Dave, stop trying to change your statements (and stop bottom
posting).
You stated that subs don't use water for ballast.
I posted a few, out of many, sites that state otherwise.



--
Scott Vernon
Plowville Pa _/)__/)_/)_



"Dave Doe" wrote in message
z...
In article ,
says...

"Dave Doe" wrote in message
. nz...
In article ,
says...

"Dave Doe" wrote in message
. nz...

Can you sink a 'positive buoyancy' boat with water? Can
you
sink it with
lead? You've proven my own point.



What do submarines fill their ballast tanks with?

positive bouyancy boat submarine - EVER.


Bzzzt...Oh, I'm sorry, the correct answer is ''WATER'' .

Thanks for playing.

Thanks for your worthless (top posted) posts and links re subs.
They
point out what I have already - that subs sink because their
overall
density is greater than that of the water they are in.

They DO NOT SINK BECAUSE OF WATER!!! - and none of those
articles you
posted suggest they do. They simply describe the bouyancy
mechanism
subs use to go up or down in the water.

Like I also suggested to you - why don't you try thinking of
something
simpler - such as a diver.

Even a simpleton like you should be able to work out that, just
like a
sub, a diver has a bouyancy device - the BCD. However it is of
no use,
no matter how much air you drain from it, or replace with
water - if the
diver is not wearing their weight belt.

Thanks for the laughs though.

--
Duncan

In article ,
says...
Dave, stop trying to change your statements (and stop bottom
posting).
You stated that subs don't use water for ballast.
I posted a few, out of many, sites that state otherwise.

a.
Indeed they do not. They probably use Lead or DU. Neither of those
sites w' the info you posted conclude that subs use water for ballast -
one mentions the key fact, a sub is denser than water. The bouyancy
ballast tanks are then regulated with air to adjust density and float or
sink as required. The water in the bouyancy ballast tanks serve only to
displace the air - and it's ideal as it has the same density as the
water the sub is in (and that alone should tell you, it can never make
the sub sink!)

b.
You are referring to the bouyancy ballast tanks - diphead! That is
*not* "the ballast". Equivalent to a diver's BCD.

c.
Without the ballast at the bottom of a sub (as said, I believe it will
be Lead (or DU for modern war subs)), OR the construction itself -
producing a vessel that is denser than water (mass/volume) - the sub
will not sink!

Just like a diver without a weight belt.

And PS: the only reason subs replace the air with water in the bouyancy
ballast tanks is because they are solid tanks - the water is irrelevant.
(A diver's BCD is not replaced with water, as it's a rubber bag that
simply deflates).

--
Duncan

You stated that subs don't use water for ballast.
I posted a few, out of many, sites that state otherwise.


Dave Doe wrote:
a.
Indeed they do not. They probably use Lead or DU.

Really? Is there a special place in the ocean where
submarines can just scoop up some lead or DU when they want
to dive?

DSK

In article ,
says...
You stated that subs don't use water for ballast.
I posted a few, out of many, sites that state otherwise.


Dave Doe wrote:
a.
Indeed they do not. They probably use Lead or DU.

Really? Is there a special place in the ocean where
submarines can just scoop up some lead or DU when they want
to dive?

You're just being a pedant aren't you.

What makes a diver sink? - the BCD? Or the weight belt?

The lead or DU is put in the sub at manufacture time, to ensure it is
"heavier than water" (it's overall desnity is greater than water).

Otherwise.. yes they *would* have to find a special place to scoop up
lead, DU, rocks - whatever - to submerge - as their bouyancy ballast
tanks would be ineffective with water in them. You'd have a positive
bouyancy vessel. You can put as much water in 'em as you like - it'd
never sink.

Ostentatious reply expected...

--
Duncan

Dave Doe wrote:
You're just being a pedant aren't you.


No, I am less interested in seeming clever, and playing
semantic games, than I am with simple facts and the physics
that make things work.

What makes a diver sink? - the BCD? Or the weight belt?


Totally different picture. The BCD is a variable volume
device. When the diver inflates it, he is increasing his
displaced volume. That would be similar to attaching a
helium balloon to a sailboat mast for added stability.


The lead or DU is put in the sub at manufacture time, to ensure it is
"heavier than water" (it's overall desnity is greater than water).


Then why does it float when the diving ballast tanks are empty?

Otherwise.. yes they *would* have to find a special place to scoop up
lead, DU, rocks - whatever - to submerge - as their bouyancy ballast
tanks would be ineffective with water in them. You'd have a positive
bouyancy vessel. You can put as much water in 'em as you like - it'd
never sink.


Really? The fact that they're made of steel, and are
ostentatiously lacking in styrofoam, would make it seem
likely otherwise.

