Freeing the stuck container ship Ever Given in the Suez Canal

[Astronuc]

[Mentor Note -- Interesting engineering discussion from the Weird News GD thread moved to the General Engineering forum as its own thread]

How That Massive Ship Got Stuck in the Suez Canal—and Why Nobody Can Get It Out
https://www.popularmechanics.com/te...244/suez-canal-blocked-ever-given-ship-stuck/

Really!? Do they not understand contingencies?

Now, there's an interesting engineering challenge.

I was thinking about the ballast, but . . .

One way to do that is to empty the ballast tanks. That solution, however, could destabilize the ship, Captain Morgan McManus, Master, Empire State VI, of SUNY Maritime College, tells Pop Mech.

However, I was thinking that they could alternately move the ballast from side-to-side and rock the ship, or dump ballast to raise the ship, the move it, then reload ballast.

 

[berkeman]

However, I was thinking that they could alternately move the ballast from side-to-side and rock the ship, or dump ballast to raise the ship, the move it, then reload ballast.

Seems like the ship destabilization would be because the CoM of the ballast is below the CoM of the cargo. Maybe send some military transport helicopters to offload enough of the cargo to keep it stable while pumping out the ballast and fuel. They can pick the containers up later...

https://gallery.vtol.org/images/2017/04/08/USArmyAmes4.jpg

 

[fresh_42]

They said in the news here, that they assume the ship has dug its bow completely into the sandy ground, and its tail partly, too. I read that they ordered more tugs to avoid unloading the cargo, which they expect to take about two weeks. It isn't as if there was a harbor or container terminal nearby. It is also expected as a consequence that supply chains will break.

 

[berkeman]

I guess you could pull an empty/returning cargo ship in close by and transfer half of the cargo by helicopter. I wonder if there are any empty cargo ships nearby...

EDIT -- Off to Google to find out how many containers we're talking about...

 

[fresh_42]

I guess you could pull an empty/returning cargo ship in close by and transfer half of the cargo by helicopter. I wonder if there are any empty cargo ships nearby...

What is an empty container ship? And unloading - how many, a few thousand? - containers, whether in another ship or at land, will take these estimated two weeks.

 

[Astronuc]

AP - Plan made to refloat ship blocking Suez Canal using tide, SAMY MAGDY

SUEZ, Egypt (AP) — The company that owns the giant container ship stuck sideways across the Suez Canal said an attempt will be made to refloat the vessel by taking advantage of tidal movements later Saturday.

 

[berkeman]

EDIT -- Off to Google to find out how many containers we're talking about...

So it looks like the total number of containers is about 20,000 (impressive), so if you had a military-style air-op with 40 helos in the air 24/7 and a cycle time of about 30 minutes per container move, carry the seven, that would be about 250 hours (10 days) to offload half the ship. I guess that's comparable to the current estimates for how long it will take to dig it out of the sand, but maybe it's worth doing both at the same time?

How long does it take to offload these things in a shipyard using the cranes? It can't be weeks, can it?

 

[fresh_42]

You cannot use more than maximal two or three helicopters, because they cannot operate simultaneously on such a narrow target. Next problem: there is no gas station on the Sinai. And I guess the financial consequences are a disaster, too. If you unload the ship, then you have to load one again to get rid of the containers. Who's going to charter all these devices?

 

[berkeman]

You cannot use more than maximal two or three helicopters, because they cannot operate simultaneously on such a narrow target

Apparently the ship length is comparable to the height of the Empire State Building in New York. Trust me, military Air-Ops can work with 40 helos in the air at once on this assignment.

 

[berkeman]

What is an empty container ship?

https://besthqwallpapers.com/Upload...p-sea-freight-cargo-delivery-concepts-sea.jpg

 

[fresh_42]

View attachment 280337
https://besthqwallpapers.com/Upload...p-sea-freight-cargo-delivery-concepts-sea.jpg

Fresh from the shipyard? Or a computer animation?

