Italy, Russia to jointly develop SSKs.

[PhillTaj]

Russian and Italian firms are working up technical drawings for a new diesel submarine for the export market, even as they start scrapping some of their own older subs.

Fincantieri and Russian submarine-builder Rubin are in the second phase of developing a 1,000-ton conventional submarine, the S1000, which will be equipped with an Air Independent Propulsion (AIP) system said to be capable of staying underwater for 10 days. The project was launched by the Italian government in April 2004.

“Rubin presented a blueprint of the submarine to the Italian Defense Ministry six months ago and is now at the second stage, preparing the technical draft that should be ready by the end of next year,” said Yuri Kormilitsyn, chief designer of non-nuclear submarines at the Rubin Central Design Bureau, St. Petersburg.

It was too early to say when the sub might begin construction, Kormilitsyn said.

Fincantieri declined to comment on its progress, but has said the S1000 will be 40 to 50 meters long with a top speed of 14 knots, a crew of 16 and maximum depth of 250 meters. The S1000 will be designed for anti-submarine warfare, intelligence-surveillance-reconnaissance, and transporting up to 12 special forces troops. Other missions could include anti-surface warfare, mine-laying and air operations support.

An Italian industrial source said Fincantieri is developing a new fuel-cell-powered AIP system.

Rubin’s Kormilitsyn confirmed that Italy would provide the S1000’s AIP technology.

The Italian source said the AIP system would not be the same one that is going on two U-212-class subs, being built under license from Germany’s HDW by Fincantieri for delivery to the Italian Navy this decade.

http://www.defensenews.com/story.php?F=1399206&C=navwar

_______________

Interesting.....however, I am not sure what market they will aim at? I was under the impression that French and German firms dominate the world industry-with Russia struggling with niche markets in India and China (but they are about to lose the India SSK market). Italy cant export to China such sensitive systems as AIP can they? Does AIP come under the EU arms ban? Anyways, China probably wont import any more foreign units.

Im just having trouble trying to figure out what the hell they think they are doing.

[Whiskyjack]

Looking at the specs I think this is a sub to operate in a Littoral environment, such as the Med for the Italian Navy and the Baltic for the Russian Navy.

As for exports, the EU has been talking about lifting the ban on arms exports to China, however I am sure that even if the ban is lifted the USN will not want to see these subs, with modern western systems deployed opposite Taiwan.

The issue will be whether Russia will have the technology to sell the subs independent of Italy.

Other nations that would be interested: Singapore, maybe some of the Gulf States? Just speculation on my part.

[Dr Phobus]

Interesting article,

Well, there are plently of country's that need SSK's, south american, far east that would be in the market for an affordable, small, cheap to operate SSK. Remeber the French export MESA S-90B's to Nuclear armed Pakistan ! Even possible some smaller european nations maybe interested, aka Demark, who are on the verge of letting their sub force go.

So I am not convinced that AIP will be an exclusive technology for too long. The Germans, Swedes, French and Russians (prototype i think) all have such systems, the Japanese are working on a system.

Singapore are also about to purchase A-35 Kochum class from the Swedes I do not know if this will have AIP unit, I argue that that in time they will do so. The Israil's new batch of Dolphin subs are rumoured to be AIP equipped (another nulcear power).

AIP will be the norm not the exception. Any one want to take a guess how long the Chinese will be without AIP, of the Inidans. Of course they can just import it form the Russians. Chilie could have purchases the AIP option, but did not.

:D

[aaaditya]

I believe this submarine will be based on amur950 in terms of design equipped with the italian aip fuel cells,the specifications provided in the article seem to match with the amur which is being developed by rubin.

However i feel that the diving depth is too low,i hope it does not effect the performance of this submarines in deep waters.

By the way would be interesting to find out more about the italian aip fuel cell.

Has anyone got any info on it or can post the link of fincanterri?

[Dr Phobus]

This design sounds primiarly like a littoral submarine design, with some ocean patrol ability. Therefore the limited diving depth would not be considered a disadvantage. Also, remember the Polish and the Iranian's had problem with their Kilo's in the Shallow waters of the Baltic and the Perisan gulf. Tradationally, Italian boats have been rather small with limited diving depth since they do not operate out of the med sea. ;)

[KGB]

Do you think SSK's might ever get cheap enough to be used to smuggle drugs? Years ago a raid on colombia drug dealer revealed a partially completed submarine, presumably for smuggling.

