Heatherwick's Rolling Bridge. 2:14 video:
https://www.youtube.com/watch?v=x0Dj7XA77hw
I like this rolling bridge model:
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More: https://en.wikipedia.org/wiki/The_Rolling_Bridge
Previously:
https://www.homemadetools.net/forum/...081#post141145
https://www.homemadetools.net/forum/...796#post140221
https://www.homemadetools.net/forum/...679#post136611
https://www.homemadetools.net/forum/...222#post116006
https://www.homemadetools.net/forum/...494#post142942