the.com/pontoon bridge
A bridge that floats on borrowed time and buoyant boxes, daring you to trust it.
means A temporary bridge supported by floating hollow structures (boats, barges, or sealed drums) instead of fixed piers, so it rises and falls with the water beneath it.
from 'Pontoon' comes from French 'ponton,' which traces back to Latin 'ponto' — a flat-bottomed boat, itself kin to 'pons,' meaning bridge. So the word was already carrying the idea of 'bridge' inside it before it ever floated one: Romans used 'ponto' boats lashed together to cross rivers their armies couldn't wait to ford properly, and the name just drifted downstream through French and into English, picking up its modern engineering sense along the way.
- origin
- Used by Persian king Xerxes to cross the Hellespont, 480 BC
- mechanism
- Floats on hollow boats or drums, not pillars
- military use
- Armies still build them to cross rivers fast
- limitation
- Sways and sinks under heavy or sustained loads