[aaaditya]

Do you think SSK's might ever get cheap enough to be used to smuggle drugs? Years ago a raid on colombia drug dealer revealed a partially completed submarine, presumably for smuggling.
well the sri lankan ltte rebels are known to use crude submarines of their own design and manufactured at their allied shipyard in thailand for smuggling and launching of suicide attacks of the srilankan navy.

[Dr Phobus]

I am sure its for a ligitmate military usage. There is a long history of sub's 1000 tons and less. Its a real interesting concept this sub and 10 days without surfacing, not to bad. I wonder whats its weapon carrying ability is.

:cool:

[aaaditya]

I am sure its for a ligitmate military usage. There is a long history of sub's 1000 tons and less. Its a real interesting concept this sub and 10 days without surfacing, not to bad. I wonder whats its weapon carrying ability is.

:cool:

10 days seems quite inadequate ,i wish it was atleast 30 days the amur (designed by rubin) has something around 45 days endurance(without aip).

[Whiskyjack]

10 days seems quite inadequate ,i wish it was atleast 30 days the amur (designed by rubin) has something around 45 days endurance(without aip).

Yes but that is not continuous, that is just patrol endurance. 10 days without surfacing or snorkelling would be good for such a small sub, I think even the U212s have only 14 days.

[Dr Phobus]

I concur, 10 days without surfacing is a good performance, I would estimate to creeps about at a constant 4-5knots, (5-7mph) 120-144miles a day, for 10 days, silent. Can be rather dangerious. Also, this of the middle eastern sales potentual, UAE, Saudi's, Kuwait. A potent little boats like that in those confinded waters.

:D

[PhillTaj]

Interesting article,

So I am not convinced that AIP will be an exclusive technology for too long. The Germans, Swedes, French and Russians (prototype i think) all have such systems, the Japanese are working on a system.

:D

I thought Japan is buying Swedish AIP Systems?

[Dr Phobus]

Hello, if you have a sourse please send me a link. The sterling system, was the firist system, used on smaller swedish type boats. German AIP technology it probably the best, the MESA system is starting to be exported. Still, I am surprized the Japanese system, is not being independently developed, Japanese boats are amoung the largest SSK's in the world. :p:

[Max_Headroom]

As far as I know, the latest subs Singapore bought from sweden, will be fitted for- if nor with AIP.

/M

Hello, if you have a sourse please send me a link. The sterling system, was the firist system, used on smaller swedish type boats. German AIP technology it probably the best, the MESA system is starting to be exported. Still, I am surprized the Japanese system, is not being independently developed, Japanese boats are amoung the largest SSK's in the world. :p:


Japan have bought a number of Sterling engines ;-) from Sweden

[aaaditya]

Japan have bought a number of Sterling engines ;-) from Sweden

on what design are the japanese submarines based ?
stirling seems to be noisier than the german fuel cells.if the japanese submarines are based on the german design that i think it would be wiser to use the german fuel cells.

[Dr Phobus]

I agree with the above statement, sterling wass the first and makes more noise because if its enclosed combustion design. The AIP system are due to be retrofitted to the Oyashiro classes displace anywhere from 2,450 tons to 3,000 tons about 7 are order or under production. However, max-headroom has better information, however, althought they have bought the system, it does not mean with will use it, it could be for study, japs are big into "improvment", just a thought

:xmas
:xmas

[G-Capo]

The capability for this submarine to attack land targets with the Club-S is very impressive.

[gf0012-aust]

on what design are the japanese submarines based ?
stirling seems to be noisier than the german fuel cells.if the japanese submarines are based on the german design that i think it would be wiser to use the german fuel cells.

not sure how I missed this post - but better late than never.

the Japanese O''s are based on the last US design. (Barbel?)

there is no relationship between design of a sub and ancilliary components (eg if a german sub, then use a german AIP system).

the japanese have sterling cycle engines - and they've been given access to sterling technology data that australia had.

interestingly enough, AIP was purchased but not fitted to Collins. The AIP engines are still sitting on pallets. AIP was not seen to give demonstrable advantages and left out.

