Does a capital ship sinking actually SUCK a swimmer down to

[M. Stradbury]

On Tue, 22 Dec 2015 08:53:14 -0500, (PeteCresswell) wrote:

> Dunno what a capital ship is but am guessing it's big.

My bad for not defining it, but you, sir, are correct, although
in looking it up, I realized I was not correct:

https://en.wikipedia.org/wiki/Capital_ship

 

[Poutnik]

Dne 22/12/2015 v 04:51 Sylvia Else napsal(a):

On 22/12/2015 11:04 AM, M. Stradbury wrote:
Is it true (or an urban myth) that a swimmer would be sucked
under (presumably to drown) when a capital ship sinks?


Mythbusters tried it, and concluded that there was no significant
sucking sown.

I have often the impression their experiments are designed
in the first place rather for the effect,
than to really investigate the nature of phenomena.

E.g. I watched their investigation of economic effect
of frequent switching on/off
the incandescent, fluorescent and LED lights.

They were over focused to refute the obvious nonsense
the light at switching consume more power
than saved by being off, and were successful there.

OTOH, experiment part about saving power
versus shortening device life was very poorly designed
and result had no statistical value.

--
Poutnik ( the Czech word for a wanderer )

Knowledge makes great men humble, but small men arrogant.

 

[Micky]

On Tue, 22 Dec 2015 10:18:34 +0100, Poutnik <poutnik4nntp@gmail.com>
wrote:

Dne 22/12/2015 v 02:56 Micky napsal(a):
On Tue, 22 Dec 2015 00:04:23 -0000 (UTC), "M. Stradbury"
mstradbury@example.com> wrote:

Is it true (or an urban myth) that a swimmer would be sucked
under (presumably to drown) when a capital ship sinks?

I would think so. I was in a 6-man rubber raft that went over a
small falls and under water and though I wasn't tied to the raft, I
went under water too. How much more so with a big ship.

But it could be because of your motion dynamics,
as you inertially continue water under,
until your buoyancy gradually reverted your velocity.

True. I'm no longer convinced. (Even though I doubt mythbusters on
general principles). If one were right by the ship when it went
quickly down, one would fall into the hole it left, but the water it
pushed aside would be crashing back right after the ship passed also.
How deep the person would go is a question.

I think if you were standing on the deck, whether the deck was
horizontal or leaning, you could drop as fast as the ship did. Why
not? Until there was enough water surrouding you for buoyancy to
matter.

But if you were 3 inches from the ship, already floating in the water,
would you fall over like in a waterfall? I think so, but like I say,
you'd be competing with the water to see who and what dropped first.

One could experiement with little floating balls and big rocks dropped
close to them, or better yet, held close to them at surface level and
then released. A method for determining how deep they go would be
needed.

Anyhow my point originally was no swirling. I coudl have kept silent
on other stuff.

 

[Poutnik]

Dne 22/12/2015 v 08:58 Sylvia Else napsal(a):

On 22/12/2015 4:19 PM, Tony Hwang wrote:

Do you have any maritime experience? Worked on any kind of ocean
going vessel(s)? Possess any knowledge gained from real life
experience?

Experience of ships? No. How would any of that help in deciding whether
the vessel would suck me down if it sank?

Or do you think there's some sort of mechanism that allows enlightenment
by osmosis?

Nautical society has advantage of collective experience
of huge number of people, surviving the ship sinking.

Even if I had been Nobel laureate for physics,
sailors would know more about surviving on sea than me.

If personalizing,
Sea has already laughed to many theoretical thoughts.

--
Poutnik ( the Czech word for a wanderer )

Knowledge makes great men humble, but small men arrogant.

 

[Poutnik]

Dne 22/12/2015 v 05:36 M. Stradbury napsal(a):

Theory 1:
Air mixes with water makes the water less dense, hence
sucking you down.

I have seen a video where a boat was in a lab sinked by this way,

in document about the Bermuda triangle,
following the hypothesis
about sudden huge gas release
from the sea bad or underwater vulcanos.

Sinking a swimmer with density close to water
is much easier than sinking a boat.

--
Poutnik ( the Czech word for a wanderer )

Knowledge makes great men humble, but small men arrogant.

 

[Poutnik]

Dne 22/12/2015 v 07:06 O napsal(a):

Back then, the reason to get away from the sinking ships was not the
suction but the boilers exploding.

I agree it is the best to get far from a wreck
independently on if whirl sucking is a danger or not.

--
Poutnik ( the Czech word for a wanderer )

Knowledge makes great men humble, but small men arrogant.

 

[Micky]

On Tue, 22 Dec 2015 11:13:47 +0100, Poutnik <poutnik4nntp@gmail.com>
wrote:

Dne 22/12/2015 v 05:36 M. Stradbury napsal(a):

Theory 1:
Air mixes with water makes the water less dense, hence
sucking you down.

