Which movable bridge type is commonly referred to as a drawbridge?

• A. Bascule Bridges
• B. Swing Bridges
• C. Lift Bridges
• D. Arch Bridges

Answer: (A)

A drawbridge is the image most people have of a bridge that lets ships pass by lifting a section of the deck. The mechanism that matches this concept is the bascule design: a portion of the bridge deck pivots on a hinge and is counterweighted so it can be raised or lowered with relatively little effort. That counterweighted, hinged leaf is what gives the bascule its characteristic “draw up” action, which is exactly what the term drawbridge evokes.

Swing bridges, by contrast, rotate the whole span horizontally like a door, which is a different motion. Lift bridges raise the deck straight up vertically, not by rotating around a hinge. Arch bridges are fixed and do not move at all.