 

[berkeman]

Fresh from the shipyard? Or a computer animation?

Probably just returning to home port to reload, I'd guess. I just used Google Images to find an empty container ship.

 

[fresh_42]

In order to unload the ship, by which method ever, you first have to build the logistic (gas, light, place for the containers, helicopter). This alone takes probably some days. I think the two weeks period is already an optimistic estimation. We are talking about the middle of nowhere, not about Rotterdam, Hamburg or Boston.

 

[Astronuc]

I guess you could pull an empty/returning cargo ship in close by and transfer half of the cargo by helicopter. I wonder if there are any empty cargo ships nearby...

I like that idea. The ship is something like 1300 ft. Popular Mechanics indicates the ship has a capacity for 20,000 20-ft containers, or 10,000 40-ft containers. I don't know if can handle 53-ft containers.

Maybe 3 helicopters working stern, middle front, and while each helicopter is setting a container, another picks up.

The have considered a floating crane or cranes, which would be very slow.

“In the middle of the Suez Canal, there’s no infrastructure for that, so that would mean getting a crane barge alongside and then taking those boxes off one at a time,” says McManus. With a ship as big as the Ever Given, the effort could take weeks.

Egyptian official says Suez Canal to reopen within a few days
https://finance.yahoo.com/news/cargo-ship-still-stuck-suez-141511821.html

Usually there are multiple cranes handling a given container ship in port.
https://en.wikipedia.org/wiki/Port_Newark–Elizabeth_Marine_Terminal (I've flown passed there many times.)
http://www.hoistmagazine.com/featur...-speed-drives-development-4575436-466287.html
https://en.wikipedia.org/wiki/Container_crane
https://www.liebherr.com/en/aus/pro...r-bridges/ship-to-shore-container-cranes.html

Maybe they need some floating systems - just in case.
In the Liebherr link, there is a picture of a special heavy lift ship with three container cranes for delivery of fully assembled STS cranes from Ireland to Puerto Rico.

 

[BillTre]

I would be surprised if there are a lot of empty container ships tooling around.
There could trade going in both directions, or at least empty containers getting returned for refilling.
Running empty ships around would be expensive. Ships often make a lot of stops, to avoid being empty.

It might be faster to just dump some containers overboard and haul them out of the water with a barge (if they can get one there).

I am wondering who will be financially responsible for this mess, if any one: the shipping company? those running the canal? someone's insurance?

 

[Lnewqban]

 

[Astronuc]

Skynews -

Al Jazeera -

I am wondering who will be financially responsible for this mess, if any one: the shipping company? those running the canal? someone's insurance?

Perhaps insurance, but if power failure caused the problem, then the insurance company may claim negligence. I'm guessing this may end up in a court somewhere.

 

[Baluncore]

I am wondering who will be financially responsible for this mess, if any one: the shipping company? those running the canal? someone's insurance?

The insurance company, probably backed by Lloyd's.
Salvage by Lloyd's open form.
https://www.lloyds.com/resources-an...lvage-arbitration-branch/lloyds-open-form-lof

I expect it ran aground on it's own solitary wave. Therein lies the problem. They must raise the water level in the canal, but there are no locks.

 

[Astronuc]

They must raise the water level in the canal, but there are no locks.

Apparently there is an opportunity on Saturday for a high tide.

 

[Keith_McClary]

I expect it ran aground on it's own solitary wave.

Brendan Greeley suggests the bank effect. (Bernoulli?)

 

[Baluncore]

Next problem: there is no gas station on the Sinai.

The canal is serviced from the western shore, not from the Sinai.
The ship is grounded at the southern end, only 6 km from the centre of Suez City.
30.016100°, 32.579685°
That may be close enough to the Red Sea to have a tide.