I have seen a video where a boat was in a lab sinked by this way,

I knew a guy who drowned in club soda.

I think there was a lot of scotch, too.

 

[Sylvia Else]

On 22/12/2015 9:06 PM, Poutnik wrote:

Dne 22/12/2015 v 08:58 Sylvia Else napsal(a):
On 22/12/2015 4:19 PM, Tony Hwang wrote:

Do you have any maritime experience? Worked on any kind of ocean
going vessel(s)? Possess any knowledge gained from real life
experience?

Experience of ships? No. How would any of that help in deciding whether
the vessel would suck me down if it sank?

Or do you think there's some sort of mechanism that allows enlightenment
by osmosis?


Nautical society has advantage of collective experience
of huge number of people, surviving the ship sinking.

Even if I had been Nobel laureate for physics,
sailors would know more about surviving on sea than me.

For most things, perhaps. But how many sailors have experience of a
sinking, much less such experience from the the immediate vicinity of
the ship. Those who got sucked down, if any, won't be around to tell the
tale. Those who didn't get sucked down, and survived, would be
counter-examples.

Sylvia.

 

[Poutnik]

Dne 22/12/2015 v 12:13 Sylvia Else napsal(a):

On 22/12/2015 9:06 PM, Poutnik wrote:


For most things, perhaps. But how many sailors have experience of a
sinking, much less such experience from the the immediate vicinity of
the ship. Those who got sucked down, if any, won't be around to tell the
tale. Those who didn't get sucked down, and survived, would be
counter-examples.

I do not say current sailors, but history
of survival records and withnesses.

There are 2 other options.

Those surviving seeing others being sucked down,
Those being sucked down not enough to die.

--
Poutnik ( the Czech word for a wanderer )

Knowledge makes great men humble, but small men arrogant.

 

[Poutnik]

Dne 22/12/2015 v 04:51 Sylvia Else napsal(a):

On 22/12/2015 11:04 AM, M. Stradbury wrote:
Is it true (or an urban myth) that a swimmer would be sucked
under (presumably to drown) when a capital ship sinks?


Mythbusters tried it, and concluded that there was no significant
sucking sown.

https://www.youtube.com/watch?v=rvU_dkKdZ0U

But the did not make any attempt
to maintain geometrical similarity.

IF a sailor size was 1/4 of a ship size,
he would not be sucked either.

I am not sure, if the viscosity has to be scaled
as well for that matter, but I guess it has.

As I mentioned in my other post
the Mythbusters do not care much
about reliability of their experiments and interpretations.

--
Poutnik ( the Czech word for a wanderer )

Knowledge makes great men humble, but small men arrogant.

 

[taxed and spent]

"Sylvia Else" <sylvia@not.at.this.address> wrote in message
news:ddrvmlF4vpjU1@mid.individual.net...

On 22/12/2015 11:04 AM, M. Stradbury wrote:
Is it true (or an urban myth) that a swimmer would be sucked
under (presumably to drown) when a capital ship sinks?


Mythbusters tried it, and concluded that there was no significant sucking
sown.

https://www.youtube.com/watch?v=rvU_dkKdZ0U

Sylvia.

mythbusters is a crock.

 

[(PeteCresswell)]

Per M. Stradbury:

Is it true (or an urban myth) that a swimmer would be sucked
under (presumably to drown) when a capital ship sinks?

Dunno what a capital ship is but am guessing it's big.

I saw an interview clip in which Lord Louis Mountbatten told of
surviving his destroyer's sinking - along with a senior NCO who said at
the time something like "Well sir, the scum always rises to the surface"
so I am guessing that both were in the water when the ship went down
under them.

--
Pete Cresswell

 

[Phil Hobbs]

On 12/21/2015 07:04 PM, M. Stradbury wrote:

Is it true (or an urban myth) that a swimmer would be sucked
under (presumably to drown) when a capital ship sinks?

Yes. The main mechanism iirc is that air escaping from the sinking ship
causes enough bubbles that the swimmer can't stay afloat, and sinks too
deep to get back to the surface.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net

 

[Bob F]

M. Stradbury wrote:

Is it true (or an urban myth) that a swimmer would be sucked
under (presumably to drown) when a capital ship sinks?

I would think that huge bubbles of air coming out of a sinking ship could easily
drop people deeply under water. If a bubble surrounds you, you will not be
floating anymore. You will be falling.

 

[Bob F]

M. Stradbury wrote:

On Mon, 21 Dec 2015 18:51:29 -0700, Tony Hwang wrote:

Like toilet bowl water swirls.

