Crazy Ivan maneuver in Red Storm Rising

[gf0012-aust]

I'm not sure if the Submarine League is till around. It used to publish its own mag which was available for subscription. Funny enough, the operatind manuals/booklets of certain sub sims have very interesting and detailed info, not found on many books.

Naval Sub League. Still exists. I'm a life member. the articles do not go in to tech detail and the war stories are from "safe eras" for a reason

USN sub service does have an internal mag available through service subscription or through the US Def publishing service (Undersea warfare). Not commonly available

Does anyone know if India has sent any of its skippers to attend the RN perisher course? Another navy which conducts a similar course, which is open for foreign navies, is Holland. There was a report in Janes Weekly that came out in the late 80's about the Canadian navy having problems finding skippers of the Upholder class as the first bacth it sebnt to the UK had failed the Perisher course.

Something wrong with the story. UK Perisher is for nukes only. Conventional drivers do Perisher via the Ducth and Australian navies. In fact we have assisted in the assessment of a few USN sub drivers qualify on some of the elements as they are looking at understanding how conventionals work and train. Less than a handful of USN drivers have gained Perisher passes, but IIRC only one has "failed"

Also the Upholders did not go to canada until after the late 90's so they canucks would not have done Perisher anyway. I'm aware of this as I attended a few meetings on whether RAN would purchase Upholders as a 2nd interim squadron and we walked away really quickly (1998) as they were regarded as basket cases. RAN made its opinions on the Upholders clear in 1999 when Adm Chris Barrie made some public comments about how busted they were when some idiot journalist made a comment about them as a suggestion to replace collins

 

[localhost127]

Flow noise takes a while to settle down as the ship/sub reduces speed and a submarines is usually in a better position to detect whether the surface ship is coming off a sprint and reduce speed accordingly..

what frequencies are relevant to flow noise? subsonic?

 

[localhost127]

There are practically no detailed books no modern sub warfare, never mind detailed stuff on sonars,

tell me about it. as a hobbyist, it's generally not the "solutions" im after, but the "questions" ... eg, it's pointless to read about solutions to problems when im not even aware of what the problems are to begin with! at least with orbital mechanics or air platforms, etc - the design challenges and "problems to solve" are known (and sometimes obvious) ... even while some solutions may be classified. with subs, i can't even figure out what the damn challenges are on a detailed level - there's an information black-out on both sides of the equation.

 

[vivtho]

what frequencies are relevant to flow noise? subsonic?

No idea about the exact frequency ... but I would guess it'd be over a broadband range tending towards the lower end of the spectrum.

 

[NICO]

can anyone recommend books on the subject? active and/or passive sonar, tactics, etc. anything i can get my hands on would be appreciated.

Not many books, this one is dated, "Modern Submarine Warfare"David Miller,J.Jordan, Military Press,late 80s. Nice book but a lot has happened since so it shows it's age.

 

[STURM]

Something wrong with the story. UK Perisher is for nukes only. Conventional drivers do Perisher via the Ducth and Australian navies. In fact we have assisted in the assessment of a few USN sub drivers qualify on some of the elements as they are looking at understanding how conventionals work and train. Less than a handful of USN drivers have gained Perisher passes, but IIRC only one has "failed"

In Tom Clancy's 'Submarine', he mentions there is a version of the Perisher that is open for SSK operating navies in which all the nuclear aspects have been omitted.

Also the Upholders did not go to canada until after the late 90's so they canucks would not have done Perisher anyway. I'm aware of this as I attended a few meetings on whether RAN would purchase Upholders as a 2nd interim squadron and we walked away really quickly (1998) as they were regarded as basket cases.

I'm sure you're right but there definitely was a report in JDW about the problems the Canadians were having in finding skippers who could graduate Perisher.

gf,

I know this is going off-topic but what exactly was the problem with the Upholders? Officially, they were retired from RN because a decision was made to go all nuke, but was the RN experiencing major technical problems with them? At one stage it was reported that Saudi was interested. When I was at the RN sub museun at Gosport in 1995, the chap counducting the tour [ex-RN sub man] had nothing good to say about the Upholders. As the Royal Malaysian Navy already had a requirement for SSKs in the early 1990's, I was hoping then that the Upholders would have been offered to us.

 

[STURM]

Apogies - double post again.

