Iranian Missiles And Torpedos

Looks like Iran is testing more missiles and torpedos:

http://www.cnn.com/2006/WORLD/meast/....ap/index.html


Excerpt: "Iran said the torpedo tests were conducted Sunday and Monday. The
torpedo -- called a "Hoot," or "whale" -- is able to move at 223 mph, too
fast for any enemy ship to elude."


223 mph ?? Does that number sound correct ?


JD

Excerpt: "Iran said the torpedo tests were conducted Sunday and Monday.
The
torpedo -- called a "Hoot," or "whale" -- is able to move at 223 mph, too
fast for any enemy ship to elude."


223 mph ?? Does that number sound correct ?


A tube with a high density (water) projectile cap at one end and a rocket
motor near the other end may go even faster. Care has to be taken that
sufficient velocity is reached before water can enter the tube and
extinguish the motor as well as fins, guidance and other particulars.

At Strategy page there was an article on this. It seems this underwater
missile is very short range, 5-7 km, and extremely limited steerage. Notice
that no one else has developed such a missile, only the Russians make them.
Per the article the missile is a last ditch defense system.

"Juergen Nieveler" wrote in message
. ..
"George" wrote:

But if they can't aim it, it means nothing. They say it can evade
radar. Yeah, who's radar? They're radar is 1970s vintage. Ours?
Highly unlikely.

Extremely likely, actually - Torpedoes rarely get picked up by radar :-)

Incorrect, since we use airborne radar to detect torpedos (among other
technologies, such as sonar) and can detect supercavitating missiles. You
did note that Iran bragged about the radar-evading material they've coated
this thing with, didn't you?

They make it sound like something special, but the fact is that the
U.S. has supercavitating weapons already.

The Iranians weren't saying "We got something you don't have", only
"Look at what we have".

They can prance all they care to. It makes no difference whatsoever.
Saddam had exocet missiles, and they couldn't hit the broad side of a barn
with them, despite the fact that the Exocet is a good system.

They have nothing new here,

No doubt about that. GUIDED supercavitating torpedoes would be
something new, but I doubt that Iran was able to copy the "Barracuda"
:-)

We've already got something that will knock a Barracuda right out of the
water. I think I posted a link to it already.

nothing that can't be taken out during the first days of any air
campaign.

That's a totally different story... Unlike Iraq, Iran still has a
working air defense system and has had lots of opportunities to learn
from the demise of its former enemy.

And as we have seen, air defenses are completely vulnerable to aircraft and
missiles they cannot see. Not a problem there either.

George

"George" wrote in message
news:Fem_f.675720$084.456492@attbi_s22...

"Juergen Nieveler" wrote in message
. ..
"George" wrote:

But if they can't aim it, it means nothing. They say it can evade
radar. Yeah, who's radar? They're radar is 1970s vintage. Ours?
Highly unlikely.

Extremely likely, actually - Torpedoes rarely get picked up by radar :-)

Incorrect, since we use airborne radar to detect torpedos (among other
technologies, such as sonar) and can detect supercavitating missiles. You
did note that Iran bragged about the radar-evading material they've coated
this thing with, didn't you?

I suspect you are confusing your weapons. I've seen claims of radar
invisibility in relation to the ground-effect craft, but not the
supercavitating missile. The GE craft did have that slab-sided "stealth"
look about it. If the water craft are invisible to radar as claimed, they
would still have to get within a few km of a ship to be effective. There
might be a chance that, combined, the two weapons could get a hit in, before
a ship could get out of the way or deploy countermeasures.

In sh'allah, we will never know.

Aussie Infidel

"Aussie Infidel" wrote in message
...


I suspect you are confusing your weapons. I've seen claims of radar
invisibility in relation to the ground-effect craft, but not the
supercavitating missile.

Agree. I saw the radar evading claim assigned to their surface-to-surface
missile and not to a torpedo.


JD

"Aussie Infidel" wrote in message
...

"George" wrote in message
news:Fem_f.675720$084.456492@attbi_s22...

"Juergen Nieveler" wrote in message
. ..
"George" wrote:

But if they can't aim it, it means nothing. They say it can evade
radar. Yeah, who's radar? They're radar is 1970s vintage. Ours?
Highly unlikely.

Extremely likely, actually - Torpedoes rarely get picked up by radar
:-)

Incorrect, since we use airborne radar to detect torpedos (among other
technologies, such as sonar) and can detect supercavitating missiles.
You did note that Iran bragged about the radar-evading material they've
coated this thing with, didn't you?

I suspect you are confusing your weapons. I've seen claims of radar
invisibility in relation to the ground-effect craft, but not the
supercavitating missile. The GE craft did have that slab-sided "stealth"
look about it. If the water craft are invisible to radar as claimed,
they would still have to get within a few km of a ship to be effective.
There might be a chance that, combined, the two weapons could get a hit
in, before a ship could get out of the way or deploy countermeasures.

In sh'allah, we will never know.

Aussie Infidel

But do you truly believe that our Navy is going to let Iran get close
enough to actually use this weapon? Then there are the porblems with
steering this thing, which I'm sure is a huge issue.

