Pods on the tail of USSR SSN
Edmund Hon
From: h...@hans.scs.carleton.ca (Edmund Hon)
While we are on the subject of submarines, does anyone know what is the
purpose of a mysterious "pod" on top of the tail fin of some of the newer
class of USSR SSNs? These classes includes: Akula, Sierra, and Victor III.
I've heard of 3 different explainations: a housing pod for towed array
sonar, a decoy, or a propulsion device.
Also, does anyone know why there were only one boat of the Papa and the
Mike class? (Well, the Mike was sunk, so there are none now.)
(source: Jane's Warsaw Pact warships handbook. 1986)
David Ruedi
From: ru...@dtoa1.dt.navy.mil (David Ruedi)
I recently had a chance to look at an UNCLASSIFIED photo of the
Soviet equivalent to a piping tab for a Victor III. It showed a cut
away view of the boat. The pod in the phot was definitely not a MHD
(or any other) propulsor. It looked like it contained a reel and the
machinery necessary to deploy/recover whatever was on the reel. In
my (not necessarily the Navy, Dod, or US Government's) opinion the reel
holds a towed array, I didn't see any evidence of a buoy.
To the best of my knowledge, the Papa and Mike were one of a kinds
because they were R&D technology demonstrators. Some of the technology
worked, some didn't.
LT David H. Ruedi, USN
Steve Williams
From: swil...@oasys.dt.navy.mil (Steve Williams)
> ... does anyone know what is the purpose of a mysterious "pod" on
> top of the tail fin of some of the newer class of USSR SSNs?
Jane's Fighting Ships (1986-85 & 1990-91) doesn't explain, and I won't
speculate here.
>Also, does anyone know why there were only one boat of the Papa and the
>Mike class?
"Papa" was apparently a development of the "Charlie" class submarines.
The fin is of a much more angular shaped than the "Charlie" classes
with a higher casing, a more rounded bow and with the missile tubes
having square covers. Built at Severodvinsk.
Source: Jane's Fighting Ships 1985-86
Steve Williams
Allan Bourdius
From: Allan Bourdius <ab...@andrew.cmu.edu>
>While we are on the subject of submarines, does anyone know what is the
>purpose of a mysterious "pod" on top of the tail fin of some of the newer
>class of USSR SSNs? These classes includes: Akula, Sierra, and Victor III.
I think that the generally accepted explanation is that it's a
towed-array housing.
>Also, does anyone know why there were only one boat of the Papa and the
>Mike class? (Well, the Mike was sunk, so there are none now.)
The Soviets built two new classes of SSNs as a test (Akula, Mike) to
find out which one was the best design, kind of like the current
YF-22/YF-23 competition in our defense industry. One (Mike) was found
to be inferior, so no more of that class was built (that's my guess,
anyway). The Papa is a cruise missile boat (right?) so perhaps the
first sub had design or construction problems or had an accident after
completion and the design has fallen out of favor.
--
Allan Bourdius
ab...@andrew.cmu.edu
Ronald W Sayer
From: rws...@phoenix.princeton.edu (Ronald W Sayer)
Are most hand-held or tripod-mounted anti-tank weapons
of the HEAT or of the kinetic variety (such as the TOW 2 and
HOT)?
Do the US, USSR, and Iraq tend to buy/use one kind over
the other? I wonder if the spread of reactive armor will change
the types of anti-tank weapons in the future.
Ron Sayer
rws...@phoenix.princeton.edu
Arthur Leung
From: art...@Eng.Sun.COM (Arthur Leung)
ru...@dtoa1.dt.navy.mil (David Ruedi) writes:
> I recently had a chance to look at an UNCLASSIFIED photo of the
>Soviet equivalent to a piping tab for a Victor III. [...]
>In my (not necessarily the Navy, Dod, or US Government's) opinion the reel
>holds a towed array, I didn't see any evidence of a buoy.
if this is the pod at the top of the fin seen on the stern of surfaced
soviet submarines, i believe the volume is too small to house your
average towed array. a towed array sonar is pretty large in diameter.
won't get much of a length in that small space. the towed array
housing on Los Angeles class boats looks to be about 1' tube running
a good portion of the length of the boat. might this soviet pod
be used as a housing and reel for VLF antenna? it would fit better.
-- arthur
Edmund Hon
[Reformatted to avoid excessive indentation. --CDR]
From: h...@scs.carleton.ca (Edmund Hon)
In article <1991Apr3.0...@amd.com> art...@Eng.Sun.COM (Arthur Leung) writes:
>a good portion of the length of the boat. might this soviet pod
>be used as a housing and reel for VLF antenna? it would fit better.
But why would they want to trail the antenna at the tail when you can
do it nicely from the conning tower? Why aren't the other classes do the
same? It seems to much of a coincidence for me that only the latest
SSN's (not SSGN's i.e., Oscar, Charlie, etc.) have such a pot.
Let's look at some of the possible answer to this pot, and the possible
reasons against the explainations:
i) Towed Array Sonar- Volume too small to house an average length TAS
(how long is a TAS anyway), as stated by Arthur Leung.
ii) A Decoy (Nixie) - Unless it is a "one-use" disposable one. I can't
think of anyway where the sub can detach the pod, trail it behind the
sub with a cable, then retrieve it onto the top of the fin. Seems like
a pretty tricky operation.
