chengkp75 Posted March 3, 2017 #26 Share Posted March 3, 2017 Have heard many say this class is the worst, long and narrow spells it out. roll Sent from my iPad using Tapatalk HD Well, Quantum class have a length/beam ratio of: 8.4 Freedom class is 8.8 Radiance class is 9.0 So, these seven ships in these two classes are "long and narrow"er than Quantum class. Link to comment Share on other sites More sharing options...
Clarea Posted March 3, 2017 #27 Share Posted March 3, 2017 Well, Quantum class have a length/beam ratio of: 8.4 Freedom class is 8.8 Radiance class is 9.0 So, these seven ships in these two classes are "long and narrow"er than Quantum class. So which motion (yaw, pitch, roll) is exacerbated by a higher l/b ratio? Link to comment Share on other sites More sharing options...
chengkp75 Posted March 3, 2017 #28 Share Posted March 3, 2017 So which motion (yaw, pitch, roll) is exacerbated by a higher l/b ratio? Roll. Pitch is affected by the flare of the bow, the bulbous bow, and the shape of the stern. Yaw at the stern (what I call the azipod shimmy) is an azipod issue. Overall yaw of the ship is caused by steering into seas at an angle (the preferred course, to minimize both pitch and roll), where either the autopilot or helmsman doesn't correct fast enough as the wave tries to throw the bow off the wave. Link to comment Share on other sites More sharing options...
Clarea Posted March 3, 2017 #29 Share Posted March 3, 2017 Roll. Pitch is affected by the flare of the bow, the bulbous bow, and the shape of the stern. Yaw at the stern (what I call the azipod shimmy) is an azipod issue. Overall yaw of the ship is caused by steering into seas at an angle (the preferred course, to minimize both pitch and roll), where either the autopilot or helmsman doesn't correct fast enough as the wave tries to throw the bow off the wave. I guess they figure they can let the stabilizers deal with the roll. I've always felt that of Royal's ships, Radiance class exhibited the most motion, given the same conditions. Link to comment Share on other sites More sharing options...
snowbird1 Posted March 3, 2017 #30 Share Posted March 3, 2017 Well, Quantum class have a length/beam ratio of: 8.4 Freedom class is 8.8 Radiance class is 9.0 So, these seven ships in these two classes are "long and narrow"er than Quantum class. All I know is I have had many seasoned crusier friends say there is something about those ships, they move a lot, perhaps the hull design. When you see them it certainly appears that ration would be different. Link to comment Share on other sites More sharing options...
ImpulsivePuppy Posted March 3, 2017 Author #31 Share Posted March 3, 2017 All I know is I have had many seasoned crusier friends say there is something about those ships, they move a lot, perhaps the hull design. When you see them it certainly appears that ration would be different. When you say "those ships" are you talking about Quantum class? Link to comment Share on other sites More sharing options...
Moltar Posted March 3, 2017 #32 Share Posted March 3, 2017 Any ship that is Panamax or smaller I presume to feel motion before I even board Link to comment Share on other sites More sharing options...
grapau27 Posted March 3, 2017 #33 Share Posted March 3, 2017 I thought a narrow tall ship would be the least stable especially with side winds.The most stable ships in my experience are the Allure and Harmony which are the widest. live in UK love USA and Royal Caribbean Cruises. Link to comment Share on other sites More sharing options...
knittinggirl Posted March 3, 2017 #34 Share Posted March 3, 2017 Weird question, I know. But I do enjoy feeling the movement of the ship when I am aboard. With the advent of azipods and stabilizers I don't notice the motion of the ship as much, which I guess is the point. But I'm wondering if any of RCL's ships are known for more movement or sense of movement? :p I think it depends on the sea conditions. We were told that the Rotterdam was built for sea voyages, but we a lot of rolling on several days. Just like the Legend in the middle of the Atlantic. I'm told it also depends on the type of ship Anthem had some rather scary hours during the storm a year of so ago, and the people on the thread seemed to think the Queen Mary had a better design that help prevent all that rocking. Link to comment Share on other sites More sharing options...
