Bigger ships, less motion?

[ShellyLynn3630]

With the new ships being much bigger, will we feel less motion on them?

 

[Curtis McCrea]

I hope so! I think so, anyway.

 

[NancyIL]

If the seas are rough, you will feel them no matter how large the ship.

 

[tvguy]

In my experience, the bigger the ship, the smoother the ride. Stabilizers are also a big help.

 

[Curtis McCrea]

Yes, stabilizers. I wonder if my last cruise (Carnival Sensation) had them! "Ouch! I just smashed my face on the wall!"

 

[tvguy]

Yes, stabilizers. I wonder if my last cruise (Carnival Sensation) had them! "Ouch! I just smashed my face on the wall!"

 

[jkrislc]

It really depends on the design of the ship from what I've read. Stabilizers are great, but they only control for the side to side movement of the ship. In addition, larger/taller ships are more subject to wind which can also cause motion; this was the major cause of motion on our last RCI trip as the seas were relatively calm, but the ship was moving like crazy.

Larger ships and most modern cruise ships tend to have flatter bottoms to make it into shallow harbors; as a result, the don't cut through or ride the waves of the older transatlantic ships (e.g., Queen Mary). The deeper the V of the ship, the better it can cut through the oncoming waves (at least according to what I've read).

I think modern day propulsion systems may be helping too as they can trim out the ride by having numerous propellers that can be individually turned.

 

[lovethedream]

This is a question I have had. Our experience is the DCL Wonder and RCCL Freedom. I believe we felt the rocking more on the Freedom than the Wonder, and this was even in the mall area (ie the lower decks) so I do not think it had anything to do with being higher up on the ship. As a matter of fact, I do not think the rocking felt all that different from the top deck to the lower decks.

What was the reason for this? The seas were about the same but I cannot say anything for the winds as it was impossible for me to tell.

The only major difference is that for the Freedom we were out over open water where with the Wonder we were around the islands which can help keep the rocking down, or so I was told when on board the Wonder (So the rocking may have been a result of where the ship traveled as they obviously did not follow the same route)

The only other thing I have heard is that they rock more the faster they go and the Wonder did not have that far to go each night where the freedom had quite a distance to go before and after getting down to the St. Martin area. Although I did have my GPS the second Wonder trip and she was making 21 or 22 knots that last night.

Was there something wrong with the equipment that keeps the boat stable. No indication of that for either ship.

 

[lovethedream]

It really depends on the design of the ship from what I've read. Stabilizers are great, but they only control for the side to side movement of the ship. In addition, larger/taller ships are more subject to wind which can also cause motion; this was the major cause of motion on our last RCI trip as the seas were relatively calm, but the ship was moving like crazy.

Larger ships and most modern cruise ships tend to have flatter bottoms to make it into shallow harbors; as a result, the don't cut through or ride the waves of the older transatlantic ships (e.g., Queen Mary). The deeper the V of the ship, the better it can cut through the oncoming waves (at least according to what I've read).

I think modern day propulsion systems may be helping too as they can trim out the ride by having numerous propellers that can be individually turned.

Good points. Is it possible the Freedom has a flatter hull so she can get into the same ports. What about the Oasis or the Allure? Since the seas on our two trips were the same, it was probably the wind then??

 

[Disney On A Dime!]

We were rocking and rolling on the Liberty of the Seas (RCI), and the staff said that this was the normal motion of the ship! It wasn't severe shifts in motion, but it was constant and noticeable. IMO, the Disney ships only really had more motion while navigating into and out of Port Canaveral...Oh...well, and the time that we circled around and around searching and finding a Carnival cruiser Things were falling off of the bathroom shelves!


So, in our experience, bigger does not necessarily mean less motion...


Crystal

 

[Luvstocruise]

I had never got seasick on the older ocean liners as a kid and teen that were only about 27000 tons (displacement) nor on relatively bigger ones 55000 tons as an adult. Now with the huge ships (I feel the Magic/Wonder are big ships!!) like the Oasis of the Seas, the dampening of the motion would be greater. By this I mean, the time to roll from side to side or pitch up and down (Stern to Forward section movement) would not be as fast.

But as an aside, I was violently ill (I am talking dry heaves here!)on a deep sea boat off the Bahamas, where that was the longest 4 hours I spent on a boat. I thought I was going to die out there.http://www.wdwinfo.com/images/smilies/sick.gif

So, size probably does matter (when it comes to ships that is...)

Regards,
Luvstocruise
(Dan)

 

[truck1]

Good points. Is it possible the Freedom has a flatter hull so she can get into the same ports. What about the Oasis or the Allure? Since the seas on our two trips were the same, it was probably the wind then??

Most ships built today, have the same flat hull design.Basically, when they come into drydock for their inspections, they sit on wood and steel blocks.Even aircraft carriers, and the big super tankers are flat.

Ive seen pics and ships up close and they are all almost perfectly flat.They all now have what they call a bulbous bow, which helps break the waves and surface tensions so the ship can move easier thru the water, also helps cut down on fuel consumption and also helps sync the waves to keep hull stress down.

When a ship is built, there really isnt too much control over how deep a ship sits.They can calculate how far down a ship will sit in the water, but they really cant do much with it, short of making the ship smaller and lighter.Most ships today, have steel hulls, and up to a certain point on the ship is steel, then they will use aluminum to keep the center of gravity down.The lower the cog, the better the stability.

