How Britain Built the Impossible Barrier That Saves London Every Winter

The Thames Barrier is London's flood defence against the North Sea: ten giant steel gates that rise out of the River Thames, inspired by the valve of a gas cooker. This is how Britain built it, and why it now closes far more often than it was ever designed to. The story begins with the 1928 flood that drowned people in their basements at Millbank and the North Sea flood of 1953 that killed 307 people in England. It follows engineer Charles Draper and his 3,300-tonne rotating gates, and a construction battle fought through 1970s inflation, strikes and a dock dispute that nearly stopped the last gates from reaching London. Then a dredger sinks on top of one of the gates in thick fog, the barrier closes 50 times in a single winter, and its operators set a deadline: decide what replaces it by 2040. 🔔 Subscribe to Impossibly Engineered for a new engineering documentary every week. Real megaprojects, real numbers, and the true stories of how they were built.