Tag Archive for: Attack class

Future-proofing the Attack class (part 2): performance and capacity

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In part 1, we discussed how we ensure we get the right propulsion system for Australia’s Attack-class submarines. We argued that nuclear power is an inadvisable and improbable option and observed that lithium-ion batteries, and other light-metal battery technology, could transform the nation’s submarine forces.

Here, we examine the extraordinary acceleration in the performance of light-metal batteries already being incorporated in submarines in our region. We argue that light-metal main batteries will dominate conventional submarine design and offer the promise of very significant improvements in performance.

It’s notable that the energy capacity of the lead–acid batteries used to power submarines for more than a century improved very little from the advanced German U-boats of World War II until the late 20th century.

The energy density of the batteries used in the navy’s six Collins-class submarines is similar to that of the batteries that powered Germany’s Type XXI Elektroboot in 1943.

And the output of the batteries aboard the navy’s previous class of submarines, the 1950s-era Oberons, was about 15% lower than those that powered the Type XXI.

There had been, in fact, surprisingly little improvement on the capacity of the batteries that powered submarines in World War I.

And despite the best efforts of manufacturers, lead–acid batteries today show an increase in energy output of only 10% over the batteries developed three decades ago for the Collins.

Submarine planners, builders and operators have long been aware of the potential advantages of lithium-ion main batteries for submarine propulsion. Peter Briggs provided an overview in The Strategist in March 2016.

The advantages include improved endurance at both low and high speeds, no hydrogen emissions, higher charging rates, greater practical range, significant weight reduction for individual cells and less battery maintenance. The benefits are particularly pronounced when a submerged submarine is using its snorkel to run its diesel engines and charge its batteries.

Briggs also drew attention to the primary issue constraining early adoption of lithium-ion battery technology for submarine propulsion—the risk of battery fires. These may result from overcharging, inadequate battery management or an internal failure of a poorly manufactured battery cell.

In 2017, Defence Science and Technology established the Battery Safety Research Facility, specifically to address the issue of fire safety for lithium batteries in future Australian submarines. A significant body of work with direct relevance to the Attack-class program has also been undertaken by engineering consultants BMT Design & Technology. It’s now clear that submarine planners and builders in other countries are confident that requisite levels of operational safety can be achieved and sustained for lithium-ion batteries.

Since Briggs’ 2016 review, there have been significant developments in lithium-ion technology and its use in submarines. Mass-produced lithium-ion batteries have doubled in unit capacity and their cost has reduced by more than 40%.

Japan has launched the first large naval submarine with a lithium-ion main battery and South Korea has undertaken a comprehensive 30-month technology readiness assessment of the viability of lithium-ion technology for naval submarine main batteries. South Korea has also decided to build the second batch of its KSS-III attack submarines with lithium-ion main batteries, commencing in the early 2020s. Naval Group announced late last year that its LIBRT lithium-ion battery system will be offered to Australia for the second batch of Attack-class vessels.

The unit capacity of lithium-ion cells suitable for large-scale high-power applications has increased threefold since 2005. Further increases are expected in the early 2020s, and unit capacity could double again by the mid- to late 2020s. This would result in unit capacities around 10 to 12 times greater than current lead–acid battery technology.

As the practical capacity limits of lithium-ion cells are reached in the 2030s, the next generation of advanced light-metal cell technology will be emerging from the development and early production phases. The new light-metal cells will have theoretical capacities between three and five times greater than lithium-ion cells, and this could result in unit capacities 30–40 times greater than current lead–acid battery technology.

Submarine battery capacity: actual and projected, 1945–2060

Source: Based on published data and forecasts using established technology learning curves for light-metal battery technology.

The implications of the forecast rates of lithium-ion battery and advanced light-metal battery development and increased main battery capacity for naval submarine performance are profound.

By the mid-2030s, a large lithium-ion main battery could enable the construction of a ‘megabattery’ submarine able to patrol submerged, and without needing to recharge its battery, for 30 to 45 days. It could run submerged at high speed for several hours when required, with minor impact on endurance.

