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wd40
2013-Jun-13, 09:45 AM
If ever there was ship that looks top-heavy and eminently capsizeable as in "The Poseidon Adventure", it's the new Royal Princess.

http://www.dailymail.co.uk/femail/article-2340145/Meet-Royal-Princess-Incredible-pictures-reveal-splendour-1-000ft-cruise-ship-Duchess-Cambridge-launch-maiden-voyage-tomorrow.html

The supposed dimensions of Noah's Ark are said to have made it uncapsizeable, but how would this ship cope with a real Atlantic storm or Pacific typhoon?

http://www.coolcruisenews.com/wp-content/uploads/Caribbean_Princess/IMG_0038.JPG

LookingSkyward
2013-Jun-13, 09:51 AM
I find her lack of keel...disturbing

Strange
2013-Jun-13, 10:52 AM
but how would this ship cope with a real Atlantic storm or Pacific typhoon?

I wonder if the designers even thought of that ...

wd40
2013-Jun-13, 11:01 AM
The designers of the Titanic admitted they'd made her rudder much too small. Subsequently fatal design errors can happen.

Taeolas
2013-Jun-13, 11:27 AM
Looking over the pictures, I'm a bit disappointed about the apparent "Youth Centre"


Haven: The vessel's youth centre is the perfect place for bored teens to settle down and watch TV, while their parents head to the spa or the casino



Everything they have on the ship, and the most they can do for teens is to give them a TV? Sheesh.

grapes
2013-Jun-13, 12:58 PM
Do we have a good picture of the keel?

I also have to say that the pic in the OP is foreshortened and flattened a lot--check out the photo of the ship broadside, the one with the onlookers with umbrellas, down the page at the link.

NEOWatcher
2013-Jun-13, 01:06 PM
If ever there was ship that looks top-heavy and eminently capsizeable as in "The Poseidon Adventure", it's the new Royal Princess.
Looks like, but not.
If it's anything like the Royal Oasis (http://www.cruise.co.uk/images/Cruise//cruise_gallery/1/BANNER_415x150_ROYAL_OASIS-3DEC10_0.jpg), those upperdecks have nothing in the middle.
But; that doesn't remove the issue of wind resistance.

Funny, you talk about top heavy royal princess in your link, and your link has pictures of the bottom heavy (pregnent) royal princess.

Swift
2013-Jun-13, 02:00 PM
http://www.coolcruisenews.com/wp-content/uploads/Caribbean_Princess/IMG_0038.JPG
You've been here long enough to be familar with our rule on images (rule 8). First, we ask people to limit images to less than 100kb and less than 800 pixels wide, and this image violates both. Second, such images are often copyrighted and posting them can get this site into trouble. A link is always a better choice for such an image.

Ara Pacis
2013-Jun-13, 02:01 PM
how would this ship cope with a real Atlantic storm or Pacific typhoon?

I don't think they are supposed to operate in that sort of weather.

SeanF
2013-Jun-13, 02:05 PM
Funny, you talk about top heavy royal princess in your link, and your link has pictures of the bottom heavy (pregnent) royal princess.
I knew before even clicking on the thread that it wouldn't live up to the promise of its title.

Hornblower
2013-Jun-13, 04:23 PM
To get the necessary stability, the towering superstructure is built very light relative to what is near or under the water line, to keep the center of mass low. These modern cruise ships typically have a gross register tonnage, which is an estimate of the volume of enclosed space aboard the ship, that is numerically about double the weight of the ship in tons. Typical passenger liners of the mid-20th century had those numbers about equal, and the gross tonnage of the Titanic was somewhat less numerically than its weight.

I would expect the high, flat-sided superstructure to make the ship sensitive to a strong crosswind, and a broadside smack by a monster wave such as the one that nearly capsized the Queen Mary during World War II could be dicey. I don't know what the typical bad weather policy is with the cruise companies, but my guess is that they can dodge hurricanes by altering the sequence of port calls during a cruise.

Trebuchet
2013-Jun-13, 05:06 PM
I don't know what the typical bad weather policy is with the cruise companies, but my guess is that they can dodge hurricanes by altering the sequence of port calls during a cruise.

If they're like the company we cruised with 10 years ago, they have a disclaimer in the microscopic print that says they have no obligation to take you anywhere at all. They also have one that says you're not allowed to bring cameras on board!

Under the Rose
2013-Jun-13, 08:56 PM
I don't care how opulent the fittings, it still looks like a floating cattle liner for people. As a child, I crossed the Atlantic on a large ship and was deathly ill with measles and motion sickness combined, lol... Ocean cruises hold absolutely no attraction for me, even before one begins to analyze how well this vessel might survive a sudden change in weather.

swampyankee
2013-Jun-13, 09:30 PM
In defense of the ship's designers: people and their accommodations are light, so the ship will certainly have adequate stability in the undamaged condition.

I'm less than thrilled with the idea of "cruising," mostly because they're not much more than resort hotels you can't leave. I get tired of Atlantis, in the Bahamas and you can leave any time you like: call a cab or get a rental car and you can go someplace else, even to the airport and get a flight to Miami.

wd40
2013-Jun-13, 10:42 PM
When a similar liner last year was gashed open due to gross negligence by the captain, the 4300 on board were lucky not to have all drowned
http://en.wikipedia.org/wiki/Costa_Concordia_disaster#Investigations


http://img256.imagevenue.com/loc256/th_163639606_170752745_122_256lo.jpg (http://img256.imagevenue.com/img.php?image=163639606_170752745_122_256lo.jpg)

Jens
2013-Jun-14, 12:11 AM
I don't care how opulent the fittings, it still looks like a floating cattle liner for people. As a child, I crossed the Atlantic on a large ship and was deathly ill with measles and motion sickness combined, lol...