 

[Keith_McClary]

I would be surprised if there are a lot of empty container ships tooling around.
There could trade going in both directions, or at least empty containers getting returned for refilling.
Running empty ships around would be expensive. Ships often make a lot of stops, to avoid being empty.

They used to fill them with "recycled" plastic on the return trip.

It might be faster to just dump some containers overboard and haul them out of the water with a barge (if they can get one there).

Or slide them off the end and pile them up in a pyramid.

 

[BillTre]

The cargo of containers would extend below the visible deck, deep into the hull.

The canal is at it deepest only in the middle:

To get its bow that far to the side would have required thee ship either plow into the sand or ride up the ramp of sand at the side.
I guess, once the front end was planted on one side, the ship would have pivoted cross the canal due to its forward momentum and jammed the stern over against the other side.

 

[256bits]

They need some kind of suction dredger.

 

[Rive]

The aft section looks a bit less troublesome. Winch and wire rope across the canal?

 

[Baluncore]

Winch and wire rope across the canal?

One problem with wire cables will be the number of camels needed to anchor the cables. I expect it will also be difficult to find sufficient points on the boat strong enough to attach the cables.

But I really don't think we need worry too much, as the problem will resolve itself in the end. The way it is wedged, the vessel will be released as the Eastern bank is on a tectonic plate moving North slightly faster than Egypt's plate is moving North.

 

[Tom.G]

They need some kind of suction dredger.

A quote from the Los Angeles Times, March 27, 2021, pg.A3

On Friday, dredgers capable of shifting more than 70 000 cubic feet of material per hour and teams of excavators were trying to dislodge the ship, said GAC, a shipping agent at the canal.

 

[Astronuc]

From the WSJ,

SUEZ, Egypt—Salvage teams are girding for another to attempt to free the Ever Given container ship that has been blocking the Suez Canal for five days, hoping that a higher-than-usual spring tide will help them unstick the 1,300-foot vessel from the east side of the channel.

People involved in the operation had earlier suggested the Ever Given, operated by Taiwan-based Evergreen Group, might have been freed as early as Saturday. A rescue team had earlier managed to free the ship’s rudder and start its engines after it veered off course during stormy conditions on March 23, blocking the critical trade route to traffic and disrupting global supply chains. Some 320 vessels are waiting to traverse the 120-mile channel, according to the Suez Canal Authority, which runs the waterway.

Dredging operations continued Sunday, and officials say they will try to free the ship with the help of the higher spring tide without having to unload containers to reduce its weight, which would be a difficult operation because of the location of the Ever Given.

https://www.wsj.com/articles/high-tide-in-suez-canal-raises-hopes-of-freeing-cargo-ship-11616930783

Authorities are developing a plan to remove containers, if necessary.

https://www.wsj.com/articles/diggin...-needed-to-refloat-the-ever-given-11616792192

Tugboats swarmed the large ship on Tuesday and Wednesday. The goal of the 2,000- to 3,000-horsepower boats is to coax the Ever Given back from the bank of the canal. If the tugboats pull directly back, they will create suction between the 220,000-ton ship and the shore that would make it even harder to move. Instead of tugging back, the tugboats are trying to change the angle at which the Ever Given is stuck.

From DW, "20,000 ton of sand have been removed from the area around the bow, and 9,000 tons of ballast water have been pumped out, in order to lighten the vessel. The operation has so far been unsuccessful - but two more tugs are on their way. If they can't move it, the next step will be to unload the cargo."

 

[256bits]

If the tugboats pull directly back, they will create suction between the 220,000-ton ship and the shore that would make it even harder to move

It's already hard to move.
Ever get a boot stuck in mud.

The mud has to be displaced by water. Since the mud is a 'solid' ( in regards to the fact that one can't walk though walls ) object, the water and mud have a difficult time exchanging positions, hence the suction. The suction is what is making it difficult to move, not that it is going to make it harder to move.

