Hobart-class destroyer.

Technical Data

• Design

  The Hobart-class is an Australian adaptation of Navantia's Álvaro de Bazán/F-100 design, incorporating F-105 developments and modifications for RAN weapons, sensors, electronic warfare, communications and operating requirements. Each destroyer measures 483 ft (147.2 m) overall, with a maximum beam of 61 ft (18.6 m) and draught of 17 ft (5.17 m). Full-load displacement was 6,250 tonnes at launch, while the design permits a theoretical maximum of 7,000 tonnes, leaving a 750-tonne or 12% growth margin for additional equipment and modernization during the ships' service lives. This reserve is now being used as the class receives major combat system changes under SEA 4000 Phase 6.

  The design is smaller than the Evolved Flight II Arleigh Burke alternative evaluated under SEA 4000. That proposal displaced 2,200 tonnes more, carried 64 Mk 41 cells instead of 48, accommodated two helicopters rather than one, and provided another 700 nmi (1,296 km) of range. The Hobart-class therefore has 25% fewer physical VLS cells than the 64-cell alternative, but the Navantia design was projected to cost A$1 billion less, enter service four years earlier, and present lower development risk because it was derived from an existing warship.

  Construction uses a modular architecture dividing each destroyer into 31 prefabricated blocks, comprising 12 hull blocks, nine forward-superstructure blocks and 10 aft-superstructure blocks. Individual modules averaged 200 tonnes and measured roughly 49 × 39 × 30 ft (15 × 12 × 9 m). The nine forward-superstructure blocks containing sensitive combat system equipment were built at Osborne, while the other sections were distributed among Australian yards before production difficulties resulted in the redistribution of work and a direct Navantia involvement. For instance, three blocks associated with the hull-mounted sonar were assembled by Navantia in Spain and the United Kingdom.

  The internal arrangement accommodates a 48-cell strike-length Mk 41 VLS, a 127 mm Mk 45 Mod 4 gun, Aegis equipment, four fixed AN/SPY-1D(V) radar faces, two propulsion shafts, four principal propulsion engines, four electrical-generation prime movers, hull-mounted and towed sonar equipment, aviation facilities and accommodation for more than 200 personnel. The 48-cell VLS is a fixed physical constraint: its capacity has not increased as the weapons inventory expanded from principally SM-2s and ESSMs to include SM-6s, Tomahawks, and SM-2 Block IIICs.

  The superstructure is strongly shaped by the Aegis sensor arrangement. The AN/SPY-1D(V) uses fixed S-band phased-array faces integrated into the structure rather than a rotating main surveillance antenna, while an AN/SPQ-9B X-band radar, two AN/SPG-62 continuous-wave illuminators and two X-band navigation radars provide complementary radar coverage. Electro-optical and infrared equipment includes the Ultra Electronics Series 2500 director, Sagem VAMPIR infrared search-and-track system, and Rafael Toplite stabilized sights.

  The standard ship's company is 186 personnel, supplemented by 16 aviation personnel for the embarked MH-60R Seahawk helicopter, giving a normal complement of 202. Maximum accommodation is 234 personnel, including up to 31 officers and 203 sailors, leaving 32 additional berths beyond the standard ship-and-aviation complement. Each destroyer has a flight deck and enclosed hangar for one MH-60R Seahawk and carries two 23.6 ft (7.2 m) RHIBs for boarding, personnel transfer, and other small boat operations.

  The design's growth allowance is particularly relevant to the Destroyer Capability Enhancement, which introduces Aegis Baseline 9, Saab Australia's Australian Interface, and changes to electronic warfare, communications, and weapons integration without replacing the hull, propulsion arrangement, or 48-cell VLS. The HMAS Hobart's combat information centre was completely dismantled during the first DCE installation, illustrating the depth of the internal modification. The available information does not specify the additional displacement created by the DCE, so the remaining margin below the 7,000-tonne design maximum cannot be quantified.

