Gallery · 27. October 2013

Lower rotation ring in place

After a long hiatus (day job duties, family activities and holiday travel), the lower rotation ring is now in place.

Thirty-four 16 mm bolts cast in concrete hold the ring in place. The ring consists of four equal segments of steel plate. The dome is secured against wind by eight C-shaped assemblies of thick steel. These contain vertical and horizontal rollers. The horizontal rollers prevent lateral movement of the rotation ring.

Before bolting, the diameter of the ring was adjusted to 350 cm, with a margin of error of only one millimeter in all directions. This high accuracy is ensures that the upper ring will rotate freely, without being squeezed by the horizontal side rollers.

The next step is to mount the upper rotation ring.

Six large urns with the proper botanics will add that vital organic touch. The concentric block wall will raise ground level about fourty-five centimeters higher so that the height of the entire structure doesn't exceed municipal limits.

Although it was many hours of very tedious work, grinding down the crown to a laser-controlled level makes the ring and dome installation much less work.

The placement of the 16 mm bolts came out nicely.

The HEY-DI plaster for exterior masonry is very high quality, and ensures a tight moisture seal. Note the pier foundation. After the dome is in place, about 60 cm of additional concrete will be cast onto this.

Tags: observatory, 2013-2Eng