The original version of this weapon system used an off-mount radar for target search. This handed off to an on-mount Lockheed Electronics PVS-2 Sharpshooter I-band radar which was designed to acquire targets at 5,000 m (5,500 yards), allow the CIWS to achieve first impact at 1,500 m (1,640 yards) and destroy the target by 500 m (550 yards). An optronic system is provided for backup in a jamming environment and there is an off-boresight tracker to handle very-low flying targets. Later, an Israeli designed IR tracker was added. These mountings operate "open-loop," in other words, they do not correct for observed errors in the firing solution.
The current Model 2B has a more sophisticated fire control processor and a digital processor for system control. It also includes an Indra (formerly ENOSA) thermal imager.
The Spanish Navy estimates that there is an 87% probability of destroying an incoming missile with a single 12-round burst.
|Designation||Guns: Oerlikon 20 mm/120 (0.79")
Mounting: Meroka SPG-M2B
|Ship Class Used On||Principe de Asturias, Baleras and Santa María classes|
|Date Of Design||N/A|
|Date In Service||N/A|
|Gun Length oa||N/A|
|Bore Length||about 94.5 in (2.400 m)|
|Rate Of Fire
|1,440 rounds per minute cyclic (all twelve barrels)|
|Note: This weapon fires two bursts per second. Each burst consists of 4 groups of 3 rounds each. This pattern was selected in order to minimize the recoil forces. A burst takes 0.080 seconds to complete.|
|Weight of Complete Round||0.71 lbs. (0.32 kg)|
|Projectile Types and Weights||APDS-T
0.225 lbs. (0.102 kg) with sabot
0.191 lbs. (0.075 kg) without sabot
|Bursting Charge||None (solid penetrator)|
Complete Round - 7.87 in (20 cm)
|Cartridge||20 x 128 mm (actual cartridge size is 128.7 mm)|
|Muzzle Velocity||4,232 fps (1,290 mps)|
|Approximate Barrel Life||N/A|
|Ammunition stowage per gun
|60 rounds per barrel (720 total)|
1) Bazán describes the ammunition as a special "hard-core" type designed for maximum penetration into missile bodies.
2) Penetrator has a diameter of 0.47 inches (12 mm).
|Elevation||With 0.225 lbs. (0.102 kg) APDS|
|Effective||2,200 yards (2,000 m)|
|Weight||9,920 lbs. (4,500 kg) plus 928 lbs. (421 kg) off mount|
|Elevation||-15 / +85 degrees|
21 May 2006 - Benchmark
18 February 2012 - Updated to latest template