As experts question the diplomatic, strategic and economic rationale behind Australia’s purchase of nuclear-powered submarines, the gaps in the country’s defensive fleet could be filled by conventional subs. By Brian Toohey.

Does Australia actually need nuclear submarines?

A Japanese Taigei-class submarine.
A Japanese Taigei-class submarine.
Credit: Ken H / Flickr

In 1992, an Australian Oberon-class submarine entered the crowded waters of Shanghai’s port and became entangled in fishing nets. It had to surface for crew members to cut it free with axes. Chinese Navy sailors witnessed this, but nevertheless the submarine escaped. Had it not, the crew would’ve been imprisoned and Australia widely condemned and potentially convicted for an outrageous breach of international law. 

Almost a decade earlier, the Australian Navy had seriously considered scrapping submarines, according to former senior Australian Defence official Mike Gilligan. A study in 1985 had concluded they offered “little marginal benefit to Australia’s defences yet inflict a large marginal cost”. The cost could’ve been much higher given the tremendous risks the government allowed the navy to take, snooping in Chinese and Russian waters on behalf of the Americans, who wouldn’t put their nuclear submarines in danger.

Australia now faces some tough and highly consequential decisions with respect to its fleet. Some experts in the defence field question not only the utility of nuclear-powered vessels but the diplomatic, strategic and economic commitment they entail. 

In Washington last month, Defence Minister Richard Marles said Australia, the United States and Britain were moving from “interoperability to interchangeability in defence hardware”. This would effectively mean Australia could not buy high-quality defence equipment from other countries if there was a higher-cost American or British version available. Professor Clinton Fernandes at the UNSW Canberra campus says, “It’s obvious the real policy is to subsidise the US Navy’s submarine budget. Some will be located in Australia, with Australian flags and personnel, but they’re essentially US boats operated in the US’s great power interests. We’re paying for them to set up part of their current and future fleet in Australia.”


Australia has a short and patchy record on submarine purchases. The government acquired many major weapons during World War II. None were submarines. That capability had to wait until the first of a total of six Oberon-class submarines was commissioned in 1967 from a Scottish shipyard. They operated satisfactorily but weren’t considered the nation’s most important military assets.

After Kim Beazley became Defence minister in the Hawke government, he gambled on the value of submarines by ordering six large, battery-powered versions to be built in Adelaide. No other country has bought this type. The first was commissioned in 1966 and the last in 2003. Called the Collins class, it was based on a good Swedish design. But Beazley greatly increased its size and complexity, partly by adding American equipment that proved completely useless. Maintenance problems drove annual sustainment costs to $670 million. Often only two or three were available at a time, although availability later improved. And none attended the 2010 Rim of the Pacific event – known as Rimpac, the world’s largest international maritime warfare exercise, held biennially near Hawaii. 

Former prime minister Scott Morrison and his successor, Anthony Albanese, have taken a much bigger gamble than Beazley did, with their commitment to buy at least eight nuclear attack submarines – almost certainly the American Virginia class. One of the US’s most highly regarded defence analysts, Winslow Wheeler, recently pointed out the Virginia-class subs have been available only 15 times in 33 years for their six-monthly deployments. This suggests fewer than two of Australia’s eight nuclear submarines would be operationally available, on average, each year. And the cost of the purchases is likely to be stunning, possibly as high as $171 billion when accounting for inflation, according to the Australian Strategic Policy Institute, and more recent estimates are above $200 billion. The costliest previous military acquisition, for the Australian Air Force, is the inflation-adjusted $16.6 billion program cost for 72 F-35 fighter jets. 

Former submariner, naval consultant and South Australian senator Rex Patrick says, “Australia could buy 20 high-quality, off-the-shelf, modern submarines for $30 billion.” 

Patrick also makes the point that nuclear submarines are often “defeated” in exercises by ultra-quiet conventional submarines.

Major new developments are making conventional submarines even more formidable than the nuclear versions. More powerful sensors mean submarines can be detected by the noise they make and by their passage through the Earth’s magnetic field. In addition, nuclear submarines can be detected by the wake they leave at high speeds, as well as the hot water they release from cooling their nuclear reactors, operating loud steam engines and other equipment. In future, submarines may also be detected by blue-green lasers that make the ocean more transparent. 

A prize-winning essay published in the US Naval Institute’s magazine Proceedings in June 2018 said the US Navy would do well to consider acquiring “some quiet, inexpensive and highly capable diesel-electric submarines”. Until recently, conventionally powered submarines frequently had to rise close the surface to expose a mast and snorkel to obtain fresh air for their diesel engines to recharge the batteries. This process can be detected by radar.

Most conventionally powered submarines – except Australia’s – use what is called air independent propulsion (AIP), which allows them to remain silent for four to six weeks before snorkelling. That often entails using a hydrogen fuel cell to propel the submarine, but it takes up significant space on the vessel.

