Up close and personal: the survival of warships in the littoral environment depends on layers of close-in defence systems to defeat both conventional and asymmetric threats.

The primary role of small and medium calibre guns has shifted to protection against asymmetric threats that are particularly acute in littoral operations. Warships routinely operate in coastal regions and shipping channels that are crowded with commercial vessels and pleasure craft of all nationalities and descriptions. In such situations an attack from terrorists using fast inshore attack craft, possibly approaching in swarms, usually comes with no warning. Terrorists can use guided missiles, man-portable rockets or pack their craft with explosives for a suicide attack. The scope of such attacks was demonstrated in October 2000 when a suicide craft attacked the US Navy's DDG 51 destroyer USS Cole in the port of Aden. Israeli Navy patrol boats have long faced the danger of suicide attacks as they inspect vessels approaching Israel's coast and Tamil Tiger separatists have successfully used fast craft against the Sri Lankan Navy. Small and medium-calibre guns, autonomously or remotely controlled, are regarded as the best solution to respond quickly and accurately to asymmetric threats without causing collateral damage to either military or civilian ships.

Since entering service with the US Navy in 1980 the Mk 15 Phalanx, based on the six-barrel 20 mm M61A1 Vulcan gun, has become the most widely deployed close-in weapon in the world, with more than 850 produced and sold to 21 countries. All 350 Phalanxes in US Navy service are being upgraded to the Block 1B standard. Raytheon is working on a $57 million contract awarded by the Canadian Department of National Defence to overhaul and upgrade the Canadian Navy's 19 shipboard Phalanx guns to the Block 1B standard. The Block 1B has also been bought, either as a new weapon or an upgrade package, by Bahrain, Egypt, Japan and Portugal.

Similar in concept, although not as widely employed, to the Phalanx system is the 30 mm Goalkeeper produced by Thales Nederland. In mid-2004 the company received its latest order covering three systems to be installed on the Republic of Korea Navy's KDX III destroyers. This followed earlier contracts for 16 Goalkeeper systems for installation onboard Korea's KDX I and KDX II destroyers, and the LPX landing platform. More than 50 systems have been sold with other major customers being the Royal Netherlands Navy and the UK Royal Navy. With a system weight of 9902 kg and depth penetration of 2.5 metres the Goalkeeper is intended for larger ships. The Royal Navy deploys three systems on its Invincible class aircraft carriers. Goalkeeper's seven-barrel General Dynamics GAU-8/A Gatling gun automatically engages targets between 350 and 1500 metres firing 4200 missile-piercing discarding sabot rounds per minute. Reaction time against a Mach 2 sea-skimming missile is claimed to be about 5.5 seconds with the engagement starting at 1500 metres and ending with a kill by 300 metres.

Seeking a low-cost, self-defence system that could defeat missiles at a longer range than the Phalanx, Raytheon teamed with Ram-System to develop the Rim-116 (Rolling Airframe Missile). The original Block 0 (Rim-116A) missile design, which entered service in 1992, was based on the infrared seeker of the man-portable Stinger missile, and the warhead, rocket motor and fuse from the Sidewinder air-to-air missile. The Block 1 (Rim-116B) missile incorporates the added capability of autonomous infrared-all-the-way guidance to counter cruise missiles that do not employ onboard radar seekers. The German Navy plans to fit Ram launchers to about 30 ships while as many as 83 US Navy ships could receive launchers.

In November 1998 Germany and the United States amended the Block I development Memorandum of Understanding to include a helicopter/aircraft/ surface craft (Has) upgrade of the Ram. The type successfully engaged low-flying drones during tests in 2002 and a coastal patrol craft posing as a terrorist craft in 2004. The missiles can be fired from the standard 11- and 21-cell Ram launchers. Raytheon is adding a third option intended as a cost effective upgrade to the Phalanx. It has stripped the Gatling gun and all of its ancillary equipment from the Phalanx 1B and replaced it with an eleven-cell missile launcher to produce the SeaRam. Unlike the standard Ram launcher, which relies on the ship's sensor suite, the SeaRam is a complete package with the same sensors as the Phalanx Block 1B. The US Navy has indicated that all Ram installations on its amphibious assault ships and aircraft carriers will be the Has configuration by 2009.

