A pontoon bridge is a bridge that floats on pontoons: hollow, watertight tanks or boats that serve as a floating foundation. The bridge deck rests on the pontoons and moves with the water level. Pontoon bridges are used where a fixed bridge is impractical or too expensive, for example across wide rivers, at temporary crossing points or in military operations.
Characteristics of a pontoon bridge
| Feature | Description |
|---|---|
| Load-bearing structure | Floating pontoons (tanks or boats) |
| Bridge deck | Roadway or walkway on top of the pontoons |
| Flexibility | Moves with water level and wave action |
| Navigation | May include a movable section for shipping |
Types of pontoon bridges
- Permanent pontoon bridge: permanently installed, with anchored pontoons
- Temporary pontoon bridge: quick to assemble and disassemble
- Military pontoon bridge: foldable or modular bridge for army units
- Public pontoon bridge: for pedestrians and/or vehicle traffic
Components
- Pontoons: the floating elements (steel, aluminium or plastic)
- Bridge deck: the walking or driving surface
- Anchorages: cables or chains that hold the bridge in position
- Approach ramps: the connections to the shore, accommodating height differences
- Couplings: connections between the individual pontoons
Advantages and disadvantages
Advantages:
- Relatively inexpensive for large spans
- Quick to build and relocate
- No underwater foundation required
Disadvantages:
- Moves with wave action and current
- Limited load capacity for heavy traffic
- Maintenance of pontoons and anchorages required
- Can obstruct shipping
Related terms
- Pontoon
- Bascule bridge
- Swing bridge
- Bailey bridge
- Floating jetty