A close-in weapon system, often pronounced "sea-whiz," is a
point-defense weapon for detecting and destroying short-range incoming missiles
and enemy aircraft which have penetrated the outer defenses, typically mounted
shipboard in a naval capacity. Nearly all classes of modern warships are
equipped with some kind of CIWS device. There are two types of CIWS systems. A
gun-based CIWS usually consists of a combination of radars, computers, and
multiple-barrel, rotary rapid-fire cannons placed on a rotating gun mount.
Missile systems use infra-red, passive radar/ESM or semi-active radar terminal
guidance to guide missiles to the targeted enemy aircraft or other
threats. In some cases, CIWS are used on land to protect military bases.
Gun systems A gun-based CIWS usually consists of a
combination of radars, computers, and multiple-barrel, rotary rapid-fire
cannons placed on a rotating, automatically-aimed gun mount. Examples
of gun-based CIWS products in operation are:
AK-630 DARDO
Denel 35mm Dual Purpose Gun Goalkeeper CIWS
Kashtan CIWS Meroka CIWS
Myriad CIWS Oerlikon Millennium 35 mm Naval Revolver
Gun System Phalanx CIWS
Sea Zenith Type 730 CIWS
= Limitations of gun systems= Short range: the maximum effective range
of 20 mm gun systems is about 4,500 metres; systems with lighter projectiles
have even shorter range. The expected real-world kill-distance of an incoming
anti-ship missile is about 500 m or less, still close enough to cause damage
to the ship’s sensor or communication arrays, or to wound or kill exposed
personnel. This also makes the timeframe for interception relatively short; for
supersonic missiles moving at 1,500 metres per second it is approximately
one-third of a second. Limited kill probability: even if the
missile is hit and damaged, this may not be enough to destroy it entirely or to
alter its course enough to prevent the missile, or fragments from it, from
hitting its intended target, particularly as the interception
distance is short. This is especially true if the gun fires
kinetic-energy-only projectiles. Guns can only fire at one target at a
time; switching targets may take up to one second to re-train the gun.
A gun must predict the target's course and aim at the predicted position.
Modern anti-ship missiles make intentional erratic moves before impact,
reducing the probability of being hit by unguided projectiles.
= Comparison of some current CIWS= Missile systems
Missile systems do not have the same limitations as gun systems. Because of
their greater range, a missile-CIWS can also be dual-used as a short-ranged
area-defense anti-air weapon, eliminating the need for a second mount
for this role. After an inertial guidance phase, a CIWS
missile relies on infra-red, passive radar/ESM or semi-active radar terminal
guidance, or a combination of these. The ESM-mode is particularly useful since
most long-range anti-ship missiles use radar to home in on their targets. Some
systems allow the launch platform to send course-correction commands to the
missile in the inertial guidance phase. A drawback of the missile system is the
low number of immediately available projectiles and longer reload cycles and
higher costs per shot in training. A further advantage of the gun systems the
fact that a fired projectile cannot be jammed or lured away from its trajectory
by active electronic or infrared countermeasures. For this reason, larger
military vessels are often protected by combinations of both systems.
Examples include: 9K33 Osa missile, is used on various
Russian ships. 9K331 missile, used by the Russian Navy,
it is stored and fired from Vertical launching systems of various ships. It
along with the Tor missile system is the first air-defense system designed from
ground up to intercept precision guided munitions like the AGM-86 ALCM
9M311 missile, used by the Russian and Chinese navies as part of the Kashtan
CIWS gun-missile system. Barak 1 an Israeli point defence missile
system also used by Indian Navy. Barak 8 jointly developed by Israel and
India. Crotale-NG
HQ-7 missile, a Chinese missile system, standard for all ships.
RIM-116 Rolling Airframe Missile - jointly developed by the US and Germany,
it is used extensively on German warships and many American ones - SeaRam
is a plan to mate the Phalanx sensor system with an 11-missile RAM launcher
Sadral, using a version of the Mistral missile
Sea-Sprint, using the ADATS missile Modernized Sea Wolf
Sea Sparrow Block 1, Missile used by the Nimitz class carriers, and other USN
ships, as a short- to medium-range anti-aircraft weapon.
Evolved Sea Sparrow missile, used aboard all Sea Sparrow-capable warships, plus
other warships of the Netherlands, Canadian, Spanish, Japanese, Turkish and
Australian navies. Land-based CIWS
CIWS are also used in a land-based anti-mortar and missile defense role to
protect fixed and temporary bases and other facilities.
On a smaller scale, active protection systems are used in some tanks, and
several are in development. The Drozd system was deployed on Soviet Naval
Infantry tanks in the early 1980s, but later replaced by explosive reactive
armour. Other systems that are available or under development are the Russian,
Israeli, American and the South African-Swedish.
Laser CIWS Systems Laser based CIWS systems are being
researched. In August 2014 an operational prototype was deployed to
the Persian Gulf aboard USS Ponce. The Scientific and Technological
Research Council of Turkey is the second organisation after the US to have
developed and tested a High Power Laser CIWS prototype System which is intended
to be used on the TF-2000 class frigate and on Turkish airborne systems.
See also Active protection system
Metal Storm Armour-piercing discarding sabot
References External links
Spanish CIWS System Meroka