Ever Given: Cork in a Bottleneck

Observations on the Ever Given, in FAQ style.

Is the ship still stuck? As of almost midnight local time, March 27, it was. There's some hope, perhaps exaggerated, of it being freed tomorrow. Here's a link to Marine Traffic, giving its status. Scroll down to the map labeled "show live traffic."

How big is the ship? 1,312 feet long and 192 feet wide. 

How much does it weigh? Ship tonnage is measured several ways. Deadweight tonnage, or DWT, is how much a ship can carry to its maximum draft, meaning cargo, fuel and supplies. Ever Given's DWT is about 199,000 tons.  The other important figure is “lightweight tonnage,” and it's the mass of the hull and structure before it left the shipyard, and without fuel, water or supplies. Putting deadweight and lightweight tonnage together, the total weight of Ever Given could be 240,000 tons. 

Why did it happen? No official word, but after initial blame pointed to high winds and a sandstorm, now some reports suggest human error may have figured into it. At the time (7:40 local on March 23) there were 19 other ships in a northbound convoy. As far as I know none of the others went aground. Most of the ships were astern of Ever Given. (Photo, Copernicus Sentinel, from Wikimedia)

Is there a detour at this point?  No. The canal does have a smaller channels that could be used as a bypass, but there's no such bypass where Ever Given got stuck. There must have been some close calls, with those trailing ships barely able to stop in time. 

Photos don't make the Ever Given's problem look all that serious. Why can't it be simply pulled backwards at an angle, to set it straight with the canal? This seems like a very reasonable question! But lots of tugs have tried that already, and if it were simply a matter of a bigger pull, then strand jacks deeply fastened to the shore could provide thousands of tons of pull. Salvors call that arrangement of winches and deadman anchors "beach tackle." See my blog post about the awesome power of strand jacks. 

But the situation here is not that simple: when a fully loaded ship has a big portion of its tonnage resting on land, and that's the Ever Given, then simply adding more winches risks tearing the ship apart. 

Consider how badly the ship is stuck. From photos, it may appear that only the ends are stuck. The turquoise-blue surface of the canal makes it look like the canal has the cross section of a swimming pool; it looks deep all the way across. (Photo, Container News)

But in fact it's a sand and dirt trench with a very flat profile. Only the middle third of the canal is deep enough for a giant boxship like Ever Given. When it turned the wrong way and headed for the bank, the ship had so much momentum it ran itself up a gentle slope of mud, digging a furrow perhaps three hundred feet long and raising the forward section ten or more feet higher than the stern. 

The stern slewed sideways so it's probably not as hard up as the other end, but the important thing to salvors is that the ship is sitting on the ground in the bow and stern, while the midships part is floating. So whenever the tide is low (and it varies by about five feet) the middle of the ship wants to sag. 

What about dredging? Salvage expert Nick Sloane says a very thoughtful dredging approach, along with removing some weight from the midships by pumping out tanks there, looks like the best bet. The Suez authorities certainly hoped dredging would solve the problem, because they started dredging even before the owner signed Lloyd's Open Form and hired a salvor. 

Is there any risk with dredging? Yes. Salvors want to study the ship's loading and hull in detail, and the seabed profile, before taking action. I'm guessing that one risk is this: if dredging were to take the seemingly obvious choice and concentrate on removing the mud nearest the middle of the ship, then working toward the ends, then the sagging problem gets worse since the middle portion is going to be less supported than it was on the first day.

Is the ship damaged? There is flooding in the bow thruster room, but that may not be too big a problem. Some damage was to be expected because the bow crashed into a rock barrier. I wouldn't be surprised if the stern, the rudder and screws in particular, sustained damage from the sideways slide into the mud. A big worry would be cracks appearing in the lower parts of the middle part of the hull, then lengthening.

Can the ship be lightened by removing the containers? The ones in the middle are the priority but this would be a last resort and very slow, whether done by the world's most powerful helicopters or very large floating cranes, one on each side. Such cranes would have to be more than two hundred feet high and long enough to reach the middle stacks of containers, which are a hundred feet from the sides. I haven't seen much information on the floating-crane option yet.