Understanding CIWS and Fire Controls

[liveware (OP)]

So.

Got one of my nice ships blown up by a hostile NPR. Want to minimize this from occurring in the future.

Analyzing my event log, I see that it appears that only one out of my eight CIWS fired upon the incoming enemy missiles which destroyed the ship. NPR was flagged as hostile. Enemy missiles were arranged in 3 salvos of 21 missiles each and 1 salvo of 7 missiles. My ship had zero fire controls and one active grav sensor.

My expectation was that all 8 of my CIWS would fire. It seems that only 1 of my CIWS fired and destroyed 13 missiles in 1 salvo. The rest don't appear to have done anything. UNLESS I am misunderstanding things and ALL of my CIWS fired and just have horrible accuracy. But based on how the even log reads, I would have expected one log entry for each CIWS in this case, but I only have one log entry for one CIWS.

Is this due to a lack of dedicated fire controls or grav sensors? Or am I misunderstanding CIWS targeting?

[Pedroig]

Couple of things:

1.  Your "nice" ships should not have much if any CIWS at all.  They are ok for civilian/commercial ships (cause it keeps them non-military).  But one should not rely on them for true PD, especially alone.  The mantra is LAYERED DEFENSE, AMM's, LR APD, MR APD, SR APD, and CIWS.

2.  CIWS is 2 gauss cannon on a self-contained turret.  So you having 8 meant 16 shots so killing 13/16 is pretty good.  However, they are all considered under 1 FC, and in general their range is not enough to get one shot at a missile salvo.

Now if all those salvos came in the same 5 sec "tic" then they fired once in that "tic" and can't do anything more.

[liveware (OP)]

Couple of things:

1.  Your "nice" ships should not have much if any CIWS at all.  They are ok for civilian/commercial ships (cause it keeps them non-military).  But one should not rely on them for true PD, especially alone.  The mantra is LAYERED DEFENSE, AMM's, LR APD, MR APD, SR APD, and CIWS.

2.  CIWS is 2 gauss cannon on a self-contained turret.  So you having 8 meant 16 shots so killing 13/16 is pretty good.  However, they are all considered under 1 FC, and in general their range is not enough to get one shot at a missile salvo.

Now if all those salvos came in the same 5 sec "tic" then they fired once in that "tic" and can't do anything more.

1. Yes, it was an overpriced survey ship. Learned that lesson the hard way. Defense in depth...

2. So, it would seem better to design gauss turrets and custom fire controls than rely on CIWS as multiple fire controls with multiple gauss turrets could arguably target more salvos.

2*. Yes, it was all within the same 5 sec pulse, so it may not have made much difference anyway. However, in that one 'tick' I only have indication of a single CIWS firing.

[TCD]

Are you sure only one fired? If you destroyed 13 missiles in a tick then you have to have fired at least 13 shots, which sounds like all of the firing to me? I'm pretty sure that Aurora now consolidates weapon fire into a single report line (rather than per weapon) so that may be confusing you.

[SpikeTheHobbitMage]

The rules have changed in C# so you only need one BFC set to PD mode.  Each weapon/turret connected to it will then act as if it had its own PD mode BFC.

[Shadow]

Couple of things:

1.  Your "nice" ships should not have much if any CIWS at all.  They are ok for civilian/commercial ships (cause it keeps them non-military).  But one should not rely on them for true PD, especially alone.  The mantra is LAYERED DEFENSE, AMM's, LR APD, MR APD, SR APD, and CIWS.

2.  CIWS is 2 gauss cannon on a self-contained turret.  So you having 8 meant 16 shots so killing 13/16 is pretty good.  However, they are all considered under 1 FC, and in general their range is not enough to get one shot at a missile salvo.

Now if all those salvos came in the same 5 sec "tic" then they fired once in that "tic" and can't do anything more.

Bit of overkill. This was my old point-defense frigate design from VB6 5.42:

Code: [Select]

Sussex class Frigate    7,800 tons     616 Crew     2244.5 BP      TCS 156  TH 500  EM 600
6410 km/s     Armour 4-35     Shields 20-300     Sensors 36/36/0/0     Damage Control Rating 5     PPV 64
Annual Failure Rate: 97%    IFR: 1.4%    Maint Capacity 899 MSP    Max Repair 216 MSP    Est Time: 2.43 Years

GN-125M5 APOLLO MagCon Fusion Drive (8)    Power 125    Fuel Use 50%    Signature 62.5    Armour 0    Exp 5%
Fuel Capacity 150,000 Litres    Range 69.2 billion km   (125 days at full power)
Theta R300/20 Shields (5)   Total Fuel Cost  100 Litres per day

