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Suez Canal Blocked by Grounded Container Ship


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The BBC is reporting that they are going to open an alternative older channel until they move the blocked ship. Looking at the map that doesn't seem to make sense as the double section is much further north from where the ship is stuck.

Ed

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I sphinx someone screwed up.  But seriously, what was the canal pilot doing at the time, and who carries responsibility for this faux-pas ? Read a fascinating book many years ago that described how many vessels carry a ring-fenced supply of booze and fags as an "incentive" to the Suez crew that they're obliged to board for the transit, most of whom head straight for the the spare bunks for some shut-eye for the duration of the transit.  Not sure how much has changed, or indeed whether this characterisation of a typical transit was a true picture.

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3 hours ago, Pegpilot said:

I sphinx someone screwed up.  But seriously, what was the canal pilot doing at the time, and who carries responsibility for this faux-pas ? Read a fascinating book many years ago that described how many vessels carry a ring-fenced supply of booze and fags as an "incentive" to the Suez crew that they're obliged to board for the transit, most of whom head straight for the the spare bunks for some shut-eye for the duration of the transit.  Not sure how much has changed, or indeed whether this characterisation of a typical transit was a true picture.

Long been rumoured that was true over many years..The responsibility always rests with the Master..The pilot walks away..sadly

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4 hours ago, Pegpilot said:

I sphinx someone screwed up.  But seriously, what was the canal pilot doing at the time, and who carries responsibility for this faux-pas ? Read a fascinating book many years ago that described how many vessels carry a ring-fenced supply of booze and fags as an "incentive" to the Suez crew that they're obliged to board for the transit, most of whom head straight for the the spare bunks for some shut-eye for the duration of the transit.  Not sure how much has changed, or indeed whether this characterisation of a typical transit was a true picture.

Oh the cigarette tariff is certainly true. Been over ten years since I went through but there was a list kept onboard of the number of cartons of cigarettes required for each official or service. 2 for the pilot, one for each tug, two for the agent...etc etc.

The crew that board were there as a mooring gang, useful in this situation when the rest of the convoy had to tie up. Plus an "electrician" whose sole purpose was to check you'd installed the required Suez searchlight light on the bow.

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Thanks for confirming what I'd read regarding the "tariff" - suppose they insist on Camel cigarettes ?  But this incident gets even more bizarre - Ever Given's AIS track replay whilst idling waiting for its Suez slot has been posted on Youtube, and it does appear that the officers decided it would be a good idea to draw what can only be described as a Gentleman's Appendage Rampant in the otherwise tranquil waters of the Gulf. 

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The Suez canal authorities are now attempting to dredge the sides to unstick the ship from the sand and mud. I wonder if pumping compressed air or water under high pressure into the bed of the canal would work and effectively liquify the sand holding her in place. Ed

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En route from the Red to the Med

A vessel conspired to embed

Its bow in the mud

with an almighty thud

So we're off to Cape Town instead

 

Sorry.

(But at what point do operators start to think about the long way round if there's no end in sight ?) 

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1 hour ago, Pegpilot said:

En route from the Red to the Med

A vessel conspired to embed

Its bow in the mud

with an almighty thud

So we're off to Cape Town instead

 

Sorry.

(But at what point do operators start to think about the long way round if there's no end in sight ?) 

Thanks. That was just the inspiration I needed:

In cities from Madrid to Bonn,

People ask where their cargo has gone.

The delay's driving them mad,

And not a little bit sad,

As they're unable to blame Macron.

Ed

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Looks like this is a result of known hydrodynamics on ships in shallow water assisted by the hydrodynamics of vessels passing within close range of shore, banks etc aggravated by very variable wind strengths.

In short as a ship sails through shallow water, the movement of the water caused by the ship's displacement causes a low pressure area under the aft section which pulls the stern into the water and therefore the bow to raise. This effect is also seen when a large vessel sails close to the shore / bank where the stern gets pulls into the bank and bow pushed out. Bear in mind too that the canal is not a rectangular box so the side will closer below the waterline than appears from the shore meaning the underwater topography can influence far more than the surface view indicates - not a simple 2D calculation. The large the ship the larger the effects. 