Me too (minus the measles!). We hit a storm half way across the Atlantic, and I remember the water was splashing out of the pools so they had to drain them. This was an ocean liner called the France.

Hornblower
2013-Jun-14, 01:32 AM
When a similar liner last year was gashed open due to gross negligence by the captain, the 4300 on board were lucky not to have all drowned
http://en.wikipedia.org/wiki/Costa_Concordia_disaster#Investigations


http://img256.imagevenue.com/loc256/th_163639606_170752745_122_256lo.jpg (http://img256.imagevenue.com/img.php?image=163639606_170752745_122_256lo.jpg)Th at article did not mention topheaviness as a contributing factor in the capsizing.

SkepticJ
2013-Jun-14, 02:11 AM
The supposed dimensions of Noah's Ark are said to have made it uncapsizeable . . .

I was curious as to how you would link a cruise ship with Young Earth Creationism. Also, nah. (http://skeptoid.com/episodes/4279)

ipsniffer
2013-Jun-14, 02:26 AM
This thread falls somewhat short of the promised offered in the title.

Jens
2013-Jun-14, 03:04 AM
In defense of the ship's designers: people . . . are light . . .


As long as they're not Americans, right?

LotusExcelle
2013-Jun-14, 03:22 AM
Yeah the aformentioned capsizing had nothing to do with the design of the ship and everything to do with the gross negligence of the humans operating the ship. Blaming ship design, in even the slightest, on that wreck is like blaming a car manufacturer for an 18 year old hitting a guard rail at 100mph when drunk.

wd40
2013-Jun-14, 07:41 AM
The "free surface effect" occurred when rushing sloshing water entered the car deck destabilizing the Herald of Free Enterprise in 1987 and Estonia in 1994, resulting in changes in ferry stability requirements.

slang
2013-Jun-14, 07:53 AM
The "free surface effect" occurred when rushing sloshing water entered the car deck destabilizing the Herald of Free Enterprise in 1987 and Estonia in 1994, resulting in changes in ferry stability requirements.

Letting water in through the bow doors is usually in the manual under the heading "Don't do this". I don't see what that has to do with the well endowed princess.

swampyankee
2013-Jun-14, 10:00 AM
As long as they're not Americans, right?

On the other hand, Americans are more sensitive to crowding than some, so there'd be fewer adding to the ship's topweight. Or the hefty Americans could be assigned to the Pickup Truck Deck, just below the Football Hooligan Deck.

Perikles
2013-Jun-14, 10:41 AM
Of course, there would have to be some sophisticated arrangement for ensuring that the passengers are evenly distributed on both sides of the ship. It would be too risky sailing past something interesting if everybody were to rush over to one side to look. They are thus restricted to sailing where there is absolutely nothing worth looking at, or where there are things of equal interest on both sides.

wd40
2013-Jun-14, 11:52 AM
The classic case of an already top-heavy ship rolling over because of the passenger weight was the Eastland with 844 dying http://en.wikipedia.org/wiki/SS_Eastland

http://www.youtube.com/watch?v=EspkR2XMLVA

http://www.freeimagehosting.net/t/o8nt8.jpg (http://www.freewebproxy.com/)

Hal37214
2013-Jun-14, 02:08 PM
The classic case of an already top-heavy ship rolling over because of the passenger weight was the Eastland with 844 dying http://en.wikipedia.org/wiki/SS_Eastland

http://www.youtube.com/watch?v=EspkR2XMLVA

http://www.freeimagehosting.net/t/o8nt8.jpg (http://www.freewebproxy.com/)


This is all very interesting, but no one has introduced any evidence that the Princess ship actually is top-heavy, in terms of structural weight or wind loading. I know next-to-nothing about ship design, but I do know that there are multiple factors which affect stability, and all must be considered in the context of the specified operating environment. Take a ship out of the environment it's designed for, and it probably won't perform very well. I wouldn't want to round Cape Horn in a paddle-wheel steamer designed for the Mississippi River, nor would I try to pilot the Queen Mary 2 to Memphis.

I do agree, unfortunately, that the sheer size and capacity of these enormous cruise ships dramatically ups the scale of potential disasters.

Ara Pacis
2013-Jun-14, 03:28 PM
On the other hand, Americans are more sensitive to crowding than some, so there'd be fewer adding to the ship's topweight. Or the hefty Americans could be assigned to the Pickup Truck Deck, just below the Football Hooligan Deck.

I don't think there are football hooligans in America.

Hornblower
2013-Jun-14, 04:45 PM
The classic case of an already top-heavy ship rolling over because of the passenger weight was the Eastland with 844 dying http://en.wikipedia.org/wiki/SS_Eastland

http://www.youtube.com/watch?v=EspkR2XMLVA

http://www.freeimagehosting.net/t/o8nt8.jpg (http://www.freewebproxy.com/)I would advise my fellow posters to avoid making any inferences about the stability of the Royal Princess from the Eastland disaster. It should be noted that with a full load of passengers the Eastland had a vastly heavier live load in proportion to its tonnage than does the Princess.

NEOWatcher
2013-Jun-14, 05:21 PM
I would advise my fellow posters to avoid making any inferences about the stability of the Royal Princess from the Eastland disaster. It should be noted that with a full load of passengers the Eastland had a vastly heavier live load in proportion to its tonnage than does the Princess.

Not only that, but if the passengers on the Royal Princes head to the deck, it lowers the COG, not raises it like the Eastland's passengers coming from lower decks.

Also; the Eastland disaster can be related to the added lifeboats above COG mandated after it was built. More wieght that it was not designed for.

Trebuchet
2013-Jun-14, 07:25 PM
The "topheavy" Princess was also designed by qualified maritime engineers, who had the best of modern computer aided design to figure out any CG issues. I still don't want to cruise on a ship like that just because of the number of people aboard.

