AUKUS
Evertonian
Historical interest - French submarine cancellation
Reporting on a ‘leaked’ 10 page paper prepared by Kim Gillis, a member of the Naval Group board (Deputy-Secretary in Defence before that).
It it would seem many in Defence working on the project were not aware of imminent project cancellation.
I thought his description of the various values associated with the project (in billions of AUD) of 32.0, 46.5, 50.0, 90.0 & 235.0 highlighted the need to compare like-with-like
The thought of Australian nuclear submarines, or even parts of them being built in Australia is very concerning.
I hope they are not.
After a decade living and working here my observation is that compared to Britain, where I have also lived and worked, and the US which I have visited frequently for work, in general Australian industry unduly struggles to organise itself and function optimally.
It is slow-moving, unnecessarily bureaucratic, lacking in imagination and agility, small-minded and inwardly focused compared to it's counterparts in both of those AUKUS nations.
Some might say the same could be said of Electric Boat or BAE... but they have track records and established facilities with experience building nuclear boats.
Australia just cannot move quickly - and it has no sense of urgency.
Hal Brands makes a that as a country facing future economic and demographic stagnation and decline, China is dangerous right now and for the next 5-10 years.
I'm not even confident Australia will be able to make the obvious move to procure long range missiles as quickly as it needs to - or to build or acquire UUVs and XLUUVs to fill the gap between now and the arrival of the SSNs.
Dangerous times indeed.
I hope they are not.
After a decade living and working here my observation is that compared to Britain, where I have also lived and worked, and the US which I have visited frequently for work, in general Australian industry unduly struggles to organise itself and function optimally.
It is slow-moving, unnecessarily bureaucratic, lacking in imagination and agility, small-minded and inwardly focused compared to it's counterparts in both of those AUKUS nations.
Some might say the same could be said of Electric Boat or BAE... but they have track records and established facilities with experience building nuclear boats.
Australia just cannot move quickly - and it has no sense of urgency.
Hal Brands makes a that as a country facing future economic and demographic stagnation and decline, China is dangerous right now and for the next 5-10 years.
I'm not even confident Australia will be able to make the obvious move to procure long range missiles as quickly as it needs to - or to build or acquire UUVs and XLUUVs to fill the gap between now and the arrival of the SSNs.
Dangerous times indeed.
The thought of Australian nuclear submarines, or even parts of them being built in Australia is very concerning.
I hope they are not.
After a decade living and working here my observation is that compared to Britain, where I have also lived and worked, and the US which I have visited frequently for work, in general Australian industry unduly struggles to organise itself and function optimally.
It is slow-moving, unnecessarily bureaucratic, lacking in imagination and agility, small-minded and inwardly focused compared to it's counterparts in both of those AUKUS nations.
Some might say the same could be said of Electric Boat or BAE... but they have track records and established facilities with experience building nuclear boats.
Australia just cannot move quickly - and it has no sense of urgency.
Hal Brands makes a detailed and compelling argument that as a country facing future economic and demographic stagnation and decline, China is dangerous right now and for the next 5-10 years.
I'm not even confident Australia will be able to make the obvious move to procure long range missiles as quickly as it needs to - or to build or acquire UUVs and XLUUVs to fill the gap between now and the arrival of the SSNs.
Dangerous times indeed.
I hope they are not.
After a decade living and working here my observation is that compared to Britain, where I have also lived and worked, and the US which I have visited frequently for work, in general Australian industry unduly struggles to organise itself and function optimally.
It is slow-moving, unnecessarily bureaucratic, lacking in imagination and agility, small-minded and inwardly focused compared to it's counterparts in both of those AUKUS nations.
Some might say the same could be said of Electric Boat or BAE... but they have track records and established facilities with experience building nuclear boats.
Australia just cannot move quickly - and it has no sense of urgency.
Hal Brands makes a detailed and compelling argument that as a country facing future economic and demographic stagnation and decline, China is dangerous right now and for the next 5-10 years.
I'm not even confident Australia will be able to make the obvious move to procure long range missiles as quickly as it needs to - or to build or acquire UUVs and XLUUVs to fill the gap between now and the arrival of the SSNs.
Dangerous times indeed.
The way that all the issues with design and pre-production of the Hunter class FFG’s have been resolved can give us confidence that these skills will flow on to the SSN’s. Despite all the adverse press, it now looks like they are on top of the issues and expect to catch up with the original schedule by the time the 4th ship is built.