(Note: maybe the decoy is INSIDE the pod, then this becomes a very
plausible explaination. David Ruedi did say in an earlier post that
there are reeling mechanisms in the pod when he saw the cut- away of
the Victor III.)
iii) A Propulsion device - Too small.
iv) A sonar (not a TAS) - Does the size of a sonar (in general) deter-
mines the frequency which the sonar can operate? To me it seems that
small size => short wavelength => high frequency. If the pod is a
sonar, then it must be a high frequency one, which will not be very
use- ful when you consider that most of the newer, better sonars
utilizes the low frequency approach.
Any comments?
--
Edmund Hon
h...@scs.carleton.ca
Ted Kim
From: t...@CS.UCLA.EDU (Ted Kim)
art...@Eng.Sun.COM (Arthur Leung) writes:
> If this is the pod at the top of the fin seen on the stern of
> surfaced Soviet submarines, I believe the volume is too small to
> house your average towed array. A towed array sonar is pretty large
> in diameter. It won't get much of a length in that small space. The
> towed array housing on Los Angeles class boats looks to be about 1'
> tube running a good portion of the length of the boat. Might this
> Soviet pod be used as a housing and reel for VLF antenna? It would
> fit better.
In the "Soviet Navy" column of April 1991 USNI Proceedings, Norman
Polomar and LtCmdr Jurrien Noot (Royal Netherlands Navy) mention the
tear-drop shaped pod on the Victor III (which is about 29.5 feet long
and almost 8 feet at its widest point).
Their opinion is that it is most likely a housing for a THIN-LINE
towed array sonar. They mention a variety of alternative
possibilities: towed communications cable, torpedo decoy system,
auxiliary high-speed burst propulsion, auxiliary low-speed creep
propulsion. They believe any theories about MHD or EMT auxiliary
propulsion systems are not likely because of the high power
consumption necessary and because there is no opening on the front of
the pod for water intake. Also, they note the high position makes it
vulnerable to ice damage.
--
Ted Kim Internet: t...@penzance.cs.ucla.edu
UCLA Computer Science Department UUCP: ...!{uunet|ucbvax}!cs.ucla.edu!tek
3804C Boelter Hall Phone: (213)206-8696
Los Angeles, CA 90024 FAX: (213)825-2273
Scott Norton
From: nor...@manta.nosc.mil (Scott Norton)
I always thought it was a mail bouy! :-) :-)
Steve Williams
From: swil...@oasys.dt.navy.mil (Steve Williams)
>> If this is the pod at the top of the fin seen on the stern of
>> surfaced Soviet submarines, I believe the volume is too small to
>> house your average towed array.
"The notable feature of the AKULA class is a large streamlined pod
on top of the vertical tail fin. The official judgement is that it
probably contains a towed sonar array. Others have speculated that
a new type of auxiliary propulsion system, based on magnetohydrodynamics
(MHD), is involved."
Source: SOVIET SUBMARINES: Designs, Development and Tactics
by Jan Breemer
Jane's Information Group
Published in United Kingdom by Jane's Defense Data, a principal
activity of Jane's Information Group Limited
1989
Henry Spencer
From: he...@zoo.toronto.edu (Henry Spencer)
>From: rws...@phoenix.princeton.edu (Ronald W Sayer)
> Are most hand-held or tripod-mounted anti-tank weapons
>of the HEAT or of the kinetic variety (such as the TOW 2 and HOT)?
Kinetic-energy weapons require very high velocities, which are difficult
to achieve with rockets. *All* hand-held and tripod-mount anti-tank
weapons are HEAT. People are only just starting to talk about building
kinetic-energy missiles; at the moment, kinetic-energy weapons are
restricted to armor-piercing ammunition for tank guns and other artillery.
--
"The stories one hears about putting up | Henry Spencer @ U of Toronto Zoology
SunOS 4.1.1 are all true." -D. Harrison| he...@zoo.toronto.edu utzoo!henry
Chris Morton
From: cm...@ncoast.org (Chris Morton)
>From: rws...@phoenix.princeton.edu (Ronald W Sayer)
> Are most hand-held or tripod-mounted anti-tank weapons
>of the HEAT or of the kinetic variety (such as the TOW 2 and HOT)?
Almost none of these weapons develop the velocity to kill by kinetic energy.
Most kinetic energy weapons are conventional anti-tank guns, which only the
Soviet Union as pursued for quite a while. An exception is the ARES 75mm
automatic gun. Of course neither this nor the Soviet weapons is tripod mounted.
Kinetic energy weapons by definition require high velocities, and those
sorts of velocities are not usually compatible with the portability of a TOW.
> Do the US, USSR, and Iraq tend to buy/use one kind over
>the other? I wonder if the spread of reactive armor will change
>the types of anti-tank weapons in the future.
The Soviets still have a lot of AT guns. The US uses missiles and unguided
rockets with HEAT warheads almost exclusively, with a HEAT firing recoilless
rifles still around. Iraq uses mostly Soviet equipment, so expect them to
follow Soviet practice.
cm...@ncoast.org --- Chris Morton
"These opinions are mine, MINE, ALL MINE!!!!"