Pedestrians Walk through Bascule's Rolling Rings

摘要

A medieval design gets a new twist in the construction of a bascule-type bridge that is cantilevered off of two 6.6 m diameter vertical rings linked by a counterweight. The counterweight raises the bridge by rolling the rings over a rack-and-gear mechanism. Pedestrians can walk through the rings that support the bridge— even when it is in motion—by means of a link bridge that crosses over the base of the roller bearing.