Rising from the Forth

Any structure as magnificent as the Queensferry Crossing is only as good as the foundations it's built upon.

Arguably the most challenging element of the build, the underwater foundations of the three main towers and viaduct piers involved sinking huge steel caissons to the bed of the Forth, then digging down through the silt and till to bedrock. All achieved in poor visibility and the difficult waters of the Firth of Forth, as the river widens to meet the North Sea.

Click on the video below to hear Alex Lowther talk us through how the foundations for the world's longest cable-stayed bridge were constructed.