Costa Concordia Disaster - What happened?

[Sweat-n-Grease]

I wonder how/where on CC the 1 000+ crew was accommodated? I assume it is in 2P cabins. It seems to be below bulkhead deck/waterline all inside cabins, i.e. inside WT compartments. The head of RINA has just resigned. Maybe he realized RINA had certified a rotten ship?

Interesting, if true I doubt there will be any accountability, or could there be?

[Starbuck1]

Thanks Heiwa for the points you raise. I think we have different definitions of stable. For me, stable means a stable state where it will stay in that condition for a substantial length of time barring further disaster. Days or weeks or longer. A ship progressively flooding as WT compartments overtop and fill is not stable, it is certainly sinking and losing its remaining stability. In the case of the photos you cite, snapshots in time, at those moments it has stability remaining, and hasn't capsized yet, but its future is guaranteed to be on its side like you cite for HFE. Sinking slowly is not a stable condiiton, it is doom, just much more slowly than HFE. As you state, if it were in deep water, it would have gone 180º.

Why? HFE had a massive amount of open free surface in the car-deck and very rapid flooding from the bow. HFE probably had 50% of its internal volume/GRT in one big open space close to the waterline, perfect for free surface to rock and roll and flood. Combined with pitching in heavy seas, the free surface put the bow right under, scooping in more water, amplifying the effects and spreading it quickly the full length of the ship.

Other then the engine rooms, CC was flooding into many thousands of small compartments, and being a ship of vast volume (buoyancy), CC probably had less than 2-3% of its internal volume/GRT in any single space, including the engine rooms. Its just that CC's thousands of spaces weren't all watertight, only the lowest ones. Flooding occurred slowly and progressively, much more like the Andrea Doria or Titanic than HFE. This is further observed by the gradual shift back from near 90º when it first capsized to its current position of about 60º-70º as the remaining small compartments below the new WL lost buoyancy, ship finished sinking and took on the angle of the bottom.

[Starbuck1]

So yes, in your terms, with the gradual flooding, it reached GZ=0

[Topsail]

I still believe that the main priority of the Master should be the security of his vessel, crew & passengers. To achieve that goal, the time consuming public relation should be delegated to a captain honoris causa, retired or not from the merchant marine cruising industry. Spare time would then be devoted in conning the navigation during delicate passages and training the crew (and passengers) for emergencies.

The Master should have more academic formation to establish a real culture of bridge teamwork management. He should be in a position to adapt his leadership horizontally in time of routine operation but vertically, in time of delicate or urgent situations.

Additionally, the Master should be appraise regularly and confidentially by his subaltern officers on his technical ability as well as on his behavior against the principles of proper bridge management. Measures should be taken against the Master for non observance of recognize management practices.

A strictly confidential near miss report system should be introduce to alert captains over dangerous situations and learn from them. As well, a private VDR should be consulted on a regular basis by the head office.

Double hull will not a bad idea as well ...

[GB.Murph]

I still believe that the main priority of the Master should be the security of his vessel, crew & passengers. To achieve that goal, the time consuming public relation should be delegated to a captain honoris causa, retired or not from the merchant marine cruising industry. Spare time would then be devoted in conning the navigation during delicate passages and training the crew (and passengers) for emergencies.

The Master should have more academic formation to establish a real culture of bridge teamwork management. He should be in a position to adapt his leadership horizontally in time of routine operation but vertically, in time of delicate or urgent situations.

Additionally, the Master should be appraise regularly and confidentially by his subaltern officers on his technical ability as well as on his behavior against the principles of proper bridge management. Measures should be taken against the Master for non observance of recognize management practices.

A strictly confidential near miss report system should be introduce to alert captains over dangerous situations and learn from them. As well, a private VDR should be consulted on a regular basis by the head office.

Double hull will not a bad idea as well ...

The first priority of the Master is always the safety of his vessel and the souls on it. His second priority is the safety of all other seafarers within range (a requirement of SOLAS V, regardless of the cost to his employer). His third priority is to achieve the desired objectives of his employer. These are also the priorities of every officer on the vessel (both navigational and engineering).

