Undersea Technology: Future Submarine - not a pick 'n' mix design | ADM Aug 2010

Australia’s Future Submarine Project, Sea 1000, will be a highly complex program, but will in turn be shaped by three deceptively simple decisions: where will it be designed?

What are the long-term ambitions of Australia’s submarine industry?

And who will build the combat system?

Gregor Ferguson | Sydney

For all its technical complexity, Australia’s Future Submarine Project, Sea 1000, will be shaped by three fundamental decisions.

First, will the 12 submarines sought under this project be designed in Australia, or not?

Secondly, if they are designed in Australia, will Defence seek to capitalise on its investment by seeking exports, or will the sustainment model for this expanded industry be entirely taxpayer funded?

And thirdly, who will supply the combat system?

Once these questions are answered it’s possible to start identifying candidate technologies and suppliers for principal configuration items.

Taking the first question first, whether or not the submarine will be designed in Australia is really a function of three things: cost, risk and capability.

Nobody has challenged ASPI’s estimate that 12 ‘bespoke’ submarines designed and built in Australia to the requirements set out in the 2009 Defence White Paper could cost $36 billion, or more.

Would that deliver four times the capability, or wider national benefit, of 12 notionally less capable Military Off The Shelf (MOTS) submarines costing around $9 billion?

ADM also understands that the $9 billion figure relies on open source material and would not account for any Australianisation concerns.

Furthermore, does Australia really possess the design, systems integration and project management skills, and the required depth of technical knowledge, to build and sustain an all-new bespoke conventional submarine at an acceptable level of risk?

This has yet to be demonstrated.

And if the risks become realities, what genuine capability will the RAN be able to deploy when faced with development delays and possible performance shortfalls?

It’s generally accepted that Australia’s principal submarine building and sustainment firm, ASC, will build the new boats though there is some debate around this assumption.

The company would need a technology partner to support it through the platform and propulsion system design process.

Going to the second question, if Australia’s strategic intent is to sustain the submarine industry in the long term through exports, then this will require a strong, independent design capability and a qualitatively different relationship with a suitable technology partner.

While General Dynamics Electric Boat (EB) is ASC’s submarine ‘capability partner’, it hasn’t designed a conventional submarine for decades and can’t be considered an authority on all of the technology aspects of conventional boats – in particular, Air-Independent Propulsion (AIP); ASC and the RAN are no better off so far as AIP is concerned.

Notwithstanding EB’s submarine domain and technical knowledge, ASC and the RAN will need technology partners among the European conventional submarine builders: Thyssen Krupp Marine Systems (who own both HDW in Germany and Kockums in Sweden), DCNS in France and Navantia in Spain.

All of these submarine builders have established supply chains and technology partnerships with key suppliers of items such as AIP systems, batteries, electric motors and diesel generators.

However, none of them is likely to help launch and sustain a new industry rival, and none of them are suffering the sort of capacity constraints which would justify them forming an intimate, cooperative partnership with an Australian submarine industry from which it could tackle an emergent export market on a joint basis.

If Australia’s strategic intent is to sustain the long-term capability entirely through taxpayer funding (something normally done by a country with a higher GDP), then the benefits of this approach must be clearly spelt out to the Australian parliament and people.

And if this is the model adopted, the local industry still needs to design a safe, efficient, affordable platform.

It will still need to source key configuration items such as the combat system, propulsion motor and AIP system.

Selecting an AIP system from one submarine builder, and propulsion motor technology from another, and perhaps a platform automation system from a third would be impossible: the submarine builders would never agree to having their equipment integrated with a rival’s.

It’s clear Australia will need to select a single submarine builder as a technology source, and then form a close and exclusive partnership with that company.

Returning to the first question, the justification for a bespoke design is generally presented as a unique Australian requirement for range and endurance; this was one of the determinants of the size of the Collins-class boats, and the RAN wants even more than these boats can offer.

The conventional wisdom is that a smaller boat simply won’t be able to meet the RAN’s requirements.

However, although designed for an endurance of up to 70 days, the Collins-class boats rarely exceed 50 or so; smaller European–designed boats have demonstrated operational endurance of 60 days and more.

Interestingly, the head of the Future Submarine project, RADM Rowan Moffitt, told the Senate Estimates committee in June, “One of the military off-the-shelf options available from one of the European manufacturers can come in today at a stated nominal range that exceeds the Collins class range somewhat in a much smaller submarine—two-thirds the size.

“It is not an easy comparison to make, however,” he cautioned, “because it depends totally on the conditions: the climate conditions, the water temperatures, the distances over which the submarine is being asked to perform and exactly how the mission is being executed by the submarine.”

It’s not clear whether RADM Moffitt’s comparison includes a lengthy transit to a distant patrol area, which typifies RAN operations.

Nevertheless, it suggests the Navy is starting to recognise that the capability difference between a bespoke design and a MOTS design might not be as great, or as important, as originally thought.

An evolved MOTS design might provide an attractive balance of risk, reward and value for money.

In which case, it would make sense for the Commonwealth to run a competition to select a MOTS or evolved/enhanced MOTS platform and then encourage the manufacturer to form a close, cooperative relationship with ASC, or some other corporate entity in Australia’s naval industry.

That said, both HDW and Kockums have developed much larger versions of their current submarines designs, the Large Ocean-Going Submarine (LOGS) and Type 61, respectively.

