Independence-Class

The Independence-class ships are quite different from the Freedom-class in their design, most noticeably in their trimaran hull form. Austal determined this was an advantage in comfort and stability over other hull designs. These ships are far larger than the Freedom-class as a result, being over one-hundred-twenty-seven metres long, and over thirty-one metres wide, although notably their draught is similar at around four metres, which demonstrates the cleverness of the trimaran design. Like the Freedom-class, these are fast ships, capable of travelling at over forty-four knots. Both classes were designed to operate as modular warships, and so the ships can equip different weaponry, sensors, or other equipment based on the current operational needs.

This allows the ship to carry anti-surface armament on one mission and then, should a need for anti-submarine capability be required on another operation, it can switch out some of its equipment and functionality to fulfil that role instead. You can see this in the design of the ships; if you look at the bow section behind the main turret, or on top of the ships superstructure on either side of the mast, you can see large flat platforms where different weapon systems can be installed.

Standard armament includes a BAE Systems 57mm gun, with a SeaRam CIWS installed on the aft superstructure. These ships have never been fitted with the regular RIM rolling airframe missile launchers of the early Freedom-class ships. Other armament includes up to four Browning heavy machine guns placed around the ship. Optional armament from the different mission “modules” is extensive, from anti-ship missiles, autocannons, and vertical launch missiles, as well as a wide array of different sensors and decoy equipment, including unmanned watercraft and anti-mine weaponry depending on the module.

Three modules are designed for the Independence-class ships as standard. The first of these is the SUW (surface warfare) package that comes with 30mm Bushmaster autocannons and RGM-184A anti-ship missiles. Then there’s MCM (mine countermeasures) that prioritises the need for detection and neutralisation of mine threats and can include the deployment of unmanned submersibles. Finally, there’s the ASW (anti-submarine warfare) module that focuses on “detecting, classifying, localising and prosecuting” enemy submarines, through sonar and ASW-equipped maritime helicopters, as well as possessing enhanced defences against torpedo attack.

The Independence-class ships seem to have been favoured by the navy over the Freedom-class, with more ships currently on order and further development of modular weapon systems designed to work with the former, compared with the latter. However, despite this, these ships have suffered from similar issues and have been the source of much complaint amongst defence media and the navy themselves. Independence herself suffered from galvanic corrosion leading to new hull treatments being administered to all the remaining members of the class.

Then, in 2019, hull cracks began forming at the point of contact between the deck plate and the shell plate just above the waterline. The solution was identified, but Austal USA claimed the cracks do not “pose a risk to the safety of sailors on board the ships”, but with the first ship in the class being decommissioned in 2021 and plans to decommission further early ships, speculation has arisen about the strength and reliability of these vessels in sustained service, especially given their cost and the navy has placed restrictive speed orders on the remaining six vessels where this problem has been identified.