The Meroka CIWS is a Spanish Navy 12 barrelled 20 mm CIWS, using twelve Oerlikon 20 mm/120 guns mounted in 2 rows of 6 guns each. The system's primary purpose is defence against anti-ship missiles, and other precision guided weapons. However it can also be employed against aircraft, ships and other small craft, coastal targets, and floating mines. The weapon is mounted primarily on Spanish naval vessels, from frigate size upwards.
The term MeRoKa (from German Mehrrohrkanone, meaning multi-barrelled gun) can refer to weapons such as the Nordenfelt gun but is more commonly used referring to this naval CIWS defence system. The "Meroka" was developed and produced by the Spanish firm FABA (Fábrica de Artillería Bazán).
Unlike a Gatling gun, the Meroka CIWS uses individual guns firing in salvos or simultaneously; the barrels are purposely skewed in order to expand the impact area. The guns are mounted in an enclosed automatic turret and are directed by radar or an optronic thermal controlling system.
The original version of the Meroka CIWS was directed by a separate off-mount radar system. This was later changed to an on-mount Lockheed Electronics PVS-2 Sharpshooter I-band radar. The radar is designed to acquire targets at 5,500 yards (5,000 meters), with the Meroka achieving first impact at 1,640 yards (1,500 meters) and destruction of the target at 550 yards (500 meters). Later versions included an optronic targeting system, as a backup in high electronic jamming conditions. More recent modifications included an Israeli designed IR tracker and other electronic devices of Spanish design supplied by Indra Sistemas.