The Thames Barrier must never fail. Here's why it doesn't. Pt. 1 - The Thames Barrier is a wonder of engineering. If it fails, then London floods. Here's how the engineers there make sure it doesn't fail. | Tom Scott

The Thames Barrier must never fail. Here's why it doesn't. Pt. 2 - Here's how the engineers of the Thames Barrier make sure it doesn't fail. If it fails, London floods. | Tom Scott

Forty years ago today, the Thames Barrier was officially opened. It was designed to protect London from flooding until 2030. It’s now expected to function until 2070. One notable incident in the barrier's history was when a 3,000-tonne dredger crashed into it on a foggy morning in October 1997. According to a report, the dredger hit one of the barrier’s concrete piers, causing extensive damage to the vessel and superficial damage to the barrier. The master of the dredger was found to have failed