This is a question I have had. Our experience is the DCL Wonder and RCCL Freedom. I believe we felt the rocking more on the Freedom than the Wonder, and this was even in the mall area (ie the lower decks) so I do not think it had anything to do with being higher up on the ship. As a matter of fact, I do not think the rocking felt all that different from the top deck to the lower decks.

What was the reason for this? The seas were about the same but I cannot say anything for the winds as it was impossible for me to tell.

The only major difference is that for the Freedom we were out over open water where with the Wonder we were around the islands which can help keep the rocking down, or so I was told when on board the Wonder (So the rocking may have been a result of where the ship traveled as they obviously did not follow the same route)

The only other thing I have heard is that they rock more the faster they go and the Wonder did not have that far to go each night where the freedom had quite a distance to go before and after getting down to the St. Martin area. Although I did have my GPS the second Wonder trip and she was making 21 or 22 knots that last night.

Was there something wrong with the equipment that keeps the boat stable. No indication of that for either ship.

Weve had a similar motion on our last night, on the Wonder, when we were booking beam on to the waves to help look for Sensations man overboard.There was a pronounced roll to the ship as we were booking.


Some ships will pull their stabilizers in to cut down on drag at high speeds, which may have cut down on their roll stabilization abilities.
Some of the other factors that will affect a ships stability at sea, are which way the ship is facing relative to the currents,wind,and waves.
Waves coming from almost bow on, or stern on, youll probably never notice,but waves coming from the sides, youll notice, even with stabilizers.Where a ship getting 6-8 footers almost beam on (directly at the sides) youll feel the ship roll,but with stabilizers itll fell sluggish and almost non existint.The faster a ship is moving,with beam on waves, the more pronounced the roll. If the waves are coming bow on, youll feel them more as a shudder.Winds can come from a different direction then the current and that will help make things worse. Ive heard reports, and I think they have been on the Freedom class,and the bigger ships with the same design, that in heavy seas, if you stood at 1 end of the mall,( I think its the Freedom class, where the mall runs from 1 end of the ship to the other and fairly high)and looked to the other end, you can see the ship flex and watch the walls move in different directions.


Heres the other thing to keep in mind. A ship has a center of gravity, and its got nothing to do and usually nowhere near, the center of the ship.And it will move thoughout the cruise.Things that will affect it is fuel load,whether they burn it off or just took on a full load,how much water is onboard to drink,if it was just topped off or later in the cruise,and if the ballast tanks are full or empty, to compenstate for the fuel load. Its where the loads are on a ship.Generally, its fairly high, such as deck 6ish on the Magic class. It is near the center of the ship,side to side.The farther you get from this point, the more pronounced the ships movement is.If your cabin for example is the farthest foward,on deck 2 on the port side, youll feel it more then an interior room on deck 6 near the midship elevator.
Think of it this way.Take a box from a bar of soap, and hold it between, your thumb and index finger,halfway up from the bottom of the box, and and halfway back, and with you other hand push down with your index finger on one end of the box.The farther down the front (bow of a ship) of the box goes, the back will move the same distance up.Same if you moved it from side to side.The same motions are applied to a ship.

 

[truck1]

Oh...well, and the time that we circled around and around searching and finding a Carnival cruiser Things were falling off of the bathroom shelves!





Crystal

We were on the same cruise.Its very disconcerting when you go to the balcony, and realize that not only are we not moving, but the Senastion was only a few hundred feet away from the bow.And there not moving either.

 

[Disney On A Dime!]

We were on the same cruise.Its very disconcerting when you go to the balcony, and realize that not only are we not moving, but the Senastion was only a few hundred feet away from the bow.And there not moving either.

We were not aware of what had occurred until breakfast the next morning. Thank goodness we were able to scoop that guy out of the ocean!


On a different note, have you all been able to take a cruise on one of the larger ships? With all your knowledge about the ships and their build...you would really enjoy the freedom-class with RCI. Even though the motion was more than Disney...we still loved the ship! We are also looking forward to the new Disney Dream...guess we have to try them all! Oasis or Allure should be next summer...we'll see!


Crystal

 

[truck1]

We were not aware of what had occurred until breakfast the next morning. Thank goodness we were able to scoop that guy out of the ocean!


On a different note, have you all been able to take a cruise on one of the larger ships? With all your knowledge about the ships and their build...you would really enjoy the freedom-class with RCI. Even though the motion was more than Disney...we still loved the ship! We are also looking forward to the new Disney Dream...guess we have to try them all! Oasis or Allure should be next summer...we'll see!


Crystal

We found out since we had a balcony, I heard the lifeboat arms being run out, and saw lightnening on the horizon.When I got up to look, I saw the stern thrusters kicking in to keep us in place, the Sensation on our bow, and Staff Cat.Guus making the announcement, that we could talk again since the man overboard had been found.

I havent had a chance to get on the RCL ships yet, though my fiance, and I talked about taking 1 by ourselves. 1 day we will and they are on our to do list.The other line were thinking of is Princess.Ive seen 1 of the rest.on the stern that spans 2 arches, and want to try it.

Ive always been interested in behind the scenes things, and have seen hundreds of shows, that not only show what I posted, but also how they figure it out. Ive also worked in boat yards which is where Ive picked up some info and first hand experience, along with living on the water and owning/running a boat for my family for close to 15 years.
There was a show on DIY called Project Xtreme, and they showed the Magic in drydock, and showed her bottom.Same thing with the old Soverign of the Seas.There was a show on cable that showed her 2 week drydock.