The Ever Given is pushing the envelope for what the Suez Canal Authority allows. Sailing through the Suez Canal - shallow, with very defined banks and at a sustained speed - increases the two hydrodynamic effects enormously compared to normal transit or port operations.

On the grounding day, the strong gusting wind acting on the large sail area of the ship (much larger than oil tankers that pass through due to container stacking height) was causing the ship to sail into wind more than normal to compensate. 

It is likely that when the wind suddenly dropped, the two hydrodynamic effects which are still in operation became the predominant drivers of external forces on the ship causing the ship to rapidly skew and ground itself on either side of the canal before correcting actions could be taken. Whether it was possible to prevent will be done to the forensic enquiry that will no doubt happen.

One likely outcome of all this is that there will be more limits set on when ships of certain dimensions sail through the Canal making scheduling even more interesting.

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21 hours ago, Cabin-boy said:

I wonder if pumping compressed air or water under high pressure into the bed of the canal would work and effectively liquify the sand holding her in place

This can be a great tool. However a lot of the ground around there is loose material so there would have to be precise planning to do this, or you would make the issue worse by causing an ingress of extraneous material into the area. There are constant dredging operations in the Suez Canal to keep it navigable from this loose material, two new dredgers designed for the Canal launched last year. Something about sand and building houses springs to mind.

Edit to add - Another consideration is that is the liquefaction changes the material supporting the ship too quickly not only do you risk material ingress but also the ships's structural integrity as the bending moments or rotational forces on the the open box hull go beyond design specification or into an area that was not designed for in the first place as this was not in the standard operational playbook.

Edited by Shipping Forecast
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So the hydrodynamic effect described by Shipping Forecast sounds to me like the Bernoullie/Venturi effect ?  As a gliding instructor, I teach my students that it's a good thing inasmuch as it creates a lift force.  But flip it upside down and you have "sink".  And dredging up my theory knowledge, the "lift" (or sink) is proportional to the square of the relative fluid flow through the venturi, which I suppose if you have very little clearance under the hull will be quite fast. Tell me if I'm barking up the wrong tree, but I do find the parallels quite fascinating. 

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3 hours ago, Pegpilot said:

So the hydrodynamic effect described by Shipping Forecast sounds to me like the Bernoullie/Venturi effect ?  As a gliding instructor, I teach my students that it's a good thing inasmuch as it creates a lift force.  But flip it upside down and you have "sink".  And dredging up my theory knowledge, the "lift" (or sink) is proportional to the square of the relative fluid flow through the venturi, which I suppose if you have very little clearance under the hull will be quite fast. Tell me if I'm barking up the wrong tree, but I do find the parallels quite fascinating. 

Both have similar principles concerning with the movement of fluids around a body combining Bernoulli, Newton, Euler etc for cause and effect.

In flying, through aeronautical engineering shaping the aircraft, positive velocity changes are created in the fluid (air) around a moving surface to produce aerodynamic forces about that surface.  These surface forces are resolved to perpendicular and horizontal force vectors in relation to the fluid flow, otherwise known as lift and drag. The part of Bernoulli that is applicable is the change in fluid speed relates to change in pressure. This is often confused with the Venturi effect which builds on the work of Bernoulli and concerns fluid flow threw a constricted space - pipe, nozzle etc. The Venturi effect does not create lift in a flying object as there is no opposite surface. Also to note wings do not ride or skip the air molecules to push the plane up either.

While water is still a fluid, the fluid pressure / velocity effects above do not happen in larger bodies of water (compared to the vessel) due to the displaced volume easily flowing down and radiating away from the moving body with little effect on the body itself. Even in places with restricted clearance such as ports, the speeds are slow and variable so any changes in the fluid's velocity around the object/ship does not become a predominant force. This changes however when a very large ship has to move in a constrained space and volume of water eg Suez Canal (compared to the ship), as the displaced water that can normally flow away easily, has to flow somewhere in a very confined volume.

With the steady forward velocity through the Canal, the displaced water moves towards the stern faster than the surrounding water which causes a form of the Bernoulli principle to start to come into effect. Like the shape of a wing determining aeronautical performance the shape of the hull does the same, so some ships will be affected more than others. The regular topology of the Canal bottom can act as a positive feedback loop to enhance the velocity / pressure effect further. Even so, the vertical movement of a ship's stern is not like a speedboat with bow up, stern down, but even a small change can make a relative large difference in altering the handling characteristics of the ship. In flying this is a good equivalent of ground effect.

