Will upgraded Collins last the distance?

While the navy pushes ahead with its plans to acquire a nuclear-powered submarine, there are growing calls to consider an interim conventionally powered boat.

Collins-class submarines, HMAS Collins, HMAS Farncomb, HMAS Dechaineux and HMAS Sheean transiting through Cockburn Sound, WA. Picture: Department of Defence

While the navy pushes relentlessly ahead with its plans to acquire a nuclear-powered submarine, there are growing calls inside and outside Defence to consider an interim conventionally powered boat.

While Deputy Prime Minister and Defence Minister Richard Marles said as late as the middle of October that he’s keeping all options open, both proposals depend on the successful completion of the $4.3-$6.4bn Collins Life of Type Extension (LOTE) program.

The problem is, such work hasn’t been undertaken in Australia before and will involve cutting each submarine in two to replace obsolescent components. The first of six Collins-class boats entered service in 1996 and while survey work has been carried out on their pressure hulls to provide assurance they can be extended from that standpoint, there is significant risk in the unknown.

One company with experience in submarine LOTE work is Saab Kockums, the original designer of the Collins-class, which is now completing a Mid-Life Upgrade (MLU) on the Swedish Navy’s Gotland-class submarines – a contemporary of the Collins boat.

In parallel, it is carrying out the LOTE of the last Södermanland-class boat and building two new Bleckinge-class (A26) submarines for the Swedish Navy.

ASC, the original manufacturer of the submarine, has been selected as the prime contractor for the LOTE program, but media reports in June suggested offers from Saab Kockums to partner with ASC and share expertise were rejected by the company.

However, Defence denies the media reports, saying the Swedish sub builder will have an important (but undefined) role to play in the Collins LOTE.

“ASC is leading Collins LOTE design and implementation activities,” a Defence spokesperson said in late June. “Contrary to uninformed reporting, ASC is actively engaging with Saab Kockums and they have not been excluded from playing an important role in the successful delivery of Collins LOTE.”

The LOTE program is designed to extend the life of each submarine by 10 years and work on the first of the six Collins boats, HMAS Farncomb, will begin in 2026. The last submarine to remain in service post-LOTE, HMAS Rankin, is currently due to leave the water sometime in 2048.

Parallel to the LOTE, Collins submarines are also being upgraded with new communications, electronic warfare and sonar systems as well as an optronic mast.

A feasibility study is also underway to determine if the design is capable of integration with the UGM-109E Tomahawk Land Attack Missile (TLAM).

Despite the upgrades and the LOTE – all of which bear their own risks – the question must be asked whether Collins will be a credible and survivable capability into the 2040s, almost 50 years after they first entered service.

When explaining the cancellation of the Attack-class program, then-PM Scott Morrison said strategic circumstances had deteriorated and the new subs would be obsolete on delivery in the late 2030s.

“This submarine, when it went in the water, would be obsolete almost the minute it got wet,” he said of the Attack-class design.

If a contemporary submarine design would be obsolete when it entered service in the 2030s, where does this place Collins – successfully life extended and upgraded, or not – a decade beyond that?