In RIMPAC exercises the ASW hunters have tried to force mistakes by working out duration cycles for conventional subs. HMAS Sheehan and Rankine (eg) have always been able to air up even in a proscribed training box.

[aaaditya]

thanks for the info gf,can you post some info,pics or links pertaining to the japanese submarines ,i have always found them fascinating but i find it very difficult to find meaningfull information about them .

also india had recently signed a defence co-operation agreement with japan,what do you think are japan's chances of selling their latest subs to india?

[gf0012-aust]

thanks for the info gf,can you post some info,pics or links pertaining to the japanese submarines ,i have always found them fascinating but i find it very difficult to find meaningfull information about them .

The info I have is hard copy only.


what do you think are japan's chances of selling their latest subs to india?

Zero chance.

[rickusn]

"HMAS Sheehan and Rankine (eg) have always been able to air up even in a proscribed training box."

The reasons as I understand it are:

1. That it requires only a fraction of the time(indiscretion rate) required of most(maybe all) other diesel submarines to recharge its batteries.

2. It has more potent batteries than other diesel subs.

3. Its noise level (indiscretion profile) while recharging batteries apparently is orders of magnitude less than other diesel subs.

[scraw]

"HMAS Sheehan and Rankine (eg) have always been able to air up even in a proscribed training box."

The reasons as I understand it are:

1. That it requires only a fraction of the time(indiscretion rate) required of most(maybe all) other diesel submarines to recharge its batteries.

2. It has more potent batteries than other diesel subs.

3. Its noise level (indiscretion profile) while recharging batteries apparently is orders of magnitude less than other diesel subs.

This would be the time gf goes mysteriously silent..

[G-Capo]

thanks for the info gf,can you post some info,pics or links pertaining to the japanese submarines ,i have always found them fascinating but i find it very difficult to find meaningfull information about them .

also india had recently signed a defence co-operation agreement with japan,what do you think are japan's chances of selling their latest subs to india?

Maybe the Japanese would co-develop a new submarine class with India.But selling out right a new submarine to India I think not.India is buying a large capable fleet of submarines but the Indian Government and navy is stressing indigineous systems.Also wouldn't more submarines be a logistical nightmare for India.

[aaaditya]

Maybe the Japanese would co-develop a new submarine class with India.But selling out right a new submarine to India I think not.India is buying a large capable fleet of submarines but the Indian Government and navy is stressing indigineous systems.Also wouldn't more submarines be a logistical nightmare for India.

india currently operates 3 different types of submarines ,of which 2 are of russian origin(foxtrot and kilo) and one is of european origin(hdw type209),with the advent of scorpene india will have 3 different types of submarines and yet i do not think it will be a logistical nightmare,india has 2 facilities for submarines,the mazagaon docks limited on the west coast which caters to the submarines of european origin and the one at vizag on the east coast which caters to submarines of russian origin and with private companies like larsen and toubro entering into shipbuilding and maintainence ,i doubt there will be any problem for a navy operating a submarine fleet consisting of 2 or 3 types of submarines.

[Betasys]

More info was released at Euronaval about the S1000.
It is shaping up to be quite a potent machine with a complete sensors suite, WASS torpedoes, Club S antiship/antishore missile, antiaircraft missiles, remarkable special ops capabilities.

A titanium alloy hull is apparently being considered.

Defense Technology http://www.nxtbook.com/nxtbooks/mh/dti0406/index.php?startpage=20&PHPSESSID=bdad4bf56ebc0e127adf0ccbdb603133&ncd=content

[Betasys]

In the "U-214 SSK problems" thread
....
I'm not sure at all that in Italy we may gain commercially from HDW's pains. Before we manage to sell some S1000 we'll have to build a prototype with the Russians, and even the Russians themselves may still priorize Amur and Lada in their export efforts. Our country has the credibility to sell surface vessels ranging from the STOVL aircraft carrier to the OPVH, but in subs we are soooo behind... we haven't exported any since WW2.

cheers


The S1000 will feature a mix of Italian and Russian technologies.
The autopilot is likely to be derived from that sold to the Spanish for their S80 subs, the WASS torpedoes and self defense solutions are certainly state of art. Another Italian contribution is going to be the PEM fuel cell system. Regarding this Fincantieri appears confident that the system won't be violating the non-reexporting agreements that were signed with Siemens in relation to the FC system on the U-212. The Italian solution draws on studies carried out by national firms while possibly the exposure to the Siemens system would have helped in figuring out how specific submarine implementation issues have been solved. This shouldn't be cause for criticism as the Germans for example will also be implementing on their further two U-212 subs some divers operation related features originally developed by Fincantieri for the Italian units.