It’s conceivable that by the mid-2040s advanced light-metal battery technology could provide a submarine with a main battery of sufficient size to avoid the need for on-board charging.

Such a ‘gigabattery’ submarine could undertake a complete mission, including long-range transit, without the need to travel on or near the surface and with the capacity for many hours of high-speed submerged running. Running on electric power alone, it would be significantly stealthier than either conventional or nuclear submarines, with very low acoustic and thermal signatures.

Historically, most defence-related technologies have been too expensive to be widely adopted within Australian industry. Consequently, ADF equipment generally has been sourced from overseas or, if from within Australia, at a premium. The widespread adoption of advanced battery storage technologies will reverse that situation for a wide range of military propulsion systems.

Australia has significant lithium reserves and 90% of all the materials required to manufacture lithium-ion batteries. The government and opposition are now actively endorsing and encouraging the development of a vertically integrated Australian lithium-ion battery industry. A $135-million industry-backed research hub called the Future Battery Industries Cooperative Research Centre has been established in Western Australia.

Australia also has significant reserves of other materials expected to be utilised in future advanced light-metal batteries, including aluminium, magnesium, sulphur, graphite and silica.

It has the capacity to establish a sovereign light-metal battery capability within a decade or so, and to be in a position to manufacture and sustain light-metal submarine batteries for the foreseeable future.

Future-proofing the Attack class (part 1): propulsion and endurance

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A major challenge in the decades-long program to build the Royal Australian Navy’s new submarines, the Attack class, will be ensuring that they incorporate emerging transformational advances in propulsion technology.

Between 2025 and 2030, the continuing rapid evolution of lithium-ion battery technology will enable the Attack-class boats to stay fully submerged on low-speed patrols for up to 40 days without recharging. By 2035, that could increase to up to 60 days. And by 2050, it’s conceivable that the next generation of light-metal batteries will enable the boats to go on an 80-day long-transit mission without the need to resurface and recharge.

In ASPI’s Agenda for change 2019, Marcus Hellyer recommended that the government commission an independent review of the Royal Australian Navy’s plans for its future submarines. That wouldn’t be easy, considering that many independent experts have already approved crucial aspects of the program.

Hellyer suggests that significant issues include the adequacy of the scheduled delivery date in light of Australia’s deteriorating strategic circumstances, and he urges another look at nuclear propulsion.

Neither of those things should preoccupy Defence Minister Linda Reynolds. While managing the schedule for the Attack class is certainly important, a bigger challenge is aligning design and construction plans with the advances in propulsion technology that will revolutionise conventional submarines. If that’s not done, the program is unlikely to meet its objectives, with consequences that could undermine Australia’s strategic posture.

While nuclear propulsion is attractive because of the high performance it provides, Australian studies conducted from the late 1960s have concluded that the problems associated with going nuclear far outweigh the performance gains. That remained the advice in 2016 when the preferred design partner was selected for the future submarines.

It’s unlikely that the new minister will receive different advice. Nuclear propulsion isn’t a form of maritime whitegood. Some idea of what would be required to adequately sustain a RAN nuclear submarine fleet entering service in around 2044 was provided in a recent ASPI study.

The sticking point is that Australia doesn’t have a nuclear power industry on which the RAN can draw. Personnel and technical support for safety, operational deployment and sustainability would have to be developed, and funded fully by taxpayers. Expertise to manage the complex regulatory regimes that affect acquisition and sustainment would have to be generated wholly within government.

Even countries with extensive nuclear experience have had problems in this area. Development of the French Barracuda class has been delayed for three years by new nuclear norms and controls, and the UK hasn’t been able to dispose of any of the 20 nuclear submarines it has decommissioned over the past 40 years.

It’s now clear that Australia will never have its own nuclear power industry. In electricity markets, nuclear energy has been judged to be uncompetitive against coal. And coal-fired power is now likely to be moribund in the face of the rapid progress being made with renewable energy generation, advanced storage technologies and increased options for power distribution. These alternatives to fossil fuels are projected to provide electricity at historically low prices by 2030, with continuing price falls beyond 2040.

