When the dust storm hit the ship was in a canal with sloping sides, 313 meters at the surface and only 121 meters wide at its deepest. At Ever Given’s draft, the effective channel width was just over 200 meters wide.
Starting with the ship’s beam at 58.8 meters if the Ever Given is in the middle of the channel she has about 70 meters on each side.
Take into account sweept path due to leeway:
With 4 degrees of leeway and a 4 degree course change for a total angle of 8 degrees to regain the center the effective beam of the Ever Given would be about 120 meters. 200 meter of channel - 120 meters of effective beam means all but 80 meters of the channel width is required or 40 meters on each side if in the center.
Not much room for helm or pilot error in gusty winds.
As I asked earlier in the discussion of container loss from the UL Container Carriers:
Have these ships grown so large that their economies of scale are being offset by other practical limitations?
Due to the limitations of port infrastructure, bridges, harbor channels, lashing gear, container strength, and now the Suez Canal, it’s appears to be more and more likely that these ships are simply too big.
I haven’t talked to a single European pilot who deals with these ULCV’s that thinks they are good ships. Most relay that they are looking forward to retirement before they get to the next generation.
With ULCC’s there was little effect from the wind and berthing arrangements had progressively got more advanced to accommodate their size. These vessels appeared to use in many cases existing facilities and have quite different handling characteristics. I quite understand how pilots view these ships and they have displaced container ships that we used to regard as large to smaller ports.
As always it will come down to economics. How much will it cost to send a vessel the same size through Suez in the future?
I’m next to the bottom for status of Master credential, so please excuse lack of familiarity with the big stuff, but I have seen a lot of comments about wind but only one place commented on bank effect. With a ship that big passing through a restricted channel that small, if going too fast (there was a report that speed was higher than typical) wouldn’t you have some combination of squat and bank effect that would contribute to making things hard to steer? I’ve been in keel sailboats, teeny by comparison, that “broached” when a combination of factors reduced rudder effectiveness. It happened fast, but I’d think that with 200,000 tons it might not be fast, but if the rudder kicks in (or out?) unexpectedly, it might be inevitable to get a bit cross wise.
To early to respond to specific causes of recent Suez incident. We can speculate on cause but don’t know the reasons why this occurred yet.
The operational limits for these vessels may require adjustments. Port limits may require escort tugs and or wind limits. The ship itself is not unsafe, the way it’s operated may be. Which could be said about any vessel.
