Exactly. It should be strengthened, not destroyed by wind. So it has to use sails (also mentioned by keith below) or be multi-tiered - pneumatic (with a way of distributing the air that goes inside it...to the sections that need the greatest strength) - or both. I had a rough idea --not actually a 'design' just an idea--for the latter BUT people pointed out it wouldn't work when there was no wind. They were right... It is a 'wind-collection device' isn't it? That's the funny thing about it. "To free your hands..." I've also wondered whether they shouldn't be part of city-planning. Make them so that they inflate and float out of .... lamposts?.... whenever it rains, and hover over designated paths, providing cover for one small crowd at a time. "upgrade is for solar sails. " What exactly do you mean by that?