Modern CIWS & Anti-Missile Systems (Deployed and in development)

Jeff Head

General
Registered Member
We'll have to see but the present guns weak link isn't velocity of the projectiles itself, it's the aiming mechanism moving the gun barrel towards the projectile and maintaining an intercept vector.

If ASM goes high supersonic then the definition of Close in Weapon System would need to be changed in which the distance be more than 10 Kilometers since a Mach 3~4 incoming missile would reach it's target within 10 seconds even at that range.
Rail guns will move projectile CIWS well out beyond what it is now...basically line of sight to the horizon as seen from the sensors and at whatever altitude.
 

thunderchief

Senior Member
Re: PLAN Type 054 FFG Thread II

Ok I buy the speed argument, but this one has me still wondering. What do you mean by a "wider kill zone" for a gun CIWS? Dispersion of the rounds? I somehow doubt if that is considerably bigger then the blast/frag volume of a warhead. (I guess it could be, but I never saw a CIWS gun wobbling around to dispers the rounds)

Usual Phalanx engagement time (duration of burst) is somewhere around 2 sec, i.e. 150 rounds. Every machine gun has certain dispersion, it is design parameter. For example German MG-42 was considered better then Bren LMG because it had somewhat greater dispersion. Of course, it must not be to great either. For the Phalanx, it is calculated to form a "net" at usual distances with maximum hit probability . Btw, even one heavy round from Phalanx should be enough to make AShM un-aerodynamic and force it to crash .

Also, essentially you're making a shorter range a general advantage of air/missile defense systems, I'm not sure I buy that either. That way ESSM / HQ-16 are even less effective as RAM / FN-3000. I'd rather have an incoming AShM blow up 3.000m away than 1.000m. Partly because greater range offers a little more time for reattack.

Not a shorter range per se, but less prediction uncertainty where would our interceptor (CIWS round or a missile like RAM) would have to go . In that sense, laser would be ideal because it travels at the speed of light so you could just point it at the incoming AShM . But lasers have other properties that make them unsuitable for the task . So far rail guns show greatest potential for this kind of application .


Additionally, since IR guided missiles continously update intercept geometry that 2 to 3 seconds ahead doesn't make sense to me. The pseudo solution would be to fire RAM at shorter range to mitigate, which doesn't make sense.
At some point though, RAM will also be at the "half a second before impact" point and after that even closer, so in your logic in the end-game a missile CIWS will be more accurate than a gun CIWS.

Imagine AShM making 90 degrees turn at supersonic speed (like Klub AShM does) . With simple proportional navigation IR missile would suddenly need to make even harder and sharper turn , loosing speed and precious time . Klub could make maneuvers up to 10 g , and that would force RAM to go up to 30-50 g in order to stay on intercept course . I don't know what is max g of RAM, but even if it could execute such maneuver it would lack speed and time to catch up with Klub again

I'm fairly certain RAM, just like so many other missiles, never calculates the distance to it's target in mid-flight as it just doesn't need to. Being developed from an AIM-9 I guess it will use a laser operated proximity fuse to explode into the flight path of it's target.

Without information about distance things get even harder . With command guidance you could change direction of RAM as soon as you notice target changing course. With IR proportional navigation you would notice significant change of target's direction only at the end of its maneuver .
 

thunderchief

Senior Member
Gun type CIWS will become less relevant as ASM becomes faster in speed preventing the CIWS to respond to fire more then a few rounds in which the incoming missile would be ramming into the ship as a fire ball due to inertia.
At Mach 3~4 ASM covers a Kilometer in less then 1 second. Even if you get 75 rounds in that time the actuators moving the guns will not respond fast enough to maintain aim.

By the way Super sonic ASM doesn't do much evasive maneuvers like AAM due to it's much heavier payload so it will come in mostly in a straight line at terminal stage.


There are various types of supersonic missiles, and various attack profiles for same missile type . Missiles traveling at 3+ Mach usually dive on their target and they would be attacked by longer ranged SAMs first . Biggest threat are somewhat slower (around 2 Mach) but low flying maneuverable missiles that could make wild turns almost like larger AAM (AIM-54, R-33 and similar )
 

Scratch

Captain
Usual Phalanx engagement time (duration of burst) is somewhere around 2 sec, i.e. 150 rounds. Every machine gun has certain dispersion, it is design parameter. For example German MG-42 was considered better then Bren LMG because it had somewhat greater dispersion. Of course, it must not be to great either. For the Phalanx, it is calculated to form a "net" at usual distances with maximum hit probability . Btw, even one heavy round from Phalanx should be enough to make AShM un-aerodynamic and force it to crash.

Certainly every gun has a dispersion. The CIWS gun, however, is the M61 that was originally designed for fighter aircraft with an emphasis on air-air engagement. As such, it already has a low dispersion by design, for point accuracy (a fighter sized aircraft at 2.000-6.000ft distance) was required. That is it's weakness in air-ground engagements, it's so accurate that it effects only a very small area on the ground.
The latest Block 1B upgrade, among other things, sees use of a refined gun barrel with even tighter dispersion to provide greater first hit distance.

Not a shorter range per se, but less prediction uncertainty where would our interceptor (CIWS round or a missile like RAM) would have to go . In that sense, laser would be ideal because it travels at the speed of light so you could just point it at the incoming AShM . But lasers have other properties that make them unsuitable for the task . So far rail guns show greatest potential for this kind of application .

