Hunter-class frigate weight increase within design margins

Rumours that the Hunter-class frigates are greatly increasing in size and weight because of Australian specific changes have been quashed.

Construction of the Hunter-class frigate is on schedule, despite the disruption of Covid. Picture: BAE Systems

Rumours that the Hunter-class frigates are greatly increasing in size and weight because of Australian specific changes have been quashed by both Defence and prime contractor BAE Systems.

We can be sure that the ships will be 149.9m long and have a beam of 20.8m, though they will be slightly heavier at more than 8000 tonnes, which is still within the design margins.

This weight growth is not uncommon in first-of-class warships as supplier data firms up — and also because the Australian ships require a larger superstructure and more cooling than the British parent design.

The main factors driving the changes are:
● the Aegis combat management system with Saab Australia tactical interface
● the Australian-designed and built CEAFAR 2 phased array radar
● integration of the Seahawk Romeo helicopter
● Australian communications systems
●and Australian legislative requirements — this is something that affects almost every compartment of the ship. This final point applies to things that might sound trivial such as safety equipment and internal fittings including lighting and power points, but they have to be done.

The process is now well under way and the project has entered the System Definition Review phase, which will last for the remainder of the year. This will validate the work done to date that all of the changes from the original Type 26 design will not adversely affect parameters such as speed, range, seakeeping and stability.

In addition, steel cutting on the first of five test blocks occurred at Osborne last December and this activity aims to de-risk the project by prototyping not just pieces of the ship but by testing the entire enterprise — workforce, processes, tools and facilities.

Construction is on schedule to begin in 2022, despite the disruption of COVID-19. The method is that the lower part of the ship has the least number of changes — so work will start on them while allowing design to continue on the unique superstructure which incorporates the bulk of the Australian-specific changes.

This build while still designing is quite common for large complex platforms and requires careful project management and is assisted by the fact that BAE Systems is also undertaking the construction of the reference Type 26 in Glasgow, which is about four years ahead of the Hunter-class schedule.

There has been some criticism of the local content for the ships — and indeed the fine print explains that, as they will be contracted in three batches, it is only in the second tranche that a fully Australian supply chain will be up and running.

Nevertheless, even for the prototyping activity, more than 40 Australian companies have been contracted, with another 20 to come.

Defence says that the company has agreed to spending 58 per cent on local content for the current design and construction activity and a further 54 per cent for the multi-billion dollar