Math on CIWS

[TheDeadlyShoe (OP)]

I think CIWS are way too weak for their space cost.

I'm using Composite Armor and a CIWS of comparable (if not better) technology: ROF3, tracking 16000.  I'm designing an assault transport (->combat drop pods, tough) and I wanted to strap on some CIWS for survivability. But they didn't really seem to work.  I did some math to back up my feeling.

Composite Armor gives me 8 points of protection per HS, and my CIWS is 8.5 HS.  So the value of a CIWS in armor is 68.    Assume that 50% of armor is useless due to armor penetration and you get 34.  (Note: this assumes the enemy is not using ultra high damage weapons that can penetrate the armor in one go - they are not however, and missiles don't have the pattern for it.)  So my CIWS has to intercept 34 points of damage in order to reach parity with armor against missiles. (Nevermind other weapons.)   It fires 6 shots, at 50% accuracy against tracking speed 16000.  The missiles im using run at 30k and my enemies at 22-28k.  So figure an average accuracy of about 32%, or 2 hits per salvo. 4-5 damage per missile that means my assault transport has to survive 3-4 missile salvos for the CIWS to reach parity..!!  even against 9 damage missiles it needs to live through at least 2 salvos. There's no way that is viable for me.  It's the first salvo i am most concerned with  Against AMM spam, which i've been having problems with, forget it.  Armor useabilty jumps way up and theyre 1 damage warheads and the hit rate goes down.

This all leaves aside that armor is good against everything but mesons.  And this is with what I feel are quite generous assumptions.  The main benefit of CIWS seems to be that you can put it on civilian ships; any military formation needs group Final Defensive Fire far more than it needs individual defense.    And regular gauss cannons can double as weapons.

I do like the concept of integrated systems like the CIWS and wish I could use it on more things. 

Is it just the tech levels i am looking at? Does CIWS get better compared to armor later? Or perhaps something is wrong with my assumptions/math.

edit - math oops

[blue emu]

One minor point... your ship's crew Grade Bonus applies with CIWS but not with Armor.

That won't change the numbers too much, of course.

[TheDeadlyShoe (OP)]

That is a good point, I was a little hesitant to bring that up though since I figured it canceled out strategically.  Staffing a troop transport consumes a lot of academy graduates if its just for the CIWS. And the -10% from conscripts would be... not helpful.

[Hawkeye]

Quite clearly, the longer the CIWS can fire, the better it gets. Therefore, your assault transport should have both armor _and_ CIWS

Give it 12 to 15 levels of armor and put a dozen CIWS on. Then test how long it lives compared to one with a few levels of armor more, but without CIWS.
Against the AMMs, it might not work too good, but agains regular ASMs I´ll take the CIWS variant any day.

[TheDeadlyShoe (OP)]

@Hawkeye - IMO, The breakeven is just way too far in for the hullspace. That was the point of my math.  CIWS vs Armor is at best arguable, even just looking at missiles.  CIWS is better in the single case of facing a trickle of incoming ASMs... that your CIWS can actually hit. That is, if you've invested in Gauss technology equivalently with your other tech, and researched uptodate CIWS. Armor is better against heavy salvos and against AMMs and requires no additional research (as armor is pretty mandatory).

Maybe if large missiles were more prevalent CIWS would be more effective but missile design pretty much seems to favor smaller missiles.    Big missiles dont have the density to penetrate an adequate anti-missile screen.

And an assault transport must by definition close to point blank and there is always the risk of beam weapons in that scenario.  So you definitely want armor on an assault transport.  (Active defence can be provided by the battlefleet.) 

So CIWS nogood on my assault transport, it's no good on battlefleets because they want linked defence... what's it for?

12-15 levels of armor and a dozen CIWS would be like, a divisional transport? Noway it fits on my 2030 brigade transport. I guess we're looking at the situation of CIWS being good if you use single gigantic ships.   Hmmm... I just checked it out. 35000 tons for a viable divisional transport. It looks pretty sweet.  Noway I can build it tho. xD

[Hawkeye]

Don´t misunderstand me, I´m by no means arguing for CIWS, because, as you said, it _is_ a weapon for special circumstances. I like to put one or two on my "military" freighters, more for roleplay reasons than for anything else (like the armed freighters in WW2), and my troop transports get a bunch of them (also mostely for rolplaying reasons, as I am a firm beliver in the "Clear the system of any hostiles, _then_ bring in the troops" doctrine) and that´s it.
Oh, and they work inside an atmosphere, so they are good for PDCs also. Of course, the lack of integrated PD bites them in the ass there.

Maybe they _are_ too large for their effect, but the thing is, they use the same mechanics as pretty much _all_ weapons in aurora, no special rules for anything. AFAIK, this was one of Steve´s major goals. If the CIWS turns out not to be all too efficient, well, tough luck.

re. your divison transport:
Are you using a military design? I allway use comercial troop haulers (24 battalions) and military dropships (6 battalions) in concert.
realy makes it easier to build those 45.000 ton troop transports, if they are comercial.

[Andrew]

The advantage of CIWS is that it can be mounted on commercial troop transports , which cannot mount Gauss turrets to contribute to fleet defense as my commercial troop transports are rather large this is useful as they can draw fire if my fleet missed some warships

[Marc420]

The CIWS has already been modified from base Guass Cannon stats.  I'm at early tech levels, but here's what I see when I compare the two.

The CIWS has a range of 1000.  By gauss cannons have a range of 20,000
The CIWS is a twin guass cannon unit at size at size 9.4, HTK of 3, ROF of 5 seconds, and fires 4 projectiles from the dual gc's at that time.
A twin guass cannon turret of the same 12,000 km/s tracking speed would have a size of 18.84, a HTK of 4 (with no armor added), an ROF of 5 seconds and fires 4 shots.
    -- plus I need a size 4 FC to get the same 12,000 km/s tracking speed.  That's using the GC-100's that I have researched as a comparision.