Sigh. Yet another WD40 "I don't understand it, therefore..." thread.

swampyankee
2013-Jun-14, 07:40 PM
The "topheavy" Princess was also designed by qualified maritime engineers, who had the best of modern computer aided design to figure out any CG issues. I still don't want to cruise on a ship like that just because of the number of people aboard.

Sigh. Yet another WD40 "I don't understand it, therefore..." thread.

<trying very hard not to say anything snarky about WD40>

It's not always easy for non-specialists to tell what is and is not "right" with a design. There seems to be a common belief that if somebody wanted, they could just replace all the passengers with an equal mass of fuel and fly a 747|777|787|A380 around the world. Nope. The passengers simply don't weigh that much. It's like that with luggage: most airlines stopped weighing luggage during the era when the 747, L1011 (the most advanced of them...), and the DC-10 came out because the airplanes would run out of space to put the bags before they'd run out of weight, as most people filled their luggage with things like clothes vs, say, bricks.

I've never gone "cruising," but the more I think about it, the more I think "resort hotel I can't leave."

NEOWatcher
2013-Jun-14, 08:01 PM
I've never gone "cruising," but the more I think about it, the more I think "resort hotel I can't leave."
I've gone on an ocean voyage, but not a cruise. But that was over 40 years ago when transportation was not trying to cram you in to save money.
It was enjoyable. Not really my cup of tea, but not something I would resist.

As far as the "I can't leave". Most cruises that I know (based on aquaintences experiences) you are rarely stuck on the ship. Usually, they make port for the day and travel by night, with maybe one day for open sea cruising.
That would be more like going to a resort hotel in each city without having to pack each night.

Hornblower
2013-Jun-14, 08:49 PM
I've gone on an ocean voyage, but not a cruise. But that was over 40 years ago when transportation was not trying to cram you in to save money.
It was enjoyable. Not really my cup of tea, but not something I would resist.

As far as the "I can't leave". Most cruises that I know (based on aquaintences experiences) you are rarely stuck on the ship. Usually, they make port for the day and travel by night, with maybe one day for open sea cruising.
That would be more like going to a resort hotel in each city without having to pack each night.

My mother has been on three cruises, and in each case her motive was for visiting the numerous interesting ports at which they called almost daily. She would have been bored if she had stayed aboard the ship all day, which many of the passengers did. The days spent sightseeing ashore and the evenings of enjoying the amenities aboard the ship were a nice balance for her.

Trebuchet
2013-Jun-14, 11:44 PM
We've taken three cruises, two of them courtesy of my parents. One of those was to Alaska with the entire family and was great, the other was on a small ship on the Columbia and Snake Rivers with my folks and brother and his wife and was even better. The third, which we paid for ourselves, was to Alaska on the same line we'd taken with the family and was a disaster. As has been said, there are stops and shore excursions most days, some of which are better than others. On the Columbia cruise, we had one day when the scheduled excursion had to be cancelled because we were behind schedule, on account of a sister ship having damaged a lock gate at a dam. It was actually a very relaxing and lovely day. Of course, you're travelling through scenery all the time that way, not just looking at endless ocean.

Trebuchet
2013-Jun-14, 11:46 PM
The "topheavy" Princess was also designed by qualified maritime engineers, who had the best of modern computer aided design to figure out any CG issues. I still don't want to cruise on a ship like that just because of the number of people aboard.

I forgot to mention that the Princess, like all modern cruise ships, is undoubtedly equipped with active stabilization.

Ara Pacis
2013-Jun-15, 04:55 AM
I forgot to mention that the Princess, like all modern cruise ships, is undoubtedly equipped with active stabilization.

Underwire?

swampyankee
2013-Jun-15, 09:46 AM
Underwire?

The active stabilization is heavily dependent on silicon.

Hal37214
2013-Jun-15, 11:19 AM
I assume many are familiar with the history of the Vasa (http://en.wikipedia.org/wiki/Vasa_(ship)), the Swedish warship that capsized and sank minutes into her maiden voyage. This ship was, in fact, top heavy, and fell over immediately upon encountering a moderate wind.

The website of the Vasa museum features a Flash game (http://www.vasamuseet.se/sv/Skola/Prova--pa/Segla-Vasa/), that lets you play with factors such as ballast, cannon placement, and wind, to demonstrate their effects on stability. The text is in Swedish, but it's quite self-explanatory.

billslugg
2013-Jun-15, 06:02 PM
I saw the Vasa 25 years ago. They had some sort of glycol sprayers keeping it wet.

I cannot find the displacement of the Royal Princess. The Gross Registered Tonnage is an antiquated measurement having only to do with the internal volume of the ship and is used for sizing fire fighting gear, that type thing.

Length - 1083 feet
Beam - 125 feet
Draft - 28 feet
Height above water - 217 feet

From this we can roughly determine that the volume of water displaced is about 3.78E6 cubic feet of water or about 2.51E8 pounds or a bit less than 125,000 standard US short tons, given that the volume underwater is not a squared box.

One other thing that can be easily calculated is the force on the side of the ship from a given wind speed. The area of the side of the ship is 235,000 square feet. A hurricane force wind of 74 mph is 108 fps. Square this and divide by twice the acceleration due to gravity of 32.2 f/s^2 and you get 182 "feet of the fluid". Air at sea level weighs about .076 pound per cubic foot, so a column of that air 182 feet high will weigh 14 pounds.

That means the static pressure on the side of the ship is 14 pounds per square foot. For the whole side of the ship, the total force would be about 3.3E6 pounds, or 1632 tons. This is 1.5% of the weight of the ship (125,000 tons).

We would need to know far below the water line the CG is located in order to calculate restoring force. This could tell us how far the ship would roll to one side under such a steady wind.

