Columns rings and diagonals form together a web that varies over the section of the tower. The geometric shape of the tower is a ruled surface. The columns are all perfectly straight although the lean over to one direction, giving the tower a dynamic twist. They taper from bottom to top, so to further amplify the perspective view up along the tower. The diagonals are more or less everywhere the same at 800mm. they consist of straight tubes that run between columns fixing the web of nodes into a stiff web. The rings are placed on the inside and their diameter is fixed at 800mm, they are truly round, following the curvature of the facade that runs along the inside.
At the bottom of the tower the columns are 2m in diameter, constructed of 50mm thick plated steel that is bend fully round in 3.7m wide bands that are welded together. At the top of the tower the column diameter is reduced to 1100mm with a plate thickness of 30mm. Where the columns where initially thought off as telescopically stepping in small steps of about 20mm, they are finally designed to truly taper, giving a amazingly perspective effect.
for more info go to the canton tower information website: gztvtower.info