Ever wondered how bridge supports are built underwater?
Caissons (French for large box) are a watertight retaining structure to allow us land-dwellers to begin construction on underwater projects.
Caissons (French for large box) are a watertight retaining structure to allow us land-dwellers to begin construction on underwater projects. They are built to allow water to be pumped out, keeping the working environment dry.
They date back to the 18th century, where they were used to construct the Brooklyn Bridge. This involved erecting airtight wooden boxes, pinning them to the bottom of the East river with granite blocks. They were then pressurised with air and workers were transported down into them via small iron airlocks.
Unfortunately for them, little was understood at the time about the bends, or decompression sickness, they would experience when they came back to the surface after a shift underwater.