grapau27 Posted March 3, 2017 #35 Share Posted March 3, 2017 Queen Mary 2 is an ocean liner and is built to combat bad weather. live in UK love USA and Royal Caribbean Cruises. Link to comment Share on other sites More sharing options...
chengkp75 Posted March 3, 2017 #36 Share Posted March 3, 2017 I thought a narrow tall ship would be the least stable especially with side winds.The most stable ships in my experience are the Allure and Harmony which are the widest. live in UK love USA and Royal Caribbean Cruises. Stability is based on the difference in height of the center of gravity and the metacenter. The metacenter is the center of the arc that the center of buoyancy moves through as the ship rolls (because the hull shape in cross section is basically rectangular, the center of buoyancy moves from side to side as the amount of hull on each side changes during rolling). A narrow ship will have a lower metacenter, generally, than a wider one, but again, the height of the metacenter above the keel is not really relevant, if the center of gravity is different between the wider or narrower ship. Another factor affecting the height of the metacenter is draft. A wide and shallow hull will have a similar metacenter as a narrow deep hull. For instance, the Radiance class has only 13 decks, while Oasis has 18, so Radiance's center of gravity will be lower, and the "metacentric height" (the distance between the metacenter and the center of gravity), may well be the same between the two ships, so the "stability" could be the same. Ships with large metacentric heights (GM) have great initial stability, in that a very small roll angle will produce a very large righting force that attempts to move the ship upright again. This will result in it taking a larger force (higher sea) to start rolling, but once rolling, the ship will snap upright again very quickly, generating an unpleasant rolling. The stabilizers are designed to dampen this snap rolling. Ships with small GM's (loaded tankers for example) will have less initial stability, and will roll in smaller seas, but will also not generate the large righting force, and therefore the rolling will be slower yet to a greater angle. The ultimate of this are loaded tankers, and old "break bulk" ships that sailed with a few inches of GM, and the ship would roll over and hang at the end of the roll "thinking about coming back", because the stability was almost neutral (neutral stability is when the ship stays in whatever position you place it in). Link to comment Share on other sites More sharing options...
grapau27 Posted March 3, 2017 #37 Share Posted March 3, 2017 Stability is based on the difference in height of the center of gravity and the metacenter. The metacenter is the center of the arc that the center of buoyancy moves through as the ship rolls (because the hull shape in cross section is basically rectangular, the center of buoyancy moves from side to side as the amount of hull on each side changes during rolling). A narrow ship will have a lower metacenter, generally, than a wider one, but again, the height of the metacenter above the keel is not really relevant, if the center of gravity is different between the wider or narrower ship. Another factor affecting the height of the metacenter is draft. A wide and shallow hull will have a similar metacenter as a narrow deep hull. For instance, the Radiance class has only 13 decks, while Oasis has 18, so Radiance's center of gravity will be lower, and the "metacentric height" (the distance between the metacenter and the center of gravity), may well be the same between the two ships, so the "stability" could be the same. Ships with large metacentric heights (GM) have great initial stability, in that a very small roll angle will produce a very large righting force that attempts to move the ship upright again. This will result in it taking a larger force (higher sea) to start rolling, but once rolling, the ship will snap upright again very quickly, generating an unpleasant rolling. The stabilizers are designed to dampen this snap rolling. Ships with small GM's (loaded tankers for example) will have less initial stability, and will roll in smaller seas, but will also not generate the large righting force, and therefore the rolling will be slower yet to a greater angle. The ultimate of this are loaded tankers, and old "break bulk" ships that sailed with a few inches of GM, and the ship would roll over and hang at the end of the roll "thinking about coming back", because the stability was almost neutral (neutral stability is when the ship stays in whatever position you place it in). Thank you very interesting answer. live in UK love USA and Royal Caribbean Cruises. Link to comment Share on other sites More sharing options...