Reading Wiki about a similar sized ship the Oasis of the Seas, (110,000 short tons displacement), they say it has a wide beam (154 feet) and a shallow draft (31 feet) and a similar height above the sea (236 feet) as the Royal Princess (217 feet). A boat with such a wide hull and a shallow draft is said to be "snappy". It rights itself too quickly after a wave passes. There are systems to mitigate this. Presumably the same set of wheels that keeps it stable in rough seas. We have no idea of the magnitude of those restoring forces either.

Hornblower
2013-Jun-17, 12:21 AM
The center of mass of a ship need not be below the waterline for stability. It even can be above the center of buoyancy, provided the latter moves farther sideways in the direction of the roll than does the center of mass. That is a complex function of the shape of the hull. See this Wiki article for more details.
http://en.wikipedia.org/wiki/Buoyancy
A historic challenge in designing passenger ships for minimal discomfort in heavy seas is in getting an acceptable amount of stability without making the righting moment too snappy.

swampyankee
2013-Jun-17, 10:38 AM
I remember somebody telling me that the S-61 helicopter, when floating atop the water, was stable right-side up and upside-down. I believe the same as true for the Apollo capsules.

Too much stability can be a bad thing for ships: I've read (in Friedman's book on US Cruisers) that some of the USN cruisers built in the 1920s, the first of the "treaty" cruisers had far too much stability, and were hard rollers as a result, rolling out their masts on at least one occasion.

profloater
2013-Jun-17, 11:28 AM
If I were to contemplate a cruise, I would worry a lot more about bugs in the water and food than the stability of the design. Outbreaks do occur on even the most luxurious liners.

wd40
2013-Jun-17, 11:51 AM
The French aircraft carrier Charles de Gaulle has 22 tons of computer controlled weights on rails constantly sliding around underneath its flight deck to ensure stability in all conditions


http://img43.imagevenue.com/loc576/th_146454651_cogite_122_576lo.jpg (http://img43.imagevenue.com/img.php?image=146454651_cogite_122_576lo.jpg)



http://www.naval-technology.com/projects/gaulle/

SATRAP COMPUTERISED STABILISATION SYSTEM

The carrier is fitted with the SATRAP computerised, integrated stabilisation system designed to maintain stabilisation to within 0.5 of horizontal, allowing aircraft to be operated up to Sea State 5/6. As well as the carrier's two pairs of active stabilising fins and twin rudders, the system has two computer-controlled compensation units which consist of two rail tracks for trains carrying 22t of deadweight. These tracks run transversely below the flight deck. This system is designed to compensate for wind and heel and control roll, yaw and surge.

NEOWatcher
2013-Jun-17, 06:10 PM
The center of mass of a ship need not be below the waterline for stability. It even can be above the center of buoyancy, provided the latter moves farther sideways in the direction of the roll than does the center of mass. That is a complex function of the shape of the hull. See this Wiki article for more details.
http://en.wikipedia.org/wiki/Buoyancy.
That doesn't have the picture that first made it clear in my mind. It may be oversimplified, but here is a good basic picture (http://bbauv.com/wp-content/uploads/2012/10/Free-Surface-Effect.jpg) of what's going on.


The French aircraft carrier...
What's your point with this information?

Do you have any discussion of acknowledgement that we have given you some better insight into this subject? Or are you just posting relative links for the fun of it?

captain swoop
2013-Jun-17, 11:47 PM
I was on one of the old 'Tribal Class' type 81 Frigates were very 'stiff' they would snap back from a roll. Type 12 Rothesay and Leanders were about the best ships for sea-keeping although the Ikara and Exocet converted ships lost a lot of weight high in the bow when the twin 4.5 inch turret was removed that made them stiffer and more 'lively' heading into a swell.

Edit to add the worst ship for Sea-keeping I was ever on was a Type 21. Top heavy even with the alloy superstructure. You could tell they were the result of political interference. They were built to a private design with an eye on exports to 'shallow water' navies, they couldn't hold up in any kind of sea and were hopeless in the Atlantic. They looked good though.

NEOWatcher
2013-Jun-18, 06:36 PM
I would expect the high, flat-sided superstructure to make the ship sensitive to a strong crosswind...
I happened to run across a video of an "incident" (http://www.youtube.com/watch?v=AIa7WhN60Bk) on a high superstructure liner.
I don't know if the high superstructure was a contribution, but I suspect it might have been. I think they learned that they need to double up those lines in high winds.

If someone knows (Italian?), I would be interested to know what the story said.

slang
2013-Jun-18, 11:31 PM
If someone knows (Italian?), I would be interested to know what the story said.

Ummm.. something about 4 people in the water, something about 1 tourist hurt in the head? One suffering hypothermia, but all 4 saved quickly, and it happened on Palma di Mallorca. Googling..

ETA: ah, MSC Fantasia – Cruise Ship Breaks Mooring in High Winds (http://gcaptain.com/cruise-ship-breaks-mooring-in-high-winds-incident-video/).

And a BBC link (http://news.bbc.co.uk/2/hi/europe/7928289.stm). One passenger needed to be rescued from the sea.

ETA2: my italian isn't very good... aqua = water, that I'm sure of. :)

Trebuchet
2013-Jun-19, 12:15 AM
Thanks for the links, slang. I heard "quatro personna en agua" followed by "no esperanza" which I translated as "no hope". Good to know they were ok.

We actually had exactly the same thing (broken mooring ropes in high winds) happen when we were on the Queen of the Wes (http://www.queenofthewest.com/)t, a small sternwheel cruise vessel, in Astoria, OR. The bow broke free and the boarding ramp at the bow came very near to spearing an adjacent Coast Guard cutter. Most passengers were out on a shore excursion but we'd opted out. They got it tied back up but a couple of minutes later another gust hit, bringing the ship up with a shock against the new ropes. A crewmember nearby had a walkie talkie and I heard "Captain says we're outa here". Within one minute, we were. We had a nice day cruising back to Longview, WA while the other passengers got a long bus ride.

