Abstract: An offshore base-supported column structure for installation in the water on an offshore floor having an elongate column vertically supported entirely from a column foundation on the offshore floor and releasably engaged to the foundation with the top of the column extending above the offshore water level. A column support base is supported from the offshore floor and engages and provides lateral support for the column with a slidable connection. A support structure is connected to the top of the column above the water level.

Abstract: A building structure having a roof opening which is covered by a retractable closure. The retractable closure includes a plurality of panels which are pivotally mounted about the margin of the roof opening. The panels are sized and shaped so that they fit together and cover the opening when in their closed positions, and when the panels are in their open positions the roof opening is completely unobstructed. Tracks on the roof support the panels and resist vertical load forces. Support towers and guy lines are provided to bear a part of the load forces as the panels are closed. Drive means is provided for opening and closing the panels conjointly or independently to achieve a range of roof opening capability.