Staafjes

Each HBA tile is covered with a UV-resistant polyurethane cover. This secures the white polystyrene lids and provides protection against precipitation. In order to connect the cover to the timber frames, O-rings are connected from the cover edge down to S-hooks that attach to the screws in the timber. However in order to attach the covers to the O-rings, special rods called "staafjes" (Dutch for "little staves") are inserted into the folded cover edge.

Left: The tool used to put a hole into the cover rim.
Right: detail of the tool and a freshly made hole.

Another hole is cut into the cover edge.

The rods are then inserted into the cover edge using long-nose pliers, with the O-ring locked in to the cover edge.

Normally an HBA tile has 8 of these staafjes around the edge. However, in order to secure edge tiles, ASTRON recommend that an additional set of interleaved staafjes are added. However, due to the very exposed nature of the KAIRA HBA tiles, and the horrendous Arctic conditions expected on the site, this total is doubled again.

During the build, we had already added some additional staafjes, however the work has now been completed.