It is reasonable to assume that the technological areas in which Italy lags, will see the use of Russian systems. The whole object being to combine each other's strengths. This should alleviate concerns about the technical viability of the S1000.

The use of already developed systems will help keep cost down to half that of a U-212.

Doubts about Russian commitment to S1000 in light of them having a clear interest in pushing their own Amur aren't that well founded. The S1000 will have FC AIP, internal modularity, 12 divers op., western standards and systems. This is going to differentiate S1000 from Amur both on features and international appeal.

[aaaditya]

the russian subs would find a ready market in china,india and maybe african and other asian countries ,or with the countries enemical to the nato alliance,however to make their submarines attractive in the western world ,they would need some joint development and marketting with european countries.

[contedicavour]

The S1000 will feature a mix of Italian and Russian technologies.
The autopilot is likely to be derived from that sold to the Spanish for their S80 subs, the WASS torpedoes and self defense solutions are certainly state of art. Another Italian contribution is going to be the PEM fuel cell system. Regarding this Fincantieri appears confident that the system won't be violating the non-reexporting agreements that were signed with Siemens in relation to the FC system on the U-212. The Italian solution draws on studies carried out by national firms while possibly the exposure to the Siemens system would have helped in figuring out how specific submarine implementation issues have been solved. This shouldn't be cause for criticism as the Germans for example will also be implementing on their further two U-212 subs some divers operation related features originally developed by Fincantieri for the Italian units.

It is reasonable to assume that the technological areas in which Italy lags, will see the use of Russian systems. The whole object being to combine each other's strengths. This should alleviate concerns about the technical viability of the S1000.

The use of already developed systems will help keep cost down to half that of a U-212.

Doubts about Russian commitment to S1000 in light of them having a clear interest in pushing their own Amur aren't that well founded. The S1000 will have FC AIP, internal modularity, 12 divers op., western standards and systems. This is going to differentiate S1000 from Amur both on features and international appeal.

Very interesting grazie :)
Do you believe that we'll see a prototype being built anytime soon ?
It's a tough sell to persuade a foreign navy to buy a sub that your own navy doesn't have and doesn't want to have... since we all expect that Forcieri will activate the option for 2 more U212A in the CY2008 budget.

ciao

[Betasys]

Very interesting grazie :)
Do you believe that we'll see a prototype being built anytime soon ?
It's a tough sell to persuade a foreign navy to buy a sub that your own navy doesn't have and doesn't want to have... since we all expect that Forcieri will activate the option for 2 more U212A in the CY2008 budget.

ciao

If I interpret correctly what written in the article linked above Fincantieri Rubin are saying that detailed design work and configuration definition could take place in 2008-9 leading to start of building thereafter. It would appear that an order would be required to get things going... and this is where an effort would have to be made to convince potential clients of the soundness (metaphorically speaking) of the project, the limited risks (simplicity and use of off-the-shelf solutions), the operational usefulness, the competitive pricing.

One element that I find interesting is the possibility of having a titanium hull. The Russians would be leveraging their experience in this field and there can be little doubt about the feasibility. Such a solution could either be viewed as a way to increase pressure hull resistance not only to depth pressure but also to explosions shockwaves or as a way to mantain depth performances while reducing pressure hull mass fraction leading to a high density mass requirement which could be filled, for example, by increasing hydrogen-oxygen stores... (or other high density items) This would be another way to play around with the mass-volumes allotment (the reference is to the 'internal modularity' approach that characterizes this project).
And of course, whichever way you implement a titanium hull, there is always the elimination of the major source of magnetic signature.