In German service the Ram will be employed in tandem with the MLG (Marineleichtgeschutz) 27, one of the latest remotely operated small-calibre gun systems to enter naval service. This was developed by the Mauser division of Rheinmetall using the same 27 mm revolver cannon as fitted to Tornado and Typhoon combat aircraft. The German Navy is replacing its 20 mm and 40 mm guns across the fleet with the MLG 27 and in 2002 placed an order for 83 systems. More than 25 systems have been delivered to the customer since December 2003 and the Berlin, lead ship of the Class 702 combat support vessels, was the first platform to receive the MLG 27 with four weapons installed in mid-2004. In September 2005 an additional four weapons were ordered and company officials anticipate up to another 20 could be ordered over the next three years to coincide with the German Navy's shipbuilding programme.

Atlas Elektronik is supplying the MLG 27's electro-optical package that is comprised of television and infrared cameras, a laser rangefinder and a video tracker mounted on the trunnion. The complete MLG 27 mount weighs 850 kg without ammunition and no penetration of the deck is necessary to install the system.

In parallel with the development of the MLG 27 the German firm developed a 27 x 145 mm frangible, armour piercing, discarding sabot round for naval use. After it has punched through the outer shell of the target the penetrator is designed to fragment into a cloud of particles to cause the maximum damage to the interior of the target.

For export customers Mauser has integrated the ATK Mk 242 Bushmaster I 25 mm cannon onto the MLG 27 mount to produce the MLG 25 lightweight gun system.

Mauser has also completed initial engineering development of the MLG 30/ABM system using the ATK Mk 44 Bushmaster II 30 mm cannon and Oerlikon Contraves Advanced Hit Efficiency And Destruction (Ahead) air burst munition (ABM) technology. The US Navy bought the first prototype system for evaluation.

In late 2004 the Royal Danish Navy became the launch customer for the Millennium GDM-008 35 mm naval gun system when it placed a contract with Oerlikon Contraves (another member of the Rheinmetall group) for four mountings. Two guns will be installed on each of the service's two new 6300-tonne flexible support ships, the Absalon and the Esbern Snare.

Oerlikon Contraves first revealed its 35 mm revolver cannon (then designated the 35/1000) at the 1994 Farnborough Air Show. With a rate of fire of 1000 rounds per minute the gas-operated, four chamber revolver cannon is optimised for use with the Ahead munition. The gun's muzzle brake programs each Ahead round as it exits the barrel, setting distance and sub-projectile dispersal pattern. Each round disperses 152 spin-stabilised tungsten sub-projectiles to create a cone-shaped swarm of pellets to defeat sea-skimming missiles, aircraft, surface craft and near-shore targets. With a full load of 200 rounds of ammunition the Millennium gun mount weights 3200 kg.

Lockheed Martin has the license for all applications of the Millennium Ahead technology and is promoting the Millennium gun for a number of US Navy applications. Earlier this year the US Naval Sea Systems Command (Navsea) completed the initial round of ground tests of the Millennium gun and plans to conduct at-sea testing in 2006.

Rafael, for its part, has achieved significant success with its family of Typhoon Naval Stabilized Weapon Stations, including its selection by the US Navy. Using technology derived from Rafael's OWS 25 overhead weapon station for armoured vehicles, the company began developing a naval mount in the mid-1990s to equip Israel Defence Force patrol boats. A prototype system armed with an ATK M242 Bushmaster 1 25 mm cannon was mounted on an Israeli Super

Dvora patrol boat for trials in mid-1995. However, the first customer was the Sri Lankan Navy that used Typhoon mounts with 23 mm cannon in its battle with Tamil Tigers operating speedboats along the island's coast, Israel has selected the Typhoon armed with a Bushmaster I to replace most of its 20 mm naval guns. Other customers include Australia, Greece, India and Singapore.

