How much do aircraft carriers weigh?

[Spoooon]

What is the weight of a Nimitz class carrier if you were to lift it out of the water and put it on a scale? Anyone know? They displace 97000 tons.

 

[StageLeft]

Well then they weigh about 97000 tons.

 

[Atrail]

<< Well then they weigh about 97000 tons. >>



Yep Yep

 

[Spoooon]

Is displacement really the same thing as weight? They displace an amount of water that equals the volume of the submerged portion of the ship. Maybe I'm just thinking about it wrong. Someone enlighten me.

 

[SSP]

<< Well then they weigh about 97000 tons. >>



Yeah, thats what I gathered from this site.

 

[StageLeft]

Drop a boat in the water and if it weighs 100 pounds it will displace exactly 100 pounds of water

 

[Viper GTS]

<< Is displacement really the same thing as weight? They displace an amount of water that equals the volume of the submerged portion of the ship. Maybe I'm just thinking about it wrong. Someone enlighten me. >>



No, you're thinking about it right - But you're forgetting that the weight of the water displaced is equal to the weight of the object.

Viper GTS

 

[IJump]

Notes of Interest:

Construction dates:
Tons of steel used: 60,000
Pounds of aluminum used: 1,000,000
Weight of modular segments used in final construction: up to 900 tons
Number of modules making up the ship: 190
There are about 140,000 rolls of toilet paper on board
In January 1998 the crew moved aboard
Pens and paper: 600,000 ball-point pens and 1.5 million sheets of paper on board
The acceptance trial of USS HARRY S. TRUMAN took place in May, 1998

Just some info that might help in your quest to find the dry weight of an airsraft carrier......



Main Entry: dis·place·ment
Pronunciation: di-'splA-sm&nt
Function: noun
Date: 1611
1 : the act or process of displacing : the state of being displaced
2 a : the volume or weight of a fluid (as water) displaced by a floating body (as a ship) of equal weight

 

[Cyberian]

<< 2 a : the volume or weight of a fluid (as water) displaced by a floating body (as a ship) of equal weight >>

Actually, wouldn't this vary slightly from salt water to fresh water?

 

[Viper GTS]

<<

<< 2 a : the volume or weight of a fluid (as water) displaced by a floating body (as a ship) of equal weight >>

Actually, wouldn't this vary slightly from salt water to fresh water? >>



The volume of displaced water will vary, but not the weight.

A ship will float higher in salt water than in fresh water.

Viper GTS

 

[crypticlogin]

<< Actually, wouldn't this vary slightly from salt water to fresh water? >>


Nope.

Archimedes' Principle

 

[FoBoT]

how much does a submarine weigh when its submerged?

 

[HappyPuppy]

Janes is your friend.

 

[Spoooon]

<< But you're forgetting that the weight of the water displaced is equal to the weight of the object >>


But the Ohio displaces different amounts of water when surfaced and when submerged. Which makes sense of course because it displaces an amount of water equal to it's volume. But following that logic, they should be the same.



<< how much does a submarine weigh when its submerged? >>


Surfaced: 16764 tons
Submerged: 18750 tons

That's for the Ohio.

 

[Viper GTS]

<<

<< But you're forgetting that the weight of the water displaced is equal to the weight of the object >>


But the Ohio displaces different amounts of water when surfaced and when submerged. Which makes sense of course because it displaces an amount of water equal to it's weight. But following that logic, they should be the same. >>



If I use my hand to hold a ball under water have I changed it's weight?

That rule applies for floating objects.

Objects with neutral buoyancy obviously have equal density with the surrounding fluid, objects which sink displace less water than their weight - hence they sink.

Viper GTS

 

[Spoooon]

<< Objects with neutral buoyancy obviously have equal density with the surrounding fluid, objects which sink displace less water than their weight - hence they sink. >>


That makes sense. Man, I am so far removed from physics and chemistry. :disgust:

edit: Just found this at another site though.

The weight of the vessel as could be measured on a scale versus the calculated displacement are not quite the same, though the difference is not enough to concern boat owners. Displacement is the volume of water that is displaced by the hull of the vessel measured in pounds or tons. This derives from a math calculation made by naval architects during the design process. No one actually ever physically measures the displacement of a hull as that is far too costly to do. Displacement as a representation of boat weight is no longer used by pleasure craft builders, though it is always used for ships.

 

[notfred]

<<

<< But you're forgetting that the weight of the water displaced is equal to the weight of the object >>


But the Ohio displaces different amounts of water when surfaced and when submerged. Which makes sense of course because it displaces an amount of water equal to it's volume. But following that logic, they should be the same.



<< how much does a submarine weigh when its submerged? >>


Surfaced: 16764 tons
Submerged: 18750 tons

That's for the Ohio. >>



It really does apply only to floating objects (imagine a rock on the bottom of the ocean, doesn't matter how much it weighs, jsut how much space it takes up) but, regardless, To submerge, a submarine fills large ballast tanks with lots of salt water, hence, it gets heavier.

 

[Freejack2]

*Picks aircraft carrier out of the sea*
*Puts it on a scale*
5.3 lbs

 

[UltraQuiet]

Thanks for the laughs guys.

 

[Cyberian]

<<

<<

<< 2 a : the volume or weight of a fluid (as water) displaced by a floating body (as a ship) of equal weight >>

Actually, wouldn't this vary slightly from salt water to fresh water? >>



The volume of displaced water will vary, but not the weight.

A ship will float higher in salt water than in fresh water.

Viper GTS >>

If it floats higher, isn't it displacing less?
Doesn't salt water weigh slightly less than fresh water?

Be gentle - I've been out of school for 40+ years.

 

[StageLeft]

<< If it floats higher, isn't it displacing less?
Doesn't salt water weigh slightly less than fresh water?

Be gentle - I've been out of school for 40+ years. >>

If it floats higher it means it is displacing less volume. Since the mass of the boat is the same and thus its weight is the same this means that the water must be heavier so that it is displacing the same amount. The question is is salt water indeed heavier then fresh? I think it is since in the dead sea apparently people can float easily but I'm not totally sure

 

[Viper GTS]

<<

<< If it floats higher, isn't it displacing less?
Doesn't salt water weigh slightly less than fresh water?

Be gentle - I've been out of school for 40+ years. >>

If it floats higher it means it is displacing less volume. Since the mass of the boat is the same and thus its weight is the same this means that the water must be heavier so that it is displacing the same amount. The question is is salt water indeed heavier then fresh? I think it is since in the dead sea apparently people can float easily but I'm not totally sure >>



Yes, salt water is definitely more dense than fresh water.

Viper GTS

 

[UltraQuiet]

You guys are now talking about Buoyancy. Buoyancy = Volume (of the ship) x Density ( of the water). Cold salty water is more dense than fresh warmer water. Since we can assume that the volume of the ship has not changed (we don't even consider this in subs) we know buoyancy will change with density. Our main concern with maintaining nuetral buoyancy on subs is salinity and temperature which are two of the main components of density (pressure being the third). It can get a bit tricky as you approach the surface/periscope depth or move in and out of say the Gulf stream where there are vast temperature changes.