I'd actually be lots more concerned about this kind of thing in general than rolling over. That said, here's a story (from Wikipedia) about a problem caused by a malfunction of the autopilot/stabilizer system. The lurch may have been from the autopilot but the stabilizers then locked in the list:


In May 2002 the autopilot on a cruise ship failed and caused it to make a jarring turn and then list, sending plates and glasses crashing and injuring more than 70 people, the Coast Guard said. The malfunction on the 853-foot Norwegian Sky, near the mouth of the Strait of Juan de Fuca, appeared to be the result of a computer error. A crew member had to disengage the autopilot, said Lt. j.g. Scott Casad of the Coast Guard. Seventy-eight people reported injuries, and 13 were treated on Saturday in Victoria, British Columbia, Lieutenant Casad said. Two serious injuries were the result of a video game machine fallingon one passenger and another passenger suffering a broken pelvis when he was washed out of a pool due to the severe list.

That ship had done something similar, but not as bad, when we were on it two years earlier. The following year we took a sister ship and my wife was sick the whole trip because they had apparently turned off the stabilizers.

NEOWatcher
2013-Jun-19, 05:29 PM
Ummm.. something about 4...
ETA...
Thanks, Although curious about the entire story, I was more interested in the wind aspect to relate it to the thread.
It seems to confirm my thought that it was the ship catching the wind.

wd40
2013-Jul-07, 08:40 PM
Built with computer modelling and new materials, one trusts that this new Azzam "yacht" is not as fragile & top-heavy as it appears, in a side-on howling sou/sou-wester!

World's largest yacht
http://www.dailymail.co.uk/news/article-2357795/Worlds-largest-private-yacht-Azzam-takes-sea-400m-construction-project.html


http://img285.imagevenue.com/loc338/th_224239906_azzam_bow_yacht_122_338lo.jpg (http://img285.imagevenue.com/img.php?image=224239906_azzam_bow_yacht_122_338lo. jpg)

LotusExcelle
2013-Jul-07, 09:18 PM
Built with computer modelling and new materials, one trusts that this new Azzam "yacht" is not as fragile & top-heavy as it appears, in a side-on howling sou/sou-wester!

World's largest yacht
http://www.dailymail.co.uk/news/article-2357795/Worlds-largest-private-yacht-Azzam-takes-sea-400m-construction-project.html


http://img285.imagevenue.com/loc338/th_224239906_azzam_bow_yacht_122_338lo.jpg (http://img285.imagevenue.com/img.php?image=224239906_azzam_bow_yacht_122_338lo. jpg)

Doesn't appear top-heavy to me. You do realize that quite a bit of this boat is under the water line?

Jens
2013-Jul-07, 11:24 PM
Doesn't appear top-heavy to me. You do realize that quite a bit of this boat is under the water line?

You mean the ship doesn't end at the waterline?

But seriously this thread has a lot of interesting information on the handling of boats depending on the structure.

captain swoop
2013-Jul-08, 08:37 AM
Built with computer modelling and new materials, one trusts that this new Azzam "yacht" is not as fragile & top-heavy as it appears, in a side-on howling sou/sou-wester!

World's largest yacht
http://www.dailymail.co.uk/news/arti...n-project.html
I wouldn't expect a luxury super yacht to be out in a 'side-on howling sou/sou-wester!'
For a start it wouldn't be 'side on' it would head into it, second these things only ever venture out in a flat calm and never more than an hour or two away from Monaco.

That one doesn't look that big to be honest.

Trebuchet
2013-Jul-09, 05:31 PM
That one doesn't look that big to be honest.

It's 180m/590ft long, and 18000t displacement. It's not a boat, it's a ship. About as big as a WWI battleship. The picture on the Daily Mail link is a bit misleading because of the height between the decks, which looks like it may be as much as 3m. Here's a link (http://www.superyachttimes.com/yachts/details/4817) with a picture that gives a better sense of the scale. One of the articles I saw does seem to mention a surprisingly shallow draft but I lost track of where that was.

That Daily Mail link doesn't seem to work now, here's another one (http://www.dailymail.co.uk/news/article-2357795/Worlds-largest-private-yacht-Azzam-takes-sea-400m-construction-project.html?ito=feeds-newsxml).

NEOWatcher
2013-Jul-09, 06:05 PM
Built with computer modelling and new materials, one trusts that this new Azzam "yacht" is not as fragile & top-heavy as it appears
It doesn't appear anything like that to me. Especially because each deck is progressively smaller than the one below.

Lets put it into perspective by comparing this yacht (http://en.wikipedia.org/wiki/Azzam_(yacht)) to a later traditional ocean liner, the QE2 (http://en.wikipedia.org/wiki/Queen_Elizabeth_2).

Beam: 68 vs 105 ft.
Height: 6 vs 12 decks.

So; at 2/3 the width and only 1/2 the decks of a traditional liner, plus the fact that the upper decks are smaller, it would seem like it is at least twice as stable of what we consider a stable traditional ship.

Jens
2013-Jul-10, 03:56 AM
It says here (http://www.superyachts.com/motor-yacht-9161/azzam-specification.htm)the draft is 4.3 meters.

wd40
2013-Jul-29, 03:20 PM
These new breeds of "yachts" certainly appear to ride high in the water

http://www.dailymail.co.uk/news/article-2380733/Luxury-yacht-Nirvana-Spas-cinemas-reptile-house-Inside-200million-floating-pleasure-palace.html

http://img5.imagevenue.com/loc531/th_108831593_b_122_531lo.jpg (http://img5.imagevenue.com/img.php?image=108831593_b_122_531lo.jpg)

compared to the royal luxury yachts of the previous era

http://img294.imagevenue.com/loc44/th_109579535_bb_122_44lo.jpg (http://img294.imagevenue.com/img.php?image=109579535_bb_122_44lo.jpg)

HenrikOlsen
2013-Jul-29, 03:25 PM
Not to me, they don't.

