Translations:Adventist Youth Honors Answer Book/Arts and Crafts/Bridges/3/en
From Pathfinder Wiki
- b. Aqueduct
- A bridge that carries water. Popular before we had electric pumps. Lots of interesting photos here.
- c. Falsework
- The temporary support scaffolding used during the construction of some types of bridges.
- d. Compression force
- The downward pressure (usually vertical) that is applied to the supporting columns of a bridge design by the weight of the bridge materials as well as the traffic load that is on the bridge.
- e. Tension force
- The tightening or pulling together force (usually horizontal or at an angle other than vertical) that helps to stabilize a bridge design, and transfers compression force back to the supports of a bridge design.
- f. Bascule bridge
- A movable bridge with a counterweight that continually balances the span throughout the entire upward swing in providing clearance for boat traffic. They are the most common type of movable bridge in existence because they open quickly and require relatively little energy to operate. Bascule is a french word. In English this is usually called a draw bridge.
- g. Covered bridge
- A structure with enclosed sides and a roof that often has only a single lane, and typically is made of wood. Since wooden bridges tended to deteriorate rapidly from exposure to the elements, they only had a useful lifespan of nine years. Covering them protected their structural members, thus extending their life to 80 years or more. Covering them also eliminated the need to plow them during or after snowstorms.