[contedicavour]

If I interpret correctly what written in the article linked above Fincantieri Rubin are saying that detailed design work and configuration definition could take place in 2008-9 leading to start of building thereafter. It would appear that an order would be required to get things going... and this is where an effort would have to be made to convince potential clients of the soundness (metaphorically speaking) of the project, the limited risks (simplicity and use of off-the-shelf solutions), the operational usefulness, the competitive pricing.

One element that I find interesting is the possibility of having a titanium hull. The Russians would be leveraging their experience in this field and there can be little doubt about the feasibility. Such a solution could either be viewed as a way to increase pressure hull resistance not only to depth pressure but also to explosions shockwaves or as a way to mantain depth performances while reducing pressure hull mass fraction leading to a high density mass requirement which could be filled, for example, by increasing hydrogen-oxygen stores... (or other high density items) This would be another way to play around with the mass-volumes allotment (the reference is to the 'internal modularity' approach that characterizes this project).
And of course, whichever way you implement a titanium hull, there is always the elimination of the major source of magnetic signature.

You can definitively change your setting and put "defence professional/analyst", you are clearly an expert in materials (qualcosa del genere : dottorato in ingegneria dei materiali ;) ?)

You do confirm however that nobody is thinking of selling these subs to the Italian Navy ?

ciao

[gf0012-aust]

I really can't see any navy seriously considering the use of titanium hulls anymore. The soviet/russian exp didn't show sufficient expense/reward for capability. It was wonderful as an example of technological prowress at a point in time - but realtime gains? current heavy torpedoes remove the dive and speed variables that used to be the key cards in the Ti debate.

to be blunt, some of the existing steel stds available provide greater benefit.

there are far better ways to spend the money than have "nn" sq metres of titanium.

the internal design is far more important than the exoskeleton.

[Betasys]

I really can't see any navy seriously considering the use of titanium hulls anymore. The soviet/russian exp didn't show sufficient expense/reward for capability. It was wonderful as an example of technological prowress at a point in time - but realtime gains? current heavy torpedoes remove the dive and speed variables that used to be the key cards in the Ti debate.

to be blunt, some of the existing steel stds available provide greater benefit.

there are far better ways to spend the money than have "nn" sq metres of titanium.

the internal design is far more important than the exoskeleton.

What about using titanium to reduce the pressure hull mass fraction and using the freed mass requirement for increased payload fraction or propulsion systems fraction .... This would allow to increase performances for a given hull size / for a given project. Wouldn't it?

[gf0012-aust]

What about using titanium to reduce the pressure hull mass fraction and using the freed mass requirement for increased payload fraction or propulsion systems fraction .... This would allow to increase performances for a given hull size / for a given project. Wouldn't it?

Thats still more an issue of material density and flexibility when you assess performance fractions. and its relevance within the operational requirements profile. For me the more significant issue is internal design. I truly think that Titanium, (as conventionally used) is an absolute waste of money for minimal benefit against a sophisticated enemy with current weapons capabilities.

the benefits that titanium had as far as diving depth and resilience to attack have been virtually negated with new weapons technologies amongst the more modern navies - and that doesn't include some of the newer dense munitions under development.

it is of course always going to be an issue of clients requirement for perceived roles. But, the new weapons systems seriously degrade any advantages that titanium prev had.

some weapons are not subject to the vagaries and delimiters of "crush" depth. and they can certainly outdive and outpace a nuke.

I think you are going to see some significant weapons developments over the next few years.

[Betasys]

Thats still more an issue of material density and flexibility when you assess performance fractions. and its relevance within the operational requirements profile. For me the more significant issue is internal design. I truly think that Titanium, (as conventionally used) is an absolute waste of money for minimal benefit against a sophisticated enemy with current weapons capabilities.

the benefits that titanium had as far as diving depth and resilience to attack have been virtually negated with new weapons technologies amongst the more modern navies - and that doesn't include some of the newer dense munitions under development.

it is of course always going to be an issue of clients requirement for perceived roles. But, the new weapons systems seriously degrade any advantages that titanium prev had.

some weapons are not subject to the vagaries and delimiters of "crush" depth. and they can certainly outdive and outpace a nuke.

I think you are going to see some significant weapons developments over the next few years.

