Four Main Bridge Types: Fixed, Movable, Suspension, and Arch Bridges Explained

Bridges are broadly classified into four structural types:

1. Fixed Bridges: Permanent, immobile spans (beam, truss, girder, box girder). Most common.
2. Movable Bridges: Open to allow marine traffic.
   • Bascule (hinged leaf rotates up)
   • Drawbridge (span retracts horizontally)
   • Lift bridge (span rises vertically)
3. Suspension Bridges: Deck hung from cables draped over towers; ideal for very long spans (e.g., Golden Gate, Akashi Kaikyō).
4. Arch Bridges: Load carried by compression along a curved arch; stone, concrete, or steel (e.g., Sydney Harbour Bridge).

Each type suits specific span lengths, site conditions, and aesthetic goals.