Royal Australian Navy Discussions and Updates

[protoplasm]

AIP in Collins replacement

The RAN already trialled AIP on Collins - it was dropped shortly thereafter. AIP isn't a silver bullet and the advantages weren't sufficient to warrant the changes. There's some more info on the forum somewhere about this, but it's from a long time ago. The search function would be your best bet.

I'm making an assumption that AIP is unlikely to be considered in the Collins replacement subs. Has there been any technical breakthrough that would make AIP desirable from the perspective of RAN SSK CONOPS?

 

[Bonza]

I'm making an assumption that AIP is unlikely to be considered in the Collins replacement subs. Has there been any technical breakthrough that would make AIP desirable from the perspective of RAN SSK CONOPS?

There are others with far more knowledge than me to answer that question, personally I don't know. I'd bet that the technological progress in battery capacity and size will be more important to next generation conventionals than AIP.

One small quibble though - the Collins is an SSG, not an SSK. People are in the habit of calling all conventional subs SSKs, but for a real blue water submarine like Collins or Soryu it isn't really the appropriate term. SSK was originally used to define a conventional sub whose primary tasking was anti-submarine warfare. Given the wider range of duties undertaken by submarines nowadays (missile launch capability, ISR - this is a big one), the SSK definition no longer accurately describes these designs.

Or at least that's what I've learned from sources I trust. It's not a big deal though, I just like to see the right terminology used...

 

[gf0012-aust]

I'm making an assumption that AIP is unlikely to be considered in the Collins replacement subs. Has there been any technical breakthrough that would make AIP desirable from the perspective of RAN SSK CONOPS?

there have been advances in AIP - but the issue is about whether those advances are still worth giving up real estate which could be better used for other things...

thats why AIP was rejected prev - there were minimal benefits to how Collins operates. the space was better utilised for other reqs identified in the CONOPS

 

[aussienscale]

there have been advances in AIP - but the issue is about whether those advances are still worth giving up real estate which could be better used for other things...

thats why AIP was rejected prev - there were minimal benefits to how Collins operates. the space was better utilised for other reqs identified in the CONOPS

And correct me if I have this wrong GF ?

But, as I understand it, with the given weight and space taken up by an AIP system v more fuel and batteries, the fuel and batteries have a higher density of power output for that given space. The power that can be generated and stored is much greater, so you are better of having the one system, because you need the diesels in a conventional anyway, rather than trying to incoporate 2 methods of power production.

AIP may be efficient but the actual power output is basically just not worth it for the CONOPS employed by the RAN, especially if you look at the Area of Operations these boats cover.

Cheers

 

[Joe Black]

Adding a "plug" to any submarine is not a simple operation and upsets a plethora of performance criteria, buoyancy, stealth, power requirement etc It would require a total rebuild and that would not be cost effective for Collins and would detract from and delay the acquisition of their replacement.

The RAN has already bought 1 x Stirling unit IIRC and has chosen NOT to install it because it fails to provide any benefit for our submarine operational employment (CONOPS)

You seem to consider that changing and adding to these boats is as easy as changing a gun or missile system on a surface unit. These/subs are some of the most complex machines built and although it may have been easier on smaller subs as you indicated, they are not at the design limits of conventional power as is the case with Soryu and Collins.
There is a good reason why big boats are nuclear, it makes the power problem solvable

Before we are quick to dismiss the role of AIP in RAN, just have a look at this writeup.
SEA 1000 CONVENTIONAL AIR INDEPENDENT PROPULSION | Australian Defence News & Articles | Asia Pacific Defence Reporter

There is also a paper done by DSTO on this very issue. Would be most interesting to read it...
http://www.dsto.defence.gov.au/publications/scientific_record.php?prefix=1947&record=2284

BTW, the plug-in section for an AIP for Collins has already been thought of by DSTO. Don't think they have discounted this:
http://dspace.dsto.defence.gov.au/dspace/bitstream/1947/3828/1/DSTO-GD-0042 PR.pdf
(page 4)

 

[gf0012-aust]

And correct me if I have this wrong GF ?

But, as I understand it, with the given weight and space taken up by an AIP system v more fuel and batteries, the fuel and batteries have a higher density of power output for that given space. The power that can be generated and stored is much greater, so you are better of having the one system, because you need the diesels in a conventional anyway, rather than trying to incoporate 2 methods of power production.

AIP may be efficient but the actual power output is basically just not worth it for the CONOPS employed by the RAN, especially if you look at the Area of Operations these boats cover.