chengkp75 Posted March 3, 2017 #38 Share Posted March 3, 2017 I think it depends on the sea conditions. We were told that the Rotterdam was built for sea voyages, but we a lot of rolling on several days. Just like the Legend in the middle of the Atlantic. I'm told it also depends on the type of ship Anthem had some rather scary hours during the storm a year of so ago, and the people on the thread seemed to think the Queen Mary had a better design that help prevent all that rocking. Queen Mary 2 is an ocean liner and is built to combat bad weather. live in UK love USA and Royal Caribbean Cruises. A ship designed to "handle bad weather" like the QM2 does not necessarily mean it rolls less. It means it can withstand more severe weather with less damage to ship and passengers. The QM2 relies on a larger foredeck to prevent damage to forward cabins. It is deeper draft for a similar beam compared to the slightly larger Quantum class, so giving it a better metacenter, hence more stability. She also has a higher promenade deck, and hence a higher lifeboat stowage, to prevent damage. Her main design consideration for bad weather is her hybrid stern which helps with directional stability (ability to keep on course) in following seas. And yes, the only way to compare "vessel motion" is either in computer simulations, or in real life if you take the two ships traveling at the same speed, in the same direction, in the same spot in the ocean, at the same time. So, yes, it does all depend on the sea conditions. Link to comment Share on other sites More sharing options...
grapau27 Posted March 3, 2017 #39 Share Posted March 3, 2017 A ship designed to "handle bad weather" like the QM2 does not necessarily mean it rolls less. It means it can withstand more severe weather with less damage to ship and passengers. The QM2 relies on a larger foredeck to prevent damage to forward cabins. It is deeper draft for a similar beam compared to the slightly larger Quantum class, so giving it a better metacenter, hence more stability. She also has a higher promenade deck, and hence a higher lifeboat stowage, to prevent damage. Her main design consideration for bad weather is her hybrid stern which helps with directional stability (ability to keep on course) in following seas. And yes, the only way to compare "vessel motion" is either in computer simulations, or in real life if you take the two ships traveling at the same speed, in the same direction, in the same spot in the ocean, at the same time. So, yes, it does all depend on the sea conditions. Great information, I thought a deeper draft would help but most cruise ships seem to have little draft. live in UK love USA and Royal Caribbean Cruises. Link to comment Share on other sites More sharing options...
chengkp75 Posted March 3, 2017 #40 Share Posted March 3, 2017 Great information, I thought a deeper draft would help but most cruise ships seem to have little draft. live in UK love USA and Royal Caribbean Cruises. Given that cruise ships are mostly empty space, and their "cargo" doesn't weigh that much, getting a deeper draft requires more ballast water to be carried which requires more fuel to haul it around, so it isn't sensible. Again, wide and shallow is just as good as narrow and deep. Link to comment Share on other sites More sharing options...
grapau27 Posted March 3, 2017 #41 Share Posted March 3, 2017 Thank you very much I appreciate your information. live in UK love USA and Royal Caribbean Cruises. Link to comment Share on other sites More sharing options...
knittinggirl Posted March 3, 2017 #42 Share Posted March 3, 2017 On the Rotterdam, near Iceland, the ship was really rocking! It was designed for long voyages, and those few days at sea, I spent most of my walking grabbing the handrail in the corridor to keep upright. On the plane home, I found my balance had improved on the way to the restroom. So, those 35 days at sea must have helped. Link to comment Share on other sites More sharing options...
grapau27 Posted March 4, 2017 #43 Share Posted March 4, 2017 I was told some ships don't always use their stabilisers to save money on fuel. live in UK love USA and Royal Caribbean Cruises. Link to comment Share on other sites More sharing options...
teddie Posted March 4, 2017 #44 Share Posted March 4, 2017 Like I said. A bunch of Lightweights...... I'm going to assume you are being funny. Because when my middle ear problem results in me barfing on your lap, it won't be funny. :p Cheers. Link to comment Share on other sites More sharing options...
