IRAN UNVEILS UNUSUALLY BLUE COLORED SUBMARINE

[tyrant]

Kaiten - Wikipedia, the free encyclopedia
Kairyu class submarine - Wikipedia, the free encyclopedia

Japanese did two mistakes regarding midget subs:

1. They used them in the ocean instead of shallow waters. The best stealth mechanism for a country like Iran is the natural barriers. Sonars don't work good in shallow waters.
2. Japanese were not able or did not make a large enough mini submarine. Their sub was about 19 tones (about 8 times smaller than the Iranian mini-subs) . You can not fit the necessary equipment in 19 ton especially for the use in the ocean.

I compare the Iranian mini-subs vs US navy as Hezbollah vs Israel army; not equally strong at all but a problem in an asymmetric battle.

 

[Surenas]

It seems the idea is that as midget subs need to surface often to vent CO2 that the paint scheme will help reduce the likelihood of being spotted from airborne assets and possibly targeted whilst doing so. If this is the case I think the Iranians need to refine the paint-scheme choice because the current paint-job appears like it would attract attention rather than blend in.


my 2c.

If I'm right, according to Jane's Defense Review the British Navy did a couple of color experiments back in '74, and the experiments showed that turquoise is the best option for 'sandy bottom, shallow waters with clear color'. The only problem was that the color caused to much shadow, but since these subs are much smaller than the one's used in that experiment, it will cause much less shadow. I think someone in Iran's navy has payed good attention. They are basically just reviewing and using British experiments.

 

[gambit]

Sonars don't work good in shallow waters.

Keyword search 'variable depth sonar'.

Please take some time and do some basic research before making unsupportable claims.

 

[tyrant]

Keyword search 'variable depth sonar'.

Please take some time and do some basic research before making unsupportable claims.

I am glad you are familiar with 'variable depth sonar'. There are many other techniques to detect shallow water objects as well. Neither of these methods are as accurate as deep water tracking.
Would you please elaborate more about the details of the system you are thinking of, so we can discuss more effectively.
Would you please specify:
1. Number of arrays? array shape?
2. Kerf, array spacing
3. Sound frequency
4. single pulse, multi-pulse, Doppler, back propagation, combined
5. focusing on transmit (# of focal points)
6. focusing on recieve (# of focal points)
(assuming there is no jamming, and no IR sensor involved)

 

[twilight]

 

[500]

Japanese did two mistakes regarding midget subs:

1. They used them in the ocean instead of shallow waters. The best stealth mechanism for a country like Iran is the natural barriers. Sonars don't work good in shallow waters.
2. Japanese were not able or did not make a large enough mini submarine. Their sub was about 19 tones (about 8 times smaller than the Iranian mini-subs) . You can not fit the necessary equipment in 19 ton especially for the use in the ocean.

I compare the Iranian mini-subs vs US navy as Hezbollah vs Israel army; not equally strong at all but a problem in an asymmetric battle.

They did built larget mini submarines Type A Ko-hyoteki. Also useless. Minisubmarines are noisy (u cant put noise reduction in such a small body), they lack proper sonars, they have very limited range. In short useless.

 

[tyrant]

They did built larget mini submarines Type A Ko-hyoteki. Also useless. Minisubmarines are noisy (u cant put noise reduction in such a small body), they lack proper sonars, they have very limited range. In short useless.

Type A Ko-hyoteki is also about 40-50 tones and very small and it has 2 torpedoes too! Japanese used them to attack Australia and Madagascar!
There is enough of space in 150 tonnes to do acoustic/IR insulation as well as installing proper sonars. However, it is not enough to out-maneuver US larger subs. That is why I say they have to keep it in shallow waters.
Imagine one of these in an out-pouching of water in the gulf (closed from 3 sides and open only in one side), engine turned off, every thing off, waiting for an attacking ship by its periscope. ABSOLUTELY not detectable.

 

[Mani2020]

This a midget submarine, historically germans have produced this kinda submarines in quite some numbers. These are designed for shallow waters Pakistan navy too possessed these kinds ... quite an effective submarines in shallow waters specially across the coastlines where most larger submarines have certain shortcomings

btw nothing to mock about atleast they are better than most of the countries that sit on the laps of west and either beg or sell their freedom for tech or from those countries that with all the money and foreign assistance still are not able to build even a piece of mainstay weapons ...atleast iran has taken initiative ... along the lines they have better future ahead

 

[Oldman1]

Myth Of US Invincibility Floats In The Persian Gulf

Sounds like Pearl Harbor. Wonder what happened to the attackers the Japanese.

 

[jaunty]

The comments on the original yahoo article(OP) are hilarious.

*Camouflage for operating in enemy swimming pools.
*OMG, IT'S SO TINY IT'S ADORABLE! Who's the cutest little rogue nation? Who? YOU ARE! Yes you are. Yes you are.
*the Colombian narcos' make better subs. Heck subway makes better subs.
*Does that thing take "C" or "D" sized batteries?
*Looks like the propane tank outside my brother's lake cottage.

This one takes the cake

**Some gay whale is gonna come along and mount it.

 

[Juice]

Lol, you know I was thinking the narco-subs looked better built

 

[Awesome]

Its probably just for ceremonial purposes. This is a typical Iranian color found on buildings/mosques from Iran.

If you see the blue color is only on top the bottom part is black, at least appears to be.

