[motorbaad]

I just read that this "Thing" or is it a ship built in Finland is going to pass under the Storebaelt Brigde.
http://www.oasisoftheseas.com/
In order to clear this bridge it is said to have to go full speed to reduce the airdraft.
I have been presented with this before, regarding really big cruiseships passing under this bridge. Is it really true?
If so what is the theori behind this?

Michael

[Peter B]

Originally Posted by motorbaad

I just read that this "Thing" or is it a ship built in Finland is going to pass under the Storebaelt Brigde.
http://www.oasisoftheseas.com/
In order to clear this bridge it is said to have to go full speed to reduce the airdraft.
I have been presented with this before, regarding really big cruiseships passing under this bridge. Is it really true?
If so what is the theori behind this?

Michael

The theory is ok; when moving at high speed in shallow water, the escaping water below the hull (water being displaced by the hull as it moves forward) will move at considerable speed. The increased velocity generates a dynamic pressure loss which in effect will drag the hull down. This phenomenon is known as the "squat effect".
I don't know if the explanation makes sense; perhaps someone with a better understanding of the hydrodynamics and/or a better command of the english language can elaborate?

The story about cruise ships "speeding" under the bridge is not true, however. Imagine what would happen if propulsion was lost while approaching the bridge......

For the minority of you who understand Danish, there is an article and several postings about the subject here:
http://www.maritimedanmark.dk/?Id=6089

Regards
Peter

[Billieboy]

Originally Posted by Peter B

The theory is ok; when moving at high speed in shallow water, the escaping water below the hull (water being displaced by the hull as it moves forward) will move at considerable speed. The increased velocity generates a dynamic pressure loss which in effect will drag the hull down. This phenomenon is known as the "squat effect".
I don't know if the explanation makes sense; perhaps someone with a better understanding of the hydrodynamics and/or a better command of the english language can elaborate?

The story about cruise ships "speeding" under the bridge is not true, however. Imagine what would happen if propulsion was lost while approaching the bridge......

For the minority of you who understand Danish, there is an article and several postings about the subject here:
http://www.maritimedanmark.dk/?Id=6089

Regards
Peter

That's what it is Peter, on really shallow, flat bottoms, they sometimes lower the undercarriage, just in case!

[motorbaad]

Thank you very much for the information. I just wonder if it will work in this situation as the draught of the vessel from its own AIS transmission is reported to be 9.3 meters and there is between 20 and 50 meters of water on the south side of the bridge?
Storebaelt.jpg

[marco nista]

Having just looked at a video clip of the OASIS OF THE SEAS underway & deck upon deck upon deck of verandahed cabins why am I reminded of a large streamlined sheep ship ?

Cheers

Marco

[Santos]

Originally Posted by marco nista

Having just looked at a video clip of the OASIS OF THE SEAS underway & deck upon deck upon deck of verandahed cabins why am I reminded of a streamlined sheep ship ?

Cheers

Marco

Well its a live thing carrier Marco - thats really all you can say about it - its practically the same as a livestock carrier, the only thing being different is that most of its passengers wear clothes of some sort.

Chris

[Graham Wallace]

Originally Posted by motorbaad

I just read that this "Thing" or is it a ship built in Finland is going to pass under the Storebaelt Brigde.
http://www.oasisoftheseas.com/
In order to clear this bridge it is said to have to go full speed to reduce the airdraft.
I have been presented with this before, regarding really big cruiseships passing under this bridge. Is it really true?
If so what is the theori behind this?

Michael

An ex Sparks a new SN member is aboard her, working passage of sorts I believe.
They remind me of colourful shoeboxes, about the same shape

Graham

[Billieboy]

Originally Posted by marco nista

Having just looked at a video clip of the OASIS OF THE SEAS underway & deck upon deck upon deck of verandahed cabins why am I reminded of a large streamlined sheep ship ?

Cheers

Marco

The problem is, that unlike sheep, goats and cattle, this load of livestock talks!

[PhilColebrook]

Originally Posted by Santos

the only thing being different is that most of its passengers wear clothes of some sort.

Chris

That would be Hawaiian shirts, shorts and flip-flops to dinner.

[janneke]

Originally Posted by motorbaad

I just read that this "Thing" or is it a ship built in Finland is going to pass under the Storebaelt Brigde.
http://www.oasisoftheseas.com/
In order to clear this bridge it is said to have to go full speed to reduce the airdraft.
I have been presented with this before, regarding really big cruiseships passing under this bridge. Is it really true?
If so what is the theori behind this?

Michael

Yes this is true. I saw a documentary on Discovery TV about the Allure of the Seas where the captain explained this phenomenom. Compare it to the effect of a venturi where the air (or in this case water) increases in speed thereby decreasing in pressure and thus causing the ship to "sink" a little in the water. The ship is thereby a little lower in height. The same happens with a F1 racecar, by using its rear diffusor to push the car downwards.
The A o t seas also had "retractable" exhaust pipes in the stack to make the ship lower. In the end the A o t Seas had less than 1 meter clearance with the bridge.
JP

[Ron Dean]

Originally Posted by Santos

Well its a live thing carrier Marco - thats really all you can say about it - its practically the same as a livestock carrier, the only thing being different is that most of its passengers wear clothes of some sort.

Chris

An American friend of mine who loved to travel on freighters, once remarked to me "Any ship with more than 1,000 passengers, is just a Cattle Hauler God forbid that I should ever travel on one".

Ron.