The Royal Australian Navy purchased 13 Typhoon Mk 25 systems armed with the M242 coupled to Rafael's Toplite electro-optical director to arm its twelve new Armidale class patrol boats. The first of these was commissioned in late June and the government has announced plans to add a further two boats to the class

In June 2004 United Defense (now part of BAE Systems), teamed with Rafael, received a contract worth up to $395.5 million for the US Navy's Mk 38 Mod 2 Machine Gun System Ordnance Alteration programme. This will use Typhoon technology, including Toplite, to upgrade the navy's non-stabilised, manually-fired, Mk 38 Mod 1 cannon into a fully stabilised system that can be operated remotely. The modernised system retains the M242 Bushmaster gun of the Mod 1 configuration and 168 rounds of ammunition will be ready to use. The initial order covered eight systems produced in Israel. These guns were installed on the CG-47 cruisers USS Princeton and USS Port Royal in 2005. A further 13 weapons were ordered with Fiscal Year 2005 funding. Under a rolling contract that lasts until 2010 the majority of work on the more than 300 weapons covered by the project will be done at the BAE Systems facilities in Louisville.

The Mk 38 Mod 2 is only one of several gun systems the US Navy is installing on its ships for close-in defence. The new class of twelve San Antonio amphibious assault ships will be armed with the Mk 46 Mod 1 gun system, a navalised version of the turret that General Dynamics Land Systems has developed for the Advanced Amphibious Assault Vehicle for the US Marine Corps. This is armed with ATK's 30/40 mm Mk 44 Bushmaster cannon, which fires standard 30 x 173 mm GAU-8 ammunition or can be converted to fire 40 mm Super Forty ammunition.

In September 2005 the British Ministry of Defence awarded MSI-Defence Systems with a 15 million [pounds sterling] contract to upgrade 26 DS30B Mk 1 30 mm manually-operated guns aboard the navy's Type 23 frigates to the new DS30M Mk 2 configuration. MSI-Defence supplied approximately 70 DS30B guns to the Royal Navy and more than 20 to export customers including Australia and Thailand. Building on this experience it now offers the family of DS25/30 weapon mounts featuring:

* a choice of 25 mm (Oerlikon KCB and ATK M242 Bushmaster I) and 30 mm (Oerlikon KCB, ATK Mk 44 Bushmaster II and Mauser Model F) cannons, and

* options for utilising local (locsig), remote (remsig) and autonomous (autsig) gun control.

For customers seeking a more comprehensive air-defence solution MSI-Defence is offering the Sigma (Stabilised Integrated Gun Missile Array) air defence system that combines three or four low level missiles, either the Mistral or KBM Igla, with a 25 mm or 30 mm gun.

In the development of its Naval Remote Weapon Highly, Accurate Lightweight (Narwhal) mount Giat has also adopted a modular approach that allows customers to specify the gun calibre. Four variants are now on offer: the 350-kg Narwhal 20A armed with a single M621 20 mm gun, the 400-kg 20B armed with two M693 20 mm guns, the 550-kg 25 mounting two MS11 25 mm guns and the 400-kg 30 armed with one M781 30 mm gun. During the development programme a Narwhal 20A was tested at sea in 2002-03 aboard a Subahi class patrol boat being built by French shipyard Ocea for Kuwait's coast guard. Giat is seeking a launch customer for the Narwhal.

Oto Melara's most recent development is the M584 Modular Gun System that can be equipped with a 25 mm or 30 mm cannon and fire-and-forget missiles. Customers seeking a 25 mm weapon are offered the choice of the Oerlikon KBA or ATK M242 Bushmaster I with up to 200 rounds available on the mount while the 30 mm options are the Mauser Mk 30-2 and ATK Mk 44 Bushmaster II with 140 rounds of available ammunition. The United Arab Emirates Naval Forces is the launch customer for the M584. Each of the six 70-metre Baynunah class corvettes that Abu Dhabi Ship Building will deliver from 2008 will be equipped with two M584s. The United Arab Emirates systems will be armed with the Bushmaster II and twin KBM Igla-S launchers on each side of the mount. The first pair of weapons will be delivered in 2006.