The latter displaces 4,700 tonnes dived, with a 390kW Stirling cycle AIP plant, 41-strong crew, 26 full-length weapons and 70-day endurance.

The LOGS displaces 4,200 tonnes dived with a methanol-reformer fuel cell AIP system, 34-strong crew, 80 days endurance and up to 31 full-length weapons.

Like the evolved and ‘Design to Requirements’ variants of Navantia’s S80, these are ‘paper boats’ at present but could be the basis of an assisted in-country design effort if it is decided that even an evolved MOTS design is too small.

What about the combat system?

It has been an unchallenged assumption (thus far) that Australia’s future submarines will be equipped with a US combat system (probably derived from the AN/BYG-1 which equips the Collins-class boats) and US weapons, including a heavyweight torpedo, Sub-Harpoon missiles and a Tactical Land Attack Missile (TLAM).

Some argue that the quality and strategic capability of the equipment the RAN receives as a result of its close relationship with the US Navy means we should build our design around a US combat system, regardless of the costs and risks this imposes on the project.

Others believe that a default choice of US combat system and weapons, regardless of the platform design, could compromise platform performance and result in a flawed and sub-optimal submarine.

They would eschew any sole-source decisions and select every part of the submarine, including the combat system, on its merits.

The last time Australia ran a competition to select a submarine combat system, in 2000, the decision was overturned on strategic grounds: the government chose to adopt the US AN/BYG-1 despite it being shown the STN Atlas ISUS90-55 was a significantly superior system.

If there are significant, undisclosed wider strategic benefits flowing from the adoption of the US system, these have yet to be demonstrated.

It took nearly eight years for the first so-called Replacement Combat System (RCS) to enter service, and in that time there has been little sign that Australian requirements have significantly shaped the design of the core system, or that Australian technology has been able to penetrate an impervious US firewall surrounding the system.

Furthermore, a 2009 National Defense Industry Association report for the USN warned that the US is in danger of falling behind European submarine development.

This was borne out between 2005-07 when the USN leased the Swedish AIP-equipped boat Gotland to conduct ASW training off the US west coast.

Her outstanding performance against the USN’s nuclear attack boats (along with that of South Korean Type 209 boats on successive RIMPAC exercises) highlighted significant actual and incipient shortfalls in US submarine capability.

This isn’t to say that a US combat system would necessarily be inferior to anything likely to be available from Europe, but this must be put to the test – the more so because combat system performance is likely to be a key discriminator between submarines of similar size and configuration.

One of the important differences between US nuclear powered submarines and European conventional boats is that the latter demand a smaller crew and equipment with a smaller footprint and lower power and cooling demands.

Adapting the BYG-1, which was designed for nuclear boats, for the relatively impoverished environment of the Collins class has not been either easy or quick; even if the task is now done, it’s not clear what the ongoing challenges (and cost) will be of trying to adapt future BYG-1 upgrades to the Collins operating environment.

If the Commonwealth selects a US combat system, what knock-on effect does this have on its available choice of sensors?

At the USN’s insistence there is currently a firewall between the BYG-1 and the Thales Scylla sonar suite on the Collins-class boats.

This prevents the transfer of data from the RCS back to the sensors and so complicates the operation of the system and prevents the boat from developing its full operational potential.

Selecting an all-American sonar and sensor suite would probably result in the firewall being removed, to the operator’s benefit.

But submarine sonars are sensitive to platform effects: they need to be sized and configured to match the platform on which they are mounted, and most US systems are designed for nuclear boats twice the size of a Collins.

Integrating them onto a smaller boat would require significant redesign work.

That said, Spain’s 2,300-tonne S80 submarines include a Lockheed Martin sonar suite.

While adopting a common submarine combat system and weapons family with the USN creates an essential ‘comfort zone’ for the RAN, the question needs to be asked: does this approach deliver unique, essential benefits that aren’t available elsewhere?

If not, the cost-benefits of a US combat system need to be tested against those of other combat systems available through the major European constructors.

The bottom line is that the major configuration items for a submarine can’t be selected on a ‘pick and mix’ basis: they are generally a carefully balanced package assembled by an expert designer.

Developing an all-new, unique package for the RAN would require a high-order design capability which Australia may not be able to attain without the intimate support of a technology partner familiar with conventional submarines.

In any event, developing and refining the design in this country and bringing it into production would entail significant cost, schedule and capability risk.

The need to adopt this approach must be argued and justified rigorously.

Risk is likely to be the key factor shaping this project; in particular, the need (as ADM understands it) for key technology elements to be at a Technology Readiness Level (TRL) of 7 or higher at 1st Pass.

Looking at the overall submarine design, and the integration risk associated with it, it’s not clear what overall System Readiness Level (SRL) is required at this milestone – the higher the level, the lower Defence’s appetite for project risk of any kind, and therefore the closer to a MOTS or Evolved MOTS design the Future Submarine is likely to be.

The Gotland-class submarine is too small for the RAN’s needs and its planned successor, the A26, isn’t yet in production.

Realistically, the RAN today has a choice of three conventional AIP-equipped submarines; in two cases (S80 and Type 214) the AIP plant will be adopted also by the parent navy, albeit in Germany’s case aboard a different submarine.

The Germans are also developing a reformer

hydrogen source for its fuel cells, along with Lithium-Ion (Li-Ion) battery technology as canvassed in previous editions of ADM.

There is no shortage of expertise available to the RAN; the question is what sort of relationship it wants with the owners of that expertise, and how it will establish this.