 

[sreekimpact]

i think these types of submarines will be mainly used for smuggling arms .

 

[kollang]

Displacement: 120 tons
Length: 29 m
Beam: 2.75 m

Characteristics
Speed (surface): 11 knots
Speed (submerged): 8 knots


armament
Two 533 mm torpedoes
and a variety of mines

need to add that this submarine is capable of firing two hoot torpedos.hoot torpedo is the fastest torpedo in the world(100 m/s).also the submarine can carry four of them as well.

 

[gambit]

I am glad you are familiar with 'variable depth sonar'. There are many other techniques to detect shallow water objects as well. Neither of these methods are as accurate as deep water tracking.

Whenever you make a declaration, especially in the technical realm, it would help the readers, and your credibility, to support your argument, like this...

Sonars don't work good in shallow waters.

This is assuming single/fixed point/location transmission.

We know that sound velocity profiles (SVP) are affected by many factors such as salinity, temperature, and pressure...

Sound Transmission in the Ocean - sea, depth, oceans, temperature, salt, system, wave, marine, salinity, Pacific

A temperature gradient exists when the temperature of the water decreases with increasing depth. The resulting thermocline shows a characteristic decrease in the speed of sound with decreasing temperature. However, at a depth of approximately 750 meters (2,460 feet), the variations in temperature become so slight that the water becomes essentially isothermal (of uniform temperature). From that point, the speed of sound is regulated more by changes in pressure that accompany the increasing depth.

Because sound wave transmission speed is directly proportional to pressure, the speed of sound increases as the pressure increases with depth.

Sonar Propagation in Statified Waters - March/April 2010, Volume 14, Number 2 - Archive - Hydro International

Salinity Profile

The acoustic environment in estuaries changes over very short scales. The salinity profile determines the halocline depth, the stratification and the form of the sound velocity profile and hence the coverage of any sonar system.

Some use sound speed (SSP) profile instead of 'velocity'...

Multibeam Systems - Sound Velocity Instruments

The sound speed profiles can be quite variable in the ocean due to factors such as fresh water run-off, daily heating and cooling cycles, upwelling and downwelling, etc. Accordingly, an accurate and timely sound speed profile is required to process the multibeam sonar data. Normally the ship must stop to take a sound speed profile. Since time is money, when performing surveys it is important to obtain the profile as quickly as possible. This usually means profiles are taken at speeds of 1 m/s or more. Even so, a deep 2000 m profile can take over an hour. To make matters worse the profile should be refreshed at least every 6 hours. In coastal waters the profile should be refreshed more frequently due to fast changing conditions. The result is a requirement to profile as fast as possible. Due to the 'Salinity Spiking' problems associated with profiling CTDs at high speed it is always better to use a direct measuring sound speed sensor rather than a CTD.

Coastal regions, estuaries, and river/sea connections have highly brackish water -- for example -- that can produce salinity stratifications that will produce diverse localized VSP that no standard sonar system can adequately compensate as explained by the above source when it demand that these profiles must be updated even by the hours.

This is why the US regularly conduct overt and covert profiling of the world's coastal regions to gather as much data over time as possible to create -- for each country that have sea access -- a 'meta-profile' of its sonar characteristics. The electronic warfare (EW) analogy is electromagnetic (EM) reconnaissance of a country based upon everything EM, from radars of military and civilian nature to daily television and radio transmissions.

There are also multi-paths propagation, same as radar detection, in shallow waters due to sea floor and those temperature/salinity layers...

Ghosting is a common problem in both radar and sonar detection because of multi-paths propagation.

So deep channel tracking is highly successful because of the constant SVP created by high pressure and fairly uniform salinity but only if a sub is in deep water.

A 'variable depth sonar' is essentially a sonar whose operating depth can be changed on demand to compensate for those layers that can hide a body. Intentionally or not.

Would you please elaborate more about the details of the system you are thinking of, so we can discuss more effectively.
Would you please specify:
1. Number of arrays? array shape?
2. Kerf, array spacing
3. Sound frequency
4. single pulse, multi-pulse, Doppler, back propagation, combined
5. focusing on transmit (# of focal points)
6. focusing on recieve (# of focal points)

No, I will not. There are many parallels between radar detection and sonar detection, especially in the data processing realm where they are practically identical and I do not have civilian experience in either. The military does not have exclusivity in using 'variable depth sonar' systems. There are many natural threats to civilian vessels that are hidden by those underwater characteristics that require the use of these systems to expose those natural threats and enhance marine safety.

What I normally do is bring to the discussions foundational principles that many interested lay readers do not know and ended up making baseless claims. You failed to bring up those foundational principles as how I demonstrated above. Then once a reader did his own research to verify my sources, those baseless claims usually disappeared. The reader is free to make up his own mind on whether the military applications of those foundation principles, as claimed by the military and/or manufacturer of said equipment, are credible or not. It is very difficult for anyone to dispute an operational capability -- as claimed -- once he understood the foundations of said capability. That is the way it should be without me crossing any infosec threshold.

(assuming there is no jamming,...

Sonar 'jamming', while technically is real, is practically and tactically dangerous. More so than with radar detection. If you do not know where and how radar and sonar detection are similar and diverge, at the theoretical level, then there is no need to discuss this further.

...and no IR sensor involved)

How is infrared applicable in sonar detection? I could be missing something here. Must be old age and memory loss.