As everyone knows, the Morrison government has now signed an agreement to have an agreement to think about designing a submarine which will contain a nuclear propulsion unit provided by the UK and/or US and which maybe someday replace the already ageing Collins class submarines1.

To understand part of this article you need to know a bit of naval engineering. There are two main types of submarine propulsion systems and these are the diesel-electric system and the nuclear system. The diesel-electric system comprises diesel engines which are attached to electric generators which charge the enormous batteries (in the boats of the Collins class these are lead-acid batteries weighing about 400 tonnes). It is these batteries which drive the electric motors which drive the propellers. The diesel engines can only be run while the boat is on the surface or at snorkel depth. When the boat is fully submerged, the diesel engines are turned off, and the batteries run the electric motors. So, the submarine has to go to at least snorkel depth to run the diesel engines to recharge the batteries. At top speed, the battery charge would only last a few hours2,3. In addition, these submarines need to be refuelled with diesel regularly.

In a nuclear submarine, uranium in a reactor produces heat by nuclear fission. In the reactor, the uranium is surrounded by a moderator, usually water, which is required to slow the reaction neutrons so that they will interact more efficiently with the uranium. This water is called the primary loop water and it is pressurised to prevent it from boiling. It runs through a heat exchanger in which the heat is passed to another, secondary, water circuit which boils, providing the steam to turn the steam turbine, which drives the propeller4. Most nuclear submarines never need to be refuelled, with the uranium core of the reactor lasting throughout the operational life of the vessel. As a consequence, their time at sea is only limited by the amount of food for the crew. The Royal Navy maintains that it’s submarines can stay submerged for up to 90 days4,5.

In a press conference on September 16th, in Canberra, Prime Minister Scott Morrison stated, in part: “As our first major initiative, it is as we have announced today, for Australia to achieve a nuclear-powered submarine fleet. Not a nuclear armed, a nuclear-powered. And to commence that build here in Australia in Adelaide within the decade. Nuclear submarines have clear advantages, greater endurance, they’re faster, they have greater power, greater stealth, more carrying capacity.”6

After this press conference by Morrison, Peter Hartcher appeared on the Australian Broadcasting Corporation’s afternoon show, The Drum, hosted by Julia Baird. [September 16, 2021, 21:21 in to episode]7. In this, he was asked about the backflip in the submarine procurement. A transcript follows:

Peter Hartcher: There is a big tradeoff here, isn’t there. Scott Morrison is telling us that in return for getting the capability to have nuclear propulsion, and we’re not talking about nuclear weapons, just nuclear propulsion, for a design of submarine yet to be determined…

Julia Baird: And the reason that’s better is for stealth reasons, it’s quieter, like….

Hartcher: Actually, it’s not quieter. The diesel subs that Australia currently has and the one that it was planning to get, are actually quieter because you can turn off the engine completely and they go absolutely silent. With the nuclear unit, you can’t switch it off completely. The nuclear plant has to keep running. So, the advantages with the nuclear ship are, er, nuclear boat, are, like Morrison was saying, they can go faster underwater, they can stay underwater much longer, they can stay on station much longer, and carry larger loads. But the tradeoff, that Morrison is now telling us Australia is going to have to accept, is that yesterday Australia had a contract to buy 12 submarines built in Adelaide on a French design. Today Australia has no contract for anybody to supply us any submarines whatsoever. We have a high-level political agreement to supply us with US/UK nuclear propulsion technology, but we have no contract, no boat in which to put this thing, so the Morrison government tells us today that we are going to have to wait longer now. So, until today, it was going to be more than a decade to get the first new sub. Now it’s going to be even longer than more than a decade, possibly up to two decades.

Baird: Could be 2040 is what we’re told, yep.

Hartcher: Second, it’s going to cost more, the government tells us. Third, that they’re committed, conceptually at least, to buy only 8, whereas the previous deal was to buy 12 submarines. They are saying they’re more capable, so we don’t need as many but we’re going to have to wait longer. The Collins class submarines which were supposed to be retired in 2025; they keep postponing their retirement. I hope my retirement is not postponed as often as these poor labouring subs. 

Baird: What could possibly go wrong with that?

Hartcher: They’re going to be in the water till 2040 and beyond, so we’re going to have no new subs, pay more. There’s no design. The only thing the government has actually, specifically done today, is said that it is creating an interdepartmental task force to find, quote, “the optimal path” to getting Australia to acquire the nuclear technology, which could then lead to a design and a negotiation for a contract. This is a very great theatrical production this morning. Hats off, that was high value theatrics. Behind the curtains, there’s just a couple of stepladders and a bunch of bureaucrats at a meeting table, and that’s about it.

Baird: I can see what’s in it for the US, in terms of wanting a presence in the Asia-Pacific region. I can see what’s in it for the UK. Is it clear to you what’s in it for us?

Hartcher: No. That’s because, partly we don’t know what this thing is. We have no agreement any longer. Yesterday we had the French agreement, today we have no agreement. So, we don’t know what’s coming and what’s there and what the sub’s going to be. And part of the tradeoff is, as you’ve already noted, the French are feeling betrayed and upset, the Kiwis, they’ve said no nuclear-powered subs will be able to enter their waters consistent with their own practices. We, quite possibly are unnerving some of our neighbours, although the government is trying to brief ASEAN capitals on what this means, and we’ve given the Chinese, of course, justification. The Chinee government has been hostile to Australia, and that’s not going to change but we’ve now given them more justification for their own arms build-up which, by the way, is much bigger than this. They’ve got more than 70 subs; they’ve already got nuclear powered subs. They’re building an expected 6 more in the next ten years. They can crank out a new sub every one year on average, conventional and nuclear, plus and this is the big kicker, they’ve got nuclear warheads on theirs. China’s got an estimated 260 nuclear warheads and are building more. So, Australia should in no way accept that it simply getting nuclear propulsion in subs yet to be designed is a provocation. That will be China’s line, presumably, yet that doesn’t stack up. But, I do think that when China’s spokesmen stand up and fulminate against this Australian deal, they will have to pause to laugh up their sleeves every now and then because this is a very thin deal. We’ll pay a lot of price for this and it’s not clear that there’s any obvious return, yet7.

Baird seemingly took Morrison at his word when the latter stated that nuclear submarines were stealthier than diesel-electric submarines. In fact, the reverse is more often the case. Diesel-electric submarines can shut off their engines entirely and be completely silent, while nuclear submarines must always have water being pumped around the uranium in their reactor to keep it from overheating; so they are never really silent. In addition, nuclear submarines leave in their wake, a trail of heat, which can be as much as 10 degrees Celsius warmer than the surrounding seawater. This can be detected and the submarine tracked8.

This instance, though small, exemplifies what so many modern journalists seem to do; assume Morrison is not lying. This also demonstrates the sort of ‘journalism’ (or stenography?), on which Morrison relies. However, unlike that, Hartcher was all over his topic and knew some of the technical details of propulsion and of the geopolitical implications (as he should, the latter is his job). That is real journalism, and it is that on which our democracy depends.




  • Roger Crawford says:

    As everyone knows, but no one is mentioning, the French were modifying a Nuclear powered design for conventional propulsion. That is where many of the design problems lay. I would have bet my bottom dollar, at least half of these would have been Nuclear powered, in future years. Now it would seem the U.S. and U.K. want to sideline any E.U. influences in Australian Military hardware. As evidenced by MH370 the Indian Ocean remains largely unknown. That is where Australian Subs would be most usefully deployed. The Americans seem to have the Pacific fairly well covered.

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