Squall torpedo

Gord Beaman wrote:

Do torps really use trailing wire guidance now?...they sure
didn't when I was involved in ASW between 1951 and 77. Matter of
fact I never heard of that before, (although some 'missiles' do).

Air-launched lightweight torpedoes don't, with one notable exception -- the
Swedish 400mm series (Tp 42, 43, and 46; no relation to US designations).

Heavyweight submarine-launched torpedoes gernerally do. There are
exceptions, of course, but a modern heavyweight is more likely than not to
have wire guidance.

--
Tom Schoene Replace "invalid" with "net" to e-mail
"Our country, right or wrong. When right, to be kept right, when
wrong to be put right." - Senator Carl Schurz, 1872

"Thomas Schoene" wrote:

Gord Beaman wrote:

Do torps really use trailing wire guidance now?...they sure
didn't when I was involved in ASW between 1951 and 77. Matter of
fact I never heard of that before, (although some 'missiles' do).

Air-launched lightweight torpedoes don't, with one notable exception -- the
Swedish 400mm series (Tp 42, 43, and 46; no relation to US designations).

Heavyweight submarine-launched torpedoes gernerally do. There are
exceptions, of course, but a modern heavyweight is more likely than not to
have wire guidance.

Thanks Tom, Being familiar with air launched units only I hadn't
heard of this method much before.

I suppose that the Swedish job must be launched from helos only
right?...
--

-Gord.
(use gordon in email)

Q: How does a solid rocket fuel compare to liquid fuel as far as
specific thrust versus density of loading?
I can see why the two exotic torp oxidizers/monopropellants I am
familiar with, propylene glycol dinitrate and hi-test hydrogen
peroxide, are not 'sub-friendly' but I don't know how either would
compare to say ammonium perchlorate/aluminum/hydrocarbon solid fuel.
Looks like powered duration on Skval is about 90 seconds max.
Launching it will surely give a very noisy sound signature and a fix
if there's more than one searcher close by - on its origin.
If it is used against a formation it looks like there would be a trade
- one sub for one target.
Walt BJ

In article ,
(WaltBJ) writes:
Q: How does a solid rocket fuel compare to liquid fuel as far as
specific thrust versus density of loading?

I depends on the fuel. Specific Impulse is usually higher for a
liquid, but, especially with a small system, a chunk of that gets
eaten up by hte weight and volume of the tanks, pumps, and
plumbing. (For values of chunk ranging from "A fair bit" to "all").
Fuel density become imortant. Hydrogen can provide an amazing amoutn
of energy, but yyou get about 6 times the kW/l with Kerosene.
One of the early Sparrow III (AIM-7) models used a storable liquid
rocket motor. for that scale of system, it basicall provided the same
performance, in the same volume and weight, as the solids that
replaced it.

I can see why the two exotic torp oxidizers/monopropellants I am
familiar with, propylene glycol dinitrate and hi-test hydrogen
peroxide, are not 'sub-friendly' but I don't know how either would
compare to say ammonium perchlorate/aluminum/hydrocarbon solid fuel.
Looks like powered duration on Skval is about 90 seconds max.
Launching it will surely give a very noisy sound signature and a fix
if there's more than one searcher close by - on its origin.
If it is used against a formation it looks like there would be a trade
- one sub for one target.

Since it's supposedly a nuke, it would be generally considered to have
a Pk of 2.0 - the target, and the shooter.


--
Pete Stickney

Without data, all you have are opinions

On 3 Dec 2004 19:38:10 -0800, (WaltBJ) wrote:

Q: How does a solid rocket fuel compare to liquid fuel as far as
specific thrust versus density of loading?
I can see why the two exotic torp oxidizers/monopropellants I am
familiar with, propylene glycol dinitrate and hi-test hydrogen
peroxide, are not 'sub-friendly' but I don't know how either would
compare to say ammonium perchlorate/aluminum/hydrocarbon solid fuel.
Looks like powered duration on Skval is about 90 seconds max.
Launching it will surely give a very noisy sound signature and a fix
if there's more than one searcher close by - on its origin.
If it is used against a formation it looks like there would be a trade
- one sub for one target.

In strategic terms that might be a good trade. Tough on the crews,
though.

Bill Kambic

In article , "Keith Willshaw"
wrote:


The Skhval is a short range straight runner that does NOT
home in on the steering gear or screws. The Russian
torpedo that IS dangerous in this respect is the large
Type 53-65 passive wake homing torpedo,

Keith



I find this interesting. What do you mean by "passive wake homing"?

I know what passive guidance means; I'm just not sure what passive
signature a wake-homing Type 53-65 might be guiding on.

Thanks in advance!

wrote in message
...
In article , "Keith Willshaw"
wrote:


The Skhval is a short range straight runner that does NOT
home in on the steering gear or screws. The Russian
torpedo that IS dangerous in this respect is the large
Type 53-65 passive wake homing torpedo,

Keith



I find this interesting. What do you mean by "passive wake homing"?

I know what passive guidance means; I'm just not sure what passive
signature a wake-homing Type 53-65 might be guiding on.


There are a number of techniques for detecting wakes which
include detecting the velocity changes caused by eddying in
the wake and also by IR sensors which detect the temperature
changes.

Whichever method is used the sensor looks upward and the rudder is
set automatically to turn the torpedo through a fixed angle
each time the torpedo crosses the wake of its target.
This enables a torpedo to follow a sinuous track towards the ship
(provided it enters the wake at an acute angle).

It is relative simple for the seeker to determine the boundaries
of the wake, which extends many lengths behind the target.
A wake is difficult to simulate, so countermeasures relying on
seduction are ineffective which is why are Navies showing so
much interest in Hard Kill defenses.