• Armament

  The Hobart-class destroyer combines area air defense, integrated air and missile defense, long-range land attack, anti-surface warfare, anti-submarine warfare and close-in defense within a comparatively compact weapons architecture. Its principal magazine is a 48-cell strike-length Mk 41 Vertical Launch System (VLS), giving 144 physical VLS cells across the three destroyers. The original missile inventory centered on the SM-2 Block IIIB and the quad-packed RIM-162 ESSM, but the modernization program introduced SM-6, Tomahawk, and SM-2 Block IIIC missiles. The cell count remains unchanged, making magazine allocation increasingly important as four missile families compete for the same 48 positions, but the number of missiles can exceed this because four ESSMs can occupy one compatible cell.

  The SM-2 Block IIIB formed the original long-range air defense layer, operating through the Aegis, the AN/SPY-1D(V), Mk 99 fire control system and the two AN/SPG-62 illuminators. This combination provides engagement capability against aircraft and missiles at up to 90 nmi (167 km). Australia is also introducing the SM-2 Block IIIC with an active/semi-active seeker derived from the SM-6, which reduces the dependence on shipborne terminal illumination. The SM-2 therefore remains part of the future weapons architecture alongside, rather than being replaced by, the SM-6.

  The RIM-162 Evolved Sea Sparrow Missile (ESSM) provides a denser, shorter-range defensive layer because four ESSMs can be quad-packed into one compatible Mk 41 cell. For example, 12 cells could theoretically accommodate 48 ESSMs while leaving 36 cells for larger missiles, for a range of more than 50 km (27 nmi) and a speed exceeding Mach 4. The SM-6, first fired from HMAS Sydney in August 2024, adds an extended air and missile defense and a secondary anti-surface capability, associated with the transition to Integrated Air and Missile Defence (IAMD) under Aegis Baseline 9. Every SM-6 nevertheless occupies one of the same 48 cells required for SM-2, Tomahawk or an ESSM canister, for an estimated maximum operational range of 370 to 460 kilometers (230 to 285 miles).

  The Tomahawk cruise missile introduces a long-range land-attack capability absent when the ships entered service, with HMAS Brisbane conducting Australia's first ship-launched firing on December 3, 2024. This missile offers an operational range of 900 to 1,350 nautical miles (1,000 to 1,550 miles / 1,600 to 2,500 km), depending on the specific variant and block. The Tomahawk also creates a direct magazine trade-off: 12 missiles would consume 25% of the 48-cell VLS, while 24 would occupy half of it, reducing the cells available for defensive interceptors.

  For dedicated anti-surface warfare, the Naval Strike Missile (NSM) replaces the RGM-84 Harpoon Block II as the dedicated anti-ship missile and is carried in two four-canister launchers, giving eight external missile positions without consuming Mk 41 capacity. The operational range of the Naval Strike Missile (NSM), for its part, exceeds 185 km to 200 km (over 100 to 110 nautical miles) for baseline variants, with advanced upgrades extending past 250 km to over 300 km (160 to 190 miles). The HMAS Sydney conducted the class's first NSM firing in June 2024.

  Gun armament comprises a forward 127 mm/62-calibre Mk 45 Mod 4 naval gun, with a maximum range of 23.6 km (12.7 nmi), providing surface engagement and naval gunfire support without expending guided missiles. Two bridge-wing Typhoon remote weapon stations, each armed with a 25 mm M242 Bushmaster, cover small craft and other close surface threats, at an effective firing range of approximately 2,000 to 3,000 meters (about 2,187 to 3,280 yards). An aft 20mm Phalanx CIWS provides the final gun-based defensive layer against threats penetrating the missile and soft-kill defenses, with an effective range of about 1,625 yards (1.5 kilometers / 0.9 miles), with an engagement typically starting around 1.0 to 2.0 nautical miles depending on the speed of the incoming threat.

  Anti-submarine armament consists of two Mk 32 Mod 9 twin launchers, with four ready tubes for MU90 Impact lightweight torpedoes. These allow the destroyer to prosecute submarine contacts detected by its own hull-mounted or variable-depth sonar, or received from other sensors, while complementing weapons carried by the embarked MH-60R Seahawk. The MU90 uses variable-speed electric propulsion, resulting in a range of more than 12 km (6.5 nmi) at maximum speed above 50 knots and more than 23 km (12.4 nmi) at its lower 29-knot speed.