You mention the very significant experience of overseas submarine building companies but, even with all the experience that BAE had in the past, they ran into major problems with building the early Astute submarines - so much so that some senior management from GD Electric Boat were sent to Britain to assist with getting the program back on track. Also, it was discovered in 2017 that substandard steel was used in the construction of USN submarines for the previous 20 years so having them built by overseas companies doesn’t mean that the RAN would get better quality submarines.
The RAN’s experience with the Oberon’s was that the costs escalated as the submarines aged and, as the parts were manufactured in Britain, were forced to pay very inflated prices. This is why the RAN focused on having the Collins (& all subsequent classes) submarines built locally. There were some major issues early in the Collins program but, it was a significantly larger vessel than the class they were based on with many changes to allow the vessels to perform their role so it was expected that there would be teething problems. No submarine had been built in Australia prior to the Collins. As well as major savings for the Defence budget, the flow-on’s for the local economy means that we have to maximise local construction content.
While there were initial mistakes, there were many positives in the Collins construction and ongoing upgrades so that they have developed into very good operational vessels. The steel used in the hulls is stronger (& easier to weld) than the UK & US vessels which contributed to why they have been assessed as suitable for the LOTE which will see some of the Collins having a service life of 45 years - a phenomenal feat. If the SSN’s are built locally, there will be mistakes made (which will be leaked to the press who are only too willing to seize on anything negative) but, I believe that they will be built to a high quality and be very effective for their service life.
The procurement of long range missiles has been accelerated due to funds being available following the cancellation of the Attack class. This is an important capability which needs to be in service as quickly as possible.
I believe that the contract with Anduril for the XL-AUV’s was because they are a company that develops cutting edge technology in the shortest time. The contract is for the first vessel to be in the water in just 3 years - phenomenally fast, which is what is needed in these times.
Personally, I’m in the group that wants the SSN’s and all surface warships built locally.
Last edited by Going Boeing; 16th Sep 2022 at 07:59.
I sincerely hope you prove me wrong on all points!
On the boats - I'm no submariner but let's assume we opt for the Virginia class, and I've chosen Block 3 as a benchmark.
By way of comparison:
Collins class = 6 boats @ 3400 tonnes displacement, 77m long, diesel electric power, $850m per unit
Virginia class Block 3 = at least 8 boats @ 11,000 tonnes displacement, 115m long, nuclear power, $2.8bn per unit
In other words, the Virginia class Boats are over three times the submerged size of Collins.
They're about one and a half times the length, have all the additional requirements of nuclear power, and each unit is around three times the cost.
Noting your valid point about bisalloy steel - with all due respect to the engineers and yards in Adelaide, I just can't see how they'll be able to handle a project of such magnitude.
Perhaps there is a plan to build some kind of Virginia-lite, and assemble modules in different yards, splitting the work between BAE, GDEB and ASC...
On the boats - I'm no submariner but let's assume we opt for the Virginia class, and I've chosen Block 3 as a benchmark.
By way of comparison:
Collins class = 6 boats @ 3400 tonnes displacement, 77m long, diesel electric power, $850m per unit
Virginia class Block 3 = at least 8 boats @ 11,000 tonnes displacement, 115m long, nuclear power, $2.8bn per unit
In other words, the Virginia class Boats are over three times the submerged size of Collins.
They're about one and a half times the length, have all the additional requirements of nuclear power, and each unit is around three times the cost.
Noting your valid point about bisalloy steel - with all due respect to the engineers and yards in Adelaide, I just can't see how they'll be able to handle a project of such magnitude.
Perhaps there is a plan to build some kind of Virginia-lite, and assemble modules in different yards, splitting the work between BAE, GDEB and ASC...
On your benchmark assumption, the Block 4 would have been a better option, it has all the features of the Block 3 but has had a lot of systems redesigned to improve serviceability and reduce operating costs (including increasing the time between major maintenance & thus increasing the number of patrols that each submarine can do in its service life).
I think a smarter option for the RAN is to built standard length Block 6 Virginia’s as they will be in production by the time our processes are complete. The USN will probably build the longer version with the Virginia Payload Module (4 Payload Tubes) but, as that will probably be too much capability for the RAN, the standard ones would save some money. There are some new technologies being tested on the USS South Dakota which are expected to be mature enough to be included in the Block 6 design so this would give the RAN boats the latest technology which would assist in maintaining full capability throughout their life.