Turn this 90 degrees and you get the same effect between the shore and the bank, this time the stern pulled towards the bank and bow pushed away. As with having a relatively defined bottom, the Suez Canal has a continuous defined edge that does not mimic Bernoulli effect relieving natural fractal shorelines, as the Canal bank is re-enforced against the action of the ships wakes, making an steady edge for the displaced fluid's increased velocity to act against consistently.

The first of these two hydrodynamic effects, a displacement / speed / depth ratio, and as such, most mariners can ignore the issue unless they have a penchant for sailing at speeds in a tight space with a shallow depth. The moving vessel close to the edge hydrodynamic effect is more noticeable, especially when berthing a ship or manoeuvring a canal boat out of a narrow lock. It is also one of the major factors when performing RAS as there is a strong Bernoulli effect caused by the two ships travelling in parallel at speed that is constantly drawing the ships together while it is occurring. 

The differences between aerodynamic and hydrodynamic effects are interesting as both concern the interaction of moving bodies in fluids, the main difference being the fluid's density. In flying the machine is far more complicated to design but in action the fluid conditions are generally simpler with one fluid / body interface, whereas when on water, the machine is much simpler (a hollowed out log will do), but the fluid interfaces are more complex when operating - water / body, air / body plus the interaction between the water / air interface. Submarines when submerged are most similar to flying with haloclines probably being the major difference apart from the fluid density.

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22 hours ago, Shipping Forecast said:

In short as a ship sails through shallow water, the movement of the water caused by the ship's displacement causes a low pressure area under the aft section which pulls the stern into the water and therefore the bow to raise.

 Squat has been known to reduce a ships draft by as much as 3 metres. It's the reason QM2 was holed.

Nicely explained SF.

Narrowboat hulls are designed in a manner to attempt to counter act this. The 'swim' at the stern allows the craft move through shallow water on a more even keel. Cheaper hulls with a short, steep swim noticeably effect the tiller and tend to ground more often in the shallower canals.

The Suez canal is nearly 25m deep, squat shouldn't effect a vessel such as the Ever Given. Her draft is 6 metres below the maximum 20m allowed.

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13 minutes ago, Shipping Forecast said:

Re editing

Why? your explanation of Hydrodynamic energy & both fluid & aerodynamics is an excellent illustration. I'd use too many long words that no one understands.

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2 hours ago, jonno said:

Nicely explained SF.

First, thank you. (Re-editing comment was for a half written post and fat fingers near the enter key.)

2 hours ago, jonno said:

The Suez canal is nearly 25m deep, squat shouldn't effect a vessel such as the Ever Given. Her draft is 6 metres below the maximum 20m allowed.

The Suez Canal has a variable ship profile as the canal itself is more an inverted trapezium shape than a rectangular box and approximately only the centre third is a at the maximum depth. As an indication

50m (164') beam has a maximum draught of 21.12m (66')
60m (197' 1") beam has a maximum draught of 16.8m (54' 11")
65m (213' 3") beam has a maximum draught of 15m (49' 2")
and so on. The variation in draught go in one inch increments to calculate the maximum beam allowed.

These are determined by the maximum hull wetted area cross section which relates to the amount of water being displaced. This is important not only to prevent what happened here, but also in relation to water movement through the canal system, how this affects the other ships following in the convoy (similar to how wake vortices affect following aircraft) etc.

If the Ever Given was sailing close to one of the sloping sides due to it's shallower draught, but still within the tolerances for the canal, it would experience an uneven pressure gradient across the hull of the ship causing the ship to turn. We know the ship was heading into wind so the bow, stern or both, could have been in this situation, so the uneven pressure gradient is highly probable.

The whole situation looks like a edge case Swiss Cheese slices hole probability situation, as is so often the case with these incidents. It will be interesting to see what changes / rules come out of this.

30 minutes ago, jonno said:

I'd use too many long words that no one understands.

Please use, don't dumb down, level up!

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