From the French word for "see-saw," a bascule bridge features a movable span (leaf) which rotates on a horizontal hinged axis (trunnion) to raise one end vertically. A large counterweight is used to offset to weight of the raised leaf. May have a single raising leaf or two which meet in the center when closed. Compare to swing bridge and vertical lift bridge.
A type of movable, or draw, bridge. The word Bascule is from the French for seesaw, which describes the part of the bridge that moves. Three of Portland's bridges are Bascules; the Broadway, the Burnside, and the Morrison. This type of bridge allows the roadway to tilt up and out of the way of river traffic, using counterweights as the counterbalance. There are two main types of Bascule in evidence in Portland. The Broadway bridge is an example of the Rall type Bascule, in which the counterweights are on the outside of the bridge move back and forth on bull wheels. The Morrison and Burnside are Strauss Bascules, where the counterweights are hidden within the bridge supports. Strauss Bascules operate in a speedier fashion than the Rall design.
A bascule bridge is a drawbridge with a counterweight that continuously balances the span, or "leaf," throughout the entire upward swing in providing clearance for boat traffic. Bascule is a French term for seesaw and balance, and bascule bridges operate along the same principle. They are the most common type of movable bridge in existence because they open quickly and require relatively little energy to operate.
The Bascule Bridge is a paved one-lane highway bridge in Westport, Massachusetts, USA. Route 88 passes over the bridge from Westport Point and Wood Point in southern Westport to the Horseneck Beach State Reservation, connecting with John Reed Road. The bridge passes over the water between Westport Harbor and Horseneck Channel.