 

[gf0012-aust]

In Tom Clancy's 'Submarine', he mentions there is a version of the Perisher that is open for SSK operating navies in which all the nuclear aspects have been omitted.

and Clancy got it wrong (as usual). The Perisher for conventionals is basically run by the dutch with input for some treaining element quallifiers s run by RAN. When UK decided to dump the Upholders we all worked out that Perisher in its revised UK nuke format was not entirely suitable, the curricula was rewritten and management was taken over by the dutch and aust

UK Perisher is a nuke focused course

gf,

 

[gf0012-aust]

No idea about the exact frequency ... but I would guess it'd be over a broadband range tending towards the lower end of the spectrum.

once you go over 5 knots you are basically a transducer. the freq range will vary due to issues such as hull shape, speed and whats generating the cavitation in the first place - ie using a Kilo example, an Indian Kilo will be telegraphing its presence long before a Russian kilo due to the former having somewhat awful props installed

its not a "broadband" range issue

 

[STURM]

ie using a Kilo example, an Indian Kilo will be telegraphing its presence long before a Russian kilo due to the former having somewhat awful props installed

The IN has different propellers installed on its Kilos?

Is there any reason why most SSK operators have not installed anechoic tiles? As it can't be due to the costs could there technical reasons involved or differences in opinion as to how effective such tiles are? Not sure how accurate the report was but a number of years ago, there was an article which said that the Iranian navy was experiencing a major barnacle problem with its Kilos due to warm home waters and that the IN was helping out.

A few years ago as part of trials conducted to see if visibility of subs operating in very shallows waters could be reduced to avoid visual detection from the air, a Trafalgar was painted in a light blue colour scheme.

 

[My2Cents]

what frequencies are relevant to flow noise? subsonic?

Flow noise is white noise (all frequencies), but the percentage of the high frequency component increases with the speed. Total signal strength is proportional to the 4th power of the speed, but machinery noise generally exceeds hull noise as long as the flow is laminar.

Also above a certain speed, depending on geometries, the flow changes from laminar flow (low noise) to turbulent flow (noisy and damps incoming signals). In fact the flow regime on can be different on different parts of the sub’s hull, which can make the correct location of the sonar transducers critical for maximum sensitivity as speed increases.

 

[My2Cents]

The IN has different propellers installed on its Kilos?

Most vessels use different propellers depending on how they intend to operate and the maximum speed desired. Faster propellers are generally noisier and start cavitating (very noisy) at lower speeds.

Fabrication and finish are also critical to reduce noise production at low speeds. Over time marine growth, corrosion, and cavitation will damage the finish and increase the noise level. The only solution is to replace the propeller and send the old one back to the manufacturer for reshaping and refinishing. It is likely that India does this much less often than Russia, if ever. The fact that Indian subs are operating in warm water will significantly increase both marine growth and corrosion.

Is there any reason why most SSK operators have not installed anechoic tiles? As it can't be due to the costs could there technical reasons involved or differences in opinion as to how effective such tiles are? Not sure how accurate the report was but a number of years ago, there was an article which said that the Iranian navy was experiencing a major barnacle problem with its Kilos due to warm home waters and that the IN was helping out.

Why can’t it be the cost?:argue

Anechoic tiles are about 4” thick, calculate the volume and weight of the material and then guess a price based on a suitable material + fabrication + installation.

Proper installation is supposed to be a MAJOR headache due to the effects of compression and temperatures when diving. The US and Russia have put a lot of money into researching proper installation techniques, and they are still have problems with tiles falling off. Detailed information on installation techniques is not generally not shared with other countries, even apparently between the UK and the USA. The tiles also have to fit so they produce a smooth surface or the flow noise increases.

 

[localhost127]

Anechoic tiles are about 4” thick, .

are they velocity based (porous) absorbers or pressure based absorbers?

can (damaged) propellers be changed at sea? or is that a short/medium-term dry-dock function?

 

[My2Cents]

are they velocity based (porous) absorbers or pressure based absorbers?

Who knows? The exact compositions are all on the top of the MOST SECRET lists, but they are definitely either not porous or use glass micro-spheres, otherwise the pores would collapse when the sub dives.

can (damaged) propellers be changed at sea? or is that a short/medium-term dry-dock function?

Can anyone here offer a ballpark estimate of the weight of a propeller for a submarine in the 2000 ton range? I would guess 1 to 2 tons.

For a modern submarine design it is probably impractical to replace the prop outside of a dry-dock. Alignment is critical. You also have to dynamically balance the prop and shaft after installation to minimize vibration, much like the wheels on a car, so it could take a while.

