When journalists used to ask me whether I thought we should continue with the Attack-class submarine program, I’d answer with the old joke ^[1] about the American tourist lost in the back blocks of Ireland. After struggling with his map, he finally sees a shepherd and asks for directions. ‘How do I get to Dublin?’ The wizened local ponders, then answers: ‘Well, I wouldn’t start from here.’

And that was the issue. I wouldn’t have started our transition from the Collins class with the Attack class, but once we were five years into that journey, was there an alternative? Well, the government has now chosen a new path, but as we ponder the road ahead of us, we have to admit we’re even further from Dublin. Defence had been saying the first Attack-class boat would be operational in 2034. It now believes the first future submarine will be in service two to four years later, which would get us to 2036–2038. Anthony Albanese, the leader of the opposition, has said ^[2] the boats ‘would not be in the water until 2040’, which suggests that’s the date he’s been getting in his private briefings.

While we’ve been struggling with our map, time has continued to pass. Governments can make all the decisions they like, but just as Cher ^[3] lamented, they can’t turn back time. Our submarine transition journey started with the 2009 defence white paper, which stated that Australia would acquire a fleet of 12 new submarines. Back then, the first boat was meant to be operational 16 years later, in 2025. Twelve years down the track, we’re looking at a date in the late 2030s—still at least 16 years away. Put another way, over the past 12 years we haven’t gotten a day closer to the goal.

Like many of you, we at ASPI are trying to work our way through what the government’s decision means. I’m starting by being agnostic about whether it’s a good idea or not, or a better one than the previous submarine plan, and simply trying to understand what’s involved in successfully transitioning from our Collins fleet to the future nuclear-powered (SSN) fleet. In particular, we’ll be looking at the key risks and what needs to be done to address them.

The first one that stands out is the capability risk associated with the transition’s new schedule. Trying to visualise that schedule is an assumption-rich activity, but we know some aspects of it. The Collins class was originally planned to start retiring from around 2025. As we moved through time and the future submarine schedule moved off into the future, it became clear that Defence would need to perform a life-of-type extension (LOTE ^[4]) on some Collins boats to ensure they could serve long enough to prevent a capability gap emerging during the transition. Instead of retiring, the boats would go through an additional and enhanced full-cycle docking that would give them an additional 10 years of service.

As the future submarine schedule evolved ^[5], it became clear that a larger number of Collins would need to go through the LOTE, and we’ve now reached the point where Defence Minister Peter Dutton has stated ^[6] that all six Collins will be put through LOTEs. The first one will start in 2026, be completed in 2028, and allow that boat to serve until 2038. Subsequent boats will follow on a two-year drumbeat. That’s the first key point to grasp. The LOTE was our strategic mitigator for the capability risk and we’ve already played that card before we start on our new journey.

We’ve a got a reasonable idea where the Collins can get to, but what is it trying to link up to at the other end? That’s where we need to make some assumptions. Let’s say the first SSN will be operational in 2038 in line with some of the government and Defence’s comments (we’ll look in future at whether this is a reasonable assumption). But we also need to understand the delivery schedule for subsequent boats. The Attack class was going to be delivered on a two-year drumbeat to support the goal of continuous naval shipbuilding. If you want continuous shipbuilding with a fleet of eight boats, then a three- to four-year drumbeat is necessary since submarines have a planned life of around 30 years. Doing it any faster than three years seems very hard given the cold start for our submarine industry, the large size of the boats and the unfamiliar technology. Plus, a roughly three-year drumbeat is what the United Kingdom’s Astute-class SSN program has achieved ^[7]. So we’ll go with that.

I’ve entered those assumptions in a table ^[8]. The first observation we can make is that there is no ‘float’ left in the schedule. The first Collins will be due to retire as the first SSN enters service. Already there’s no margin for any slippage.

Second, the Collins boats will have an average age of 43 at retirement. They’ll have gone through an extensive program of upgrades, but that’s about 50% longer than they were designed to last. Aside from the question of whether they’ll still provide a relevant capability into the 2040s, ageing systems face reliability issues.

Third, any SSN delivery drumbeat slower than two years means Collins boats age out faster than SSNs are delivered. That means the number of boats in the fleet will fall. With a three-year SSN drumbeat, the fleet will reach a low point of four submarines around 2046. It won’t get back to six, the current number of boats, until the mid-2050s and won’t reach eight until the end of the 2050s.

Finally, SSNs provide greater capability that conventional boats, particularly when long transits to the operating area are involved, as they are for our navy. But they still need to be available for operations. Four boats gets you only one or sometimes two available for operations.

Nothing is completely carved in stone here. The Collins could potentially be operated for longer, perhaps as a training fleet ^[9], helping to grow the larger number of submariners we’ll need for the SSNs. But this look at a schedule does suggest some high-priority activities to manage risk. One is examining whether we can break out of the timelines needed to build SSNs in Australia so we can get them faster. The other is looking at complementary technologies to hedge capability risk. I’ve noted previously that our submarine fetish means we have become obsessed with them—yet there are many other areas of technology that can deliver some of the effects we seek from submarines faster.

Over the coming weeks I’ll continue to unpack these issues. But there’s a sobering thought to finish up with. A couple of days ago a conversation with an industry colleague reminded me of a thought I had when the Indonesian submarine KRI Nanggala tragically sank in a torpedo training accident on 21 April this year with the loss of all 53 crew. The parallels with where our navy will be in the late 2030s are now even more striking.

The Nanggala was 40 years old. Its last major refit had been completed nearly 10 years earlier. The Indonesian navy was in the process of bringing into service a new class of submarine, simultaneously growing the size of its force and introducing new technologies while needing to keep its older boat going. It no doubt would have been struggling to find sufficient experienced submariners to operate both classes. Meanwhile, Indonesia was being confronted with the coercive behaviour of an aggressive neighbour and its navy needed to demonstrate capability and resolve by showing it had effective submarines.

Capability transitions are difficult ^[9]. The coming one to nuclear submarines will likely be the most difficult one the Australian Defence Force has faced. There’s no margin for error when dealing with submarines or nuclear safety, let alone both together, but we are already putting ourselves under pressure.