4” portion of two ski-doo tracks that are screwed completely around the inside circumference of the dome shoe. Two of the 37 pairs of rollers on which the dome rests are visible in the top right of the photo. There are also rollers turning on a vertical axis fixed between the dome and the permanent wall below the paired rollers (not shown). These prevent any lateral or cross-movement of the dome while it is turning on the paired rollers.
The ski-do track is very firmly connected to the inside part of the dome shoe with 382 3½” deck screws and washers. Each screw after passing through the rubber track passes through a ¼” thick piece of hardwood placed behind the rubber. This is to facilitate the complete tightening of the deck screws without causing the rubber to recess because of the protruding rubber grips on back of track which are in contact with the inner edge of the dome shoe.
This photo shows the control valve with the hydraulic lines and control lever attached, in addition to what has already been mentioned.
The expression on my face might indicate that in addition to the gears turning in front of me, one might hope there are some turning as smoothly in my head, even though they sometimes feel out of sync or jammed completely!
This is a close-up view of the top of the sprocket whose cogs mesh with the holes in the track.This is a close-up view of the top of the sprocket whose cogs mesh with the holes in the track. It shows the aluminum centre that I bolted to it for extra strength. The birch block is bolted to the fixed wall with recessed leg bolts. The larger main bearing is bolted to the wall with 6” leg bolts. The smaller blue bearing is attached to the block with machine bolts.
This last picture shows the completed job. The box covering the combination power unit is lined completely on the inside with 2” SM insulation for soundproofing against the noise of the electric motor. The lack of cooling air currents around the motor is not an issue since it is engaged for only a few seconds at a time.
One complete rotation of the dome takes exactly 60 seconds with the lever at full speed. The control lever permits anything from barely moving to full speed.
The resulting speed of the system is caused by a combination of the amount of fluid flow from the hydraulic pump, the gear ratio inside the hydraulic motor and of course the type of control valve.