George

Juergen Nieveler wrote:
"George" wrote:

Incorrect, since we use airborne radar to detect torpedos (among other
technologies, such as sonar)

Can you post any links on that? I'm curious how EM waves should be able
to penetrate sal****er far enough AND get enough reflection back to the
aircraft to do that :-)

I wasn't following this thread, but saw an opportunity to use a formula
I know 8^)
The skin depth equation for EM waves in a conductor is:
d = sqrt(2p/wu)
Where
d = skin depth
p = resistivity (normally Greek letter rho)
w = angular frequency (normally Greek letter omega)
u = magnetic permeability (normally Greek letter mu)
Skin depth is the depth of penetration in a semi-infinite body (e.g.,
the ocean) through which the signal current density is reduced by a
factor of 1/e = 0.37. (It generally applies at any frequency when we
can consider the material to be a uniform mass, but breaks down once we
get to freqs so high individual photons can interact with individual
molecules.)
Plugging in typical values for seawater, we get
d = 252 metres x sqrt(freq in Hz)
However most folks aren't used to factors of 1/e so it's nice to
convert to dB; each factor of 1/e is the same as -4.34 dB. Also, most
engineers are used to talking about loss per length rather than length
per loss, so we might like to invert everything. Then we get:
Attenuation = sqrt(freq in Hz) x 0.0172 dB/m
It immediately becomes apparent why systems for signalling to
submarines like to use very low frequencies; if we plug in even, say,
160 kHz, we get attenuation of 6.88 dB/m which will give some pretty
serious path loss after just a few metres depth.

So, this brings us to radar. Typical modern radar frequencies run from
about 0.3 GHz to about 40 GHz, and even 0.3 GHz is far too high. Of
course in the olden days we had some lower freq radars, and still do in
the special case of OTH radar. However we are limited by the fact that
once the wavelength starts to get longer than the longest dimension of
the object being detected, we again lose sensitivity very rapidly. So
our wavelength can't be much more than around 6 m, equivalent to about
50 MHz. At 50 MHz, attenuation is about 120 dB/m. And note that the
beam is being attenuated coming in and going out. A torp running at a
depth of just 3 metres will give the radar beam 6 metres of seawater to
pass through, giving 720 dB attenuation even at 50 MHz. No frickin'
way.

In practice, most ASW radar are X-band or thereabouts (~10 GHz). With a
seawater attenuation of 1000 ~ 2000 dB/m, they are useless for
penetrating seawater, but the 3cm wavelength means they are able to
detect periscopes and snorkels.

"George" wrote in message
news:T71_f.915202$xm3.227305@attbi_s21...

"Juergen Nieveler" wrote in message
. ..
"Joe Delphi" wrote:

223 mph ?? Does that number sound correct ?

Why not? Shkval allegedly can reach 300 mph...

Juergen Nieveler
--
Open Windows and let the bugs in.

But if they can't aim it, it means nothing. They say it can evade radar.
Yeah, who's radar? They're radar is 1970s vintage. Ours? Highly
unlikely.
They make it sound like something special, but the fact is that the U.S.
has supercavitating weapons already. They have nothing new here, nothing
that can't be taken out during the first days of any air campaign. And
all
the while we can stand back at a distance and pound the hll of them. Iran
is blowing smoke.


The Iranians are claiming that the underwater rocket has a range of 10km,
but there's not a chance in hell that an Iranian sub or ship will get within
10km's of a U.S. aircraft carrier.

So basically the entire weapon is fundamentally flawed. It's only usefull
against oil tankers and cruise ships but those could just as easily be taken
out with normal torpedoes or even mines.


*** Free account sponsored by SecureIX.com ***
*** Encrypt your Internet usage with a free VPN account from http://www.SecureIX.com ***

"Juergen Nieveler" wrote in message
. ..
"George" wrote:

But if they can't aim it, it means nothing. They say it can evade
radar. Yeah, who's radar? They're radar is 1970s vintage. Ours?
Highly unlikely.

Extremely likely, actually - Torpedoes rarely get picked up by radar :-)

They make it sound like something special, but the fact is that the
U.S. has supercavitating weapons already.

The Iranians weren't saying "We got something you don't have", only
"Look at what we have".

They have nothing new here,

No doubt about that. GUIDED supercavitating torpedoes would be
something new, but I doubt that Iran was able to copy the "Barracuda"
:-)

nothing that can't be taken out during the first days of any air
campaign.

That's a totally different story... Unlike Iraq, Iran still has a
working air defense system and has had lots of opportunities to learn
from the demise of its former enemy.

The Iranians even have the feared Soviet SA-10 Grumble SAM system which is
among the best in the world. I'm pretty curious how the U.S. is going to
take them out. If the Iranians have any sense at all they'll move them on a
daily basis, otherwise they'll be easy bait for the cruise missiles and
F-117's.


*** Free account sponsored by SecureIX.com ***
*** Encrypt your Internet usage with a free VPN account from http://www.SecureIX.com ***