When the first of the RAN’s three Hobart class Air Warfare Destroyers (AWDs) is completed sometime around March 2016, much of the navy’s weaponry portfolio will be deployed on the one platform.
Given the current controversies over AWD cost and schedule, it’s therefore worth briefly revisiting what taxpayers will be receiving for their multi-billion dollar investment.
Central to the AWD’s capabilities is the Lockheed Martin Aegis command and weapon control system that seamlessly integrates computers, sensors such as the SPY 1D (V) phased array radar, and weapons systems to provide simultaneous defence against advanced air, surface and subsurface threats.
The open-architecture 7th generation Aegis system equipping the AWDs includes a Cooperative Engagement Capability (CEC) function. This generates a common, high quality air picture allowing the AWD to act as part of a wider grid of sensor and weapon platforms.
By fusing the track data of all participating units- in due course to include the F-35A Joint Strike Fighter, the Wedgetail airborne early warning and control aircraft and the P-8A Poseidon maritime patrol aircraft - CEC will allow any of those units to engage a target they may not necessarily have detected themselves.
Air Defence Missiles The AWDs will initially go to sea with Raytheon’s 167km-range Standard SM-2 Block IIIB anti-air missile, a development of the SM-2 Block IIIA that has replaced the obsolescent SM-1 aboard the RAN’s four Adelaide class FFGs.
While Block III improved missile performance against very low altitude threats and Block IIIA added enhanced interception capabilities against sea-skimming, high speed missiles, modifications to Block IIIB include an active infrared seeker to supplement the missile’s semi-active radar guidance.
These missiles will eventually be replaced aboard the AWDs by the SM-6. This combines the SM-2 warhead, the active seeker from the AIM-120 Advanced Medium-Range Air-to-Air Missile (AMRAAM) and the Standard Missile extended range airframe, to provide a reach of more than 370km.
CEC, Aegis, the SM-2 Block IIIB and eventually the SM-6 will fundamentally change the RAN's approach to air warfare, driving it from a within horizon air defence approach to a beyond radar horizon offensive counter-air capability.
The Mk 41 Vertical Launch System (VLS) aboard each ship comprises six modules, each containing eight cells capable of storing and launching either a single SM-2, or quad-packed Evolved Sea Sparrow Missiles (ESSMs) with a range of about 52km that will provide point defence against both aircraft and sea-skimming missiles.
Guns Unlike the RAN’s Anzac class frigates, for terminal defence the ESSMs are backed up by a single Raytheon Phalanx Mk15 Block 1B 20mm close-in weapons system mounted at the rear of the ship on the helicopter hangar. The 1B variant includes a Thales Optronics thermal imager, an improved Ku-band search and track radar and longer gun barrels providing a 4,500 rpm rate of fire.
Two Rafael Typhoon remotely-controlled 25mm guns intended to engage small surface targets at a range of up to 2.5km are mounted on the bridge wings of each AWD. As with Phalanx, each gun is integrated into the ship’s combat management system, but additionally each Typhoon is equipped with a Toplite electro-optical surveillance and fire control system that enables independent day/night and all-weather operation.
The 5inch Mk.45 Mod.4 gun located ahead of the missile cells on the ship’s bow deck is a development of the Mk.45 Mod.2 54-calibre weapon equipping the Anzacs.and features a longer, 62-calibre barrel intended to improve the gun’s effectiveness as a land support weapon.
Capable of firing 16-20 rounds per minute from a 20-round automatic loader drum, maximum range with conventional ammunition is13nm.
The US Navy had hoped a range of up to 63 km would be achievable with the longer barrel and the rocket-assisted (and extremely expensive) Extended Range Guided Munition (ERGM).
But this program was cancelled in 2008 and no replacement is in sight, although the USN did issue a Request for Information in May on guided projectile concepts compatible with the Mk.45 Mod 2 and Mod.4 gun mounts.
Strike weapons In addition to their anti-shipping role, the eight Harpoon Block II missiles carried in mid-deck quad canisters also provide a limited land attack capability out to about 125km.
The AWDs will deploy both the Eurotorp MU90 and the Raytheon Mk.56 lightweight anti-submarine torpedoes. The MU90, capable of operating both in shallow water and well beyond a submarine’s crush depth, is launched from dual tube Babcock Mk.32 Mod.9 launchers installed in the port and starboard magazine compartments of the ship.
The Mk.54 will be airdropped from the ship’s organic Lockheed Martin-Sikorsky MH-60R naval combat helicopter. The MH-60Rs will also reintroduce the vital anti-submarine dipping sonar capability lost when this equipment was removed from the RAN’s now retired Sea King helicopters in the 1980s.
The Romeos also restore the air to surface capability which was to have been provided by the SH-2G(A) Super Seasprites cancelled at great expense in 2008, albeit with up to eight 8km-range Hellfire missiles with blast fragmentation warheads rather than the much heavier, 34km range Penguin anti-ship missiles.
In an ironic twist, 10 of the 11 Super Seasprites intended for the RAN have now been modified and purchased by the Royal New Zealand Navy (RNZN), together with an undisclosed number of ex-RAN Penguins.
