Stableizers- I just have to ask

[max44]

I feel so silly for asking this question, :o ive had a look around the boards to see if anyone else as asked but cant find anything so here goes.........

 

:o Ive heard that when the seas get rough that some ships have stableizers, What are they? I know what they do but I have a vision of them sticking out for the full lenght of the ship at about wave height, Much like stableizers on a childs bike to keep their balance. :o

 

Just curious as to what they look like, hopefully we wont need them on our up-coming cruise:)

[ssantow]

They are actually like fins on a fish. They stick out from the side of the ship below water level and can be extended out or retracted in to control the roll of the ship. Many of then on newer ships are gyroscopicaly controlled to maintain as stable a ride as possible.

[audome78]

Glad you asked...because I have some info on this. Please note that this info pertains only to the Mariner of the Seas, and maybe, by extension, to the other Voyager class ships.

 

On our B2B on the Mariner last month, we could actually see the stabilizers when they were deployed. The extend at right angles to the ship. From our vantage point, in the middle of the hump, starboard side, but SEVENTH deck (so a good distance from the water), they appeared to come out only 20 feet or so, and were maybe 10 feet wide, and at a depth of maybe 10-15 feet below the water line.

 

Again, from that distance, my perception may be off, but that's what I saw.

 

Also, we were in 7618, and they were directly below us, actually directly below 7620, about 2/3 of the way to the stern.

[Druke I]

Most modern ships have stabilizers.

 

That said, do remember that they are designed to reduce roll, but do nothing to counter pitching motion, and will be retracted in pitching seas.

 

Ship's Engineers prefer not to deploy the stabilizers, as they have a very negative effect on fuel efficiency and speed.

[ehfl]

They are little wings which can be extended out below the water line. They can move like ailerons on a plane (like when you stick your hand out a car window).

 

They can create an upward or downward force on either side of the ship. When deployed, they are controlled by a gyroscope. So when a wave tries to roll the ship to the right, the starboard stabelizer creates an upward force while the port stabelizer creates a downward force. This counteracts the lifting force of the wave, so that the ship does not rock.

 

It can only control roll (it does not control pitch or yaw, but most ships do not pitch or yaw very much anyway).

[cb at sea]

All that being said, you will feel the "motion of the ocean! It's inevitable--no matter how large the ship--it's a "speck" compared to the size of the sea. Even a "stabilizer" won't keep that ship still if the seas get a bit agitated!

[Sequim88]

Me too...wondering. Sort of. I knew what they are and how they work but I have wondered if, when they are operating, if they introduce any vibration into the hull that can be detected through the decks. I would imagine when water flows around them if the angle is not just right there can be some turbulence and little "standing or shock waves" along their surface that gets conducted into the ship. Can you feel any vibration when they are in use so that even if roll is minimized you might feel it know they are in use?

[max44]

Thankyou all very much for your excellent explanations :)

[Lamar Cheeks]

A good point made ... they are reluctant to use stabilizers because they increase the demand for fuel ... on a cruise two years ago, we were told there were new guidelines as to how much they were used, and that their use had decreased dramatically.

 

At any rate, the high cost of fuel is having a dramatic effect on a lot of things, and I believe the cruise industry (along with the airline industry) is being hit hard. Maybe it's time to bring back the clipper ships.

[jwlane]

Just curious as to what they look like

On the Norwegian Wind.

[sf2]

 

this is one of the Radiance's stabilzers - with crewmembers for size reference . . .

[Dave Wojo]

Very cool photos.

 

The mechanism for retracting them when not in use must be one helluva piece of engineering.

[Little Elm]

I expected it to be bigger.

[MakinGold]

I expected it to be bigger.

 

I've heard that one before . . . :D :o

[David4]

I've heard that one before . . . :D :o

 

ROFL

[Fran Harp]

All that being said, you will feel the "motion of the ocean! It's inevitable--no matter how large the ship--it's a "speck" compared to the size of the sea. Even a "stabilizer" won't keep that ship still if the seas get a bit agitated!

 

To add to what others have said - stabilizers are only deployed when the ship is going approximately 16 knots or better - and only affect the roll motion.

 

Fran in Toronto

[TEXASMUNK]

they are not used in very heavy seas as the force of the seas could actually destroy the stabilizer