Your displacement figures seem to be inaccurate as most articles indicate that the Blocks 1-4 Virginia’s displace 7,900 tons and the longer Block 5 displaces 10,200 tons.
Your point about the cost is very valid and this project will take a large percentage of the ADF’s budget - hopefully not to the point that other important programs suffer.
I understand that there were problems during the AWD build caused by having sections of the ships build at different locations and thus the Defence Department is very reluctant to do that again (despite the political pressure from State governments to create work/jobs for them). If local building of the SSN’s does proceed, I think the plan is to massively increase the submarine building section known as Osborne North to be able to construct all sections (apart from the reactor section) locally. It’s a massive task and attracting enough workers and getting them trained is going to be very difficult. The previous government leased (with the intention of buying if it proceeds) an additional 45 hectares of land adjacent to the current facility so they have the room to expand if the plans come to fruition.
An alternative that has a lot of merit is for the AUKUS nations to jointly develop the next generation of SSN’s. For the RAN to be involved at the beginning of this (replacing the US SSN (X) & UK SSN (R) programs) would mean that the RAN would get the most up to date submarines in the world. The downside would be the extra delay to service entry that would be involved and would require some interim capability in the form of leasing SSN’s (none are currently available) or building long range SSK’s such as a Son-of-Collins incorporating a lot of commonality with the post LOTE Collins class.
I think a smarter option for the RAN is to built standard length Block 6 Virginia’s as they will be in production by the time our processes are complete. The USN will probably build the longer version with the Virginia Payload Module (4 Payload Tubes) but, as that will probably be too much capability for the RAN, the standard ones would save some money. There are some new technologies being tested on the USS South Dakota which are expected to be mature enough to be included in the Block 6 design so this would give the RAN boats the latest technology which would assist in maintaining full capability throughout their life.
Your displacement figures seem to be inaccurate as most articles indicate that the Blocks 1-4 Virginia’s displace 7,900 tons and the longer Block 5 displaces 10,200 tons.
Your point about the cost is very valid and this project will take a large percentage of the ADF’s budget - hopefully not to the point that other important programs suffer.
I understand that there were problems during the AWD build caused by having sections of the ships build at different locations and thus the Defence Department is very reluctant to do that again (despite the political pressure from State governments to create work/jobs for them). If local building of the SSN’s does proceed, I think the plan is to massively increase the submarine building section known as Osborne North to be able to construct all sections (apart from the reactor section) locally. It’s a massive task and attracting enough workers and getting them trained is going to be very difficult. The previous government leased (with the intention of buying if it proceeds) an additional 45 hectares of land adjacent to the current facility so they have the room to expand if the plans come to fruition.
An alternative that has a lot of merit is for the AUKUS nations to jointly develop the next generation of SSN’s. For the RAN to be involved at the beginning of this (replacing the US SSN (X) & UK SSN (R) programs) would mean that the RAN would get the most up to date submarines in the world. The downside would be the extra delay to service entry that would be involved and would require some interim capability in the form of leasing SSN’s (none are currently available) or building long range SSK’s such as a Son-of-Collins incorporating a lot of commonality with the post LOTE Collins class.
Last edited by Going Boeing; 19th Sep 2022 at 09:18.
I think you're right GB - if they HAVE to build them in Adelaide they should build ones that are also under sonstruction in the US, But the challenges are vast - there aren't a lot of spare engineers in S Australia for a start
There's a whole raft of different factors going on here.
Firstly, there's the need to have a viable design. That design could be off-the-shelf, or it could be from scratch. Both have pro's and cons. If you go for an OTS design, much of the up-front NRE has been done, but it does tend to tie you in to the operating concept and supply chain the boat was designed around. It also ties you into the reactor type, fuel supply and safety protocols of that boat.
Secondly, there's the build strategy. Pressure hull rating is affected by factors like Out of Circularity (OOC), alignment of frame, bulkheads etc, as well as more mundane things like weld and plate quality. The supply chain and production QA requirements for submarines are significantly in excess of those for surface ships. It's why submarines are rarely done in distributed builds. EB and HII are doing it for the VIrginia's, but that's more an attempt to sustain two build yards than anything else. You can do non-PH steel elsewhere (we're doing that with BAES and Lairds) and you can do things like rafts and decks to be inserted into the PH units in the build yard, but it will be very tricky to try and do multiple PH units in different yards.