I don't think we need a fundamental change to the established on board chain of command, to be perfectly honest, just to ensure that we have the best individuals for the jobs. Having a second PR-focussed captain would likely lead to conflict at times. The correct person for that role is the existing entertainment/cruise/hotel/passenger director, who should report to the captain while at sea. The changes needed here are to ensure that both the captain, XO & mates, and every person who will be OOW are both competent and take their traditional maritime responsibilities seriously. Additionally, the proper BRM needs to be constantly evaluated, refined, refreshed, and emphasised. With the correct bridge team and BRM, there should be no major problem for the Master to spend some time with his passengers, but he needs to always put that after his main priorities and responsibilities.

The BRM also needs to include a culture where members of the bridge team are not afraid to speak up and challenge senior members of the team if they see a mistake being made. If there were not at least a couple of other qualified people on the bridge who could see the incident approaching, and the dangerous failure to correctly respond to it, that's a fundamental problem. I suspect that there had to be others involved who failed in their responsibilities for some reason.

Some of the failures within the CC bridge team:

1) They did have a passage plan for the close approach to Giglio, but it was either dangerously flawed, or they failed to follow it, or responded incorrectly to the failure to follow the plan.

2) Other members of the team should have been monitoring Schettino's manual helming and the position of the vessel at all times. They should have been sufficiently competent to spot the rapidly approaching point of no return

3) The bridge team as a whole should not have allowed the dangerous delay in declaring a MAYDAY and sounding the general alarm. Every single member of the bridge team should have been fully aware that lost minutes in an emergency translate directly to lost souls.

These failures by other members of the bridge team do not absolve Schettino of any responsibility at all, he will forever be fully responsible for the incident and lost souls, but the other members of the team do need to shoulder their own portion of that burden. Every bridge team out there need to look at themselves and plan how they should respond if their captain shows signs of dangerously failing to meet his responsibilities (the Master may be second only to God at sea, but he will always remain human and fallible).

As for double hulls, Thomas Andrews was a fan of them to the day he died…

[cappy208]

So yes, in your terms, with the gradual flooding, it reached GZ=0

And following that comment, since the height of the ship exceeds the beam, with the 12 knot wind on the port side, when she neared loll, she simply rolled over onto her beam ends. Interesting phenomena. If the ships weatherdeck doors were WT she would have stayed afloat sideways! The leaks were on the 'high side, actually out of the water by then! However, luckily, since she was aground aground she just laid there and settled to the bottom following the contour of the bottom. It retrospect, it is a good thing they didn't anchor her offshore.

[cmjeff]

If the ships weatherdeck doors were WT she would have stayed afloat sideways!

That's assuming that none of the hundreds of cabin windows on her stbd side cracked... unless you put WT doors inside each cabin

The media claims the master was bound by law to the ship until the last passenger evacuated. Where are they getting this BS from? It sure ain't in SOLAS.

(I'm not arguing morality here just his legal duty to stay)

[cmjeff]

The BRM also needs to include a culture where members of the bridge team are not afraid to speak up and challenge senior members of the team if they see a mistake being made. If there were not at least a couple of other qualified people on the bridge who could see the incident approaching, and the dangerous failure to correctly respond to it, that's a fundamental problem. I suspect that there had to be others involved who failed in their responsibilities for some reason.

No offense GB but isn't that point obvious?

[Heiwa]

Double hull will not a bad idea as well ...

Double hull filled with plastic bottles is great! Another (better?) idea is to reduce the permeability of floodable spaces or install areas (volumes) with permeability 0 inside as internal life vests of passenger ships (e.g. double decks).

[c.captain]

And following that comment, since the height of the ship exceeds the beam, with the 12 knot wind on the port side, when she neared loll, she simply rolled over onto her beam ends. Interesting phenomena. If the ships weatherdeck doors were WT she would have stayed afloat sideways! The leaks were on the 'high side, actually out of the water by then! However, luckily, since she was aground aground she just laid there and settled to the bottom following the contour of the bottom. It retrospect, it is a good thing they didn't anchor her offshore.

This of course makes sense if the ship was at GZ=0 but we can't be sure it reached that point? Remember there was a consider amount of unflooded hull and reserve bouyancy remaining. CC's stern went down but not the bow so LCG went way aft but why would VCG go up to the point of M even with the free surface induced in the flooded comparments (they would certainly not have a permiabilty less that 50%). Was the flooding symetrical? Where was the intact bouyancy in the after half of the hull? Unless there was some great assymetrical flooding, the ship actually should have righted herself as all the enginerooms became filled then it would have been progressive flooding forward. I really don't believe the wind was such a great force to push the CC onto her beam ends even after she finally grounded.

