Upgrading old bridges
Old suspension bridges may be upgraded to cable-stayed bridges
Old suspension bridges may be upgraded to modern cable-stayed bridges, and this upgrade would cost much less than building an entirely new bridge. What's the difference between a suspension bridge an a cable-stayed bridge? A suspension bridge is supported by a pair of curved cables, while a cable-stayed bridge has straight cables holding it up. Simply put, suspension bridges have curved cables, while cable-stayed bridges have straight cables. Cable-stayed bridges do not need heavy anchors at each end other their cables, either, their entire weight is supported by the towers alone. The illustration at the top of the page shows a suspension bridge.
The illustration above shows the first step in the upgrade. The cables and roadway are removed from the suspension bridge.
The illustration above shows the same towers with new cables and a new roadway installed. This illustration shows how the bridge looks after the upgrade is complete. The towers may be modified, before the new set of cables can be installed, but the towers do not have to be completely replaced. This method of upgrading a bridge could potentially save millions of dollars in bridge-replacement costs.
Invention by Anthony Ratkov. Computer-graphic illustrations by Anthony Ratkov, November 23,2011.