The ‘snorting dilemma’:Why Australia is racing for nuclear-powered submarines

Defence Minister Richard Marles had never uttered the word “snorting” publicly until Tuesday.

But if you want to understand why Australia is racing to acquire a fleet of nuclear-powered submarines at a cost ofhundreds of billions of dollars,it’s a crucial concept to understand. For all the grand geostrategic reasons why Australia is investing in such sophisticated technology,there is a profoundly practical explanation as well.

Australia’s current Collins-class submarines have to regularly rise to the surface to “snort” to operate.

Australia’s current Collins-class submarines have to regularly rise to the surface to “snort” to operate.James Brickwood

“Snorting” describes the process by whichsubmarines rise to the surface of the ocean – similar to whales blowing – to expel contaminants,replenish their oxygen supplies and recharge batteries. Diesel-powered submarines like Australia’s current Collins-class vessels have to snort regularly to continue to operate.

The problem with snorting (also known as snorkelling) is it allows submarines to be detected by other nations’ radar and sonar systems,making them vulnerable to attack. The attribute that gives submarines a crucial advantage over ships – their stealth – suddenly disappears.

Until now,submarine captains have gotten around this problem by replenishing their vessels’ batteries away from operational areas,after dark and during bad weather. The tactic is known colloquially as “going out to snort in the bushes” (a term that may bring other legally questionable land-based activities to mind).

But rapid advances in radar detection and artificial intelligence are making it easier for other militaries to detect even brief “snorts”. As Marles said on Tuesday,the increased ability for “the process of snorting to be detected” explains why the current Collins-class submarines are becoming obsolete for Australia’s needs.

Defence Minister Richard Marles spoke of the increased ability for “the process of snorting to be detected”.

Defence Minister Richard Marles spoke of the increased ability for “the process of snorting to be detected”.Alex Ellinghausen

This problem doesn’t apply to nuclear-powered submarines given their generators don’t need oxygen,allowing them to stay submerged for months at a time and only needing to surface to restock food.

Simply extending the lifespan of the Collins boats while waiting a couple of decades for nuclear-powered submarines to arrive – a scenario that appeared likely when AUKUS was announced – was no longer an option. The much-feared “capability gap” was opening up in front of the government and needed to be plugged.

“So from that point of view,we made it really clear that we need a solution earlier than the early 2040s,” Marles told reporters in Canberra.

This urgent need led to the breakthrough development few experts saw coming:the purchase of at least three,and maybe as many as five,Virginia-class submarines from the United States. This will require Australia to spend billions of dollars subsidising shipbuilding in America on top of the cost of buying the boats themselves.

Following the announcement from Prime Minister Anthony Albanese,UK Prime Minister Rishi Sunak and US president Joe Biden,Australia has reacted to the historic AUKUS deal.

The first of these vessels is expected to arrive in 2033,giving Australia access to nuclear-powered submarines far sooner than expected. Crucially,they will help solve the “snorting dilemma” that threatened to leave our Navy ever more exposed to attack.

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Matthew Knott is national correspondent for The Sydney Morning Herald,focusing on race,culture and identity. He was previously North America correspondent for the Herald and The Age.

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