This is all tied to the idea of using titanium to increase op. depth and resistance to shock. And in that context it's true with the limitations and for the reasons you mentioned with only the added note that in a coastal environment, at low depth and with the introduction of improved self defence systems there is in my view a possible requirement for increased hull strength in absolute terms to resist shock.
However. The pure hull mass fraction argument goes like this.
In the context of coastal ops. and having a requirement for amagnetic hull, titanium being lighter than amagnetic steel would allow the advantages I mentioned essentially in either payload or range for a given design.
Without venturing right now in calculations that would always have a certain degree of uncertainty, for lack of detailed knowledge, it could be fair to assume that a coastal sub sized could be constructed combining the payload-range capabilities of larger units while retaining small size and no magnetic signature. The best of both worlds in a way. Coastal area manouver, stealth and submerged endurance better than any steel hull.

[gf0012-aust]

However. The pure hull mass fraction argument goes like this.

I do actually work on sub warfare technology and have been involved on sub building programmes. :p:

I stand by my prev that titanium offers no tangible benefits in current weapons environments.

The "Akula" (to use the common but incorrect name) is a sitting duck with current weapons systems. A smaller sub would not even remotely survive a strike using some of the current weaps systems. Titanium tech as used by the russians on their subs would fracture like an overboiled egg.

there are better ways to spend the money.

[Betasys]

I do actually work on sub warfare technology and have been involved on sub building programmes. :p:

I stand by my prev that titanium offers no tangible benefits in current weapons environments.

The "Akula" (to use the common but incorrect name) is a sitting duck with current weapons systems. A smaller sub would not even remotely survive a strike using some of the current weaps systems. Titanium tech as used by the russians on their subs would fracture like an overboiled egg.

there are better ways to spend the money.

I know who you are from months of monitoring the forums in which you write. I do not work on submarines, for me that's just an interest. However I have exhibited at UDT, and will again. :p: So maybe we'll meet someday.

And of course I stand by my argument on the titanium hull S1000 :)

[gf0012-aust]

And of course I stand by my argument on the titanium hull S1000 :)

oh well, we'll just have to have a difference of opinion on this :D.

I hope that Francois is lurking as he can provide a different perspective - and may well disagree with me as well...

[Francois]

UDT has special sessions for people with a NATO clearance.
In this closed sessions, things funny are discussed.

Now, no serious shipyard will ever think of building a hull in any Ti- alloy.
Too much pain for not that a good result.
You can get a very close result with high alloy steels.

Even Russians did come back from it.
When you have to heat the whole room and have it under inert gases like CO2 or Argon or Helium (not Nitrogen, Titanium burns in Nitrogen...).
Plus the cost of the Ti makes it no reliable.

This being said, it is getting worse, as China is absorbing more and more of the production of Ti, and the costs are raising hights every now and then.

And then there is the myth... see: Tom Gervasi.

[Betasys]

Now, no serious shipyard will ever think of building a hull in any Ti- alloy.
Too much pain for not that a good result.
You can get a very close result with high alloy steels.

Even Russians did come back from it.
When you have to heat the whole room and have it under inert gases like CO2 or Argon or Helium (not Nitrogen, Titanium burns in Nitrogen...).
Plus the cost of the Ti makes it no reliable.

This being said, it is getting worse, as China is absorbing more and more of the production of Ti, and the costs are raising hights every now and then.

And then there is the myth... see: Tom Gervasi.

I am aware of the existance of technical difficulties with using titanium (or more appropriatly titanium alloys) for a submarine pressure hull.
Taking the discussion back to the S1000 Italian Russian co-operation project I believe that those difficulties have been overcome in Russia and that they possess the know-how for building them. Also the high alloy steels have building issues of their own, they are magnetic and Italy and Russia may not have the know-how. Also I doubt the high yield steel alloys currently employed are that close to titanium alloys in terms of specific strength.
And amagnetic steel doesn't have the required characteristics of strength-density.

If with HY80 steel the pressure hull mass fraction is 40% (this and all other values are my rough estimates) I believe that that could be replaced by a titanium hull weighing around 25% of submerged displacement for the same operational depth. The mass saving would be 0.15x1000=150 tons. That mass of course has to be added to recover the required average density.
Consider the hydrogen and oxygen storage tanks (remember we are still talking of the S1000) These, to my knowledge are high density items. The tanks themselves are heavy even when empty. What is the mass of these in the S1000? Let's assume they are 150 tons. If we allocate the freed mass requirement to these items, we could double the submerged persistance of the sub.

