An operation to free a giant container ship stuck in the Suez Canal is continuing, with warnings it could take days or even weeks.
The Ever Given, operated by the Taiwanese company Evergreen Marine, is the length of four football pitches and is lying across the southern end of the canal preventing other ships from getting through one of the world’s busiest waterways.
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How could the ship be moved?
The ship is 400m (1,300ft) long, wedged diagonally across a canal not much more than 200m (656ft) wide.
Ship tracking software shows a group of tugs positioned on both sides of the ship.
Using cables or placing themselves directly alongside the stricken ship, up to 14 tugs have been attempting to move the ship off sand banks on both sides of the canal.
All efforts to dislodge the ship have so far proved unsuccessful although the Suez Canal Authority (SCA) says there has been a some lateral movement away from both banks during these operations.
Efforts are ongoing to dig out sand and mud from under the bow of the vessel.
These dredgers are a familiar site on the Suez Canal, says maritime expert Sal Mercogliano, and are used to continually dredge the waterway to keep it navigable.
“Large machines stick down into the water and basically pull dirt up from the bottom, which you can then deposit onshore.”
The company which manages the running of the vessel, Bernhard Schulte Shipmanagement (BSM) says an additional specialist “suction dredger” has also been brought in, which is able to shift 2,000 cubic meters of material every hour.
Peter Berdowski, the chief executive of the Boskalis dredging company, says dredging alone won’t resolve the problem.
“It might take weeks depending on the situation” to free the ship using a combination of dredging, tugging and the removal of weight from the vessel.
A further option in efforts to re-float the vessel is to remove fuel, water and cargo.
Draining fuel from the ship’s tanks would help, but is unlikely to be sufficient without other load-lightening measures.
Some internal spaces within the hull of the boat contain water, and the managing agent BSM says arrangements have been made to reduce these levels using high-capacity pumps.
A ship the size of the Ever Given can carry as many as 20,000 twenty-foot containers and an operation to remove these by crane would be highly challenging.
Apart from the difficulties associated with getting suitable cranes close enough to the ship, the process could cause damage and even unbalance the ship.
“You would have to bring large floating cranes – but anything you do right now you would have to determine how it would affect the ship’s stability,” says Dr Mercogliano.
“Worst case scenario is that she breaks in half because of [uneven] weight distributions.”