• Propulsion

  The Hobart-class destroyer uses a Combined Diesel or Gas (CODOG) propulsion arrangement, separating economical cruising from the higher power required for maximum-speed operations. The installation consists of two General Electric Marine 7LM2500-SA-MLG38 gas turbines, each rated at 17,500 kW (23,500 hp), and two Caterpillar Bravo 16 V Bravo diesel engines, each producing 5,650 kW (7,580 hp). The gas turbines therefore provide 35,000 kW (47,000 hp) of installed output and the diesels 11,300 kW (15,160 hp). Power is transmitted through two shafts driving Wärtsilä controllable-pitch propellers. Variable blade pitch allows thrust to be adjusted without relying exclusively on shaft-speed changes, improving control across cruising, acceleration, deceleration and low-speed manoeuvring conditions. A bow thruster provides additional control during harbour operations and confined-water manoeuvers.

  Maximum speed is more than 28 knots (52 km/h), while range exceeds 5,000 nautical miles (9,300 km) at 18 knots (33 km/h). At a constant 18 knots, covering exactly 5,000 nautical miles would require 277.8 hours, equivalent to 11 days and 14 hours, although this is a mathematical calculation rather than the ship's official operational endurance because it excludes reserves, sea state, tactical manoeuvring and variations in machinery use. The design therefore emphasizes sustained deployment over Australian operating distances rather than maximizing speed alone.

  The propulsion characteristics reflect a deliberate SEA 4000 design trade-off. The Hobart design could not maintain the higher speeds required to accompany a U.S. carrier battle group under every condition, but the RAN placed greater emphasis on endurance for Australian requirements. The competing Evolved Arleigh Burke design offered 700 nautical miles (1,296 km) more range, together with a larger hull and weapons capacity, but was not selected. The Hobart's machinery nevertheless provides sufficient output to propel this 7,000-tonne full-load guided-missile destroyer (DDG) beyond 28 knots while retaining a transoceanic cruising range.

  Electrical generation is independent of the main propulsion machinery, using four MTU diesel prime movers connected to Alconza alternators. These supply electrical power for sensors, communications, combat system equipment, auxiliary machinery and accommodation services. Machinery and auxiliary equipment are monitored and controlled through the Navantia Integrated Platform Management System, using the COMPLEX/SIMPLEX architecture.

• Sensors, Electronics, Decoys and Radars

  The Hobart-class uses an integrated sensor and combat architecture centered on the Aegis combat system and the AN/SPY-1D(V) S-band phased-array multifunction radar. Rather than relying on a single multifunction sensor, each destroyer combines the SPY-1D(V) with an AN/SPQ-9B X-band horizon-search radar, Mk 99 missile fire control system, two AN/SPG-62 illuminators, two navigation radars, hull-mounted and variable-depth sonar, electro-optical and infrared sensors, several electronic support receivers and two complementary decoy systems. The original combat architecture uses Aegis Baseline 7.1 Refresh 2, modified for Australian requirements and connected to an Australian Tactical Interface with six multifunction consoles handling sonar, electronic warfare and close-defense functions alongside Aegis air warfare functions.

  The Aegis combat system forms the central combat management architecture connecting the destroyer's sensors, fire control equipment and missile battery. Australia selected the Aegis before choosing the Navantia hull, making the combat system a fundamental SEA 4000 design requirement rather than an equipment subsequently added to a destroyer. The Australian Tactical Interface extends the basic Aegis architecture into locally selected sonar, electronic warfare and close-defense functions through six multifunction consoles. Under the Destroyer Capability Enhancement (DCE), this architecture is being replaced by the Aegis Baseline 9 and Saab Australia's new Australian Interface, with the HMAS Hobart becoming the first ship to undergo the conversion. Its combat information center was completely dismantled during the 2026 modernization to install the new equipment, supporting Integrated Air and Missile Defence (IAMD) and newer weapons including SM-6s and Tomahawks.