Do you have anything whatsoever to base your impression on?

NEOWatcher
2013-Jul-29, 06:08 PM
These new breeds of "yachts" certainly appear to ride high in the water
Are you hear for a discussion or just to post random ship pictures somewhere on the web?

I have not yet seen you acknowledge any comments made in this thread. All you seem to do is come up with just another picture of another ship and say it "looks like"...

swampyankee
2013-Jul-29, 06:19 PM
These new breeds of "yachts" certainly appear to ride high in the water

http://www.dailymail.co.uk/news/article-2380733/Luxury-yacht-Nirvana-Spas-cinemas-reptile-house-Inside-200million-floating-pleasure-palace.html

http://img5.imagevenue.com/loc531/th_108831593_b_122_531lo.jpg (http://img5.imagevenue.com/img.php?image=108831593_b_122_531lo.jpg)

compared to the royal luxury yachts of the previous era

http://img294.imagevenue.com/loc44/th_109579535_bb_122_44lo.jpg (http://img294.imagevenue.com/img.php?image=109579535_bb_122_44lo.jpg)


If I'm not mistaken, the lower picture is of HMY Brittannia, HM the Queen's yacht until its decommissioning. There are a lot of differences, first being that the was built before aircraft became acceptable means of international travel, at least for the reigning sovereign, the ship had a secondary naval role, that of hospital ship, and the lack of things like weather satellites made it easier to run into really bad weather. In other words, the Brittannia is likely to have needed to be built to much higher standards of seaworthiness than some rich man's toy: the rmt can divert around bad weather, as its captain would have access to better information about the track, extent, and strength of a storm.

captain swoop
2013-Jul-30, 03:47 PM
It depends what they are made of as well. Modern Yachts usually have steel hull and aluminium or composite upper-works.
Most of them never venture more than a few miles from a port in the Med so they will never face a severe storm.
Those under 200ft usually cross Atlantic from the Med to the Caribbean on the back of a specialist transport ship.

As for your two examples the Britannia is a much larger ship than the one in the top picture.
I don't see anything wrong with the top one. It has a good high bow with plenty of flare so she will ride a wave and won't ship too much 'green'
Add to that a raised Forecastle (no abbreviations please) extending about half her length to give increased buoyancy forward again to help ride a wave.
Ideal for rough seas.
Notice her superstructure and upper-works are well stepped to reduce top-weight and cut down wind resistance and reduce roll.

Yachts like this usually have the best and latest stabilization and thrusters that will hold them against a 30kt side-wind.
As an aside, they use 'dynamic positioning' to hold station so they don't have to drop an anchor and incur fees when they visit some of the expensive Riviera anchorages.
Most have better integrated bridges than a lot of the cruise liners plowing their furrows around the Med and Caribbean.

publiusr
2013-Aug-03, 06:53 PM
But you have to be Bill Gates just to have one.

captain swoop
2013-Aug-03, 11:00 PM
You can get a decent 140 footer with all the gear from about 15,000,000 if you don't mind second hand :)

wd40
2013-Oct-29, 03:05 AM
"Are cruise ships getting too big to sail?"
http://finance.yahoo.com/news/too-big-sail-cruise-ships-213913940.html


http://img263.imagevenue.com/loc495/th_009941479_rp_122_495lo.jpg (http://img263.imagevenue.com/img.php?image=009941479_rp_122_495lo.jpg)

Trebuchet
2013-Oct-29, 04:38 AM
Why on earth would anyone want to cruise on that? Just you and 6300 of your closest friends.

Jens
2013-Oct-29, 08:14 AM
"Are cruise ships getting too big to sail?"


I think it's worth noting that the issues brought up in that article don't have to do with the seaworthiness of the ships. Rather, it's issues like how fast can you evacuate such an enormous ship and what happens when the engines are disabled and do they have sufficient fire-fighting capabilities.

NEOWatcher
2013-Oct-29, 12:38 PM
Why on earth would anyone want to cruise on that? Just you and 6300 of your closest friends.
I agree. The QE2 was big enough for me when I sailed on her.

While travelling in Florida recently the Disney Fantasy (http://en.wikipedia.org/wiki/Disney_Fantasy) was in Port Canaveral as we left Cocoa beach. What a monster compared to the Carnivals that were there. And that thing isn't even close to some of the big ones. (the big ones are too big for Port Canaveral)

IsaacKuo
2013-Oct-29, 01:33 PM
Why on earth would anyone want to cruise on that? Just you and 6300 of your closest friends.
Just 6300? That's only 0.05 Comic Cons.

Trebuchet
2013-Oct-29, 02:08 PM
Just 6300? That's only 0.05 Comic Cons.

And with less awesome costumes, to boot.

Actually, going to a huge con like that would scare the daylights out of me.

wd40
2013-Oct-29, 02:50 PM
Why on earth would anyone want to cruise on that? Just you and 6300 of your closest friends.

6,300?!

The Queen Elizabeth and Queen Mary were used in WW2 to carry an entire US division (10,000 men) at a time across the Atlantic. The British commandeered the QEII to ship thousands of soldiers to the Falklands in 1982. I don't know under whose flag these new giant liners are beholden to, but I'd say that at a squeeze they could carry 20,000 troops (without stability problems?) anywhere in the world in one go!

Swift
2013-Oct-29, 03:22 PM
6,300?!