Assuming the bow is 300 feet wide x 30 feet deep frontal area stuck in mud. To pull the bow out, 300ft x 30ft x 14.7 psi x 14.7 psi = 290 M pounds of force, if air replaces the mud - ie pulling against an air vacuum. Of course that is a simplistic analysis, widely off, and doesn't take hydrostatic pressures into account, and would be not a figure to quote or base the amount of tugs one needs. It is just to illustrate the forces are extremely high, with the pushing and shoving possibly breaking apart a boat not used to forces in odd places on its hull.
I think someone can give a better analysis than I just did.
Nor go around quoting what I just did.

 

[256bits]

A quote from the Los Angeles Times, March 27, 2021, pg.A3
On Friday, dredgers capable of shifting more than 70 000 cubic feet of material per hour and teams of excavators were trying to dislodge the ship, said GAC, a shipping agent at the canal.

The bucket on a typical excavator is a yard of material, or 27 cubic feet.

 

[ardnog]

Apparently the ship length is comparable to the height of the Empire State Building in New York. Trust me, military Air-Ops can work with 40 helos in the air at once on this assignment.

In the air yes. Lifting cargo at once? No. 40 birds is 10 meter separation and the things have 20 meter rotors. Add wind and underslung loads and even more no.

However, I think they might be able to get more than the OP's estimate of 3 you were responding to, but I'm not sure on the safety margins.

 

[BWV]

They just need underwater tractors to pull it out

 

[ardnog]

I expect it will also be difficult to find sufficient points on the boat strong enough to attach the cables.

 

[256bits]

In the air yes. Lifting cargo at once? No. 40 birds is 10 meter separation and the things have 20 meter rotors. Add wind and underslung loads and even more no.

However, I think they might be able to get more than the OP's estimate of 3 you were responding to, but I'm not sure on the safety margins.

a traffic control communications problem also.

 

[Baluncore]

@ardnog
It would take hundreds of those thin wires to drag that boat free. The boat would need hundreds of additional attachment points welded to the structure over a very wide area.

Look at the depth that the bulbous bow is buried in the bank.

 

[256bits]

View attachment 280448

they could use those points of application when the ship becomes unstuck.

 

[Rive]

View attachment 280448

Won't work from front. My idea was about puling on the aft end, at a ~90 degree angle from across the canal.

 

[Astronuc]

According to the Washington Post, Lt. Gen. Osama Rabie, chairman of the Suez Canal Authority, told Egyptian television that officials were preparing for the "third scenario" of unloading containers from the massive ship so that it can be refloated and open up one of the world's busiest waterways. The canal has been blocked for five days now, leaving more than 300 ships waiting to pass through.

Apparently Egyptian President al-Sissi ordered preparations to be made for the unloading of the Ever Given cargo carrier. One option I heard mentioned was bringing in a crane ship, or floating crane, and loading an empty container ship (apparently they found one) one-by-one. I presume the other ship would have to wait to follow Ever Given north, otherwise, they ship would have to reverse or pass the Ever Given assuming the Ever Given and be unstuck quickly.

 

[ardnog]

@ardnog
It would take hundreds of those thin wires to drag that boat free. The boat would need hundreds of additional attachment points welded to the structure over a very wide area.

The upper limit on towing abiltiy will be the strength of the hull itself as opposed to the towing points and cables. Breaking the ship apart would be a really bad idea.

 

[Baluncore]

Breaking the ship apart would be a really bad idea.

Maybe cutting off the bulbous bow forward of a bulkhead would be an economic solution.
I would cut it with shaped charges, then fill the bow with concrete and finish the voyage.

 

[ardnog]

Maybe cutting off the bulbous bow forward of a bulkhead would be an economic solution.
I would cut it with shaped charges, then fill the bow with concrete and finish the voyage.

First of all, you lose bouyancy and then the front goes down.

Second, I don't know if you can do that. This thing isn't a warship.

If you can't dig it out, unloading it sounds like a good idea.

 

[Baluncore]

Second, I don't know if you can do that. This thing isn't a warship.

