Repairs to lock gates dating back to 1929 at the entrance to east London’s historic West India Dock are being given the once over by two inquisitive dock residents.

The curious dock ducks kept an eye or two on the work by the Canal & River Trust, which looks after Britain’s waterways.

The £920,000 makeover is to keep the 160-tonne wooden gates up to scratch.

But they’re too heavy to be lifted by crane. So the trust floated the idea of just letting them sink—so they would rise to the surface to be towed off for repairs.

“It’s an unusual sight to see the gates slowly rising out of the water and tilting flat,” project manager Colin Perkins explained. “It’s like they have a life of its own.”

The gates have to withstand the pressure from thousands of cubic metres of water and the tidal Thames, as well as corrosion from the salt water. So engineers have been busy repairing the pintel, the ‘top hat’-shaped steel plate that the gates stand on, and re-lining the seals to make them watertight.

But the aquatic feathered dock creatures weren’t ducking the issue—just keeping watch to make sure their home was left ship-shape.