Then there's the supply chain. There are literally tens of thousands of equipment items on a boat, from simple things like fuse panels, display screens, junction boxes etc, through valves, pumps, chiller plants, flexible couplings, electric actuators, hydraulic actuators, to main gearboxes, turbines and so forth. Every single one has to undergo a significant level of design, qualification and testing - let alone production QA - before it gets on the boat. Many of which are non-trivial and can incur quite a bit of cost, which is usually why you see "inflated prices". It's rarely a question of just picking one out of a local supply catalogue, because if it doesn't match or exceed the requirements of the original bit of kit, it compromises the safety argument for the system. There won't be many equipment suppliers who qualify their products for submarines "just in case someone wants to put one in". This is often the hidden part of why operating submarines (and particularly nuclear ones) costs a lot of money.
Then there's the manpower - to design, specify, QA, build, accept and operate the boats. Again, the particular nuances of submarines - especially those with a kettle - are not the same as those for ships. One can reduce the direct need for specialists by using an OTS design, but you need an indigenous expert design and operating authority once you've got the boats in service, so it's still a stretch.
All of these things can - and I hope will - be done. But the timescale and budget will need very careful balancing and consideration.
Firstly, there's the need to have a viable design. That design could be off-the-shelf, or it could be from scratch. Both have pro's and cons. If you go for an OTS design, much of the up-front NRE has been done, but it does tend to tie you in to the operating concept and supply chain the boat was designed around. It also ties you into the reactor type, fuel supply and safety protocols of that boat.
Secondly, there's the build strategy. Pressure hull rating is affected by factors like Out of Circularity (OOC), alignment of frame, bulkheads etc, as well as more mundane things like weld and plate quality. The supply chain and production QA requirements for submarines are significantly in excess of those for surface ships. It's why submarines are rarely done in distributed builds. EB and HII are doing it for the VIrginia's, but that's more an attempt to sustain two build yards than anything else. You can do non-PH steel elsewhere (we're doing that with BAES and Lairds) and you can do things like rafts and decks to be inserted into the PH units in the build yard, but it will be very tricky to try and do multiple PH units in different yards.
Then there's the supply chain. There are literally tens of thousands of equipment items on a boat, from simple things like fuse panels, display screens, junction boxes etc, through valves, pumps, chiller plants, flexible couplings, electric actuators, hydraulic actuators, to main gearboxes, turbines and so forth. Every single one has to undergo a significant level of design, qualification and testing - let alone production QA - before it gets on the boat. Many of which are non-trivial and can incur quite a bit of cost, which is usually why you see "inflated prices". It's rarely a question of just picking one out of a local supply catalogue, because if it doesn't match or exceed the requirements of the original bit of kit, it compromises the safety argument for the system. There won't be many equipment suppliers who qualify their products for submarines "just in case someone wants to put one in". This is often the hidden part of why operating submarines (and particularly nuclear ones) costs a lot of money.
Then there's the manpower - to design, specify, QA, build, accept and operate the boats. Again, the particular nuances of submarines - especially those with a kettle - are not the same as those for ships. One can reduce the direct need for specialists by using an OTS design, but you need an indigenous expert design and operating authority once you've got the boats in service, so it's still a stretch.
All of these things can - and I hope will - be done. But the timescale and budget will need very careful balancing and consideration.
I think you've pretty much explained why it will be very very difficult to build SSN's in Australia Boffin. It is a MAJOR long term investment in all sorts of things that politicians 9and some military) never think about.
I can see a lease/operate model working but a design/build one.... very hard
I can see a lease/operate model working but a design/build one.... very hard
The SSN(R) project is being run specifically as an RN/RAN UK/Australian joint project. They will be built in both countries to a common design and the sub will be designed to be able to include Australian specified equipment, systems and weaponry.
They won't be available before circa 2040 so expect an interim Collins class life extension & capability upgrade program.
They won't be available before circa 2040 so expect an interim Collins class life extension & capability upgrade program.
Thanks for your contribution, Boffin, you’ve detailed the difficulties of submarine construction very well. It shows why Australia needs assistance in setting up the manufacturing and QA to make this program work.
Flap Track, it sounds like you have some inside information, are you saying that the decision has been made and will be building SSN (R)’s or is this one of the proposals that is being assessed?
Flap Track, it sounds like you have some inside information, are you saying that the decision has been made and will be building SSN (R)’s or is this one of the proposals that is being assessed?
My information is that it's a high level agreement, hence Def Sec Marles' visit to Barrow for HMS Anson's commisioning recently.
The British Govt and military industrial complex are really pushing this. Lots of upsides for the British military and industry and it will give the Aussies a pathway to SSN capability.