Keith

In article , "Keith Willshaw"
wrote:

wrote in message
...
In article , "Keith Willshaw"
wrote:


The Skhval is a short range straight runner that does NOT
home in on the steering gear or screws. The Russian
torpedo that IS dangerous in this respect is the large
Type 53-65 passive wake homing torpedo,

Keith



I find this interesting. What do you mean by "passive wake homing"?

I know what passive guidance means; I'm just not sure what passive
signature a wake-homing Type 53-65 might be guiding on.


There are a number of techniques for detecting wakes which
include detecting the velocity changes caused by eddying in
the wake and also by IR sensors which detect the temperature
changes.

Whichever method is used the sensor looks upward and the rudder is
set automatically to turn the torpedo through a fixed angle
each time the torpedo crosses the wake of its target.
This enables a torpedo to follow a sinuous track towards the ship
(provided it enters the wake at an acute angle).

It is relative simple for the seeker to determine the boundaries
of the wake, which extends many lengths behind the target.
A wake is difficult to simulate, so countermeasures relying on
seduction are ineffective which is why are Navies showing so
much interest in Hard Kill defenses.

Keith




Interesting.

I hadn't seen any prior suggestions that torpedoes might conduct wake
homing via IR or eddy detection. This'll give me something to do after
football and a couple of pints.

Thanks.


----
"Eddies in the time stream"
"Is he. What's he doing there?"

"Keith Willshaw" wrote in message ...
"Eunometic" wrote in message
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The site refered to at the begining of the thread refers to a switch
from solid propellant to liquid propulsion. This would appear to give
several advantages.

1 Higher specific impulse therfore speed and range.

And considerable increase in risk, liquid propellants in
the torpedo room - shudders !

Perhaps.

The Brits and the Ruskies may have screwed up H2O2 but the Swedes
definetly didn't. I don't think a lot of torpedo propulsion systems
are particularly nice to think about except for silver batteries.


2 The rocket-torpedo can be ejected from its own tube: manouever and
aligne itself towards the target at low speed by varying its thrust
and then accelerate at high speed rather than relying on a propellor
based system to achieve initial alignment.

Throttlable rocket engines are considerably more complex
and the risk to the launcher just went up again.

Once the move to liquid propellants has occured then throttling the
engine is relatively trivial. Hybrid liquid solid systems where the
relatively congeniel fuel is sprayed into a chamber lined with an
solid and stabalised oxidiser are a solution here.


3 After having intercepted its target at high speed it can slow down
for a 'look' using its terminal homing system and then re-alinge and
re-accelerate.


Not without turning off the gas generator for the supercavitation

And then restarting it at the same time it restarts its rocket motor.

I suspect a ballistic launch out of the water close to the ship with
infra-red or radar terminal homing followed either by skipping back
into the water or a direct attack is even an option.



I also can see why the system can't use a trailing wire command
guidence systemn as conventional torpedos and missiles use. It may
have uses as a torpedo intercept system.


That wire would trail behind the torpedo where the rocket exhaust is

Oops

Hellfire, HOT, TOW, Swingfire, Trigat, Milan all manage quite well and
they aren't even sea water cooled.

The Germans even have a small imaging infrared missile called Triton
(based on the air breathing Polyphem) that can be submarine launched
against both land, sea and air targets. It trails a fibre optic cable
and is rocket propelled through the water before exiting.



Keith

"Eunometic" wrote in message
om...
"Keith Willshaw" wrote in message
...
"Eunometic" wrote in message
om...
"Keith Willshaw" wrote in message
news:colm61$gr5$1

The site refered to at the begining of the thread refers to a switch
from solid propellant to liquid propulsion. This would appear to give
several advantages.

1 Higher specific impulse therfore speed and range.

And considerable increase in risk, liquid propellants in
the torpedo room - shudders !

Perhaps.

The Brits and the Ruskies may have screwed up H2O2 but the Swedes
definetly didn't. I don't think a lot of torpedo propulsion systems
are particularly nice to think about except for silver batteries.



High energy liquid rocket propellants are rather more
hazardous than anything the Swedes used


2 The rocket-torpedo can be ejected from its own tube: manouever and
aligne itself towards the target at low speed by varying its thrust
and then accelerate at high speed rather than relying on a propellor
based system to achieve initial alignment.

Throttlable rocket engines are considerably more complex
and the risk to the launcher just went up again.

Once the move to liquid propellants has occured then throttling the
engine is relatively trivial. Hybrid liquid solid systems where the
relatively congeniel fuel is sprayed into a chamber lined with an
solid and stabalised oxidiser are a solution here.


Doesnt sound capable of being shut off to me.


3 After having intercepted its target at high speed it can slow down
for a 'look' using its terminal homing system and then re-alinge and
re-accelerate.


Not without turning off the gas generator for the supercavitation

And then restarting it at the same time it restarts its rocket motor.


A non trivial design task

I suspect a ballistic launch out of the water close to the ship with
infra-red or radar terminal homing followed either by skipping back
into the water or a direct attack is even an option.



I also can see why the system can't use a trailing wire command
guidence systemn as conventional torpedos and missiles use. It may
have uses as a torpedo intercept system.


That wire would trail behind the torpedo where the rocket exhaust is

Oops

Hellfire, HOT, TOW, Swingfire, Trigat, Milan all manage quite well and
they aren't even sea water cooled.

The Germans even have a small imaging infrared missile called Triton
(based on the air breathing Polyphem) that can be submarine launched
against both land, sea and air targets. It trails a fibre optic cable
and is rocket propelled through the water before exiting.



But have MUCH smaller engines

These proposed developments change what is
currently a cheap and simple last chance defensive
weapon into a highy complex and expensive one.

This may be achievable but I rather doubt the Russians
have the cash to do so.

Keith