The Queen Elizabeth and Queen Mary were used in WW2 to carry an entire US division (10,000 men) at a time across the Atlantic. The British commandeered the QEII to ship thousands of soldiers to the Falklands in 1982. I don't know under whose flag these new giant liners are beholden to, but I'd say that at a squeeze they could carry 20,000 troops (without stability problems?) anywhere in the world in one go!
I have no interest in sailing on a big cruise ship, though I have friends who have done it multiple times. But none of them compared the experience to being transported on a troop ship into battle. I would hope that if I took a cruise it would be a little better experience than a troop transport. At a minimum I would expect no U-boat attacks. ;)

publiusr
2013-Nov-02, 08:24 PM
The ports they go to are often islolated from the general populace, or so I've heard...

slang
2013-Nov-03, 01:52 AM
The Falklands certainly were, if that's where you were gettin' at... :)

publiusr
2013-Nov-03, 08:48 PM
Nah--there was an article I remember a few years ago about poor people fenced off from the tourist area. The tourists think they are visiting a foreign contry--that is no more real than a movie lot in many respects...

swampyankee
2013-Nov-09, 04:37 PM
I have no interest in sailing on a big cruise ship, though I have friends who have done it multiple times. But none of them compared the experience to being transported on a troop ship into battle. I would hope that if I took a cruise it would be a little better experience than a troop transport. At a minimum I would expect no U-boat attacks. ;)

The troop transport is also likely to have removed some comforts, like buffets, carpets, and stewards. Troops, unlike passengers, can be made to clean up after themselves.

publiusr
2013-Nov-09, 08:52 PM
In terms of roll-over naval salvage--you have this:

http://theparbucklingproject.com/

That would make a good foundation--footing for a hotel once Concordia is moved off it.

wd40
2014-Jan-12, 11:15 PM
There sure is a lot of salvageable metal (http://www.dailymail.co.uk/news/article-2538109/Italy-prepares-mark-second-anniversary-Costa-Concordia-tragedy-operation-lift-stricken-cruise-liner-begins.html) on the Concordia!

Hornblower
2014-Jan-13, 01:20 AM
6,300?!

The Queen Elizabeth and Queen Mary were used in WW2 to carry an entire US division (10,000 men) at a time across the Atlantic. The British commandeered the QEII to ship thousands of soldiers to the Falklands in 1982. I don't know under whose flag these new giant liners are beholden to, but I'd say that at a squeeze they could carry 20,000 troops (without stability problems?) anywhere in the world in one go!

Are they as storm-worthy as the classic liners? They are much higher above the waterline than the oldies of similar displacement.

swampyankee
2014-Jan-15, 04:34 PM
Are they as storm-worthy as the classic liners? They are much higher above the waterline than the oldies of similar displacement.

Possibly not, but because of weather satellites, they've got a better chance of avoiding them.

Trebuchet
2014-Jan-15, 05:30 PM
There sure is a lot of salvageable metal (http://www.dailymail.co.uk/news/article-2538109/Italy-prepares-mark-second-anniversary-Costa-Concordia-tragedy-operation-lift-stricken-cruise-liner-begins.html) on the Concordia!

Very expensive salvageable metal! Perhaps the least cost-effective recycling project in history. At least it appears they won't be hauling to one of those horrible ship-breaking beaches in India or Pakistan.

A couple of things that caught my eye in the pictures were the crushing where the starboard side was sitting on the rocks, and the obvious anti-looting provisions in a couple of shots.

captain swoop
2014-Jan-15, 07:16 PM
Seems it might be coming to Able UK on Teesside.
Among lots of other things including building and servicing Oil Platforms they are a Ship Breakers.
They just broke up a French Aircraft Carrier Le Clemenceau and before that a whole flotilla of US Navy supply ships.
They usually break up Oil Platforms
They have a huge 10 hectare (25 acre) dry dock – one of the world’s largest.
http://www.ableuk.com/wp-content/uploads/2013/04/ABLE-Seaton-Port-Image-2.jpg

http://www.ableuk.com/

wd40
2014-Jul-02, 03:46 PM
$10 million yacht rolls over immediately at launch (http://www.cnbc.com/id/101730758)

Hornblower
2014-Jul-02, 03:59 PM
$10 million yacht rolls over immediately at launch (http://www.cnbc.com/id/101730758)

Can you give us a summary in your own words?

Trebuchet
2014-Jul-02, 04:04 PM
$10 million yacht rolls over immediately at launch (http://www.cnbc.com/id/101730758)

Due, apparently, to a problem with the launching apparatus, not to the design of the boat.

HenrikOlsen
2014-Jul-02, 05:24 PM
<sarcasm>Yep. Someone taking a yacht and forcibly tipping it on its side is an excellent argument for a completely different ship being unstable.</sarcasm>

starcanuck64
2014-Jul-03, 10:41 PM
Dang, this thread isn't about what I thought it would be.

Nicolas
2014-Jul-04, 08:18 AM
It is the most misleading thread title on all of Cosmoquest. It is the best thread title on all of Cosmoquest.

wd40
2014-Jul-04, 03:18 PM
A couple of things that caught my eye in the pictures were the crushing where the starboard side was sitting on the rocks, and the obvious anti-looting provisions in a couple of shots.

Eerie new video from inside the Costa Concordia
http://news.sky.com/story/1295066/costa-concordia-eerie-new-video-from-wreck

publiusr
2014-Jul-06, 07:37 PM
Eeesh.

DonkeyGirl
2014-Jul-06, 07:51 PM
Dang, this thread isn't about what I thought it would be.
It certainly doesn't refer to the princess I saw in Harrogate on saturday.

Trebuchet
2014-Jul-06, 09:05 PM
Eeesh.