Rheinmetall R3 Quad Gauss Turret (2x12)    Range 30,000km     TS: 16000 km/s     Power 0-0     RM 3    ROF 5        1 1 1 0 0 0 0 0 0 0
Fire Control S06 90-16000 (2)    Max Range: 180,000 km   TS: 16000 km/s     94 89 83 78 72 67 61 56 50 44

Sentinel 3R19 Missile Defence LADAR (1)     GPS 108     Range 19.4m km    Resolution 1
Artemis ALS 86-20 (1)     GPS 2160     Range 86.9m km    Resolution 20
Hunter PST 2.36 (1)     Sensitivity 36     Detect Sig Strength 1000:  36m km
Hunter PSE 2.36 (1)     Sensitivity 36     Detect Sig Strength 1000:  36m km

ECM 40

This design is classed as a Military Vessel for maintenance purposes
I think I recall experimenting with AMMs on a previous game, but found them too effective. So layered defense would definitely be overkill. I'm not sure how things are in C# (waiting for 1.10 at least), but I wanted some intermediate battle drama, not an all or nothing game. Which is why, I think, I limited myself to projectile-based area defense and CIWS.

[Froggiest1982]

DISCLAIMER: Please note my answers are based to the scenario described and limited to such situation. In any case you should assume my criticism on the single entry to be the rule. In the specific I do believe it is important to have both CIWS and some sort of beam weapons in larger scale conflicts and/or small skirmishes.

Couple of things:

1.  Your "nice" ships should not have much if any CIWS at all.  They are ok for civilian/commercial ships (cause it keeps them non-military).  But one should not rely on them for true PD, especially alone.  The mantra is LAYERED DEFENSE, AMM's, LR APD, MR APD, SR APD, and CIWS.

2.  CIWS is 2 gauss cannon on a self-contained turret.  So you having 8 meant 16 shots so killing 13/16 is pretty good.  However, they are all considered under 1 FC, and in general their range is not enough to get one shot at a missile salvo.

Now if all those salvos came in the same 5 sec "tic" then they fired once in that "tic" and can't do anything more.

1. I disagree. CIWS for a commercial ship is good but you need more protection if there is only one ship (more on the second point). So the layered defence may work for them or big fleets when not all ships can waste tonnage on PD. I think CIWS is more than enough (I use sets of 4x4) in lower mid-tech.

2. You can stack CIWS. Yes, it was very good (bringing the conversation to my next point). The rules in aurora have changed so you can target as many salvos with a CIWS or a PD for instance. The final consideration is your tech VS the tech of your opponent. There are some fights you cannot win and some others that even if you have a better design you may lose because of poor design. And that is with or without CIWS or layered defence.

So.

Got one of my nice ships blown up by a hostile NPR. Want to minimize this from occurring in the future.

Analyzing my event log, I see that it appears that only one out of my eight CIWS fired upon the incoming enemy missiles which destroyed the ship. NPR was flagged as hostile. Enemy missiles were arranged in 3 salvos of 21 missiles each and 1 salvo of 7 missiles. My ship had zero fire controls and one active grav sensor.

My expectation was that all 8 of my CIWS would fire. It seems that only 1 of my CIWS fired and destroyed 13 missiles in 1 salvo. The rest don't appear to have done anything. UNLESS I am misunderstanding things and ALL of my CIWS fired and just have horrible accuracy. But based on how the even log reads, I would have expected one log entry for each CIWS in this case, but I only have one log entry for one CIWS.

Is this due to a lack of dedicated fire controls or grav sensors? Or am I misunderstanding CIWS targeting?

I think the reason you died was simple: 1 ship against enemy multiple ships and or too many batteries to face. If you had 4 destroyers or scouts all equipped with CIWS your enemy would have scattered the salvos between your ships rather than targeting only one. This would have made the salvos manageable for your CIWS (as you saw you could shot 13 just with one).

In my last game, my simple patrol of 1 leader destroyer and 4 missile destroyers all equipped with 5 launchers each and a magazine of 200 missiles could manage to hold off 7 NPR ships with tech just a bit below mine. There were salvos of 8 missiles per ship, probably 10 or 12 of them and not a single hit thanks to my CIWS 4x4 12,000km/s tracking. And that is a tier 3 CIWS, imagine at higher levels.

Now if you were fighting a bigger enemy (say 9 or 10 ships, one of which a carrier) then you would have been in serious trouble because a 2:1 ratio will be hard to manage only with CIWS.

Also if you were facing 24000km/s missiles you definitely would have required some PD to take advantage of the bonus in tracking and be more effective, then maybe calibre your CIWS to a 25,000km/s tracking for the future.