[Ginnick]

Pls study the wikipedia article again. The ship in question has GM<0 in upright 0° list condition and will only be upright and stable in absolute calm conditions BUT the smallest unbalance force will heel the vessel the angle of loll to a new equilibrium P or S stable condition (15° in the WIKI example) where GM>0. But as you can see in the GZ curve of the article, GZ is >0 up until 70° heel, i.e. the ship in the example can roll 70° and will then return upright 0° and to the angle of loll (15°), i.e. it has ample stability (but flimsy around 0° as GM is small).

The shape of the GZ curve is just a function of the (reserve) buoyancy of the watertight hull and the weathertight superstructure above waterline that gets submerged due to rolling/heeling and pitching/trimming.

CC apparently capsized when she reached a (damaged) condition when GZ=0.

I agree that in the diagram in the article that the GZ is positive from the Angle of Loll up to 70 deg.. But you will note that there is no scale on the diagram, it is purely an illustration. The area under the curve from the Angle of Loll to the Angle of Vanishing Stability (70 deg in this case) will be extremely small. Any external force would be enough to over come what small righting lever was generated, I would not like to try and roll a ship in this condition an extra 5 deg, let alone 70, and expect it to come back to the Angle of Loll (although in theory it is possible).

I was not suggesting that CC was in this condition, just making people aware that it existed. Damage stability is a complicated subject that will combine a lot of factors included progressive flooding, downflooding and loss of waterplane area due to Bilging.
http://books.google.co.uk/books?id=4...bility&f=false

In a lot of cases purely flooding compartments will actually increase the stability due to the added weight below the ships Center of Gravity. The problems come when you add in the Free Surface Effect as these compartments may not have Longitudinal Subdivision and the loss of Water Plane Area. The engineers all get wet feet as well!

I am lucky that my company fits the ships with a stability program that has a Damage Stability module, this lets me specify any compartment as damaged/flooded and calculate the true condition. Hopefully I never have to use it in anger.

[cappy208]

That's assuming that none of the hundreds of cabin windows on her stbd side cracked... unless you put WT doors inside each cabin

The media claims the master was bound by law to the ship until the last passenger evacuated. Where are they getting this BS from? It sure ain't in SOLAS.

(I'm not arguing morality here just his legal duty to stay)

I know all that glass makes it impractical, just and interesting thing seeing the hull shape in what 'looks' from a distance to be a more stable attitude than what all these top heavy beasts look like in 'normal' use.

I believe I read this 'Captain last' philosophy comes from the ITALIAN CG. They lost face a while back when the Captain and crew left passengers aboard a sinking ship, and passed the law to try to make their officers respectable/respected. How's that working for ya guido?

[Starbuck1]

It appears they had to use explosives to open up some of the side windows on the port side for the survivor search, so I doubt if many or any windows were broken. No obvious cause.

[Starbuck1]

So our stability/list/capsize scenario at the moment is: Due to a badly done turn on a close pass-by, the port side is ripped open for 150', opening 5 WT compartments to the sea. As the ship coasts to a stop, over the next 30 minutes, at first there is a port list due to loss of buoyancy on the port side, but it gradually returns to an even keel as the flooding spreads across the full beam of the ship in 5-20 minutes. (Is there any other information on timing of changes in list?). The ship is steered in a slowing gradual turn to the right, past the eye of the wind when it finally stops, we guess on a roughly even keel.

The 12kt NNE wind pivots the ship around the flooded and deeper drafted stern until the wind is on the port quarter and, while the ship is gradually flooding, it drifts back toward Porto Giglio. The wind pressure of the NNE wind on 100,000 square feet of the port side heels the ship slightly to starboard. (Is 40-60 tons of wind pressure 50' high really sufficient to do this?) (Has the flooding in the ship reached a point where it will loll significantly with modest pressure?) This causes the flooding in the ship to move to starboard and gradually amplify the overtopping of the remaining watertight compartments onto the starboard side. Now the progressive flooding is dumping the water into the starboard side of each compartment as it overtops. As the ship runs around, aft first, the now lower starboard side touches ground at 0.5 knots (but if aft hit first wouldn't it kill the speed while the ship pivots on the stern to its semi-final alignment?). The captain drops the anchors to hold it in place and finally calls Mayday and begins to abandon ship. Momentum is zero.