Yeah. That concierge desk, or whatever it is, is downright spooky. It appears to have a fish tank in the base!

wd40
2014-Jul-08, 01:09 PM
At 230,000 tons, 1200' long and 5,400 passengers, the even bigger than the Royal Princess and equally high-riding in the water, the new floating town Royal Caribbean (http://www.dailymail.co.uk/sciencetech/article-2684329/Google-CRUISE-View-Take-stroll-luxurious-interior-worlds-largest-liner-without-seasickness.html) looks well suited to cruising in the generally calm Mediterranean, as I wouldn't be too happy crossing the Atlantic in her.

NEOWatcher
2014-Jul-08, 01:42 PM
At 230,000 tons, 1200' long and 5,400 passengers, the even bigger than the Royal Princess and equally high-riding in the water, the new ..
The 4 year old...


floating town Royal Caribbean (http://www.dailymail.co.uk/sciencetech/article-2684329/Google-CRUISE-View-Take-stroll-luxurious-interior-worlds-largest-liner-without-seasickness.html) looks well suited to cruising in the generally calm Mediterranean, as I wouldn't be too happy crossing the Atlantic in her.
Compare it (http://en.wikipedia.org/wiki/MS_Allure_of_the_Seas) to a known ocean liner (http://en.wikipedia.org/wiki/Queen_Elizabeth_2)...
The length is double, the beam is double, but the height is only 38% more.
It just looks ominous because the ratio of the freeboard to superstructure is much smaller. Although, the freeboard is probably just as high.
Also, the superstructure is basically hollow.

I wouldn't be too happy on it because I would take it to get away from the city, not move to a more expensive crowded city.

Swift
2014-Jul-08, 03:12 PM
I wouldn't be too happy on it because I would take it to get away from the city, not move to a more expensive crowded city.
Yes. Of all the reasons I have for not taking a cruise on a huge liner, rolling over doesn't even make the list. Sharing a voyage with 5000 of my closest "friends" is top of the list; noroviruses are pretty high up that list.

Trebuchet
2014-Jul-08, 04:42 PM
Yeah. I don't get the allure of "biggest cruise ship". We took an absolutely wonderful cruise on the Columbia River about 10 years ago on a boat with just 100 passengers.

NEOWatcher
2014-Jul-08, 07:09 PM
The other issue is that these big cruise ships try to nickel and dime you to death.
Simple things like laundry and a lot of ship activities, movies, etc cost money.

When I was on the QE2, there was no problem stepping into a movie, playing a game of shuffleboard or ping pong or anything like that without worrying about how much it cost. In fact, it was only at meals that you ran into a lot of passengers. The passenger densities were much smaller then which made a big difference.

wd40
2014-Jul-08, 07:40 PM
Do these Royal class liners actually have lifeboats for 5400 passengers plus 1500 crew?!

Is lifeboat drill still mandatory on such liners? A lifeboat drill for such numbers would be a real spectacle worthy of the comedy film "Carry on Cruising"!

NEOWatcher
2014-Jul-08, 08:07 PM
Do these Royal class liners actually have lifeboats for 5400 passengers plus 1500 crew?!
Is lifeboat drill still mandatory on such liners? A lifeboat drill for such numbers would be a real spectacle worthy of the comedy film "Carry on Cruising"!
Absolutely, by law, and for about 100 years. Ever since the Titanic.

Trebuchet
2014-Jul-08, 09:18 PM
They don't actually have you board the boats during the drill, however. Mainly just collect your life vest and gather at the assigned station.

Jens
2014-Jul-08, 10:58 PM
They don't actually have you board the boats during the drill, however. Mainly just collect your life vest and gather at the assigned station.

And on airplanes they don't even have you do that. They just ask you to watch a video. And in all fairness, on both an airliner and a cruise ship the odds of having to actually get into a lifeboat or life raft are pretty remote.

HenrikOlsen
2014-Jul-09, 11:38 AM
On the other hand, the chances that knowing the drill makes a difference is probably better on ships.

captain swoop
2014-Jul-10, 07:13 PM
I don't understand wd40s pre-occupation.

Any ship can capsize if it has just had its hull ripped open by a rock.

Trebuchet
2014-Jul-10, 11:57 PM
I don't understand wd40s pre-occupation.

Any ship can capsize if it has just had its hull ripped open by a rock.

Perhaps inappropriate, but I don't understand ANY of WD40's preoccupations.

Swift
2014-Jul-11, 12:56 PM
Perhaps inappropriate, but I don't understand ANY of WD40's preoccupations.
Yes. Let's not go there.

wd40
2014-Jul-14, 08:41 AM
A triumph of modern marine salvage: the 290 m long 114,000 ton Costa Concordia refloated (http://news.sky.com/story/1300222/costa-concordia-cruise-ship-being-refloated) today in one piece.

Trebuchet
2014-Jul-14, 05:09 PM
A triumph of modern marine salvage: the 290 m long 114,000 ton Costa Concordia refloated (http://news.sky.com/story/1300222/costa-concordia-cruise-ship-being-refloated) today in one piece.

The same will never happen to Captain Schettino's career.

NEOWatcher
2014-Jul-14, 05:34 PM
What advantage does having the attached tanks be pressurized air, rather than just having them be like tanks and pump the water out?

cjameshuff
2014-Jul-14, 09:29 PM
What advantage does having the attached tanks be pressurized air, rather than just having them be like tanks and pump the water out?

The tank walls would then have to be built to resist considerable crushing forces, making them basically as heavy as an actual ship of the same displacement (heavier, really, due to the abuse they might take during the salvage operation), and much more expensive and time consuming to design, build, and transport. Simpler to just pressurize them.

Trebuchet
2014-Jul-15, 12:00 AM
Back on topic, I'm feeling the need to point out that the Costa Concordia capsized NOT because she was top heavy, but because some idiot drove her into a rock, puncturing the hull and causing it to fill with water. When the same idiot initiated a sharp turn, the free surface effect (http://en.wikipedia.org/wiki/Free_surface_effect) caused her to roll over. He was just lucky to have killed as few people as he did.