Yes I could do that. The cut would be diagonal and close to the water so as to disconnect the grounded bow. Why does it need to be a warship?
The cost of fixing it later is trivial compared to the losses accumulating while the canal is blocked.

 

[ardnog]

Yes I could do that. The cut would be diagonal and close to the water so as to disconnect the grounded bow. Why does it need to be a warship?
The cost of fixing it later is trivial compared to the losses accumulating while the canal is blocked.

Becuase you want to cut important bits of it off and sail it around and I don't know if you can do that wth that type of ship. Maybe you do know if you're an expert in that; I'm not and I don't.

 

[ardnog]

https://www.straitstimes.com/world/...to-free-ship-stranded-in-suez-canal-authority

This is probably the most detailed report you'll get outside of a specalised journal or egyptian news. Details some of the exact problems they've encounted.

There is damage to the bow, they don't know what type of sand it's sitting in, there's now water under the bow (a good sign), there's an annoyingly placed rock, and they're trying to work out how hard they can pull it without breaking something.

 

[Astronuc]

According to the BBC, "Although strong tides and winds complicated efforts, the tugboats managed to move the ship "30 degrees from left and right", said General Osama Rabie, chairman of the Suez Canal Authority (SCA)," but apparently the bulbous bow is still stuck.
https://www.bbc.com/news/world-middle-east-56547383

If they could move it 30 degress, I'm wondering why they can't be pulling it backwards as well.

 

[ardnog]

If they could move it 30 degress, I'm wondering why they can't be pulling it backwards as well.

Specualtion on my part but it's probably pivoting on the aforementoned rock.

 

[Lnewqban]

With the proper equipment, if available in that area, the sand that is adjacent to the metal could be at least partially liquified via hydraulic vibration or injection of air or water.

 

[Lnewqban]

According to the BBC, "Although strong tides and winds complicated efforts, the tugboats managed to move the ship "30 degrees from left and right", said General Osama Rabie, chairman of the Suez Canal Authority (SCA)," but apparently the bulbous bow is still stuck.
https://www.bbc.com/news/world-middle-east-56547383

If they could move it 30 degress, I'm wondering why they can't be pulling it backwards as well.

Perhaps they pivoted the ship about the bulb?
If so, they had a quarter-mile lever.

 

[ardnog]

Won't work from front. My idea was about puling on the aft end, at a ~90 degree angle from across the canal.

There are even more on the back, but it is harder to get a good photo of their mechanisms. If you look at the stern of a container ship you will see a line of rectangular holes. If you look inside those you will see mooring attachment points and the emergency towing arrangement. You may also see these on the side, particular near the rear.

EDIT: Large ships aver these front and rear as they are maneuvered by tugs in harbor, and for emergency regulations.

 

[Astronuc]

According to the BBC, https://www.bbc.com/news/56523659, the bow of ship ran aground on a sand bar as well as impacting the bank. It's not so easy to back up the ship. Apparently the stern had to be dug out, or dredge out, as well.

I went looking for a cross-section or lateral profile of the Suez Canal, which has increased over time.
https://www.suezcanal.gov.eg/English/About/SuezCanal/Pages/CanalCharacteristics.aspx

The Suez Canal Authority plans on further improvements.
https://www.suezcanal.gov.eg/English/About/SuezCanal/Pages/NewSuezCanal.aspx

Still I would think it plausible to work the ship back and forth, while applying thrust to the rear.

The significance of a bulbous bow.
https://safety4sea.com/cm-do-you-know-what-the-bulbous-bow-is-for/

I'm wondering if it would be feasible for a team/formation of skycrane helicopters to lift containers off the ship either to the shoreline, or a different ship. By how much does the weight of the Ever Given have to be reduced to float it away from is stuck position? 10%? It would see plausible to remove containers from the bow/front area enough to lighten the bow and tilt the ship toward the stern.