So it is aground with a 20º? starboard list, lights on, about 1 deck of hull showing below the boat deck, launching the lifeboats. The list is gradually steepening as the hull fills. Within a half hour, the water is up to the boat deck, the list is up to about 30º but most/all of the starboard boats are away now and a few are nosed into the ship to pick up more passengers. The port side boat launching has problems due to the list, but eventually all but 3 are launched.

So far the arguments have all been based on no damage to the starboard side adding to the list, and no asymmetric loading of internal tankage or transfers of ballast/counterflooding by the ER crew since we have no data on this, although all three are possible.

Here's where it gets messy. Even though the list is modest, 20-30º, and the starboard bilge is aground (?), the ship continues to roll to starboard until by 2400 or 0100, it is on its side with 300 or so survivors walking off along ropes or ladders on the side of the ship. The main wound is fully exposed now. (Would it really be so top-heavy that only a 20-30º list would be past the point of no return? Why didn't it settle back to port, pivoting on the starboard bilge rather than going all the way to starboard?). A rock under the hull? Asymmetric flooding/buoyancy? Flooding from the boat deck level (many openings open) on the starboard side of middle decks rather than flooding all the way to the bilges increasing the height and starboard side bias of the CG ? hmm.

[Heiwa]

Let's not exaggerate. Let's say hull damage was 35 meters long and three WT compartments at around 1/4L from AP were symetrically flooded. Damaged ship just trimmed on stern ... and floated. The VDR bilge alarms data will clarify. The ship thus survived the initial contact incident enabling succesful evacuation of 99% of all persons aboard. Not bad actually!

Later damaged ship trimmed more one stern and heeled to starboard and mooring deck and embarkation deck aft were submerged. It seems more compartments aft, i.e between AP and 1/4L fwd AP, were flooded and it should be established how! Open W/T doors? Maybe she then grounded - a second incident. But ship was still upright or with slight starboard heel (due to wind?)

And then vessel listed 90° to starboard and came to rest on its side, i.e. righting lever GZ became 0. A third incident. Why has to be established. Why didn't she remain upright or with 10° list?

And finally dry compartments forward were flooded from above (via superstructure and deck house below water) and ship partially sank (easy to explain) to present position.

The above summary will also assist how to plan the salvage, i.e. to what position you need to move the vessel (on the rocks) to pump the undamaged compartments dry! And re-float the vessel!

It is recommended to do an underwater survey of ship and sea floor below and to establish contact points ship/sea floor, describe local ship damages starboard (down) side and to chart the bottom below/around the wreck. I wonder why it hasn't been done ... or why it hasn't been reported in the media!

[c.captain]

wing tanks...why has nobody discussed wing tanks here? I am certain that the CC had them alongside her machinery spaces. It is not a SOLAS requirement for passenger ships?

[cmakin]

wing tanks...why has nobody discussed wing tanks here? I am certain that the CC had them alongside her machinery spaces. It is not a SOLAS requirement for passenger ships?

I don't believe that it is a requirement, either for SOLAS or Class (Class rules are largely driven by SOLAS Construction requirements).

[c.captain]

I don't believe that it is a requirement, either for SOLAS or Class (Class rules are largely driven by SOLAS Construction requirements).

It's staggering to think that main machinery spaces in a passengership would only have thin shell plating seperating them from the sea outside, but maybe this was the case with the CC?

[Sweat-n-Grease]

The above summary will also assist how to plan the salvage, i.e. to what position you need to move the vessel (on the rocks) to pump the undamaged compartments dry! And re-float the vessel!

If repaired and placed back in service what name will grace the vessel, La Costa Phoenix, perhaps Costa Concordia Due ?

[Sweat-n-Grease]

It's staggering to think that main machinery spaces in a passengership would only have thin shell plating seperating them from the sea outside,

Yes, doesn't it?

but maybe this was the case with the CC?

Bet'cha you'll find more in Costa's Fleet.