Top heavy

I believe the Millenniun class ships draw 26-28 feet.. They are some 12 decks high. At what point does it become top heavy and more subject to less stability? What size wave would capsize a vessel? Everything has limits. Any thoughts?

That's why as the ships get bigger, they get wider and longer. They also use lighter wieght materials at the top of the ship. When the seas get too rough, they empty the pools to take away the added weight swaying back and forth

I have always thought that Princess's ships look top heavy. When you watch them bobbing in the sea, they look too narrow for there height.

Over all I wonder if there is a particular class of ship that has the reputation of not handling the seas as well as others.,..:confused:

I have had some real rough water cruises, but in calm water has anyone experienced a ship that sways side to side?

yes cc

last dec (08) we were on the caibbean princess in the caribbean (dont ask why)

the seas were not rough at all imo but it was quite windy.

that ship is so high i forget but i think it had 18 decks and it had a lot of movement (rolling), more than we have ever experienced on smaller ships caused by the wind hitting the ship not the waves.

i think that ship has a very shallow draght for its height and is more like a barge (flat bottom).

anyway there was a lot af movement in relatively calm seas

Thanks for all your comments. As I viewed various ships the upper decks looked to be wider especially forward.

yes cc

 

last dec (08) we were on the caibbean princess in the caribbean (dont ask why)

 

the seas were not rough at all imo but it was quite windy.

 

that ship is so high i forget but i think it had 18 decks and it had a lot of movement (rolling), more than we have ever experienced on smaller ships caused by the wind hitting the ship not the waves.

 

i think that ship has a very shallow draght for its height and is more like a barge (flat bottom).

 

anyway there was a lot af movement in relatively calm seas

I enjoy sailing in rough seas, but that feeling of topheaviness and the ship tipping side way does bother me.:eek:

None of them have topped over yet :eek:.

Tom in Long Beach ( I work on the ship that inspired the POSIDON ADVENTURE) :rolleyes:

Well I do know that modern cruise ships are very stable vessels, and it would take quite a lot to capsize one. Something in excess of a 70 foot rogue wave hitting it broadside. Most of the major cruise line ships (Carnival, Celebrity, Princess, RCI, etc.) are not meant for regularly scheduled trans-atlantic or pacific crossings, but they can handle them fine. The Queen Mary 2, however, is pretty much the only modern cruise liner that IS designed for trans-ocean crossings on a regular basis. There is a recent podcast (Cruising Authority) in which the host interviews a fellow (Ben) that served as a navigation officer on the QM2. He noted on how boring it was because the QM2 easily handled anything thrown at it.

If you are worried about a capsizing event due to weather, you shouldn't be. These ships are deisgned by some of the best naval engineers in the world. The entertainment ammenities of a cruise ship are built AROUND the basis of a stable, seagoing vessel, not the other way around.

I do recall, however, that the Crown Princess ship had an incident in which a junior officer on the bridge panicked and innappropriately responded to the ship's auto-pilot, switched into manual, and tried to correct a hard port turn the ship automatically performed. He somehow tried to correct a non-existent problem causing the ship to suddenly jerk, and list severely to the port side. A bunch of people were injured from thrown furniture and lounge chairs on the upper decks. I suppose such an incident could be worse. It does support the hypothesis that a previous poster stated about the Princess ships looking top heavy. :eek:

Here's the wikipedia article about the Crown Princess listing incident:

http://en.wikipedia.org/wiki/Crown_Princess_(ship)

Cheers ;)

The Princess ship's look to be much top heavier than they actually are. However, I have heard the general consensus that the Grand Class ships tend to handle like floating bathtubs. For a quick comparison, look at a picture of the Grand Princess, then compare it to one of the Caribbean Princess. CB looks like she is more top heavy because of the addition of Riviera Deck, when they are actually the same in stability.

On the Caribbean Princess, we encountered some moderate seas and the ship definately moved a bit, but otherwise smooth sailing. I think more movement is seen on the Grand ships that have Skywalkers suspended over the stern then on the ships with Skywalkers more forward, just aft of the funnel. Skywalkers over the stern causes a significant amount of flexing on the hull in heavy seas, which may increase the noticeable roll.

The actual movement results more from the shape of the hull, and I think the Grand Class have slightly more blunt bows. It is also notable that ships with longer lengths and smaller beams (ex, QM2) will be more stable than a similar-sized ship with a shorter length and wider beam.

To add to the Crown Princess listing discussion, here are some videos taken from security cameras during the listing.

http://www.youtube.com/watch?v=cmpcwWo63sY

http://www.youtube.com/watch?v=Rgiumz3RRhI&feature=channel_page

http://www.youtube.com/watch?v=lPJP6OrcJ9A&feature=channel

http://www.youtube.com/watch?v=xc9EL_O1B7s&feature=channel

http://www.youtube.com/watch?v=jRCxZ_p5sY4&feature=channel

From those videos, you can see that she REALLY listed. So much so that her lifeboats were pretty much touching the water's surface. So, there is a large amount of room for a ship to tilt until it would actually capsize. Basically, unless she's completely on her side, she will right herself.

the Golden Princess the highest back decks were 17 decks I think. I do know that just looking at the Celebrity Solstice makes me cringe. I don't see how that thing stays afloat.

actually, Celebrity Solstice is the first cruise ship to have been designed and build according to the latest SOLAS stability requirements. She is very seaworthy, although obviously as smooth sailor as QM2, which is normal as they have different roles...

We're a little off-topic here, given that this is the Celebrity forum, but I thought people might want these links.

Incidents such as the Crown Princess heeling incident, and also the Star Princess fire, are investigated by the relevant authorities. This can either be the UK's Marine Accident Investigation Branch (many Carnival ships are registered in ports that utimately fall under this jurisdiction, or use it in lieu of having their own resources), or the US National Transportation Safety Board, or indeed a combination of both. These bodies publish reports, which give the official and final version of what happened, why it happened, and what needs to be done to prevent it happening again. The reports also often discuss wider safety issues, and these sections of the reports are often very interesting.

Here's the link to the NTSB report in the Crown Princess heeling:-

http://www.ntsb.gov/publictn/2008/MAR0801.pdf

In addition to a very detailed account of the events, there is quite a of discussion about heeling angles, ship stability, 'squat', and various other maritime matter. It's a good if rather frightening read.

Also, for those interested, here's a link to the MAIB report on the Star Princess fire:

http://www.maib.gov.uk/cms_resources/Star%20Princess.pdf

Again, a fascinating document.

They're both PDFs, so once they've been opened they can be saved for off-line perusal and study.

Shipyards are not in the business of manufacturing unsafe vessels. There are laws and rules that are followed in the building of a ship.

It's ridiculous to suppose that ships are built top heavy and will tip over.

I hope you are really not worried about your ship toppling over! Chances are so very very very slim I wouldn't give it a thought.

Certain ship designs do handle the seas better than others, but often the difference is the type of waves and the direction they are coming from. Meaning, heading directly into a wave will have less of an effect on 'rolling' than being hit with them from the side. I do not think there is significant difference in major cruise lines as to how they handle the waves.

Often you will see posters talk about how their cruise ship handles the waves so well because their particular cruise was so smooth. Surprisingly (not!), you'll later see similar comments from people riding the same ship (different time) who will tell you that their ship does not ride smooth because their cruise was so rocky. The major differences are the seas on that cruise, not the ship. Again, won't argue that some designs are marginally better, but not enough to make much of a difference in mid-to-large sized major cruiselines IMHO.