Accident to the Crown Princess


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Aug 29, 2000
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There will be more to this story you can be sure- and some law suits to follow. One passenger interviewed said he was lying on deck in a deck chair and when he looked over his shoulder the ship was pitched to where he was looking at the ocean right over the railing. I smell a made-for-tv-movie in here somewhere!
 
Mar 22, 2003
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Well Shelley, if they make that made-for-tv-movie you can be sure that they will have the ship roll over on its beam for dramatic affect, done in super slow motion, and last for at least 20-30 minutes.

I'm sure the real facts will come out soon enough which Hollywood will embellish.
 

John Zoppina

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So, if I may ask, does anyone know if there is any regulation on the tolerances of the roll of a cruiseship? Just what is the "point of no return" today?
 
Jul 9, 2000
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>>So, if I may ask, does anyone know if there is any regulation on the tolerances of the roll of a cruiseship?<<

Not sure but I don't know how anyone can trump physics with ink on a piece of paper. Trust me, physics wins out every time.

>>Just what is the "point of no return" today?<<

That would depend on the centre of gravity and the metecentric hight, (Such information would be aquired by what's known as an inclining experiment.) and it's going to be different with each ship. If I recall correctly, the figure you're looking for would be the righting arm, which is to say, the most extreme point to which the ship could roll before she actually turns turtle on you.
 
Dec 3, 2005
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That might be hard to tell. None of modern cruise lines seem keen on specifying the metacentric heights and such of their ships, from what I've seen. I have heard that modern davits are designed to work with a list of up to 30 degrees, and some ships have superstructures built of ultra-lightweight materials so they can stack the decks as high as they do. Norwegian Dawn tackled a 70 foot rogue wave a while back. She was shaken and bruised, but not sunk or capsized, so I imagine they must be quite stable nowadays.
 

James Doyle

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I'm sorry, I just can't get the image of Belle Rosen screaming "Manny...Manny!!!"

I have a feeling more "shocking footage" will be released as time goes on. If these cruise ships continue to get larger and larger, I have a sinking feeling (no pun intended) that the public is in for a much more rude awakening than this in the future.
 

Grant Carman

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Jun 19, 2006
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James

I tend to agree with you. As we all know, every ship has a roll over point. With the newest ships being so top heavy, I would think that theirs would be quicker.

All you have to do is look at the new Freedom of the Seas, or Fincantieri's "Vista" class ships to see my point. There are so many decks above the the ship, that it must have a certain amount of "top heaviness" to her.

Although a friend of mine who went on one of the new ships says that they are so wide, that the width compensates for it. She compared the new ships to supersize barges, with the decks stacked on top of it. I think that was a little harsh tho.
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But I will defer to Michael's opinion. He seems to be the most knowledgable.
 
Dec 3, 2005
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I might be completely insane (Captain Wood or Mike Standart, please tell me if I am) but I'm tempted to doubt that cruise ships are all that top heavy, even if they look it. There have been a number of cruise ship mishaps over the last two decades and if there were some sort of severe Imperator-esque design flaw, I feel like it probably would have showed itself by now in some spectacular fashion. Of course, I would never mean to suggest that cruise ships are foolproof. Truth be told, I'd say we're overdue for some sort of horrible cruise ship accident, too, but I don't know that it'll be related to a stability problem. I've been looking since the story first broke and I can find only very little in the way of stability data, so this whole thing's really tough to hypothesize about.
 

Joe Russo

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Apr 10, 2006
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Yes, they look so top-heavy, but their superstuctures must be a lot lighter than the hull. It seems it would have to be since they only have about 25 feet of draft (2 or three decks) and then almost 14 decks above the waterline. They are also a lot more airy and hollow with the atriums, theaters and promenades these days, so I guess that could contribute to the weight distribution. Must be all ballast on the bottom deck. Anybody in the shipbuilding business to clarify?

Just a side note: I read that the original Queen Mary's actual weight (displacement in tons) is more than the QM2 (80K vs. 76K). In comparison, the Voyager of the Seas is only 64K so the Freedom of the Seas must be a little more than 64K. The QM2 is still very large and heavy and I'm sure much more solid than the Freedom of the Seas.
 
Dec 3, 2005
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It's actually that airy that I would worry more about. The big open spaces probably aren't much benefit to the overall structural strength and they would probably flood very quickly in a sinking.
 
Jun 12, 2004
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Peter,

I would tend to agree, EXCEPT that smaller, closed in spaces spell doom for those who may be trapped there during an accident or sinking. I would like to think that wide and airy spaces would give people room to move, and move faster, should the need arise, and even swim clear of the structure, if those individuals have the opportunity to do so. True, large rooms (especially those that extend across the width of a ship) tend to flood very quickly, but I'd rather be there than be stuck in some walk-in closet. Something tells me that if I were in the latter during the sinking, and unable to get out, that space would be my coffin.

