Costa Concordia, 80 deg list, really scary !!

[nettersheim]

Don't be so optimist with new damage stability rules...

Solas 2009 has been established on an "harmonization based" work. International Maritime Organisation (IMO) has decided this harmonization because it was clearly impossible to continue with Solas 90 deterministic rules for large passenger vessels.

But the idea has not been to improve the rules. During 10 years IMO has worked to shift rules from deterministic to probabilistic philosophy on a basically constant level of vessel 's resistance to damage (passenger vessels).

Roughly speaking we may say that IMO has based the new Solas 2009 rules on a set of calculations carried out on "good" Solas 90 vessels and has adjusted the required index of subdivision R of the new rules to the attained index of subdivision A of these previous design. Therefore there is no real positive jump in safety.

Some improvements have been introduced in the course of this long period of harmonization under the pressure of few researchers and naval architects but we can't really say that rules have been improved drastically.

Positive aspects of Solas 2009 (passenger vessels)=
Better consideration of what really happen (damage statistics)
Freedom for the designers and builders (no more rules for compartments, total freedom for internal architecture)
Better consideration of intermediate stage of flooding

Negative aspects of Solas 2009 (passenger vessels) =
No real sinking limit (no more margin line)
Opacity of calculations
Quasi impossibility for masters and officers to interprate the damage control plans issued from probabilistic calculations

Just remember that Solas 2009 is less safe in many cases for passenger ferries (ropax) compared to the Stockholm Agreement (Solas 90 + Stockholm Agreemnet / water on deck calculation)... This is the reason why European Union still require ropax vessel to be designed under [Solas 90 + Stockholm Agreement] on top of Solas 2009 !

I say again, don't be so optimistic with the new rules...

I had a dream = researchers and NA doing complet re-calculation of "Costa Concordia" according to Solas 2009 probabilistic rules, compare to the deterministic Solas 90 calculation (which was the rules CC had to comply with), carry out deep analysis of the results and make public their work...

[Starbuck1]

Clifford,
Based on earlier comments in this stability forum, if Captain S had anchored in deeper water, rather than letting it ground a second time, the ship would probably have rolled over at anchor, maybe 180º due to the massive flooding and starboard list, probably with much greater loss of life.
It is good that they grounded and could only roll 90º, allowing most of the last 300-400 to escape.

At some point they did drop the anchors since they are sitting on the bottom in several photos, apparently after they were grounded and stopped, since the chain was piled on top of the anchor.

[Pascal Warin]

I will complete a little :

Originally Posted by nettersheim

Positive aspects of Solas 2009 (passenger vessels)=
Better consideration of what really happen (damage statistics)
Freedom for the designers and builders (no more rules for compartments, total freedom for internal architecture)
Better consideration of intermediate stage of flooding
No more magic border at B/5

Negative aspects of Solas 2009 (passenger vessels) =
No real sinking limit (no more margin line)
Sorry but wrong : now limit is more realistic as it refers to escape routes, muster stations a.s.o.

Opacity of calculations
When you perform calculation you know exactly what happens

Quasi impossibility for masters and officers to interprate the damage control plans issued from probabilistic calculations
Maybe they need additional training in this field ?

Just remember that Solas 2009 is less safe in many cases for passenger ferries (ropax) compared to the Stockholm Agreement (Solas 90 + Stockholm Agreemnet / water on deck calculation)... This is the reason why European Union still require ropax vessel to be designed under [Solas 90 + Stockholm Agreement] on top of Solas 2009 !
Sorry but this is not "the reason why".
Water trapped on deck is completely different approach of classical damage stability (whether deterministic or probabilistic). It is normal that it remains required "on top" and does not mean new regulation is "less safe".

I say again, don't be so optimistic with the new rules...

Remember that regulation 8 is re-using old Solas damages and criterions. Thus new one is old one plus something.

[Heiwa]

Originally Posted by nettersheim

Don't be so optimist with new damage stability rules...


Just remember that Solas 2009 is less safe in many cases for passenger ferries (ropax) compared to the Stockholm Agreement (Solas 90 + Stockholm Agreemnet / water on deck calculation)... This is the reason why European Union still require ropax vessel to be designed under [Solas 90 + Stockholm Agreement] on top of Solas 2009 !

I say again, don't be so optimistic with the new rules...

Re the Stockholm Agreement I have written a little about it at http://heiwaco.tripod.com/epunkt321.htm .
The result was that you had to fit watertight (!?! LOL) barriers on the car deck of ropax ferries like:

and

Note the watertight door in the barrier. Isn't it stupid? The barrier is not watertight on top and as any water on the car deck will heel the ship, water will just pass above the barrier.
N.European ropaxferry owners spent millions on these stupid, useless barriers. In the end they were not even closed because real seamen realized they were useless.
I am happy to add that the Stockholm agreement was not applied to ferries in the Mediterranean due to my intervention.

[nettersheim]

Hi Pascal Warin,

Thank you so very much for your post 378... I was quite sure you would react to my comments ! I would like going on a little bit with the discussion regarding Solas 2009 rules (passenger vessels) probabilistic damage stability.

You are definitely right when you say "No more magic border at B/5".

I have mentioned "No real sinking limit (no more margin line)" and you have reacted telling "Sorry but wrong : now limit is more realistic as it refers to escape routes, muster stations a.s.o". I maintain that the new sinking limitation is of some concern: if you position the escape routes for example at the center of the vessel then you may flood the corresponding deck to this limit! If the considered deck is the bulkhead deck this means it is submerged to nearly middle of the vessel...etc.