  The destroyer's principal radar is the Lockheed Martin AN/SPY-1D(V), an S-band electronically scanned phased-array multifunction radar integrated directly with the Aegis. Fixed arrays and electronically steered beams provide the principal air and missile surveillance, tracking, and engagement-support functions without mechanically rotating the main radar antenna. The available information states that the combination of SPY-1D(V), Aegis, and SM-2 can engage hostile aircraft and missiles beyond 150 km (93 miles). That distance, however, represents the combined engagement capability rather than the maximum detection range of the SPY-1D(V).

  A Northrop Grumman AN/SPQ-9B X-band pulse-Doppler horizon-search radar supplements the SPY-1D(V). Its dedicated horizon-search role is particularly relevant against low-altitude aircraft and sea-skimming threats appearing close to the radar horizon, where target altitude and the curvature of the Earth reduce warning time. The SPQ-9B therefore complements rather than duplicates the S-band radar, providing another frequency band and a sensor optimized for a different part of the air defense problem.

  Missile fire control uses the Raytheon Mk 99 system with two AN/SPG-62 continuous-wave illuminating radars. These provide terminal illumination for semi-active radar-homing Standard Missile variants, particularly the SM-2 originally carried by the class. The SPY-1D(V) performs broader surveillance and tracking while the Mk 99 and the SPG-62 provide the dedicated fire control component needed during the terminal engagement phase. Each destroyer has two SPG-62 illuminators, although this should not be interpreted as limiting the ship to only two simultaneous missile engagements because the Aegis schedules missile flight and terminal illumination. The introduction of the SM-6 and SM-2 Block IIIC missiles equipped with active seekers further reduces the dependence on continuous shipborne illumination.

  Two L-3 Communications SAM Electronics X-band navigation radars provide navigation and local surface picture functions independently of the principal air warfare radars. Passive and electro-optical surveillance is provided by an Ultra Electronics Series 2500 electro-optical director and Sagem VAMPIR infrared search-and-track system, allowing both surveillance and identification without relying exclusively on active radar emissions. The two 25 mm Typhoon weapon stations additionally use Rafael Toplite stabilized target-acquisition sights, giving each close-range weapon station a dedicated electro-optical targeting support.

  Underwater surveillance is provided by the Ultra Electronics Sonar Systems Integrated Sonar System, combining hull-mounted and variable-depth towed sensors. The towed component incorporates a quad-directional active-passive receive array, a passive torpedo-detection array, and a high-powered towed sonar source. The hull sonar remains continuously available without deploying a towed body, while the variable-depth component can operate away from the fixed depth of the hull to improve detection under changing acoustic conditions. The passive torpedo-detection array provides a separate underwater warning function against incoming weapons. The sonar suite also connects directly to the destroyer's anti-submarine engagement chain, including the two Mk 32 Mod 9 twin torpedo launchers and the embarked MH-60R Seahawk helicopter.

  The electronic warfare architecture uses at least four separately identified receiving systems. The ITT EDO ES-3701 provides radar electronic-support measures, while the SwRI MBS-567A covers communications ESM. An Ultra Electronics Avalon Systems multipurpose digital receiver provides an additional electronic collection and processing channel, and a Jenkins Engineering Defence Systems low-band receiver extends coverage into lower-frequency emissions. This distributes passive electromagnetic surveillance among specialized receivers rather than relying on a single ESM installation. These systems allow the destroyer to detect electromagnetic activity without necessarily transmitting from its own radars, providing another source of threat warning and identification. SEA 4000 Phase 6 includes electronic warfare modernization, but the available information does not establish which individual original receivers will be retained, modified or replaced.

  Soft-kill missile defense includes four Nulka active-decoy launchers, designed to seduce radar-guided anti-ship missiles away from the destroyer by generating an alternative electronic target physically separated from the ship. Four launcher positions permit repeated or multi-directional employment, although the number of launchers should not be confused with the total number of Nulka rounds embarked. The ships additionally carry four six-tube multipurpose decoy launchers, providing 24 ready decoy tubes. These can deploy radio-frequency, infrared, and underwater acoustic countermeasures, giving the destroyer different soft-kill responses against radar-guided, infrared-guided, and underwater threats. Combined with the four Nulka installations, each destroyer therefore has eight identified physical decoy-launcher installations.

