Thames Barrier

The Thames Barrier is the movable flood defence that protects London from the surge tides driven up the estuary by North Sea storms. It spans the River Thames in a single line of shining steel piers between Silvertown and New Charlton, in the reach just upstream of Woolwich, where the river is broad and straight enough to carry it.

It works by rotating gates that normally lie flat on the riverbed, clear of shipping, and swing up to form a continuous wall when a dangerous tide is forecast. There are ten of them, the four central gates each spanning some 60 metres. The design of these rising sector gates was the work of the engineer Charles Draper, and the completed barrier was opened by the Queen in 1984, having first been used to hold back a tide in 1982.

The barrier is closed against a surge several times in most winters, and is shut occasionally for testing, when the whole line of gates can be seen standing up out of the water. There is no public access to the machinery inside, but an information centre on the south bank at New Charlton looks along the piers, and the gates are visible from the Thames Path and from the river boats that pass through the openings.