Much of this development rests on light-metal batteries, which have accelerated rapidly in performance in recent years.

In 1988, Southern California Edison commissioned the world’s largest storage system for lead–acid battery energy, with a 40-megawatt-hour capacity and 10-megawatt power rating. The plant was decommissioned in 1997 because it was unable to cope with grid load demands.

In December 2017, a Tesla Powerpack system was commissioned in South Australia. It’s currently the world’s largest lithium-ion battery storage system, with a 40-megawatt continuous, 100-megawatt peak power rating and a 130-megawatt-hour capacity.

That’s comparable to the effective capacity of 10 main lead–acid batteries in a Collins-class submarine, which provides less than a week’s submerged endurance. And it’s the same order of capacity that will be available for the Attack class by 2030, which will enable a boat to remain deeply submerged for 30 to 40 days without having to raise its snorkel to ‘breathe’ while running its diesel engines to recharge its batteries.

The South Australian system has now been working continuously for more than 500 days at levels of operational tempo and intensity well in excess of those experienced in the Collins.

The South Australian installation will soon be overtaken by a system under construction in California, and then by another, larger system to be commissioned in Florida in 2021. A 1,000-megawatt-hour, 250-megawatt system has been proposed for the Robertstown region in South Australia.

The technology used for utility storage systems is directly transferrable to submarine propulsion and will transform conventional submarines.

If the emerging opportunities are taken, lithium-ion battery technology will enhance major objectives of Australia’s submarine program. The two most important influences determining this process are the concept of operations (CONOPS), which is focused on deploying submarines at great distances in an adversary’s sea approaches, and control over intellectual property, which needs to be sufficient to allow Australia to maintain a sovereign submarine capability.

The CONOPS requires a submarine with long range and enhanced endurance.

The designs of both the Collins and Attack classes achieve this through large hull displacement to accommodate a big battery and big electrical-generation capacity (a combination that obviated the need for air-independent propulsion in the Collins class).

Light-metal battery propulsion power will greatly enhance the mission effectiveness of such a submarine at long range.

The requirement for a sovereign submarine capability is in part a response to deficiencies in the development and sustainment of the Collins class. It also recognises the need to safeguard our strategic independence in developing and operating the submarine force for perhaps 50 years—a horizon over which Australia’s strategic circumstances and the politics of potential technology partners are difficult to predict. Australia is well suited to generating its own intellectual property in light-metal battery technology and manufacture and to becoming a world leader in the field.

If Australia misses its opportunity, the RAN’s submarines could be at risk if they attempt to operate against a regional counterpart operating lithium-ion-battery-powered boats. Our ally Japan has already launched its first lithium-ion-battery-powered submarine, South Korea isn’t far behind, and other regional players including China are likely to acquire lithium-ion submarines soon.

In part 2, we’ll look in more detail at the transformative potential of light-metal batteries for submarine propulsion and, in part 3, we’ll discuss the consequences of failing to integrate the technology into the Attack-class program.

Submarine transition plan takes shape

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The future submarine has achieved key milestones with the signing of the overarching strategic partnering agreement on 11 February and in quick succession the design contract on 5 March. This is good news for the future submarine platform itself, but there have also been developments in the broader submarine transition picture.

Moving Australia’s submarine capability from where it is now with a fleet of six Collins-class submarines to a future fleet of 12 Attack-class submarines will be the most challenging capability transition that the Australian Defence Force has ever undergone. Last October, in an ASPI special report, I attempted to refocus the discussion from the future submarine itself to the key issues that the government and the Department of Defence will need to resolve in order to transition successfully.

It will of course take time to develop a complete picture of how the transition will work, but some pieces of the puzzle are starting to fall into place.