Cheers

basically yes. I can see the advantages for a smaller sub, but I'm less convinced for a bluewater "fleet" conventional with RANs area of interest/ops

 

[gf0012-aust]

Before we are quick to dismiss the role of AIP in RAN, just have a look at this writeup.
SEA 1000 CONVENTIONAL AIR INDEPENDENT PROPULSION | Australian Defence News & Articles | Asia Pacific Defence Reporter

There is also a paper done by DSTO on this very issue. Would be most interesting to read it...
DSTO > Publications > The Stirling engine power source for advanced marine applications

BTW, the plug-in section for an AIP for Collins has already been thought of by DSTO. Don't think they have discounted this:
http://dspace.dsto.defence.gov.au/dspace/bitstream/1947/3828/1/DSTO-GD-0042 PR.pdf
(page 4)

there are a number of vectors here:

collins was designed from the onset to be plugged, it's been a while since I was in the guts of the shell, but IIRC the whole section aft of the combat cell was designed to be lanced. the issue is more about capability and then cost benefit - its not a tech issue

the reason why AIP never progressed was because there was no significant advantage - the space for AIP was allocated to other "business needs"

the USN ran trials and dummy combat runs against Gotland (Collins "mini-me") and it "underperformed" in comparison. Granted the tests were to see how they would cope against an AIP conventional to extrapolate against an emergent PACRIM threat, but there are some significant bits of data that can be extrapolated against Collins from Gotland

 

[protoplasm]

There are others with far more knowledge than me to answer that question, personally I don't know. I'd bet that the technological progress in battery capacity and size will be more important to next generation conventionals than AIP.

One small quibble though - the Collins is an SSG, not an SSK. People are in the habit of calling all conventional subs SSKs, but for a real blue water submarine like Collins or Soryu it isn't really the appropriate term. SSK was originally used to define a conventional sub whose primary tasking was anti-submarine warfare. Given the wider range of duties undertaken by submarines nowadays (missile launch capability, ISR - this is a big one), the SSK definition no longer accurately describes these designs.

Or at least that's what I've learned from sources I trust. It's not a big deal though, I just like to see the right terminology used...

Thanks guys, and yes Bonza I'll use SSG from now on. I had the idea that the power density hadn't changed enough through technical development for AIP to be worth it for our CONOPS. If batteries and fuel give the greatest benefit do that, and it does mean that there is one less complex element that needs to be designed in for the Collins replacement.

 

[aussienscale]

Defence Ministers » Minister for Defence and Minister for Foreign Affairs – Joint Press Conference – 2+2 Foreign and Defence Ministers

Joint press conference 2+2 meetings Japan, some interesting comments, can't wait for final agreement to be signed between Abe and Abbott to hear a little more detail, here is an extract from above:

"Allow me to speak about the submarine-related question. I will be very brief.

Minister Johnston mentioned that [Australia] appraises highly Japan’s submarine technology. Once again, we do appreciate his highly positive remarks. Japan has its three principles for transferring defence equipment and technology. This is the new three principles which we have created; we take into consideration the appropriateness of the destination for transfer and the threats to the situation. Based on the views on the international situation we would assure that the transfer was appropriate. In that context at the 2+2 meeting held this time, we were managing properly the issue of transferring equipment and technology and we were able to reach a substantial conclusion of the contents of the agreement for transfer of that relevant equipment and technology between the two countries. As for specific issues, we are looking forward to conducting joint research in marine hydrodynamics and we hope it can be started in the next fiscal year. So in the meantime until then our work will be more specific. The substance of the joint research contents will be technologies that can be commonly applicable to many areas not only for submarines. These matters do not involve any of the constitution-related issues or problems. Thank you."

Any insights into what the "Marine Hydrodynamics" could entail ? and for it to be starting hopefully next FY is rather interesting, understand some may not be able to comment

Cheers

 

[gf0012-aust]

Any insights into what the "Marine Hydrodynamics" could entail ? and for it to be starting hopefully next FY is rather interesting, understand some may not be able to comment

Cheers

from my prev involvement with acoustics on subs - I'd suggest that it's about hull design.

the Soryu's were in the equation boundary of being acoustically perfect in specific operating parameters.

only one other conventional was regarded as superior in some areas - and that one was never for sale/export

 

[ASSAIL]

from my prev involvement with acoustics on subs - I'd suggest that it's about hull design.

the Soryu's were in the equation boundary of being acoustically perfect in specific operating parameters.

only one other conventional was regarded as superior in some areas - and that one was never for sale/export

And was Collins superior in some areas?

 

[gf0012-aust]

And was Collins superior in some areas?

Acoustic sig performance covers a wide operational range, and Collins was always in the top 3 across those various test ranges

... and we did know the acoustics on subs like the Kilo as some "customers" would provide us with realtime performance data

 

[StobieWan]

Before we are quick to dismiss the role of AIP in RAN, just have a look at this writeup.
SEA 1000 CONVENTIONAL AIR INDEPENDENT PROPULSION | Australian Defence News & Articles | Asia Pacific Defence Reporter

There is also a paper done by DSTO on this very issue. Would be most interesting to read it...
DSTO > Publications > The Stirling engine power source for advanced marine applications

BTW, the plug-in section for an AIP for Collins has already been thought of by DSTO. Don't think they have discounted this:
http://dspace.dsto.defence.gov.au/dspace/bitstream/1947/3828/1/DSTO-GD-0042 PR.pdf
(page 4)

The operational needs for the Collins are somewhat different than most of the AIP owners out there - traditionally the Australian boats have run long distances - even up to Russian harbours - most of the AIP fleet out there is devoted to shorter runs with more time spent defending or denying smaller tracts of water.

For them, a smaller, handier boat with lower endurance is a good tradeoff vs the benefits of AIP.

