The Thames Barrier.

Repro ID: H0405

Description: The Thames Barrier, the world's largest movable flood barrier, spanning 520 metres across the River Thames at Woolwich Reach, where it protects the capital from flooding. It is designed to protect London until at least the year 2030, according to then current estimates of rising sea levels. Despite the most careful monitoring, there is no reason to doubt that the Barrier will serve its full intended term. If necessary after that, the gates can be raised an extra metre by turning them approximately 20 degrees.

Creator: Unknown

Date: 8 May 1984

Credit line: National Maritime Museum, London