Fact- water ballast works just fine.

Fact- any physics used to try & pretend it doesn't must be
false... just like any physics explaining why airplanes
can't really fly... or is that going to be your next hobby?

I do have one suggestion for you.... look up 'metacentric
height' and ponder the relationship of the ceneter of
gravity to the center of bouyancy. It's easier than the
sound of one hand clapping.

DSK

In article ,
says...
Dave Doe wrote:
You're just being a pedant aren't you.


No, I am less interested in seeming clever, and playing
semantic games, than I am with simple facts and the physics
that make things work.

What makes a diver sink? - the BCD? Or the weight belt?


Totally different picture. The BCD is a variable volume
device. When the diver inflates it, he is increasing his
displaced volume. That would be similar to attaching a
helium balloon to a sailboat mast for added stability.

What if the BCD was a solid container (non variable volume device) - and
when the air was displaced it was replaced with water. What difference
would that make?

The lead or DU is put in the sub at manufacture time, to ensure it is
"heavier than water" (it's overall desnity is greater than water).


Then why does it float when the diving ballast tanks are empty?

Because the tanks are not empty, they are full - with air.

Otherwise.. yes they *would* have to find a special place to scoop up
lead, DU, rocks - whatever - to submerge - as their bouyancy ballast
tanks would be ineffective with water in them. You'd have a positive
bouyancy vessel. You can put as much water in 'em as you like - it'd
never sink.


Really? The fact that they're made of steel, and are
ostentatiously lacking in styrofoam, would make it seem
likely otherwise.

You may be right. However are you forgetting they are also full of air
"where the people are" - and furthermore it must be reasonably
uncompressed (don't wanna kill those folk). As I have pointed out - a
sub must have an overall density greater than the water it is in. It
*may be* that the basic production of, makes 'em that way (I've said
that already). If not - they put ballast weight at the bottom of them -
but I admit, I don't know that for a fact. What I do know for a fact,
is that one OR the other MUST be true - or you have a positive bouyancy
"sub" - and it will *never* work - no matter how much water you put in
the bouyancy ballast tanks.

Fact- water ballast works just fine.

That depends on purpose. We are talkiing about *yachts*. How many
yachts use water ballasts vs lead keels? Is there a reason for that?
What's your boat got BTW?

Fact- any physics used to try & pretend it doesn't must be
false... just like any physics explaining why airplanes
can't really fly... or is that going to be your next hobby?

I do have one suggestion for you.... look up 'metacentric
height' and ponder the relationship of the ceneter of
gravity to the center of bouyancy. It's easier than the
sound of one hand clapping.

Yet more reason you'll find lead or DU at the bottom of a sub. (I guess
the thing could be underwater and upside down - damn hard to work in
those conditions though).

--
Duncan

"DSK" wrote in message
...
You stated that subs don't use water for ballast.
I posted a few, out of many, sites that state otherwise.


Dave Doe wrote:
a.
Indeed they do not. They probably use Lead or DU.

Really? Is there a special place in the ocean where
submarines can just scoop up some lead or DU when they want
to dive?


yes, in Doe Doe land.

SV

"Dave Doe" wrote in message a.


b.
You are referring to the bouyancy ballast tanks - diphead!
That is
*not* "the ballast". Equivalent to a diver's BCD.


diphead? My my, getting a bit testy, are we?



c.
Without the ballast at the bottom of a sub (as said, I believe
it will
be Lead (or DU for modern war subs)), OR the construction
itself -
producing a vessel that is denser than water (mass/volume) -
the sub
will not sink!


Oh, right, I keep forgetting, water weighs zero in Doe Doe land.

SV

In article ,
says...

"Dave Doe" wrote in message a.


b.
You are referring to the bouyancy ballast tanks - diphead!
That is
*not* "the ballast". Equivalent to a diver's BCD.


diphead? My my, getting a bit testy, are we?



c.
Without the ballast at the bottom of a sub (as said, I believe
it will
be Lead (or DU for modern war subs)), OR the construction
itself -
producing a vessel that is denser than water (mass/volume) -
the sub
will not sink!


Oh, right, I keep forgetting, water weighs zero in Doe Doe land.

And in water - given weight = a force (not mass - as many folk make this
false assumption).

Must be happy sailing in Doe Doe land Diphead. Don't fall in the water
though, in Doe Doe land you'll fall straight to the bottom.

--
Duncan

"Dave Doe" wrote in message
diphead? My my, getting a bit testy, are we?



Must be happy sailing in Doe Doe land Diphead. Don't fall in
the water
though, in Doe Doe land you'll fall straight to the bottom.


What's that saying about the first one in an argument to call
names?

SBV