Nexter Advances with Lightweight Naval Remote Weapon Systems“Smarter and lighter” appears to be the name of the game in the next generation of naval remote weapon systems. They form an integral part of modern ship self-defence architectures. There are many challenges facing maritime forces and the industry in terms of remote weapon systems capable of combating all sorts of asymmetric threats. The biggest one is how to use them effectively to combat completely new threats as posed by swarming attacks carried out by fast inshore attack craft (FIAC) or suicide fast craft. As any solutions for fighting tyranny at sea are being designed to go to be 100 percent effective, remote weapon systems can be brought in today as a valuable part of a shipboard security inventory.
Naval ships will have to be shaped-up to better defend against asymmetric threats. A key factor of the presence of maritime fleets in blue and brown waters is that modern threats will not only include Cold War-style threats like manned aircraft, helicopters, anti-ship missiles or even anti-ship cruise missiles, but most notably unmanned aircraft and very small, but highly agile surface threats as represented by powerboats, interceptors, rigid inflatables, and jet ski-type vehicles carrying dangerous weapons, including machine guns, rocket-propelled grenades, and other explosives.
A gun-based CIWS used to combat such threats typically consists of a rapid-fire, small- to medium-calibre (20-35mm) gun placed on a rotating gun mount plus a combination of EO fire control systems or EO director (EOD), radars, and C2 elements.
Nexter Systems developed the fully stabilised NARWHAL (Naval Remote Weapon Highly Accurate Lightweight) rapid-fire gun system in two variants: NARWHAL 20A with a 20mm M621 cannon and NARWHAL 20B with a 20mm M693 cannon. The company acknowledges that a 20mm remote weapon makes absolute sense to defeat the range of small objects manoeuvring on the water surface and in the air like FIAC, jet ski-type vehicles, and highly miniaturised unmanned aircraft (drones). For exactly this purpose, the gun mount can be easily integrated into modern shipboard self-defence architectures. Nexter Systems delivered the NARWHAL system to a number of customers operating patrol vessels, light frigates, fast patrol boats, FAC, and inflatables.
The 20A configuration consists of a gyro-stabilised mounting armed with a 20mm M621 cannon firing 20mm x 102 NATO rounds (offering a rate-of-fire of 750rds/min), a daylight camera, and a C2 terminal. The magazine contains 200 ready-to-fire rounds, weighing in total 390kg. Nexter Systems said the M621 cannon has a muzzle velocity of 1,005m/s (armour-piercing) and 985m/s (high explosive incendiary).
The French Navy selected the NARWHAL 20B configuration for its 11 “Aquitaine” class (FREMM) frigates. DCNS, the builder of the vessels, ordered 22 systems in November 2011. Consisting of a 20mm M693 cannon, this configuration forms a force protection system best suited to defend against the spectrum of airborne and surface threats that also include ‘leaker’ missiles. The French Navy declares that the 20mm x 139 rounds fired by the 20B variant will also be able to hit mortar rounds fired from a hostile craft.
According to Nexter Systems, the 20B’s rate of fire is up to 800rds/min, which gives the weapon sufficient stopping power in case of a terrorist attack. Firing one burst of 20-25 rounds, small airborne targets can be destroyed at ranges of at least 1.35nm (2.5km). The missile kill range is reportedly in excess of 1.1nm (2nm), compared with existing CIWS where this range is typically less than 0.27nm (0.5km).
Nexter Systems also confirmed that DCNS ordered a single 20B system for the FREMM frigate “Mohammed VI” the shipyard is building for the Royal Moroccan Navy. Nexter Systems said the gun mount carries approximately 200 rounds of 20mm M693 ammunition in the magazine inside the turret, with the ammunition weighing in total some 470kg.
In the ‘see first-decide-act’ triad, which is most characteristic of today’s and tomorrow’s operations at sea, the grade of automation of the NARWHAL remote weapon station can be increased through the use of other shipboard sensors, including radars, IR search and track (IRST), and FLIR suites.
|The gyro-stabilised NARWHAL 20mm cannon pictured here in Le Bourget is optimised for close-in defence against all kinds of asymmetric threats, including suicide fast boats, frogmen, and low-speed flying aircraft and drones.|
(Photo: Stefan Nitschke)