Wildlone, I felt just like you about gaps in bridge timbers, but height isn't the problem. I've had it on a bridge only two feet off the water. And seaside piers. And platforms made of expanded metal. There's one in Bristol out from an old cave below the camera obscura. Deadly. But the top of the Eiffel Tower was fine. And the plane to Jersey. Bored everyone to tears with my analysis of the feild patterns of Sussex, and where my family lived!

Penny