Should Australia procure nuclear submarines?

The most important acquisition included in the government’s defence white paper, released in February, is the decision to procure 12 new submarines for the Royal Australian Navy. With an acquisition cost of at least $50 billion (and with a much higher through-life sustainment cost), this is by far the largest defence program in Australia’s history.

Australia has made some extremely costly errors in defence procurement in the last few decades — particularly naval acquisitions. The Hawke government’s decision to specify a unique requirement for the Collins class submarines and to build them locally has caused very considerable problems related to cost and availability. It is more than 10 years since the Howard government awarded the air warfare destroyer project to ASC (formerly the Australian Submarine Corporation), and still not one ship has been delivered, with the cost per vessel in excess of $3 billion and still climbing. As Hugh White has pointed out, if Australia had ordered three Arleigh Burke destroyers from the US at that time, they would have cost around $1 billion each for more capable ships and been delivered long ago.

In this context, the proposed acquisition of the future submarine (FSM) raises a number of complex issues and involves substantial risks. Because of the extremely high cost of the project, these issues should be thoroughly evaluated before any binding commitment is made. The fundamental issue concerns the high risks involved both in the decision to develop a unique Australian submarine and in the possible government disposition to build it locally. We also need to remember that these issues involve not just financial risks but also the risk of sending service personnel into harm’s way using inadequate equipment.

In order to compensate for its numerical inferiority, a traditional objective for the Australian Defence Force has been to maintain a level of technological superiority in its equipment relative to potential adversaries. The white paper states that “maintaining Australia’s technological edge and capability superiority over potential adversaries is an essential element of our strategic planning”. In relation to the FSM:

“[T]he Government has determined that regionally superior submarines … are required to provide Australia with an effective deterrent … The key capabilities of the future submarine 
will include: anti-submarine warfare; anti-surface warfare; intelligence, surveillance and reconnaissance; and support to special operations.”

In the light of previous statements, and given the requirement for a very long range, it seems clear that operations in the South China Sea would lie at the heart of the FSM’s mission. Activities in those congested waters would include reconnaissance, intelligence gathering and, perhaps, special operations, moving to anti-shipping and anti-submarine interdiction should hostilities break out. The question then is: will the FSM embody the advanced technologies required to discharge this mission?

The statement in the white paper that the FSM will be regionally superior in terms of its technology is highly contestable. In general terms, a conventional submarine (SSK), however advanced its design, will be inferior to a nuclear submarine (SSN), particularly in prosecuting a force-projection role in distant, contested waters.

First of all, a nuclear boat is a true submarine; it will not need to refuel during its service life and its underwater range is limited only by the endurance of its crew. A SSK needs to come to periscope depth from time to time to run its diesels (“snorting”) and recharge its batteries; this “indiscretion” makes it much more vulnerable to detection. For a conventional submarine like the Collins — without air-independent propulsion (AIP) — the indiscretion rate ranges typically from around 7-10% on patrol at four knots, and 20-30% in transit at about eight knots.

Secondly, an SSN has a high underwater speed (over 35 knots) and can withdraw from any threat very quickly. An SSK can only generate a burst speed of about 20 knots submerged for a short period of time (less than one hour) and then, using AIP if fitted, its speed underwater is limited to around three to five knots.

Thirdly, the size and power of an SSN means it can carry much more kit (such as torpedoes, anti-ship missiles, cruise missiles and mines) than an SSK.

A very important attribute of an SSN is the ability to generate sufficient electrical power so as to run today’s advanced electronic sensors and systems for as long as is required. Already the power-hungry sensors in the Collins class, including the vital combat system (of US origin and originally designed for nuclear boats), make a heavy demand on the available power, requiring the submarine to undertake more frequent snorting to recharge the batteries, thereby raising the indiscretion rate. This will become increasingly important as submarines are required to carry more and more sophisticated electronic equipment.

On the other hand, although contemporary SSNs are extremely quiet compared with legacy designs, the one advantage still possessed by an SSK is its ability to run very quietly underwater. Once detected, however, every submarine skipper would exchange this advantage for the very high speed capability of an SSN. As a US expert notes, “AIP does not give … the sort of high-speed power which saves a submarine once it is being pursued. Only nuclear power can give that…”

In terms of the White Paper’s goal of regional technological superiority, it is true that potential adversaries in the Asia Pacific (with the important exception of Russia) do not currently deploy many nuclear submarines and the ones that are operational are not particularly effective. It may well be that the new submarine, if it were in commission now, for a few years could boast technological superiority in the South China Sea, where it is clearly designed to spend most of its time. While China already has nuclear submarines, they are crude by contemporary western standards, noisy and not considered a significant operational threat. On the other hand, if it realised its potential, Australia’s new submarine would be very quiet and its AIP system (or alternatively substantial banks of lithium-ion batteries) would allow it to patrol submerged, albeit at a slow speed, for around a month.

But the problem is that the FSM is not in the water now. The first boat will not be available for at least 15 years. This makes it highly unlikely that it would be technologically superior even when it is introduced, let alone in 2050, when the final FSM will be commissioned.

*Read the rest at John Mendaue’s Pearls and Irritations.