The S1000 sub is described as implementing internal modularity. In reason of this assume that the placement and other issues are addressed and possibly the very same concept I am illustrating here hasn't been missed.

If the steel S1000 has submerged persistance of 10 days at 4 knots, a titanium hull S1000 will have 20 days at the same speed plus no (or smaller) magnetic signature. How much would one pay for this and how much would it cost? I don't know. But it certainly is extremely interesting.
Plus it would allow the S1000 to be in direct competition with the bigger SSKs that dominate the market: the Scorpene (>Marlin) and the U-212 / 214 that have in their inevitably longer range (both on diesel and underwater) an apparently irremediable advantage.

[gf0012-aust]

Also the high alloy steels have building issues of their own, they are magnetic and Italy and Russia may not have the know-how. Also I doubt the high yield steel alloys currently employed are that close to titanium alloys in terms of specific strength.
And amagnetic steel doesn't have the required characteristics of strength-density.

If with HY80 steel the pressure hull mass fraction is 40% (this and all other values are my rough estimates) I believe that that could be replaced by a titanium hull weighing around 25% of submerged displacement for the same operational depth. The mass saving would be 0.15x1000=150 tons. That mass of course has to be added to recover the required average density.
Consider the hydrogen and oxygen storage tanks (remember we are still talking of the S1000) These, to my knowledge are high density items. The tanks themselves are heavy even when empty. What is the mass of these in the S1000? Let's assume they are 150 tons. If we allocate the freed mass requirement to these items, we could double the submerged persistance of the sub.



There can be in excess of 36 different metal types in a modern submarine. Its not the exoskeleton that counts - its the internal design that is critical.

There are far too many variabless involved to argue that a reduction of weight by using Ti is going to allow an increase in range or depth of operation.

eg, The Oyashios are the deepest diving conventional in the world - they rival some of the numbers thrown around for russian nukes. They don't use titanium.

[Betasys]

There can be in excess of 36 different metal types in a modern submarine. Its not the exoskeleton that counts - its the internal design that is critical.

There are far too many variabless involved to argue that a reduction of weight by using Ti is going to allow an increase in range or depth of operation.

eg, The Oyashios are the deepest diving conventional in the world - they rival some of the numbers thrown around for russian nukes. They don't use titanium.

You are referring to the ring stiffners and bulkheads? Then the greater depth of the Oyashios being a conseguence of having accepted a more performance driven internal layout in order to achieve failure pressure nearer to the hull material yield stress. Could their large size have favored a more efficient balance being struck in the efficient layout-habitability trade-off? I take the reference to different metals as an indication that different structural elements are optimized using different metals. Yes? The greater technical prowness of the Japanese could also indicate closer tolerances as further justification of the asserted greater op. depth. relative to the materials used.

The relationship between the specific strength of the structural materials and the performances still stands in principle, but now it's clearer that it's not a matter of simple substitution, but of complete redesign.

Which leads to a question. Do bigger subs offer more scope for improving hull structural efficiency than small subs?

[gf0012-aust]

Could their large size have favored a more efficient balance being struck in the efficient layout-habitability trade-off? I take the reference to different metals as an indication that different structural elements are optimized using different metals. Yes?

Yes - the comment about the number of different metal types was also in relationship to Collins. The point about titanium usage in general applies to both Collins and Oyashios.

The greater technical prowness of the Japanese could also indicate closer tolerances as further justification of the asserted greater op. depth. relative to the materials used.

The design of the sub is central to their own build philosophies - the build philosophy is closer to an australian similarity than a french or german.

The relationship between the specific strength of the structural materials and the performances still stands in principle, but now it's clearer that it's not a matter of simple substitution, but of complete redesign.


Its a whole of concept design issue. You just cannot substitute material "x" for material "y". There are implications on the whole design.

Which leads to a question. Do bigger subs offer more scope for improving hull structural efficiency than small subs?

