Water as weight rather than lead?

[sb_diver]

Hey wanna see how a submarine works, check out this site
http://people.howstuffworks.com/submarine.htm

On this page, the animation shows how it changes its buoyancy
http://people.howstuffworks.com/submarine1.htm

 

[dweeb]

the problem being what to do with the excess electricity. Anyone have any ideas?

It's useful for interrogating Iraqi prisoners.

 

[Seabear70]

It's useful for interrogating Iraqi prisoners.

How many can you fit in a boomer???

Light 'em Up!!!!!!!!!!!!!!!!!!!

 

[redacted]

You must first determine your bouyancy and then add that much dehydrated lead to the water. It will absorb all the water you need to become neutrally bouyant.

 

[wolfen42]

No, depleted barely radiates. It was used for counterweights on some airplanes I worked on in the Navy. The A-4 stabilizers if I remember right. You did have to fill out some special forms if you had to remove/replace it though.

Heck, DU was used as counterweights on some commercial aircraft until all the hysteria about it was started by the know-nothings.


Hmm... sorry about the zombie thread. I was poking around looking for potential cheap lead sources for weighting and started reading this one.

 

[perdidochas]

the question:

can you use water as weight, instead of lead weight?

For example, say that you take containers of water instead of lead. Yes, water weights six pounds per gallon, so you would have to take two gallons of water to equal 12 pounds, but...

Say you tie two milk gallons full of water to your waist...

Wouldn’t it be the same as wearing lead weights?

We were having this discussion, and someone was saying that wouldn’t work, because the water would “float on water."

is this correct?

Well, fresh water jugs in salt water would float very slightly. Salt water in salt water would be neutrally bouoyant--neither sink nor float you. However, those gallon jugs will weight you down outside of the water.

 

[perdidochas]

Lead is used primaryily becuase of the weigh you get for small size. less bulky. althought some of my students who need a lot of lead might disagree about the less bulky comment. i guess you'd have to show them how big a sand bag you'd need for equal bag of lead shot so make the point more believeable.

Lead is used because of density. 1 kg of sand will not sink a person in water as well as 1 kg of lead. 1 kg of sand will displace about 1/2 liter of water. 1 kg of lead will displace 1/11th liter of water. The amount of water displaced is buoyancy. Hence the 1kg of sand will only be a net negative buoyancy of 1/2 kg. The lead will have a net negative bouyancy of 10/11 kg. To have the same effect as 11 kg of lead, you would need 20 kg of sand. The lead will take up 1 liter of space, the sand will take up 10 liters of space.

 

[perdidochas]

Monty Python movies aside, rocks are about 3.0 to 3.5 times as dense as water but very small rocks will still remain on the surface due to surface tension. So Monty is, after all is said and done, right.

You are forgetting about pumice, which is basically gas filled hardened lava, which floats, regardless of size.

BC's (or wings for the technically inclined diver) function just like ballast tanks where air is used to displace water and create bouyancy.

Now, some ROV's are also being designed with an electrically actuated piston to add or reduce space for water in a ballast tank to enable bouyancy changes to be made without having to rely on limited air supplies.

So you could cut the bottom out of your old AL 80 when it develops fatigue cracks, insert a suitable piston and actuator and develop an entirely new airless ballast system for scuba divers.

 

[Gil57usa]

Is this really a thread ?

 

[Damselfish]

I bet someone's bummed it got dredged up...