Those are my thoughts on that, anyway.

Take care

Mark
 

Grant Carman

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Joe

Freedom of the seas is 158k tons, according to Maritime Matters. The next 2 they will build will also be 158k, and the one after that will be 220k tons.
Still sounds top heavy to me.
 
Dec 3, 2005
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I suppose you could estimate Freedom's weight by her draft and dimensions if the hull is relatively square below the water. Wiki says 28 foot draft, 126.65 foot beam, 1,112 length. At those maximum dimensions, I get a displacement of 112,668 Long Tons, but of course, that's much higher than the real number since this calculation would assume the ship was perfectly square. Even so, it's still much less than 158,000 Tons. I'll bet that the real number is in the ballpark of 80,000 Tons.
 
Jul 9, 2000
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>>I might be completely insane (Captain Wood or Mike Standart, please tell me if I am) but I'm tempted to doubt that cruise ships are all that top heavy, even if they look it.<<

You may not be all that insane. For what it's worth, the way that cruise ships cut down on the topweight is to use much lighter construction in the superstructure and also to use materials of lighter weight such as aluminium. Also, it helps to know that such vessels typically operate in the balmier climes of the tropics were the seas tend not to be as rough. I don't know whether or not fin stabilizers are still en vogue among shipbuilders but they have been common enough in the past and with generally good results.

On the question of tonnage, a lot of what you see can be very misleading since the tonnage figure typically quoted is the gross registered tonnage which is a measure of the internal volumn, and not the actual weight of the ship. The actual weight of the ship is the displacement tonnage. Net register tonnage refers to the actual revenue earning capacity of the vessel.

For a fuller explaination, go to http://users.senet.com.au/%7Egittins/terminology.html and then click on "TONNAGE."

On matters of wide open spaces, I can't say as I like them a lot. There's a lot to be said for smaller spaces which are watertight and where any flooding could be contained, if not stopped completely, long enough to get everybody off if the need arises. However, if you have water ingress up high enough where it's getting into the wide open spaces and not getting out, you're already in heap BIG trouble anyway and you had best be long gone by that time.
 

Joe Russo

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The Voyager's gross tonnage is 2.22 times her displacement (142k/64k). If the Freedom is basically a larger or longer version of the Voyager, then her displacement would be about 72K tons.


According to Wikipedia...

Tonnage is a measure of the size or cargo capacity of a ship. The term derives from the taxation paid on tuns of wine, and was later used in reference to the weight of a ship's cargo; however, in modern maritime usage, "tonnage" specifically refers to a calculation of the volume or cargo volume of a ship. The term is still sometimes incorrectly used to refer to the weight of a loaded or empty vessel.
 
Mar 22, 2003
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The question concerning modern cruise ships has been addressed before. It should be noted that Titanic had a displacement-to-gross tonnage ratio of 1.1, compared to modern cruise ships that have displacement-to-gross tonnage ratios of about 0.5 or less. The Titanic had a beam-to-length overall ratio of 0.10, and modern cruise ships such as Voyager of the Seas have about 0.15. They also have lower draft-to-beam ratios by about a factor of two, Titanic at 0.37 while Voyager at 0.18. Today's large cruise ships tend to have large open atriums, shopping areas, and theatres of low density; i.e. large volume but little weight. The main hull structure tends to be tear resistant from having a welded construction, and use strong, lightweight materials. Side scuttles, portholes and outboard drains that could become a route for in-flooding have been eliminated for the most part in modern designs.
 
Dec 3, 2005
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I've read somewhere (I wish I could site my source) that the Princess ships, because of their lightweight materials, have their full load centers of gravity about twenty feet above the waterline. In a 200-foot-tall ship, I suppose its pretty good to have a center of gravity only a quarter of the way up from the bottom.
 

Erik Wood

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Aug 24, 2000
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Top heavy was perhaps the wrong use of words. What I should have said is that there is a much taller portion of the ship that is out of the water or above the girder. No matter what the material, this section will act like a sail in heavy wind, and the ship will be all that more difficult to manuever. In addition, the more the ship sways from side to side, the more violent that sway will be, because there is more surface area for the wind or ships momentum to take.

This is evident in the early problems they had in the design in the newest Carnival class. Turning the ship hard in one direction or the other was found to be a big fat no no. As a result certain operating procedures had to be adopted which would allow the ship to operate and navigate safetly all the while using the technology that had at there fingertips.

There are several aspects of the azipod system. Some of those aspects are used in natural rudder ships.

All ships that require a passenger certificate in the United States are required to meet certian criteria. Those criteria are based off what the ship is made of, it's length...etc. That information is in turn used by the Coast Guard to regulate class's of ships.
 
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