  The communications suite includes HF, VHF and UHF radios, Link 11 and Link 16 tactical data links, ASTIS MCE satellite communications equipment and Inmarsat. Link 11 and Link 16 allow the destroyer to exchange tactical tracks and other operational information with compatible ships, aircraft and command elements rather than constructing its tactical picture solely from its own SPY-1D(V), SPQ-9B, sonar and electro-optical sensors. This networking capability is particularly relevant to the class's area air defense mission because the ships are intended to protect a wider naval force rather than operate only as self-defending surface combatants. ASTIS MCE and Inmarsat provide satellite communications in addition to the ship's other radio and tactical-network connections.

• Helicopter Capability

  Each Hobart-class destroyer can embark one MH-60R Seahawk multi-mission naval helicopter, giving the three-ship class an additional capacity to hunt submarines and surface ships when all destroyers deploy with their aviation detachments. Aviation was incorporated into SEA 4000 from the outset, with the requirement specifying an embarked helicopter for surveillance and combat missions. The selected Navantia-derived design accommodates one helicopter, compared with two aboard the competing Evolved Arleigh Burke proposal. The MH-60R nevertheless operates as an extension of a ship already equipped with hull-mounted and variable-depth sonar, MU90 torpedoes and surface surveillance sensors.

  The helicopter's principal contribution is anti-submarine warfare (ASW), where its mobility allows sensors and weapons to operate independently of the destroyer's position. Australian MH-60Rs carry the Airborne Low Frequency Sonar System (ALFS), giving a Hobart three spatially separated submarine-search elements: its hull-mounted sonar, variable-depth towed sonar and the helicopter's dipping sonar. Radar, sonar, electro-optical and electronic-support information can be fused aboard the MH-60R and exchanged through high-speed data links, allowing the helicopter to extend the destroyer's tactical picture beyond the geometry imposed by shipborne sensors.

  For submarine prosecution, the MH-60R can carry the Mk 54 lightweight torpedo, complementing the destroyer's ship-launched MU90 Impact torpedoes. The distinction is operationally important because the helicopter can carry a torpedo away from the ship and attack a submarine without requiring the destroyer to close to the ship-launched torpedo distance. The MH-60R also supports anti-surface warfare (ASuW) with AGM-114 Hellfire missiles and Advanced Precision Kill Weapon System (APKWS) weapons, providing an airborne attack option against surface targets for which a Naval Strike Missile or 127 mm naval gun may not be appropriate.

  Beyond combat missions, the MH-60R can conduct surface surveillance, vertical replenishment, passenger and cargo transfer, and search and rescue. This makes the aircraft useful for investigating contacts at a distance, transferring personnel or supplies, and conducting rescue missions without requiring the destroyer itself to approach the objective. The available information gives the helicopter a speed of 180 knots (333 km/h) and a range of 470 nautical miles (870 km), although the latter is not an armed combat radius and does not account for hover time, sonar operation, weapons, reserves, or ship movement.

  The MH-60R has a three-person flight crew, consisting of one Navy pilot, one maritime aviation warfare officer, and one aircrewman, but operating the helicopter at sea requires a substantially larger detachment. A Hobart-class destroyer normally carries 186 ship personnel plus 16 aviation personnel, producing a combined standard complement of 202, while total accommodation reaches 234. The 16-person aviation element therefore represents 7.9% of the normal combined complement and includes the maintenance and support personnel required to sustain helicopter operations during deployment.

  An October 2021 incident involving the HMAS Brisbane demonstrated the operational importance attached to retaining this capability: after the ship's MH-60R made an emergency landing in the Philippine Sea and its crew was rescued, an RAAF transport aircraft delivered a replacement helicopter to Japan, and the HMAS Brisbane embarked it at Yokosuka. The Australian Government has approved a common fleet of 36 MH-60Rs, with the available information identifying 23 in service and 13 on order. When ashore, the helicopters operate from HMAS Albatross at Nowra, New South Wales.

The Hobart class's 48-cell Mk 41 VLS can launch SM-2 and SM-6 missiles for long-range air and missile defense, quad-packed ESSM for shorter-range air defense, and Tomahawk cruise missiles for long-range strikes against land targets.