Oto Melara has also recently developed a lightweight remotely operated turret for both naval and ground applications that can be fitted with 12.7 mm heavy machine gun and up to 400 ready rounds or a 40 mm automatic grenade launcher and 32 rounds. The naval turret, designated the Model 517, weighs between 220 and 260 kg depending upon the amount of 12.7 mm ammunition carried. The United Arab Emirates bought twelve for its new Transportboat 2000 amphibious transport boats built under Project 'Ghannatha', the Mexican Navy has bought twelve systems for its Acuario and Polaris class patrol boats and Italy's Guardia di Finanza has bought 13 systems for the twelve Series IV Bigliani class patrol boats now entering service. The Italian Navy is considering the turret for various applications.

The South African Navy's four new German-built Meko A-200 corvettes are being equipped with Denel's twin 35 mm Dual Purpose Gun (35DPG). The two GA-35 guns are effective against aerial targets to a maximum range of 4000 metres and against surface targets out to 6000 metres. For this first application the 35DPG will be coupled to a Reutech Optical/Radar Tracker. The manufacturer claims that with a single 25-round burst the weapon can destroy cruise missiles at ranges of at least 2.5 km and 'high speed' missiles at a range of 1.5 km.

In south East Asia, Singapore Technologies Kinetics has developed its new 30 mm Naval Remote Weapon Station (NRWS) to the prototype stage. Intended as a lightweight (1500 kg) mount for smaller craft the weapon can be armed with a 25 mm or 30 mm cannon and a 7.62 mm coaxial machine gun.

To enhance the protection of larger platforms most navies also install a soft kill decoy system. One example attracting international attention is the Soft Kill Weapon System (SKWS) developed in the 1990s by Terma of Denmark in co-operation with the Royal Danish Navy for installation in the service's corvette/frigate size ships. Designed to provide 360-degree coverage the system is based on two DL-6T launchers for small vessels or two DL-12T launchers for larger vessels, one mounted on each side. These can be configured to provide 12 to 48 130mm launcher tubes. The system has been exported to Australia, the Netherlands, Norway and Romania. Following their partnership on the Norwegian F-310 frigate project Lockheed Martin selected Terma's system for installation in the US Navy's new Littoral Combat Ship (LCS).

Rheinmetall has sold its Multi Ammunition Softkill System (Mass) to Finland, Germany, Norway, Sweden and most recently the United Arab Emirates. In the latter case the 4.5 million [euro] contract covers four Baynunah class multi-purpose corvettes. The [euro] eight million Swedish order covers the installation of the Mass in the navy's five new Visby class corvettes, two Goteborg class and two Stockholm-class corvettes. Systems were installed on the corvettes Stockholm and Malmo in January this year, only nine months after contract signature. That same month the first Mass twin launcher was installed on the Finnish R2000 class ship Tornio. The Mass fires sequential volleys of programmable omni-spectral decoys claimed to provide effective protection in all relevant wavelengths (UV, EO, laser, infrared and radar) of the spectrum.

RELATED ARTICLE: A Silver Star.

With a range of up to 30 km MBDA's vertically launched Aster 15 is able to provide both point and local area defence. The active radar missile was designed to defeat highly manoeuvrable anti-ship cruise missiles, anti-radiation missiles, fighter and maritime patrol aircraft. Capable of sustaining loads of 60 G in its terminal phase, the Aster can make trajectory corrections up to the moment of interception. The French aircraft carrier Charles de Gaalle was the first warship to be fitted with the Aster 15. The first Italian Navy vessel to be fitted with the Aster 15 will be the carrier Andrea Doria. It will also equip the three new Saudi Arabian Al Riyadh (F3000S Sawari II) frigates.