In a major change, Japan’s new Taigei-class submarines don’t need AIP because they’re equipped with particularly efficient lithium-nickel-cobalt-aluminium oxide batteries, rather than the lead-acid batteries that the Australian Navy prefers, due in part to the risks of lithium-ion batteries catching fire. Other navies are increasingly confident the new types of battery will prove safe. Hans Ohff, a submarine specialist and visiting fellow at Adelaide University, told The Saturday Paper, “Generally speaking, lithium-ion batteries have a 1.5-times range advantage over lead-acid at lower speeds and an incredible four-times range advantage at high speeds.” 


Since the Collins class is due to start retiring in 2026, a replacement is urgently required to help fill the gap until the first nuclear submarine might arrive, near 2045, and the last in 2065. Senator Patrick says the time it takes to do this can be reduced by choosing one of the three available “off-the-shelf” submarines: Japan’s Taigei, which has passed numerous tests demonstrating the safety of its new batteries; Singapore’s Type 218SG, made by Germany’s thyssenkrupp Marine Systems; and the Spanish S-81. The latter two still use conventional lead-acid batteries, but Ohff says a French and German joint venture is under way to develop their own lithium-ion batteries. 

These options have advantages and drawbacks. The new Taigei class – of which Japan is acquiring 22 – requires a costly crew of 70 per vessel. The Type 218SG’s German manufacturer is the biggest submarine exporter in the world, with an enviable reputation for low maintenance costs across its range. Extensive automation means it needs only 28 crew members, and the vessel has a longer range than the Taigei’s 12,500 kilometres. Spain’s S-81 has a crew of 32 but a less experienced manufacturer.

With China being the principal concern of Australian diplomatic and defence policymakers, Ohff says the navy will never accept off-the-shelf submarines unless it can “Australianise” them – meaning they must have the range to operate for long periods, many thousands of kilometres away, probably in Chinese waters or nearby. Ohff says the navy’s preferences would take a minimum of 10 years to deliver the first boat and additional two-year intervals for the following boats. He says delivery of a Swedish “Son of Collins” could take nine years. 

Patrick says influential Australian intelligence and defence officials are ignoring the point that there is no need for Australian submarines to spend much time in China’s waters: Japan, South Korea, Singapore and Vietnam have high-quality submarines closer to China. The main attraction of nuclear submarines for these officials is they could fire subsonic cruise missiles at land targets in China from more than 1000 kilometres off its coast. However, cruise missiles can be shot down by fighter planes overhead. Once a nuclear submarine fired its missiles, it would be detected and swiftly targeted. Even if it survived, reloading would require the help of a tender – a large depot ship that supplies and supports submarines – probably from the distant base at Fremantle, which recently hosted a reloading for a US nuclear submarine. In any event, an attack on Chinese territory could provoke a heavy counterattack on Australia’s forces or its mainland.

Gilligan says most of the capability offered by submarines is better provided by Australia’s maritime and land-based aircraft. He says submarines, including nuclear ones, are slow compared to aircraft. Technically, a plane could sink a ship off Australia’s west coast in the morning, refuel, then sink another off the east coast in the afternoon. Gilligan also warns that the shallow and warm waters around Australia’s north are unsuited to large nuclear submarines. 

Deploying nuclear submarines far from Australia marks a return to the previously discredited doctrine of “forward defence” in South-East Asia that concentrated on a big British naval base in Singapore, which was swiftly overrun by the Japanese in 1942. When this doctrine failed during the Vietnam War, the Coalition government in the late 1960s adopted a “defence of Australia” doctrine, which survived until its recent abandonment. Patrick and other proponents of this latter doctrine expect a revised doctrine would put more emphasis on having medium-sized conventional submarines to help deny hostile forces access to the approaches to Australia, unless they could detect and destroy all the submarines, drones, planes and land-based missiles blocking their way.

Finally, from a defence perspective, much of the planning around nuclear submarines assumes – implausibly – that Chinese and US policies will proceed in a predictable way until past 2060. A purely geopolitical analysis, however, could easily underplay the disruptive role of climate change.

In purely geopolitical terms, the region may become more peaceful or more dangerous. The only urgency for Australia is to forget about nuclear submarines and get some conventionally powered submarines to enhance deterrence.

This article was first published in the print edition of The Saturday Paper on August 6, 2022 as "Sub-optimal".

For almost a decade, The Saturday Paper has published Australia’s leading writers and thinkers. We have pursued stories that are ignored elsewhere, covering them with sensitivity and depth. We have done this on refugee policy, on government integrity, on robo-debt, on aged care, on climate change, on the pandemic.

All our journalism is fiercely independent. It relies on the support of readers. By subscribing to The Saturday Paper, you are ensuring that we can continue to produce essential, issue-defining coverage, to dig out stories that take time, to doggedly hold to account politicians and the political class.

There are very few titles that have the freedom and the space to produce journalism like this. In a country with a concentration of media ownership unlike anything else in the world, it is vitally important. Your subscription helps make it possible.

Select your digital subscription

Month selector

Use your Google account to create your subscription