Nuclear vs. Conventionally-Powered Subs--and the Australian Turn to a Nuclear Submarine Fleet

It appears that most have misperceptions about non-nuclear subs, and in particular their underwater endurance. This seems partly reflective of misapprehensions about the history of submarines. Remembering the submarine campaigns of the First and Second World Wars they rarely realize just how much time those vessels spent on the surface, and submerged only when actually on the attack or evading attack themselves--precisely because when underwater they had to run on the batteries of that earlier day, and because when underwater they could operate only at much lower speed.1 Submarines were, properly speaking, submersibles, capable of going under the water, with the capability important, but subsurface not where they spent most of their time. This was one reason why it was such an important turning point in the Battle of the Atlantic when the Allies extended their aerial patrols to cover the entirety of the trans-Atlantic convoy routes (and the increasing equipment of those aircraft with radar)--on the surface the U-boats were not much less detectable than any other surface ship of comparable size and profile. It was also why the advent of the snorkel was important--it let submarines use their diesel engines when just below the surface, permitting some trade-off between stealth and endurance.

Nuclear power plants, however, enabled submarines to effectively operate underwater for as long as their crews and their supplies could hold out, while running as fast as any other vessel afloat, over ranges limited only by their speed and endurance, and all that while carrying a far heavier armament. This made them virtually a requirement for large ballistic missile submarines; for any submarine intended to attack them or protect them from attack; for subs simply intended to carry large payloads of tactical weapons for any other purpose, like large loads of cruise missiles for anti-ship or land-attack; and for subs which are simply intended for rapid dispatch to distant regions, whether out in the open ocean or littorals far from home.

To use that horribly overused and misused term, they were a game-changer.

Of course, impressive as the performance afforded by a nuclear power plants is it comes with significant downsides. Those plants are not cheap or easy to build, operate, refuel, maintain—and bring all the safety risks so famously dramatized in, for example, Kathryn Bigelow's K19. And the vessels with all the extra capabilities that are the whole point of going in for a nuclear power plant are not cheap. Even limiting the comparison to attack-type boats a high-quality diesel submarine like the German Type 212 or Swedish Gotland runs about a half billion dollars--while a Virginia-class boat runs about three billion, six times as much. It is even the case that the quietest diesel-electric boats tend to be quieter and therefore stealthier than their nuclear counterparts—-while, as if all that were not enough, air independent propulsion has wrought a great improvement in the underwater endurance of non-nuclear vessels, perhaps to the point of giving conventionally-powered subs with trans-oceanic range while submerged (exemplified by the Ocean-class submarine concept).

The result is that a government with purely local security concerns--which wants its subs mainly for coastal defense purposes--or which has a limited budget, has enormous incentive to stick with the simpler, cheaper conventional boats. Indeed, the attractions have been such that those who follow the naval literature have likely seen over the years many analysts make the case for the long all-nuclear U.S. Navy supplementing its forces with such boats for littoral warfare.

What, then, does it mean that Australia has taken the nuclear submarine path?

One may see the matter in terms of the country's position being fairly unique, starting with the plain facts of its physical geography. Australia has what may be the world's seventh-longest coastline (about 16,000 miles), and its third-largest Exclusive Economic Zone (some 3.4 million square miles). Moreover, there are Australia's additional military commitments across Southeast Asia and the South Pacific (with troops and planes still rotating through Butterworth Air Field in Malaysia, its membership in the Five Power Defence Arrangements tying it in also with Singapore and New Zealand, its preparedness for interventions as far afield as East Timor, the Solomon Islands and Fiji as seen in the past) extending the Australian Defence Force's expected zone of operations considerably beyond that. And Australia undertakes all this with relatively small forces--recruiting from its population of 25 million an armed forces of 60,000, with 15,000 in the navy--with comparatively little military back-up furnished by large allies close at hand (in comparison with other countries with small populations and vast areas of concern like Canada, with its proximity to the U.S., or Norway, with its inclusion within the European NATO space).

Seen from the purely naval perspective that is a lot of "battlespace" to cover, especially with the military resources at hand, with one reflection how, given its combination of unavoidably small forces and desire for a long reach has long played an important part in Australian procurement decisions (the country the only customer for the F-111 strike aircraft besides the U.S. Air Force). With the region ever more intensely militarized it is unsurprising that the tendency is particularly evident now, with the submarines just one element in a shift to a larger, longer-ranged armed forces, navy included (with the manning of the Australian Defence Force to go up a third to 80,000, and the navy replacing its little, relatively lightly armed frigates with "frigates" like cruisers, with long-range cruise missile and anti-ballistic missile capabilities part of the package).

Even if one takes entirely for granted the broader political premises of the course the Australian government is taking (a larger subject than I care to discuss here), this does not in and of itself make the nuclear sub decision the right one, of course (there is the cost-effectiveness issue, and the technical problems are vast--especially when one remembers that, in spite of the expectations of local construction, Australia has no nuclear technology sector), but the point is that this is part of a larger complex of decisionmaking in regard to a profoundly shifting military posture that seems to get too little attention in such coverage of the issue as I have seen.

1. I remember a straight-to-video remake of The Land That Time Forgot where a World War I-era German submariner spoke of spending weeks beneath the surface of the sea--something submariners of that time never did.