how far will a ship roll without capsizing? - PeachParts Mercedes-Benz Forum

t walgamuth · #1 04-08-2011, 04:49 AM

At lunch yesterday we were talking about ships and the subject came up of how far over a warship like a cruiser will roll and still right itself?

Anybody have an idea?

One of my cronies is an ex navy man. He said maybe fortyfive degrees. I thought as long as the ship was undamaged and boyant it would nearly go upside down and still right itself.

Another fellow said the big guns on a ship are just sittting in their places and if the ship goes upside down they will simply fall out. I was skeptical of this but do not know.

I just googled it all and found many many articles on it but no real hard information. ONe artical used an example which showed a ship and said it would go past ninety degrees but at one o seven it would capsize.

jplinville · #2 04-08-2011, 04:52 AM

I suspect it will be able to do it just before the point of no return.

Actually, I think it has to do with gun placement, weight, center of gravity, length of rudder, etc. Basically, it depends on design.

Skid Row Joe · #3 04-08-2011, 04:54 AM

Heck, I don't know - but the Disney Cruise Line and Virgin America airline ads come up at the top of the thread. Prices start in the low $1K range for cruises & $99 for flights from San Francisco, CA.

t walgamuth · #4 04-08-2011, 05:03 AM

You guys are a lot of help!

Skid Row Joe · #5 04-08-2011, 05:07 AM

Insomnia - it's Friday morning. The story of the Edmund Fitzgerald ship going down was a frightful story for me to hear about that happened on one of the Great Lakes not all that long ago. Water and it's destructive forces terrify me more than flight - go figure.

t walgamuth · #6 04-08-2011, 05:24 AM

Yeah, I am suffering with either allergies or a spring cold and am restless.

So with your fear of water how are you flying over the ocean?

Gordon Lightfoot's song about the Edmund Fitsgerald is a favorite of mine....mournful and musical but based on a true story.

jplinville · #7 04-08-2011, 05:28 AM

I'm awake only because I can't sleep well without my wife beside me. She's staying with my mom for two weeks, as dad's birthday is Sunday, and he passed away in November. It's the first BD since his passing.

Anyway, I spent many summers on the shore of Lake Erie as a child, and am mystified by the stories of all the cargo ships that the lakes have taken.

TheDon · #8 04-08-2011, 05:38 AM

The massive guns on the WWII battleships and destroyers are actually just sitting on rollers if I am not mistaken. . If they capsize the guns would fall out of place

t walgamuth · #9 04-08-2011, 05:42 AM

Quote:

Originally Posted by jplinville

I'm awake only because I can't sleep well without my wife beside me. She's staying with my mom for two weeks, as dad's birthday is Sunday, and he passed away in November. It's the first BD since his passing.

Anyway, I spent many summers on the shore of Lake Erie as a child, and am mystified by the stories of all the cargo ships that the lakes have taken.

Lake Superior is fearsome in bad weather.

t walgamuth · #10 04-08-2011, 05:45 AM

Quote:

Originally Posted by jplinville

I'm awake only because I can't sleep well without my wife beside me. She's staying with my mom for two weeks, as dad's birthday is Sunday, and he passed away in November. It's the first BD since his passing.

Anyway, I spent many summers on the shore of Lake Erie as a child, and am mystified by the stories of all the cargo ships that the lakes have taken.

We have this glorious King bed (we have not gotten over how great it is even after 20 years of it) and once we go to sleep it is impossible to tell if the other person is still there except by lookng or reaching over there and feeling around. I miss her when I am awake if she is gone but once in bed asleep I am oblivious.

jplinville · #11 04-08-2011, 06:05 AM

Quote:

Originally Posted by t walgamuth

We have this glorious King bed (we have not gotten over how great it is even after 20 years of it) and once we go to sleep it is impossible to tell if the other person is still there except by lookng or reaching over there and feeling around. I miss her when I am awake if she is gone but once in bed asleep I am oblivious.

Foe some reason, I can't sleep in bed without her. We, too, have a HUGE king sized bed that doesn't move if someone tosses and turns. it's just that I have become so used to hearing her breathe or her reaching back to put her hand on me. I know, I'm sounding sappy, but she means that much to me.

Now, if I'm traveling without her, I have NO problems falling asleep or staying asleep...it's just when I'm home that I'm that way.

My dad used to have the same problem concerning my mom.

rocky raccoon · #12 04-08-2011, 06:08 AM

A ship has two critical dimensions related to the capsizing moment.

(1) The Center of Gravity; Cg
(2) the Center of Bouyancy; Cb

Cb is the center of gravity of the volume of water displaced by the ship.
A ship is designed so that the Cb is below the Cg on the same vertical line when the ship is upright. It is then stable. As a ship rolls, the Cb moves outward from the vertical line and rises toward the Cg. Once the Cb rises ABOVE the Cg the ship will not recover from the roll.

IRT to deck guns simply sitting in recesses in the deck, I don't know for sure but it sounds unlikely. The recoil forces and rotational forces of big guns would require them to be firmly mounted. If not so mounted normal movements, however small, would at best destroy accuracy and at worst damage the ship structure.

Warships are simply heavily ballasted to keep that Cb low.

TheDon · #13 04-08-2011, 06:35 AM

Quote:

Originally Posted by rocky raccoon

A ship has two critical dimensions related to the capsizing moment.

(1) The Center of Gravity; Cg
(2) the Center of Bouyancy; Cb

Cb is the center of gravity of the volume of water displaced by the ship.
A ship is designed so that the Cb is below the Cg on the same vertical line when the ship is upright. It is then stable. As a ship rolls, the Cb moves outward from the vertical line and rises toward the Cg. Once the Cb rises ABOVE the Cg the ship will not recover from the roll.

IRT to deck guns simply sitting in recesses in the deck, I don't know for sure but it sounds unlikely. The recoil forces and rotational forces of big guns would require them to be firmly mounted. If not so mounted normal movements, however small, would at best destroy accuracy and at worst damage the ship structure.

Warships are simply heavily ballasted to keep that Cb low.

Those deck guns have to be sitting on rollers

http://forums.navalwarfare.net/showthread.php?660-The-return-of-Battleship-Musashi/page3

discussion of a certain battleship that sank during battle and how it lays on the ocean floor. Talk of the turrets falling out

http://en.wikipedia.org/wiki/Montana-class_battleship#cite_note-33

article on the proposed Montana class, see section on Main Battery, then footnote 34

The Bismarck as it was discovered on the ocean floor. Clearly it turned over while sinking and the turrets simply fell out.

Same thing with tanks, I know for a fact that the M1A1/2's turret just sits inside its mount on the tank.

layback40 · #14 04-08-2011, 06:43 AM

I know in my kayak I can go 360 deg & not sink. I think they call it a Eskimo roll. Some how I dont think a cruiser would do that !!

BobK · #15 04-08-2011, 07:08 AM

My father was in the USN. One day he was at the wheel in bad weather. He said he saw the ship roll to something like 47-49 degrees (I'll have to get the exact number from him). It would have been slightly easier to walk on the bulkhead than the deck. I think my poor pop spent a good bit of his time in the Navy sea-sick. I guess "driving" the ship was a little easier on him.