What is the difference between a bascule bridge and a drawbridge?

What is the difference between a bascule bridge and a drawbridge?

A bascule bridge (also referred to as a drawbridge or a lifting bridge) is a moveable bridge with a counterweight that continuously balances a span, or leaf, throughout its upward swing to provide clearance for boat traffic. The name comes from the French term for balance scale, which employs the same principle.

What is a bascule bridge work?

Bascule bridges have spans that pivot upward utilizing gears, motors and counterweights. Unlike vertical lift bridges, when opened, there is no vertical obstacle to river traffic. The machinery for opening the bridge is located above the structure. The Burnside Bridge is a Strauss-type, double-leaf bascule bridge.

What type of bridge is Bascule?

A bascule bridge is a kind of widely used moveable bridge whose main girders can be lifted together with deck about the hinge located at the end of the span. Depending on the bridge width, the bascule bridge can be designed as either single or double leafed.

What are the common features of a bascule bridge?

A type of movable bridge, a bascule bridge contains one or two spans, one end of which is free and swings upwards. A counterweight at the pivoting end of the span or spans balances the weight as the free end rises.

What are the disadvantages of bascule bridge?

Disadvantages of Bascule Bridge

• Bascule bridge is subjected to considerable wind load especially when it is opened.
• The machinery used to control bascule bridge should be crucially strong and robust compared to the case where wind load is not present.

What holds up a bridge?

Pile: A pile is a vertical support structure that’s used, in part, to hold up a bridge. It can be made of wood, concrete, or steel. Superstructure: The superstructure is the part of the bridge that absorbs the live load. (The abutment, piers, and other support elements are referred to as the substructure.)

What kind of lift is used on a bascule bridge?

The rolling lift trunnion (sometimes a “Scherzer” rolling lift), raises the span by rolling on a track resembling a rocking-chair base. The “Scherzer” rolling lift is a refinement patented in 1893 by American engineer William Donald Scherzer. The rarer Rall type combines rolling lift with longitudinal motion on trunnions when opening.

How did the bascule bridge get its name?

A bascule bridge (sometimes referred to as a drawbridge) is a moveable bridge with a counterweight that continuously balances a span, or “leaf”, throughout its upward swing to provide clearance for boat traffic. It may be single- or double-leafed. The name comes from the French term for balance scale,…

Why do bascule bridges have counterweights on them?

The counterweights help balance each side of the bridge during the upward swing, which assists in the lifting motion. Bascule bridges are the most commonly found movable bridges in the world, most likely because they open quickly and easily once established, and operate on very little energy.

How does a rolling lift raise a bridge?

Animation of a rolling lift bridge (such as the Pegasus Bridge) The rolling lift trunnion (sometimes a “Scherzer” rolling lift), raises the span by rolling on a track resembling a rocking chair base.