A toilet bowl is too small to show the Coriolis effect, but a pool
isn't according to Sandlin and Muller.

http://mashable.com/2015/06/04/water-toilet-swirl/#vRjaqfm0bSqs
"Derek Muller and Destin Sandlin, the minds behind the Veritasium and
Smarter Every Day YouTube channels, respectively, do show that water
(and even hurricanes or cycloness) preferentially spins
counter-clockwise in the north and clockwise in the south, you just
might not be able to see it with your toilet water."

I just flushed both my toilets. One went clockwise. The other went
counterclockwise. QED.

 

[(PeteCresswell)]

Per M. Stradbury:

https://en.wikipedia.org/wiki/Capital_ship

Then I guess my little anecdote is moot because a destroyer looks much
smaller than an aircraft carrier or battle ship...
--
Pete Cresswell

 

[Poutnik]

Dne 22/12/2015 v 17:19 Bob F napsal(a):

M. Stradbury wrote:
On Mon, 21 Dec 2015 18:51:29 -0700, Tony Hwang wrote:

Like toilet bowl water swirls.

A toilet bowl is too small to show the Coriolis effect, but a pool
isn't according to Sandlin and Muller.

http://mashable.com/2015/06/04/water-toilet-swirl/#vRjaqfm0bSqs
"Derek Muller and Destin Sandlin, the minds behind the Veritasium and
Smarter Every Day YouTube channels, respectively, do show that water
(and even hurricanes or cycloness) preferentially spins
counter-clockwise in the north and clockwise in the south, you just
might not be able to see it with your toilet water."

I just flushed both my toilets. One went clockwise. The other went
counterclockwise. QED.

There are too strong forces, fast current speeds
and random turbulent processes
for Coriolis force to have any effect.

--
Poutnik ( the Czech word for a wanderer )

Knowledge makes great men humble, but small men arrogant.

 

[M. Stradbury]

On Tue, 22 Dec 2015 11:41:02 -0500, (PeteCresswell) wrote:

Then I guess my little anecdote is moot because a destroyer looks much
smaller than an aircraft carrier or battle ship...

What I had meant, in the OP, was "big ship" (not a life raft or tugboat,
for example, which is what the MythBusters seem to have tested).

To "me", a destroyer qualifies as a 'big ship' (when it's sinking out
from under you); but I was wrong in the definition since the Wikipedia
article said a Capital ship is an "important" ship (so to speak).

What I meant though was a "big" ship (big enough to suck you so far
down, if it's gonna suck you, that you'd drown before coming back up).

I think the most reliable things that came out of this quest
so far were:

a) Mythbusters said busted - but they tested what amounts to a
very "tiny" ship.
b) People swim away for *lots* of reasons (all good) not the
least of which are explosions, fire, oil slicks, rigging,
falling objects, etc.

So, the mere fact they're taught to swim away doesn't really
tell us whether or not they're sucked under at the time of
sinking.

I don't actually know if we have a definitive answer that most
of us would agree fits the typical definition of 'scientific'
evidence yet, either way.

But the capital-air-bubbles-aren't-buoyant theory does sound
plausible (it seems to me it would be easy to test with ants
and toy ships or something).

I'll keep reading and looking and observing ... until we find
out the answer.

 

[taxed and spent]

"Poutnik" <poutnik4nntp@gmail.com> wrote in message
news:n5buih$4bn$1@dont-email.me...

Dne 22/12/2015 v 17:19 Bob F napsal(a):
M. Stradbury wrote:
On Mon, 21 Dec 2015 18:51:29 -0700, Tony Hwang wrote:

Like toilet bowl water swirls.

A toilet bowl is too small to show the Coriolis effect, but a pool
isn't according to Sandlin and Muller.

http://mashable.com/2015/06/04/water-toilet-swirl/#vRjaqfm0bSqs
"Derek Muller and Destin Sandlin, the minds behind the Veritasium and
Smarter Every Day YouTube channels, respectively, do show that water
(and even hurricanes or cycloness) preferentially spins
counter-clockwise in the north and clockwise in the south, you just
might not be able to see it with your toilet water."

I just flushed both my toilets. One went clockwise. The other went
counterclockwise. QED.


There are too strong forces, fast current speeds
and random turbulent processes
for Coriolis force to have any effect.

When I was in Ecuador, I did my own test. Quite a bit north of the equator,
I filled a wash basin with water and pulled the plug. The water swirled one
way.

AT the equator, I did the same thing, and the water just drained.

A bit south of the equator, I did the same thing, and there wasn't much of
interest.

Further south of the equator, I did the same thing, and the water swirled
the opposite way.

I eliminated water current, toilet bowl rim jet patterns, etc.

Q.E.D.

 

Tony Hwang wrote: - show quoted text -
"Basic fluid mechanics. You know that the swirl direction of opposite of
Southern hemisphere. CCW and CW. Rotating earth. "

Coriolis does not apply to toilets. The direction of
rotation in a toilet bowl is determined by how the
jets(holes underneath the rim) are angled.