AIP is *not* a magic bullet - you're giving up space and weight for both the AIP system and the fuel/oxidiser which will allow the boat to run underwater for a fairly short time. Given the power output vs volume/weight ratio of the AIP unit, you'll see that they usually kick out around 40kw or so, which is not enough to charge the batteries while running at anything over a few knots.

Collins plugged in very large gensets to rapidly charge their batteries so they can run quietly and snort every so often, giving them a higher advance rate (the rate at which they progress towards their patrol area) than other SSK's - it's not a huge margin, 10 knots vs about 8, but much higher than an AIP boat, which is nearer 4 knots.

Once you're out of fuel and oxidiser, that AIP set is a large chunk of nothing useful. In the Collins, the area formerly reserved for the AIP set was given over to tasks felt more relevant (a lockout area for divers I seem to recall)

It's best you understand what the Collins were intended for, look at a map and see the distances involved for the boat to even get to the patrol area, before you start seeing utility in fitting AIP.

AIP gets you some relatively fast submerged speeds for a short period of time, maybe twenty hours or so at high speeds of 18 or more knots.. Maybe less.

That's no good for Australia and the ops it's tasking it's subs with.

 

[gf0012-aust]

AIP is *not* a magic bullet

Can't be said enough - technology benefit has to be tied into the CONOPs - and all the fluff about AIP drives me nuts - its not as if we are new to the tech - and we have substantial info available from various partners including training exercises against AIP subs

there is a vast difference between a 212/214 sized sub running AIP and a large fleet conventional designed for LRP/ISR fitted with it The mission profiles are different by some degree

DSTO RO's write papers on a variety of technologies - its not an auto tick for endorsement. Although a bit more sophisticated than letters to the editor, some of the pubs are just academic dissertations and can have no bearing on an actual requirement - and that's what's caused some dislocation in the past between DSTO and the user community. I've seen papers written which had no input from uniforms and as a result the assumptions about benefit and need were somewhat parlous.

Quite franlky the people who use he current space originally allocated for AIP would have a far stronger claim to NOT having AIP and sacrificing their needs as a result.

 

[aussienscale]

from my prev involvement with acoustics on subs - I'd suggest that it's about hull design.

the Soryu's were in the equation boundary of being acoustically perfect in specific operating parameters.

only one other conventional was regarded as superior in some areas - and that one was never for sale/export

Cheers for that, would that also extend into tiles as well ?

I was also intrigued by the statement that the research/program is not just exclusively subs but also other applications as well, which to me would suggest skimmer hull design as well ?

Cheers

 

[gf0012-aust]

Cheers for that, would that also extend into tiles as well ?

I was also intrigued by the statement that the research/program is not just exclusively subs but also other applications as well, which to me would suggest skimmer hull design as well ?

Cheers

Oz developed its own tiles due to an inability to get the tech from partners - we also developed a "better" bonding process. (better adhesion properties)

hard to guess on what other tech could be, but in the past we've been able to provide sig management tech to skimmer hulls based on lessons learnt from sub hull mgt

the above was private sector driven. a few of the allies have benefited from tech advances identified in managing sub acoustics - it has been a 2 way street though.

 

[aussienscale]

Oz developed its own tiles due to an inability to get the tech from partners - we also developed a "better" bonding process. (better adhesion properties)

hard to guess on what other tech could be, but in the past we've been able to provide sig management tech to skimmer hulls based on lessons learnt from sub hull mgt

the above was private sector driven. a few of the allies have benefited from tech advances identified in managing sub acoustics - it has been a 2 way street though.

Thanks for that, I knew we had developed a superior solution to the tile bonding process, but thought it was developed by DSTO for some reason, was not aware it was private sector.

Are you able to comment on who has benefited from the bonding process ? is this something that Japan would be interested in, if they have not already ?

I would assume anything in the future will be a 2 way street as well, I know we have some "stuff" they would be very interested in

 

[the road runner]

Thanks for that, I knew we had developed a superior solution to the tile bonding process, but thought it was developed by DSTO for some reason, was not aware it was private sector.

I read somewhere the bonding (glue) was similar to how cat eyes are fixed on Australian roads.

Edit... bottom of the page on the below link

http://info.olsonb.com/index.php?p=Anechoic_tile

 

[Goknub]

Diverging from subs for moment, a senior RAN Officer Navy chief Vice Admiral Ray Griggs has come out in support of a continuous build of surface ships. Ideally reducing the number of types in service at the same time.

The details, 14 different ship designs from 13 different designers says plenty. If the RAAF can see the benefit of reduced aircraft types hopefully the RAN can follow suit.

Hopefully the government listens as well.

Too many ship types lift Navy costs.
Cookies must be enabled. | The Australian

 

[gf0012-aust]

Thanks for that, I knew we had developed a superior solution to the tile bonding process, but thought it was developed by DSTO for some reason, was not aware it was private sector.

Are you able to comment on who has benefited from the bonding process ? is this something that Japan would be interested in, if they have not already ?

I would assume anything in the future will be a 2 way street as well, I know we have some "stuff" they would be very interested in

bad structure on my part. the tiles and bonding were dsto - we did other things in sig mgt