OPINION | Should Australia’s navy have more Hobart-class air warfare destroyers?

Photo: Australian Department of Defence

A recent Strategist article by ASPI’s Marcus Hellyer highlighted issues becoming evident with the Hunter-class future frigate as the planned construction date slides another 18 months to mid-2024. A lot of the delay is put down to modifications to the British Type 26 design to accommodate Royal Australian Navy requirements. This has had negative impacts, including increasing the weight from 8,000 tonnes to 10,000 tonnes.

Contributors to The Strategist have previously discussed what makes a frigate a frigate or a destroyer a certain type of destroyer and whether they’re really cruisers. One writer implied that this might be an insider trick to improve the RAN’s capability without the “bean counters” realising it’s happening.

But if we want to increase the RAN’s capability quickly, there already is a vessel meeting most of its frigate requirements—the Hobart-class air warfare destroyer. Simply continuing to build the AWD as the replacement frigate (or whatever you want to call it) may have many advantages over designing a separate platform.

“It seems that the implementation of some RAN specifications is causing considerable engineering challenges.”

At first glance, the Hunter frigate’s requirements are remarkably similar to the Hobart AWD’s specifications. They have similar missiles and guns, they’re both designed to use the MH-60 Romeo helicopter and both have hull-mounted sonars and towed arrays, so they are roughly equivalent for anti-submarine warfare.

Their dimensions are close. The Hobart class is 146.7 metres long with a beam of 18.6 metres, and the Hunter class is said to be 149.9 metres long with a beam of 20.8 metres. But the weight of the Hobart class is stated as 7,000 tonnes, far less than is suggested for the Hunter class.

The Hunter class is reported to have a range of over 7,000 nautical miles, compared with the Hobart’s 4,500 nautical miles. However, if the reported weight increases in the redesign of the Hunter are to be believed, that range might well decrease.

It’s also assumed that the RAN is comfortable with the AWD’s range for its surface warfare needs. The Arafura-class offshore patrol vessel is an apparent replacement for the Armidale-class patrol vessel, but it’s more like a corvette, so it could be argued that the RAN isn’t losing patrolling capability.

Requirements for the future frigates remain straightforward, but it seems that the implementation of some RAN specifications is causing considerable engineering challenges. The design reportedly needed significant modifications to enable the use of the Australian CEAFAR radar system, the Aegis combat system, US weapons already in Australian service and the Seahawk maritime combat helicopter. The contract also covered any other modifications that might be needed to meet Australian regulatory requirements. The Hobart-class AWD already meets those requirements except for the CEAFAR radar.

It’s not clear why this radar system is essential. The AWDs don’t use it as their air search and detection radar, yet they are considered excellent air warfare fighting platforms.

It can be assumed that the CEAFAR radar is included because it’s Australian made. Its design and installation in the Anzac-class frigates, as documented by ASPI, is a great advertisement to the world of Australia’s engineering capabilities. It fulfilled a dire need for a more effective air warfare system on the Anzacs and greatly enhanced their capabilities.

“Increasing the number of Hobart-class vessels could reduce maintenance costs per vessel and make it easier to support them in the long term.”

However, to insist that the system be used because it is Australian seems to be the equivalent of insisting that the South Australian car industry must remain open simply because it’s Australian, regardless of the cost.

The long-term survivability of a technologically advanced company such as CEA Technologies should be guarded as it makes a huge contribution to national security. However, since the future frigate requirements are very close to the current AWD’s capability barring the CEA radar, it seems appropriate to ask how crucial the CEA radar is.

Since the Hobart class is already operational and mission capable, we could start building more AWDs very quickly, potentially on the original timeline for the future frigates, starting at the end of 2022. The design is already done if we resist the temptation to tweak it. Rectifying a few system design or obsolescence issues would be orders of magnitude easier than making the Type 26 modifications.

Australia’s 2020 force structure plan provides $45.6 billion (in out-turned dollars) for the nine Hunter-class vessels. In constant, current-day dollars, that’s in the $30–35 billion range. The final cost of the AWD program will be less than $8.5 billion, but the “sail away” cost of the third Hobart will be around $2 billion, possibly even less than that. Whichever way you look at it, any additional Hobarts will cost less than Hunters. Aside from being a mature design, they will be substantially smaller.

As has been clearly documented, despite a huge increase in defence spending, the navy’s capability is hardly going to increase in the next decade. However, with solid data from the AWD build, one could come up with accurate schedules for building more Hobarts. The RAN could have new vessels sooner, as long as the hard lessons from the original AWD build are learnt.

This would also introduce economies of scale.

Today’s decision to drop the Attack-class submarine and move to a nuclear vessel demonstrates the huge challenges with making major modifications to an existing design. It also acknowledges the difficulties with operating and maintaining unique platforms. Concerns have been rightly raised about the huge logistical cost of the RAN maintaining these unique AWDs. Increasing the number of Hobart-class vessels could reduce maintenance costs per vessel and make it easier to support them in the long term. The government and RAN made a courageous decision accepting these realities with the submarines, it should apply such thinking to other platforms.

Article reprinted with permission from the Australian Strategic Policy Institute’s analysis and commentary site The Strategist.

Darren Gloury

Darren Gloury is an engineer with 20 years’ experience in defence.