A key date in the transition process, namely, when the first Attack-class submarine will provide actual operational capability, is a crucial stick in the sand for planning the transition process. Over the past six months or so that date has firmed up. Based on a delivery date of around 2032 followed by a two- to three-year test and evaluation phase, Defence is saying the first submarine will be operational in 2034 or 2035. That’s a little later than the date I used in the transition study. Of course, that date could still slide, but Defence has to base its planning around something.

One of the key questions that Defence needs to resolve in planning the transition is whether the government’s goal is to increase the number of submarines in service as quickly as possible, in which case the navy would keep Collins submarines operating as Attack submarines entered service, or to get out of the Collins business as soon as possible without a capability gap, in which case the navy would retire a Collins whenever an Attack submarine arrived. That, however, would mean we wouldn’t have more than six submarines until sometime in the early to mid-2040s.

Defence has consistently said that the minimum capability that it will provide during transition will be at least six submarines, although the number of Collins that Defence has said it would need to put through a life-of-type extension to achieve this has drifted over time from at least one to at least three. What has not been clear is when the combined fleet would go beyond six.

But at recent Senate estimates hearings, Chief of Navy Michael Noonan said, ‘We’re expecting we will upgrade at least five’ (page 41). And, assuming at least five Collins-class submarines are life-extended, ‘I would expect that the Navy will have a force of eight or more submarines by the late 2030s’ (page 42). Since the navy will only have two, or best case three, Attack-class submarines by then, the only way to get to eight or more in total is to keep all the Collins in service.

Of course, Defence officials were quick to assure the committee that the government had made no decisions on the number of Collins to be upgraded, but Defence’s hand is now clear—it wants to move beyond six with the arrival of the first Attack-class submarine. And this is of course a good thing, both to increase capability and to enhance the navy’s ability to train the very much larger number of submariners needed to operate the fleet. Incidentally, my analysis suggests that even if Defence puts all six Collins through a life-of-type extension, the fleet can’t get beyond nine until around 2050 without accelerating the build of the new submarines (see table 2 on page 18). But nine is still better than six.

If the idea is to keep more Collins going longer, potentially well into the 2040s, Defence will need to retain the ability to maintain and upgrade them for potentially another 25 years, and that gets at the issue of the viability of ASC, which sustains the Collins. In the face of the ramp-up of other naval construction activities seeking skilled workers, ASC will need to keep and renew its skilled, experienced Collins workforce. At successive estimates hearings, ASC has noted that it is already losing some of its workforce to that competition (page 11). An environment of unbridled competition for workers would be catastrophic for all naval capabilities.

So it is very encouraging to see that Naval Group and ASC have signed a framework agreement to work together in Australia’s sovereign submarine programs including on workforce development. It is particularly encouraging to see the plural programs used—it’s vital to manage both the Collins and Attack programs as part of a single enterprise.

I have also argued that it’s vital for Naval Group to draw on ASC’s understanding of Australian supply chains to ensure the future submarine is designed for sustainment in Australia. So again, the fact that the framework agreement also includes supply chain services is a good thing.

And this latest signing follows earlier agreements between ASC and Naval Group subcontractors Jeumont Electric, FIVA and ENDEL to support the future submarine program. So even though the issue of who will sustain the Attack submarine is still open, it seems that ASC is setting itself up for a long-term future, in partnership with Naval Group.

A key transition question that remains unresolved is the location of full-cycle dockings. It is no secret that Defence has asked ASC to study the feasibility of moving submarine full-cycle dockings out of the submarine shipyard in Adelaide to Western Australia. Of course, there is no way the government will make any announcement on such a politically sensitive issue before the election.

But Defence’s head of naval shipbuilding programs, Stephen Johnson, made the telling remark at estimates that ‘somewhere around the 2032 to 2034 timeframe, perhaps sooner, we’ll run out of room to do everything in South Australia’ (page 45). And considering that the design of the future submarine shipyard has commenced, one would think that it would be helpful for its designers to know whether they had to include a full-cycle docking facility in their plans.

And as for progress on an east coast submarine base, we’ve got nothing new to report.