Why do the hulls of ships usually contain large volumes of air?

Question

I have this as a science question, but Im not really sure about it.

So far, I have:

The metal and the air together are lighter than the water they displace, allowing a ship to float.

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Thanks

Answer 1

Often those spaces for air are used for ballast. When I was in the US Navy, depending on which side the ship was listing (leaning towards), the Engineering department would pump in sea-water into those empty air spaces (called voids or tanks).  The weight of that water would help stabilize the ship, and correct for any listing problems - allow the ship to travel on an even keel.

When the ship no longer needed the water for ballast purposes, it would be pumped out and fresh air would be brought back into the void/tank.

Answer 2

for the bouyancy...to make the ship float...

Answer 3

As the speed and power of surface ships rise, the reduction of ship acoustic signature and self-noise is becoming an important task of naval engineering. A significant decrease in underwater noise can be achieved by using gaseous layers on the ship hull. Two mechanisms for sound radiation from low-drag air-lubricated hulls are discussed.

Answer 4

yeah that would be why a boat floats. duh!

Answer 5

Yes ,water weighs 1gram per cubic centimeter. Calculate. the total weight the boat and all the extra equipment must have a minimum displacement equal to that weight. The air spaces

allow the area of the boat to be lighter than the area of the water it displaces.

Answer 6

it's just bouyancy and volumetrics. your answer is the most concise and direct while steph's cut and paste from the wikipedia is an engineer geek's version and will probably get you low marks. stay on track.

Answer 7

to make them float

Answer 8

That is real good reason.  That is what i put on my science paper.

Answer 9

a simple test use a glass jar if you leave the stopper off,the glass fills  with water , with stopper fully on, sink the water chases  out the air, if reversed  the sealed container  holds the air thats what  makes it float just like when you do the dishes a cup would float,,hope this helps

Answer 10

Because if they contained large volumes of water, they'd be sunken wrecks!!!

Answer 11

yep floating is important for boats....jeesh

Answer 12

Its so it can float if there is no air if its just solid i dont think the displacement of water would work because it would be heavier and just sink, so i think its because it has a lower density then water which helps with the boat floating. :)

I totally made all of that up. I dont know anything about boats, but it sound pretty offical.

Answer 13

You've got the answer my friend.

Answer 14

You could work the word "buoyant" or "buoyancy" in there.

Answer 15

They have large volumes of air because nature abhors a vacuum.

Answer 16

try not to think of it as a room full of air look at it more like a empty room that was made for the purpose of bouyancy, but its not just the room full of air that makes these things float, the design itself plays an important role. but these empty spaces are known as voids or tank, take for example your house, when you stand out side and put your hand on the wall you are not touching the back side of the wall  thats in the house you surely know that their is an empty space between the outer and inner wall, no different on a vessel, but in the vessels situation its purpose is for floatation, and the spaces vary in size depending on the size of the vessel, if it is a ship then the space is greater for more support and buoyancy of the ship, and yes these tanks or voids can be flooded and pumped dry when needed, the resons for this can be , to correct a lean, or if the ship is listing(leaning) to the port(left side)then you will pump water into on of the stbd.(right side) voids to correct the list and straighten the ship, others reason can be light on fuel and the ship cavitates (shakes) real bad and their for pumps water in to heavy the ship and correct the shaking, also if one of the tanks happens to get a hole in it and floods or fills up with water then the water will stay in their until repairs are made and it will call for the flooding of other voids to level the ship, i hope this helps you out