The British Govt and military industrial complex are really pushing this. Lots of upsides for the British military and industry and it will give the Aussies a pathway to SSN capability.
The main industrial partners for UK SSNs (BAES, RR & Babcock) are all looking at expansion into Australia for their Marine business units. All three already have Australian subsidiaries and significant in country marine design and manufacturing operations already. The head of BAES Australia Marine is a former head of Babcock UK Marine Division.
An Australian SSN program is something they all wish to be heavily involved with and are looking at significant local workshare.
An Australian SSN program is something they all wish to be heavily involved with and are looking at significant local workshare.
The main industrial partners for UK SSNs (BAES, RR & Babcock) are all looking at expansion into Australia for their Marine business units. All three already have Australian subsidiaries and significant in country marine design and manufacturing operations already. The head of BAES Australia Marine is a former head of Babcock UK Marine Division.
An Australian SSN program is something they all wish to be heavily involved with and are looking at significant local workshare.
An Australian SSN program is something they all wish to be heavily involved with and are looking at significant local workshare.
Ecce Homo! Loquitur...
Thread Starter
Not sure what spare UK capacity there is.
As previously noted Barrow is fully booked for Dreadnaught and then SSNR. With slippages they are already having to consider refuelling the early Astute boats to last until SSNR arrives, which poses problems, as they found with the current Trafalgar boats, as they weren’t designed to allow it.
SSNR will use the same reactor as Dreadnaught and is mooted to, effectively, be the same design with the missile module removed and replaced by a UUV dock. It is also mooted, as with the new carriers, to be highly automated in weapon handling etc to enable a much smaller crew than the Astute class even though it will weigh in at over 9000 tons.
The RR Derby reactor plant claims to be on schedule with PWR3 production and eager to provide the RAN with reactor modules.Which would also get around the ossicle export problems with a US reactor.
https://www.express.co.uk/news/scien...t-news-defence
The only feasible UK based route would seem to be for the RAN to take the SSNR design and, instead of removing the Trident missile module altogether, replace it with a VPM - and built it in Australia to create and sustain the required parts and maintenance base.
As previously noted Barrow is fully booked for Dreadnaught and then SSNR. With slippages they are already having to consider refuelling the early Astute boats to last until SSNR arrives, which poses problems, as they found with the current Trafalgar boats, as they weren’t designed to allow it.
SSNR will use the same reactor as Dreadnaught and is mooted to, effectively, be the same design with the missile module removed and replaced by a UUV dock. It is also mooted, as with the new carriers, to be highly automated in weapon handling etc to enable a much smaller crew than the Astute class even though it will weigh in at over 9000 tons.
The RR Derby reactor plant claims to be on schedule with PWR3 production and eager to provide the RAN with reactor modules.Which would also get around the ossicle export problems with a US reactor.
https://www.express.co.uk/news/scien...t-news-defence
The only feasible UK based route would seem to be for the RAN to take the SSNR design and, instead of removing the Trident missile module altogether, replace it with a VPM - and built it in Australia to create and sustain the required parts and maintenance base.
Your post has certainly given me food for thought, ORAC. I hadn’t seriously considered the SSN(R) as an option as I thought that it was so far in the future that it would create a lengthy capability gap.
The first thought is that making the SSN(R) a cutdown version of the Dreadnought would mean less risk than a clean sheet design as the early Dreadnoughts would be used to debug the systems as well as provide experience with operation of the new PWR3 reactor. As the PWR3 is heavily based on the Virginia’s S9G reactor, I hope it has the S9G’s convective cooling capability and 33 year fuel endurance rather than the 25 years of the PWR2.
The Dreadnought & Columbia SSBN classes will share a Common Missile Compartment (CMC) consisting of 4 missile launch tubes in each section. The Dreadnought will have 3 CMC’s providing 12 missile silos (16 in Columbia). As was shown when 4 Ohio class SSBN’s were converted to SSGN’s, the 87” diameter silos can store and launch 7 Tomahawk missiles in each one. When hypersonic missiles become available, these silos are expected to house 3 in each of them. There have also been suggestions of UUV’s to deliver Special Forces, Mines, ISR, expendable decoys (AURAS project), etc that would be housed in these silos. Thus, it would be highly desirable that the SSN(R) retain at least one CMC (4 silos) to have a very flexible vertical launch capability. The lack of vertical launch capability in the Astute was one of the reasons why there’s been a stronger preference for the Virginia class.