The point here is that a gun CIWS, at the time of the projetile leaving the barrel, will need to know exactly were the intercept will occur, because the bullets cannot update/manceuver in flight.
A guided missile does not need to know, it does update the calculation in flight. As such it simply doesn't matter if there's more time between launch and intercept. A higer prediction uncertainty doesn't matter then, because it is lowered in flight by the updating calculations of the missile.

Imagine AShM making 90 degrees turn at supersonic speed (like Klub AShM does) . With simple proportional navigation IR missile would suddenly need to make even harder and sharper turn , loosing speed and precious time . Klub could make maneuvers up to 10 g , and that would force RAM to go up to 30-50 g in order to stay on intercept course . I don't know what is max g of RAM, but even if it could execute such maneuver it would lack speed and time to catch up with Klub again

The problem of intercepting missiles having to make much tighter turns than their targets has been existing for a long time now, and it is the same for every missile there is, no matter what it's guidance mode. Older Sidewinders are said to be capable of 20-30g I think.
I also believe people overestimate the size of the maneuver such AShMs make. After a 90° turn, it points away from the targeted ship and will then need to make 100+° turn to come back. And there's the problem of the seeker loosing lock.
If RAM is capable of executing such a maneuver, which naturally is a design requirement, it'll maneuver to the intercept point and not fall in a chase. As such, it will never fall in the position of having to catch up. Especially since in the endgame the AShM will have to go towards the ship. Othersise all the maneuvering is useless.

Additionally, modern seekers are so sensitive about small changes in relative movement, they're hardly lacking compared to a radar tracking the target.
 
Re: PLAN Type 054 FFG Thread II

Usual Phalanx engagement time (duration of burst) is somewhere around 2 sec, i.e. 150 rounds. Every machine gun has certain dispersion, it is design parameter. For example German MG-42 was considered better then Bren LMG because it had somewhat greater dispersion. Of course, it must not be to great either. For the Phalanx, it is calculated to form a "net" at usual distances with maximum hit probability ...

so, this dispersion of a CIWS gun, can like work to the advantage of defenders?? but let me quote wiki on
Please, Log in or Register to view URLs content!
(which the Goalkeeper uses)
The GAU-8/A accuracy when installed in the A-10 is rated at "5 mil, 80 percent", meaning that 80 percent of rounds fired will hit within a cone with an angle of five-milliradians. ... By comparison, the M61 has an 8-milliradian dispersion.
this seems to praise lower dispersion ...
 
...



The problem of intercepting missiles having to make much tighter turns than their targets has been existing for a long time now, and it is the same for every missile there is, no matter what it's guidance mode. Older Sidewinders are said to be capable of 20-30g I think.
...

now I used google to search for maximal g an AAM can pull, found this interesting article:
Please, Log in or Register to view URLs content!

(I mean interesting for me :) maybe you know all what's inside ...)
 

thunderchief

Senior Member
Dispersal patterns of Phalanx and Goalkeeper are certainly not the same as on M-61 or GAU-8, as they have different roles . Check this, for example

The current methods for producing dispersion are random movement of the gun barrel or unparallel gun barrels on a gatling gun, A target will have varying optimum dispersion patterns depending on size, distance, and speed. What is needed then, is a method of dispersion that is accurate, can be varied for individual targets, and is easy to produce. A true optimum dispersion pattern could then achieve a greater hit probability.

Please, Log in or Register to view URLs content!
 
Dispersal patterns of Phalanx and Goalkeeper are certainly not the same as on M-61 or GAU-8, as they have different roles . Check this, for example



Please, Log in or Register to view URLs content!

thanks, but it's kinda long :) so your point is the dispersion of the gun used on a CIWS is higher (as compared to the same gun mounted on for example an infantry fighting vehicle), which is beneficial while shooting at the incoming ASuM?
 

thunderchief

Senior Member
A guided missile does not need to know, it does update the calculation in flight. As such it simply doesn't matter if there's more time between launch and intercept. A higer prediction uncertainty doesn't matter then, because it is lowered in flight by the updating calculations of the missile.

Yes it does, because missiles don't have infinite time or energy for intercept . Read the link that Jura posted, and you would understand that AAM missiles need to pull much more g then target , loosing energy in process . And AShM like Klub doesn't have pilot inside who could pass out , therefore it could perform pretty sharp maneuvers .


I also believe people overestimate the size of the maneuver such AShMs make. After a 90° turn, it points away from the targeted ship and will then need to make 100+° turn to come back. And there's the problem of the seeker loosing lock.

AShMs usually target group of ships, and modern ones are capable of prioritizing between targets . They would have relative position and speed of vessels in the group memorized and approach pattern pre-programmed with various zig-zag maneuvers in 3 dimensions . In such scenario, defender has hard time distinguishing real target (ship to the left, ship to the right or me :D )
 
Last edited:

thunderchief

Senior Member
thanks, but it's kinda long :) so your point is the dispersion of the gun used on a CIWS is higher (as compared to the same gun mounted on for example an infantry fighting vehicle), which is beneficial while shooting at the incoming ASuM?

Point is , it's the same gun but tweaked for different purpose and with different firing pattern . Fires at the same spot but there is delay in shells arriving , creating curtain of rounds .
 
Top