sockmonkeygirl Posted March 5, 2017 #45 Share Posted March 5, 2017 I agree, the movement is great.It let's you know your on a ship. Never could understand all the Lightweights with those patches on.. As one of those lightweights with the patch on, I have to say, I'm feeling green just reading this! Id love to tolerate the rolls and girations, but I can't, and it's one of the worst feelings in the world. Luckily, the Anthem was very good to us last week. Patch on (always) and still one full day of bed/bathroom bound sea sickness. DH got some meclizine from floor 2 and I still lost an entire day. I believe that day we had 10/11 foot waves max. That was the roughest day of the week. It was an uncanny 72 degrees sailing away from NJ in the middle of February. :cool: Link to comment Share on other sites More sharing options...
DJLDRUMS Posted March 5, 2017 #46 Share Posted March 5, 2017 My vote for a lot of movement is for the Anthem for a large ship. Two years ago our 11 nighter turned into a 12 nighter because of a bad storm in mid January and only one stabilizer was operational.(Especially during the winter the North Atlantic can be brutal. If you've been on the Anthem you'll notice that it's narrower than the Voyager, Freedom or Oasis class ship. It's also tall which causes more sway. Tall and narrow translates into getting more movement. I agree with other posts saying the Sovereign,Radiance and Vision class ships can present a problem as well not a lot of weight...been on them as well and have felt motion of the ocean. Link to comment Share on other sites More sharing options...
chengkp75 Posted March 6, 2017 #47 Share Posted March 6, 2017 My vote for a lot of movement is for the Anthem for a large ship. Two years ago our 11 nighter turned into a 12 nighter because of a bad storm in mid January and only one stabilizer was operational.(Especially during the winter the North Atlantic can be brutal. If you've been on the Anthem you'll notice that it's narrower than the Voyager, Freedom or Oasis class ship. It's also tall which causes more sway. Tall and narrow translates into getting more movement. I agree with other posts saying the Sovereign,Radiance and Vision class ships can present a problem as well not a lot of weight...been on them as well and have felt motion of the ocean. Not sure where you're getting your figures, but Anthem is narrower than Oasis, and narrower than Freedom in maximum beam (bridge wings, hump balconies, lifeboats), but the only thing that really affects stability is beam at the waterline, and Anthem is wider than both Freedom and Voyager here: Oasis: 47m Anthem: 41.4m Freedom and Voyager: 38.6m Link to comment Share on other sites More sharing options...
DJLDRUMS Posted March 6, 2017 #48 Share Posted March 6, 2017 Well just one example, if you're in the dining room of the Anthem and stand on one side of the ship by the window and look across to the window on the other side of the ship you'll note with narrower at that point. Also another place that shows it narrower is if you look at each class ship in the RCI brochure you'll see that the Quantum Class ships are more narrow than Oasis Freedom and Voyager. Link to comment Share on other sites More sharing options...
Clarea Posted March 6, 2017 #49 Share Posted March 6, 2017 Well just one example, if you're in the dining room of the Anthem and stand on one side of the ship by the window and look across to the window on the other side of the ship you'll note with narrower at that point. Also another place that shows it narrower is if you look at each class ship in the RCI brochure you'll see that the Quantum Class ships are more narrow than Oasis Freedom and Voyager. The RCI brochure is not comparing apples to apples. They are measuing beam at two different places. As the Chief said, the beam at the waterline is a few feet more on Quantum (136') than on Voyager/Freedom (127'). Link to comment Share on other sites More sharing options...
juliea344 Posted March 6, 2017 #50 Share Posted March 6, 2017 Not sure where you're getting your figures, but Anthem is narrower than Oasis, and narrower than Freedom in maximum beam (bridge wings, hump balconies, lifeboats), but the only thing that really affects stability is beam at the waterline, and Anthem is wider than both Freedom and Voyager here: Oasis: 47m Anthem: 41.4m Freedom and Voyager: 38.6m Are you saying I'm going to puke on Independence? I sure hope not ;p Link to comment Share on other sites More sharing options...
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