Bigger subs (and I'm talking about anything over 3000 tonnes - in very very broad terms offer greater scope for signature management and control. A sub is a big underwater transducer. Mass has a singularly important effect on noise propogation.

Contrary to lots of popular assumptions, and again, on very very broad terms - smaller subs do not necessarily provide a smaller object of interrogation and/or for detection.

[Francois]

I am aware of the existance of technical difficulties with using titanium (or more appropriatly titanium alloys) for a submarine pressure hull.
Taking the discussion back to the S1000 Italian Russian co-operation project I believe that those difficulties have been overcome in Russia and that they possess the know-how for building them. Also the high alloy steels have building issues of their own, they are magnetic and Italy and Russia may not have the know-how. Also I doubt the high yield steel alloys currently employed are that close to titanium alloys in terms of specific strength.
And amagnetic steel doesn't have the required characteristics of strength-density.
Well, I think I said that even russians gave up the idea.
No, there are no solutions to the problem. The rest is blah-blah-blah.
Italians haven't designed a sub since WWII.
If the steel S1000 has submerged persistance of 10 days at 4 knots, a titanium hull S1000 will have 20 days at the same speed plus no (or smaller) magnetic signature. How much would one pay for this and how much would it cost? I don't know. But it certainly is extremely interesting.
Eh? What is the relation between submerge time and the composition of the hull. I am scared you are mixing things up a bit here.

See, gf, I was right.

[contedicavour]

Well, I think I said that even russians gave up the idea.
No, there are no solutions to the problem. The rest is blah-blah-blah.
Italians haven't designed a sub since WWII.

Eh? What is the relation between submerge time and the composition of the hull. I am scared you are mixing things up a bit here.

See, gf, I was right.

Ehm... we haven't exported a SSK since WW2. We have however designed 2 classes of subs, the coastal SSKs of the Toti class in the '60s and 4 separate batches of the Sauro SSK class. Fincantieri also designed a follow on class in the '90s, but given the small numbers that could be ordered, unitary costs were sky-high and it was obvious to all that participating to the German HDW U212A made much better sense.

Btw, in terms of design, Fincantieri and Ansaldo even conceived a SSN in the late '60s, that was to be called Marconi. Except that budget cuts and the notoriously anti-nuclear power Italian public opinion killed the project before it could be built.

cheers

[Francois]

Ehm... we haven't exported a SSK since WW2. We have however designed 2 classes of subs, the coastal SSKs of the Toti class in the '60s and 4 separate batches of the Sauro SSK class. Fincantieri also designed a follow on class in the '90s, but given the small numbers that could be ordered, unitary costs were sky-high and it was obvious to all that participating to the German HDW U212A made much better sense.

Btw, in terms of design, Fincantieri and Ansaldo even conceived a SSN in the late '60s, that was to be called Marconi. Except that budget cuts and the notoriously anti-nuclear power Italian public opinion killed the project before it could be built.

cheers
Wasn't Toti class a derivative of an aborted US design?

[contedicavour]

Wasn't Toti class a derivative of an aborted US design?

Not that I am aware of. The Toti class was a small coastal sub, I don't see why the USN would have been interested in it !
The Sauro (in its 4 batches) was a 100% Italian design, which btw almost got exported to Iraq together with the FFGs, corvettes and AOR which were in the final package.

cheers

[Francois]

Not that I am aware of. The Toti class was a small coastal sub, I don't see why the USN would have been interested in it !
The Sauro (in its 4 batches) was a 100% Italian design, which btw almost got exported to Iraq together with the FFGs, corvettes and AOR which were in the final package.

cheersWell, actually, there was a program at the start of the cold war, initiated by the US Navy, for building like 2 or 300 small submarines to lay astraside of russian's subs routes.
That was mainly the answer to the Whiskey program.
I don't remember the name of the program, as I don't have my references by me right now.

The Italians got something in the program and ended with designing their own (Toti) by iteration of the former program.

Now, I think (but can't do much now, have to check my data again) that somewhere the Germans were involved in the design of the Sauro class.
But history kept that the design/built is Italian.

[contedicavour]

Could you also check your references on the design of the SSN Marconi ? I'm interested in the history of the design phase, especially if Fincantieri and Ansaldo did it all on their own or with foreign help.

thks

cheers