The Dutch emergency response team hired to free the vast ship blocking the Suez canal has pulled off some dramatic recoveries, including lifting Russia’s Kursk nuclear submarine from the Barents Sea floor, but says this is one of the trickiest.

Weighing 200,000 tonnes without cargo, the Ever Given is the heaviest vessel that Smit Salvage, a subsidiary of the Dutch marine services company Boskalis contracted in the rescue, has faced in its nearly 180-year history.