RAN expands its weapons inventory

The RAN's current program of platform upgrades will also see a new generation of surface to air and undersea weapons brought into service, with a significant benefit to the RAN's combat capability.
Is there really a distinction between offensive and defensive weaponry? If so, the Navy's inventory of defensive weapons can be said to be slowly expanding to meet future threats to its capital ships. For offensive roles these are balanced by the introduction of Penguin and Harpoon anti-ship missiles and (eventually) new lightweight and heavyweight torpedoes.

But maritime mining, a third, strategic category of weaponry, which offers an enormous return for a very modest investment, is a RAN capability which, with the cancellation of Joint Project 2045, now depends solely on whatever outdated warstocks Navy holds, or what can be begged or borrowed from our allies in the event of an outbreak of hostilities.

Navy's defensive weapon systems provide protection against air, surface ship and submarine attack. Surface to air missiles fall into two classes: area defence and point defence. The area defence missile is a long range, medium-high altitude missile designed to provide a defensive umbrella over a fleet or a convoy against attack by aircraft carrying air to surface missiles. The purpose of this class of missile is to keep the aircraft beyond attacking range. The RAN's first area defence missile, the US-made SM-1 (Standard Missile-1) came with the three DDGs in the 1960s and the same missile is fitted to the six FFGs, although it will be withdrawn as part of their current upgrade.

SM-1 was a development of Terrier and is a medium range, semi-active radar homing missile capable of intercepting medium-high altitude aircraft. The missile is launched from a short rail launcher one at a time. In its day, SM-1 was widely used internationally by nations such as Germany, France, Taiwan and Japan as well as Australia, but it is now obsolete and is no longer supported by the US Navy.

SM-2 replaces SM-1 and only the heritage is common, SM-2 having a considerably longer range than SM-1, and being faster and more agile. Although SM-2 has been in US Navy service for some 30 years the RAN has been slow to adopt it because of missile cost and the need for a sophisticated 3D radar, such as the AN/SPY-1, which in addition to multiple detection and tracking provides fire control solutions. This class of radar is required if all the operational modes of the missile are to be used. However, the least complex and least cost mode for firing the missile is Home-All-the-Way (HAW) in which the target is continuously illuminated by the ship's fire control radar and the missile homes on its reflected RF energy. This mode is likely to be adopted by the RAN.

Another mode involves firing the missile in the target direction, using inertial guidance and then providing command guidance using an up-link from the ship to the missile until the target engagement sequence is selected at which time the missile uses semi-active radar terminal guidance homing. This mode is used for salvo firing and obviates the need for continuous high power radar transmissions from the ship for target illumination.

SM-2 will continue to be developed for many years to improve its performance against threats and increase its range. Compared with SM-1 that had a range of about 38km, the latest configuration, SM-2ER (Extended Range) Block lV, missile has a range of about 150km and is 6.5m long compared with 4.5m long for SM-1.

The point defence missile (PDM) is designed to defend the launch ship from anti-ship missiles at ranges varying between two and 15km. The PDM is a high speed, very agile, missile capable of engaging targets at altitudes from three to 5,000 metres. The Anzac Ship was designed from the outset to carry the US Navy's ubiquitous Sea Sparrow, RIM-7, in a vertical-launch configuration. Adopted by the NATO Sea Sparrow Consortium RIM-7 is a naval variant of the aircraft-launched, semi-active radar homing, AIM-7 Sparrow. Later versions of this missile combine radar and IR homing capabilities.

Shortly after selection of the RIM-7, the Evolved Sea Sparrow Missile (ESSM) program was initiated by some of the members of the NATO Sea Sparrow Consortium, which the RAN joined to be able to buy ESSM. Next to the USN the RAN has been the greatest contributor of development funds and, as a result, Australian industry has benefited from this project. The forebody of the ESSM is essentially the same as that of the RIM-7, but the aft body is larger due to the use of a higher thrust, longer-burning motor which significantly improves the missile's kinematic performance and its ability to engage threats at both longer and shorter ranges. Tail control is also used to improve agility.

A four-to-one improvement in the packing density of the ESSM in the Mk 41 vertical launcher (VL) configuration, as compared with the standard VL RIM-7, has also been achieved and Anzac-class ships will be capable of carrying 32 ESSMs. The FFGs, post-upgrade, will also carry ESSM in the same VL (Mk 41 Tactical Length) configuration.