The British plans to maximise automation throughout these vessels and thus reduce the manning requirements would be highly desirable for RAN operations. The structure of RAN submarine operations have been based on RN procedures so it would be an easier transition to stick with a British design rather than having to adjust to USN required procedures.
The main negative to this plan is the amount of extra design work to fit these vessels with US combat systems and weapons - doable (especially because of the extra room in the larger diameter hull) but, how much extra time would be required for the design changes to be incorporated. Any extra time delay in getting these vessels in the water will create major problems for the RAN.
With the heavy workload at Barrow finishing the last of the Astute’s and building the 4 Dreadnought’s, as well as the RAN’s need for the SSN’s to be in service as quickly as possible, is there a chance that construction of the first SSN(R) will be at Osborne, SA (with a lot of UK assistance)? The first UK SSN(R) could commence construction a couple of years later when Dreadnought assembly permits.
The first thought is that making the SSN(R) a cutdown version of the Dreadnought would mean less risk than a clean sheet design as the early Dreadnoughts would be used to debug the systems as well as provide experience with operation of the new PWR3 reactor. As the PWR3 is heavily based on the Virginia’s S9G reactor, I hope it has the S9G’s convective cooling capability and 33 year fuel endurance rather than the 25 years of the PWR2.
The Dreadnought & Columbia SSBN classes will share a Common Missile Compartment (CMC) consisting of 4 missile launch tubes in each section. The Dreadnought will have 3 CMC’s providing 12 missile silos (16 in Columbia). As was shown when 4 Ohio class SSBN’s were converted to SSGN’s, the 87” diameter silos can store and launch 7 Tomahawk missiles in each one. When hypersonic missiles become available, these silos are expected to house 3 in each of them. There have also been suggestions of UUV’s to deliver Special Forces, Mines, ISR, expendable decoys (AURAS project), etc that would be housed in these silos. Thus, it would be highly desirable that the SSN(R) retain at least one CMC (4 silos) to have a very flexible vertical launch capability. The lack of vertical launch capability in the Astute was one of the reasons why there’s been a stronger preference for the Virginia class.
The British plans to maximise automation throughout these vessels and thus reduce the manning requirements would be highly desirable for RAN operations. The structure of RAN submarine operations have been based on RN procedures so it would be an easier transition to stick with a British design rather than having to adjust to USN required procedures.
The main negative to this plan is the amount of extra design work to fit these vessels with US combat systems and weapons - doable (especially because of the extra room in the larger diameter hull) but, how much extra time would be required for the design changes to be incorporated. Any extra time delay in getting these vessels in the water will create major problems for the RAN.
With the heavy workload at Barrow finishing the last of the Astute’s and building the 4 Dreadnought’s, as well as the RAN’s need for the SSN’s to be in service as quickly as possible, is there a chance that construction of the first SSN(R) will be at Osborne, SA (with a lot of UK assistance)? The first UK SSN(R) could commence construction a couple of years later when Dreadnought assembly permits.
Last edited by Going Boeing; 21st Sep 2022 at 23:06.
SSNR will use the same reactor as Dreadnaught and is mooted to, effectively, be the same design with the missile module removed and replaced by a UUV dock. It is also mooted, as with the new carriers, to be highly automated in weapon handling etc to enable a much smaller crew than the Astute class even though it will weigh in at over 9000 tons.
It is generally hard to get even two organisations with considerably different national perspectives to agree on a design, as evidenced by any number of Anglo-French and Franco German equipment projects which speared in because, notwithstanding all the joint statements and political fudge, fundamental national requirements were incompatible. Trying a threesome on a new design SSN sounds pretty high risk to me, especially where one partner has limited experience of SSK design and none of SSN design. It will get even more difficult, and very expensive if there are a lot of RAN specific differences needed.
Even so, SSN(R) still looks to be the least bad bet to me. It is the only approach that will deal with the shortage of current capacity in in US and UK, it has a reactor design that, once complete, can be manufactured and is in a timeframe practical for all partners. It leaves the RAN with a life problem for the Collins boats, perhaps. That is somewhat easier to deal with.
N
Even so, SSN(R) still looks to be the least bad bet to me. It is the only approach that will deal with the shortage of current capacity in in US and UK, it has a reactor design that, once complete, can be manufactured and is in a timeframe practical for all partners. It leaves the RAN with a life problem for the Collins boats, perhaps. That is somewhat easier to deal with.
N