 

[gf0012-aust]

Proper installation is supposed to be a MAJOR headache due to the effects of compression and temperatures when diving. The US and Russia have put a lot of money into researching proper installation techniques, and they are still have problems with tiles falling off. Detailed information on installation techniques is not generally not shared with other countries, even apparently between the UK and the USA. The tiles also have to fit so they produce a smooth surface or the flow noise increases.

if you consider how close and how much info UK and Aust share with the US (and vice versa) it shows just how protective we all are of this technology

one of the major achievements of Collins was the fact that DSTO were able to develop a tile that was considered to be more stable than its US developed counterpart. The US provides Aust with access to a significant amount of technology, but they weren't going to provide us with their tile and bonding technnology for all the tea in china....

 

[STURM]

Apart from the Kilo are any other SSKs fitted with anechoic tiles and which navy was the first to use it?

 

[Bonza]

Apart from the Kilo are any other SSKs fitted with anechoic tiles and which navy was the first to use it?

From what I understand the technology (or at least its submarine-related applications) dates all the way back to German efforts during the Second World War. Apparently they developed a compound under the name "Alberich" and intended to use this to reduce noise and sonar return on U-boats, although I don't know how much progress they made or if they achieved any practical benefits before the war's end. I assume the technology ended up in the United States or the Soviet Union (or both), given the thoroughness with which German military research was appropriated post-war... I should add the disclaimer however that I'm just going by information I stumbled across online, so I could be off-base.

If the principles behind such technology have been understood for so many decades, I'd expect that pretty much any modern military submarine would make use of it to some extent. However there are presumably some significant differences between specific variations on technology of the same historical origin, based on advances in materials, application, design intent, etc.

Take all that with a grain of salt though, just guesswork on my behalf.

 

[STURM]

Hi Bonza, aprreciate the feedback.

If the principles behind such technology have been understood for so many decades, I'd expect that pretty much any modern military submarine would make use of it to some extent. However there are presumably some significant differences between specific variations on technology of the same historical origin, based on advances in materials, application, design intent, etc.

I'm sure there are sound reasons as to why many or most navies have not gone for
anechoic tiles for their SSKs. It could be purely due to the high costs involved or mainly due to differences of opinion as to how effective the tiles are. Or despite advances made in Australia and the U.S., some navies feel the technology is not mature enough to justify an investment.

Off-topic but it just occured to me that some navies, e.g, Sweden, Germany, have not installed ASMs on their subs, even to their latest designs. Do you think there any pacticular reasons for this or it just boils down to individual operational requirements and doctrine?

 

[Bonza]

Hi Bonza, aprreciate the feedback.



I'm sure there are sound reasons as to why many or most navies have not gone for
anechoic tiles for their SSKs. It could be purely due to the high costs involved or mainly due to differences of opinion as to how effective the tiles are.

That's quite possible, although as I said it wouldn't surprise me if the technology (in one form or another) is present on a wide range of submarines. Perhaps it is simply not frequently examined or discussed due to the secrecy with which submarine-related details are typically treated. I could be wrong, but if the concept began development over half a century ago, it seems to me that current submarine types would be very likely to include such features as a matter of course. But then maybe I'm underestimating the cost and complexity involved.

Off-topic but it just occured to me that some navies, e.g, Sweden, Germany, have not installed ASMs on their subs, even to their latest designs. Do you think there any pacticular reasons for this or it just boils down to individual operational requirements and doctrine?

I think it probably comes down to individual requirements more than anything. For example, the German-built Type 209 submarine employs a Harpoon capability in the navies of several export customers, and while I think the Germany Navy could quickly roll out a similar capability for their own Type 212, I'm sure they have a good reason for not doing so. I suppose there is always a degree of risk, cost, training, inventory and so on associated with integration of new weapons - perhaps in light of these factors and the Type 212's normal duties, deployment of an AShM capability is not considered necessary.

All conjecture of course, but then it always is when it comes to submarines

 

[My2Cents]

If the principles behind such technology have been understood for so many decades, I'd expect that pretty much any modern military submarine would make use of it to some extent. However there are presumably some significant differences between specific variations on technology of the same historical origin, based on advances in materials, application, design intent, etc.

The principles of quantum mechanics date back to the 1930’s and the patent for a transistor to 1925. Charles Babbage set down the design principles for programmable binary computers in 1812, but never finished construction of his first machine (His son completed part of one in 1910. It worked! :cheers). But the CPU on a chip could not be built until the 1970’s. :type

That is the difference between understanding the principles and implementing a technology. :fly