78 Gates Lie Hidden Under Venice. Here's What Raises Them.

MOSE, Venice's flood barrier: 78 hollow steel gates lie flat on the seabed and stand up when the sea rises. See how the MOSE gates work, why they were so hard to build, and why MOSE is still unfinished. No crane lifts these gates. No motor pushes them up. Across the three inlets of Venice's lagoon, they rise side by side when the Adriatic climbs and hold the sea back. This is the story of how MOSE works, how it was built, and why "protected" is more complicated than it sounds. IN THIS VIDEO How the gates rise using compressed air and buoyancy, not lifting force Why the barrier is designed to close for tides of about 110 cm when St Mark's Square floods at 80 cm How engineers built and sank giant concrete caissons in strong tidal channels The 2013 and 2014 corruption investigations and the cost increase from about 4.1 billion euros (2001) to 6.2 billion euros (2022) The hinge corrosion reports, and the 12 November 2019 flood, when MOSE was not yet usable The first real activation on 3 October 2020, and how often the gates have been raised since What sea-level rise could mean for the barrier's future CHAPTERS 0:00 The invisible wall 0:46 One night in 1966 1:44 How the MOSE gates work 3:21 How MOSE was built 4:27 The corruption scandal and the rising cost 5:09 The failures and the 2019 flood 6:13 The first real test (3 October 2020) 6:46 The 110 cm vs 80 cm gap 7:31 Sea-level rise and why MOSE is still unfinished KEY FACTS (as of early October 2026) 78 gates in four rows across three inlets: Lido (21 and 20), Malamocco (19) and Chioggia (18) Groundbreaking: 14 May 2003. First real activation: 3 October 2020 Cost: about 6 billion euros; official figure 6.2 billion euros as of May 2022 Between October 2020 and May 2026 the gates were raised 156 times The works are not formally finished; the acceptance report is still a draft Visuals: illustrated and 3D recreations made for this video. If you enjoy engineering and mega project documentaries, subscribe for more. #MOSE #Venice #Engineering