Another point defence missile system is known as the Inner Layer Defence System (ILDS). These systems are beginning to emerge and like Sea Sparrow are frequently adapted from Within Visual Range air-launched missiles. The BAE-Matra Mistral is a ty
The RAN has adopted two ASMs, the US Navy's Harpoon and the Norwegian Penguin. Harpoon is an autonomous all-weather ASM with an over the horizon range of more than 67nm.The missile may be launched from ships, aircraft and submarines. Propulsion is provided by a small short-burn solid propellant boost motor followed by a small turbofan liquid hydrocarbon fuel sustainer motor. Sub-Harpoon is enclosed in a canister and launched from a torpedo tube until it broaches the surface when the boost is ignited. The missile climbs initially and then dives to begin low altitude flight using INS/GPS navigation. Terminal phase homing uses active radar. The VL system now adopted for the Anzacs and FFGs is fundamentally capable of launching Harpoon which, being autonomous, does not require radar support from a launch ship.

Like SM-1/2, Harpoon has been under continuous development since its introduction into service circa 1977 to increase range, improve guidance accuracy and reduce cost. The range of the Block 1 missile has been extended from about 90km for the Mk1A/B to about 240km for the Mk 1D with the longer range being suitable for land attack from stand-off platforms.

The Block 2 missile, now in development, uses higher accuracy INS/GPS navigation components from other programs and is capable of long range strikes against land targets, and ships in harbour and at sea. For attack against ships at sea the missile is navigated to the designated area and then engages a target using its active homing radar. Harpoon carries a 500lb blast warhead.

The Penguin ASM is currently being fitted to the Super Seasprite helicopters that will be carried by the Anzacs, though not to the Seahawks, carried by the FFGs. Along with Penguin, radar and IR detection these helicopters provide a significant increment in a ship's self-defence capability. The missile uses an INS and IR (passive) terminal homing. The range of the two-stage solid propellant Mk1 version is about 18km and the Mk2, purchased by the RAN, has a range of about 27km. Notably, the warhead weighs about one third of the missile's total weight of 330kg at launch and this 120kg semi-armour piercing warhead is capable of causing very extensive damage to a ship.

The development of maritime mine warfare technology and capability is a major activity for the RAN, but greater emphasis has been placed on mine countermeasures, rather than mine development, because of the relative ease with which laid mines could disrupt Australia's trade. All of Australia's major ports have relatively small harbour entry points which could be choked by mines.

The RAN had a single project (JP2045) for the acquisition of a modern, low signature, programmable multi-influence bottom mine capable of both air drop and ship launch. Following extensive evaluation of maritime mines with these characteristics the RAN selected the then-GEC Marconi (now BAE Systems) updated Stonefish mine, along with a commitment by the company to place manufacture and development of the mine in Australia. This project has now been cancelled but will almost certainly be resurrected in the distant future.

The ADF's requirement for torpedoes now centres on the acquisition of a new anti-submarine warfare (ASW) lightweight torpedo which will improve this country's ASW capability in ships, helicopters and maritime patrol aircraft, particularly in shallow waters; and a new heavyweight torpedo to replace the ageing Mk48 weapon in the Collins-class submarines.

There were a number of contenders for the lightweight ASW torpedo requirement and just over a year ago Defence's first Alliance Agreement was signed with Thomson Marconi Sonar (TMS) for the $3 million risk reduction study, aimed at identifying budget, integration and logistics requirements prior to the next, acquisition phase. This next phase will see the acquisition of the ASW capability, consisting of the Eurotorp MU90, in sufficient quantities to fulfill stockholding requirements, which may mean the eventual acquisition of more than 100 weapons.

Although no in-service date has been made public, it is anticipated that the acquisition phase will receive funding approval in the current (01-02) Budget. The official Phase 2 cost band is $250m to $500m.

There were a number of potential contenders for the Replacement Heavyweight Torpedo but the RFP shortlisting process reduced these to just three: Whitehead Alenia A184 Black Shark, STN Atlas DM2 A4 Seehecht, and Raytheon Mk 48 Advanced Capability (ADCAP).

A Project Definition Study involving all three contenders is likely to lead to a preferred tenderer, with funding for the second, acquisition phase also anticipated in the 01-02 Budget. The official cost band for this requirement is $100m to $250m. Because of the current use of the MK48 in the Collins and the development of a fire control system to be able to fire and guide it, it is considered most likely that the MK 48 ADCAP will be selected to avoid the costs of purchasing a significantly different fire control system.

By Fred Haddock and Tom Muir