I don't have a current GC-50 design to compare to, but that seems to be the equivalent of the CIWS, in that the CIWS is about half the size of my GC-100 turret, but has 50% accuracy at the close range of 1000 km where my fire-controls would be much closer to 100% accuracy at that near-zero range.  So, the main modification to the CIWS system over a GC is in the range.

If the CIWS seems out of balance, then other stats on the CIWS could be modified to compensate while keeping with the same combat mechanics.  I'm thinking primarily of the number of shots fired per volley.  If the CIWS is designed specially to throw a lot of metal up in short range, last-ditch fire against missile, then I could easily see that the GC's would be modified to provide more shots per volley.  Maybe as a default the CIWS gets 6 or 8 shots from its Dual GCs (instead of the default 4) since they are specially designed for this sort of short-range, quick-burst firing.  This could also be another line of Technology to research.  Since this research would apply only to CIWS and not to all GC's, then the player would then have the option to spend the effort to increase the amount of shots the CIWS could throw up.

Generally, there seems to be an issue with a player's idea as to what this system is.  In the current game, a CIWS is a kit-type solution that you can mount on commercial vessels to get some point defense there.  I think in a lot of people's minds, what they are expecting is the sort of military, last-ditch missile defense like the systems (Phalanx??) that the USN currently uses on its ships.  Allowing research in specific CIWS areas like the volume of fire might allow players to create the sort of system they are imagining that the CIWS is.

[Brian Neumann]

The other major difference between the standard gauss cannon and the ciws system is that the ciws has an active sensor built in also.  It is a very short ranged active sensor but it does give you the ability to see those missiles before they hit and get your pd shots against them.  This does give you an option also for the rest of your beam weapons.  Currently you can only turn on/off all of the active sensors on a ship together.  If you have mutliple active sensors you tend to have at least one that has a fairly big signature.  The ciws active is independant of this so you could have your entire fleet with their actives turned off and still be able to engage at beam weapons ranges, or fire in final defensive fire mode against incomming missiles.  The down side is of course that even when you tell your ships to turn their active sensors off you will still have a small active signature from the ciws systems.  It is however small enough that by the time most passives could spot it you would already be at beam weapons range.

Brian

[Deoxy]

The main use I've found for CIWS is the ability to put them on civilian ships.

It's been a while since I played, actually, but the last game I was playing, I built a "brick" to lead with: a commercial ship with nothing but engines, lots of armor, and a good bit of CIWS.  Since it was so big, it drew LOTS of attention from the AI, soaking up huge volumes of missile fire.  My military ships trailed a bit behind (matching speed), using it as a shield.

Relatively cheap, this "brick" could withstand enormous punishment on the cheap, then swap out with its twin and go home for repairs - the cost of repairing the armor was far less than all the missiles it absorbed, much less what the losses that could have been from all of those missiles.

[Erik L]

I still believe that any ship classed "cruiser" or higher should mount one. And definitely on battleships or bigger. Yes, I know that's what escorts are for, but if the escorts miss, then it's nice to have something with a chance to swat the bandit down.

One nice thing about Aurora, there is no "right" way to play

[UnLimiTeD]

Had to chip in in this old thread.
While no right way, there's definitely the most efficient ways. 
I'm pretty certain after some tests where I got hitrates above 100% and below 0% that both ecm and crewgrade aplly somewhat clunky to weapons with a base hit chance modifier.
Someone will have to test it, but it might actually be additive.
So long as the enemy missiles don't have more ecm than you have eccm mounting a lot of small ones with an experienced crew might give an over-proportional benefit.
as for large ships, I'd expect one to just mount a single gauss turret instead of a ciws, if you have more than 2 ships, it might pay off.

[Peter Rhodan]

My 2 cents worth
I abandoned CIWS in this campaign as I decided it lacked flexibility. My 12kT Frigates mount proper guass turrets which have a much greater range and can also be used as area defence and to mop up disabled enemy ships and thus save on missiles. And in the last resort the can be used to directly combat enemy vessels when all your missiles have run out. (Had a clsssic case of rushing off to battle with some 30k battleshps which I forgot to check their missile loads before arriving int the battle zone - derrrr!!!! Fortunately the enemy were only few precursor ships which I had enough AMMs onboard which with my guass turrets enabled me to prevent serious damage from their missile attacks and when we closed my shields absorbed their lasers until my quad guass turrets shredded them)
As to arming civilian ships - I haven't worried this time around yet as I have no conflicts except Precursors and Swarm  - I keep thinking about arming my survey ships but haven't got around to it - A CIWS takes a lot of space on a 6kT survey ship.....

[Brian Neumann]

I use ciws systems on only a couple of types of ships.  The biggest use is for civilian ships that are going into hostile systems.  By this I meen ships that I build that have the "commercial" no maintenance required stamp.  I use these as resuply/refuel, ect type ships.  I want to have some limited point defense on them so they are not helpless.  By putting 2-3 ciws on a tanker and giving it a armor value of 5+ it makes the ship far harder to kill.  This really makes a difference when the original target of a missile salvo is destroyed and the missiles have their own sensors.  They tend to go for the biggest target in sight which is almost always going to be a civilian ship. 

The second type of ship that I mount the ciws on are really high value military ships that don't already have any beam point defense.  This would include carriers, battleship missile boats, and my big sensor equipped scouts.  All three tend to be major targets, especially the sensor ship as it will have really huge active sensors (res 100 size 30-50).  All of these ships are usually operating without more than 1 other of the same size in a fleet so they are almost always the primary targets.  By using the ciws systems I give them more point defense without loading them down with a heavy energy battery.

Brian