When I have recalled the "Opacity of calculations" you have precised that "When you perform calculation you know exactly what happens". Obviously I believe you as a specialist of such calculations, but on the other hand when you go through the calculations and the results from an "external" point of view (administration, NA not involved in the calculations, owner's superintendent, master) then the opacity is there !

I agree completely to your last point which was an answer to my question regarding the "Quasi impossibility for masters and officers to interprate the damage control plans issued from probabilistic calculations". You say that "Maybe they need additional training in this field ?". You are absolutely right. I have some experience in training captains on the matter and it is a real necessity to improve their training on this rather complicate issue.

Regarding the Stockholm Agreement I don't agree with your statement. Solas 2009 has been claimed by many people to include the water on deck consideration and the same have lobbied for the abandon of Stockholm Agreement. The problem is that recent researches (2009/2010 + the on going work) have clearly indicated that there is a serious doubt. I know that some works (from Shipyards origin) have also shown that Solas 2009 was giving proper result... This kind of theoretical confusion explains the EU attitude and is a supplementary reason to maintain questioning on Solas 2009 rules.

You have given me arguments to debate again on Solas 2009, when you have recalled the reg. 8...This rule is a deterministic one mixed in the probabilistic corpus. The damage to be considered for calculation is a little one compared to Solas 90 damage. The problem is that some Solas 2009 projects (passenger vessels) show clearly that the most demanding KG limit is coming from this little deterministic rule inside the probabilistic corpus !

What about my dream to see the "Costa Concordia" re-calculated with Solas 2009 ?

[Pascal Warin]

Originally Posted by nettersheim

Thank you so very much for your post 378... I was quite sure you would react to my comments ! I would like going on a little bit with the discussion regarding Solas 2009 rules (passenger vessels) probabilistic damage stability.

You are definitely right when you say "No more magic border at B/5".

I have mentioned "No real sinking limit (no more margin line)" and you have reacted telling "Sorry but wrong : now limit is more realistic as it refers to escape routes, muster stations a.s.o". I maintain that the new sinking limitation is of some concern: if you position the escape routes for example at the center of the vessel then you may flood the corresponding deck to this limit! If the considered deck is the bulkhead deck this means it is submerged to nearly middle of the vessel...etc.

The non submersion of escape route is not sole parameter. In addition they are some specific rules about the way these routes should be organized (dead-ends, number of stairs, a.s.o.) Unfortunately I ma not enough aware about that to discuss.

Originally Posted by nettersheim

When I have recalled the "Opacity of calculations" you have precised that "When you perform calculation you know exactly what happens". Obviously I believe you as a specialist of such calculations, but on the other hand when you go through the calculations and the results from an "external" point of view (administration, NA not involved in the calculations, owner's superintendent, master) then the opacity is there !

The master get allowable KG curves which are rather clear. But I agree that in real damage situation this is not enough.
Actually, in real damage situation damage stability documents are absolutely useless. I deeply regret that there is no regulation asking for on-board calculation software.

Originally Posted by nettersheim

I agree completely to your last point which was an answer to my question regarding the "Quasi impossibility for masters and officers to interprate the damage control plans issued from probabilistic calculations". You say that "Maybe they need additional training in this field ?". You are absolutely right. I have some experience in training captains on the matter and it is a real necessity to improve their training on this rather complicate issue.

I cannot object that.

Originally Posted by nettersheim

Regarding the Stockholm Agreement I don't agree with your statement. Solas 2009 has been claimed by many people to include the water on deck consideration and the same have lobbied for the abandon of Stockholm Agreement.

Never heard about that. Who are these people ? Lawyers ?

Originally Posted by nettersheim

The problem is that recent researches (2009/2010 + the on going work) have clearly indicated that there is a serious doubt. I know that some works (from Shipyards origin) have also shown that Solas 2009 was giving proper result... This kind of theoretical confusion explains the EU attitude and is a supplementary reason to maintain questioning on Solas 2009 rules.

Sorry but I still don't get the point. Stockholm agreement is clearly an added layer to SOLAS 2009.

Originally Posted by nettersheim

You have given me arguments to debate again on Solas 2009, when you have recalled the reg. 8...This rule is a deterministic one mixed in the probabilistic corpus. The damage to be considered for calculation is a little one compared to Solas 90 damage. The problem is that some Solas 2009 projects (passenger vessels) show clearly that the most demanding KG limit is coming from this little deterministic rule inside the probabilistic corpus !

You are right. This is way to say that these probabilistic rules are not so firmly theoretically asserted.

Originally Posted by nettersheim

What about my dream to see the "Costa Concordia" re-calculated with Solas 2009 ?

Ask Rina or Costa ...

[Heiwa]

One way to make a ropax or passenger ship virtually unsinkable is to arrange the hull sides B/5 wide with compartments with permeability 0.1 (e.g. filled with secured, empty but sealed plastic bottles preventing water filling).
Permeability is always overlooked when designing ships and is left at the order 0.6-0.94, so breached hull spaces are filled with water, buoyancy and stability are lost and ships sink.
It is a pity that many administrations support the Stockholm agreement with the crazy moveable barriers in the superstructure nonsense proving that the administrations don't know what they are making rules about.
Of course no ro pax today is built with barriers in the superstructure for well known reasons.

[Bluec0de]

where can i find the map the Costa Concordia Decks: 0, A, B, C ???