Bottom line, based on your description of the events, another battery of CIWS would suffice to get away of that fight and if you were approaching them, let's say with 3 ships, I wouldn't be worried too much unless they have other surprises waiting for you. Then it would be your call if said ships are meant to explore or to attack.

[liveware (OP)]

Excellent, many interesting points brought up here.

First, I was certainly overwhelmed on a numerical ship to ship basis. My one (scout) ship could not hope to defeat the 8-10 hostiles I stumbled upon, I merely wished to escape. This has led to a reevaluation of my scout design philosophy. Namely, better sensors and higher engine mass efficiency are required for future designs.

Second, it seems likely that all of my CIWS did fire based on what others have said and what I observed. The velocity disparity between my CIWS tracking and the incoming missiles was about 8/35 = 0.22 which is close to my observed accuracy and when taking crew grade and the ship commander bonus into account, is probably spot on for chance to hit.

I'm still on the fence about whether CIWS or customized gauss turrets would be better. Seems like gauss has the potential to outperform CIWS but without rigourous testing on this I'm flying blind in gauss territory, so CIWS is more appealing for now. However with more testing gauss may prove the superior choice.

With my existing missile tech, I don't think AMM will be viable, but I will probably play around with this some more before writing it off entirely.

[orfeusz]

The rules have changed in C# so you only need one BFC set to PD mode.  Each weapon/turret connected to it will then act as if it had its own PD mode BFC.

But will it be able to target multiple salvos? I was under impression that you can attach any number to guns/turrets to one BFC but in PD mode that will mean they all will target only one salvo of incoming missiles. 

[Pedroig]

To try clearing up confusion preexisting and created here.  Let's all make sure we understand what is happening.

1.  CIWS and in fact all PD weapons which are set to Final Defensive Fire (self or not) only engage missiles when they hit (or in the increment they would hit) 10,000 km from the platform.  So they only get to have one firing chance.  This means unless your ships are within 10,000 km (on top of each other as far as the game is concerned) it is very difficult for ships to provide supporting fire to their squadron mates using these settings.  For all practical purposes, they only protect the ship itself.  Area Defensive Fire is superior in every means for ships not travelling alone.

2.  You only see summary information, not individual weapon results.

Therefore, C# Aurora uses a condensed system where you no longer see each individual weapon firing, or the damage from individual hits. Instead weapon fire and any resulting damage are shown in a summary format.

3.  MFC and BFC work differently in PD roles.  MFC targets a single salvo per MFC per 5 seconds, meaning multiple PD-MFC's are required to engage multiple salvos in the same 5 second tic.  BFC's works differently, each gun under a PDBFC can engage a single salvo in the 5 second tic, however the BFC allocates them to the largest, fastest, nearest salvo as determined at the beginning of the 5 second tic, in that order.  So if there are 4 CIWS targeted to defend against 3 salvos of equal size and speed, whichever salvo they choose to fire upon will have to be destroyed before the next unit will target another salvo.  This is done by the gun, not the turret.  So 4 shots per gun versus  a 5 missile salvo will require a minimum of 2 guns firing to destroy the salvo. 

4.  Given the above, and the fact that CIWS is a self contained unit, that means for each CIWS you get 2 guns and a PDBFC, in theory, that means each CIWS could/should engage a different salvo each.  However, that is not the way it works in practice, because the PDBFC's all use the same methodology of targeting, so in essence, they will ALL target the same salvo in order, which means the possibility of overkill per gun ( 4 CIWS is 8 guns, but it would be treated as two sets of 4 each firing ROF each)

5.  CIWS are nice on commercial ships because they are their only weapon option for defense.  On military ships they are last ditch defense, and should not be used in isolation, they are the back-up to your AMM and Area PD defense against leakers.

[DFNewb]

IMO CIWS is good when you have like 1 - 5 ships and making Gauss turrets is better when you can put them on more than just a few ships (or just have a lot on 1 ship) as it protects all the ships while CIWS only protects 1 ship.

[Zincat]

CIWS should really be left for ships operating alone/in pairs at most. Like carriers meant to be FAR away from the main fleet, or lone scouts meant to be spread alone in hot systems and never inside a fleet. And civilians. In any other situations, it's better to have normal PD if you can.

You never know how you might need to divide your fleets, what will happen in a battle, which ships in a fleet you will lose etc. But normal PD, be it gauss or even lasers or railgun, is preferrable because you will usually have moderate to large number of ships in a fleet and the number of PD guns tend to add up.

For a normal military ship, it's safe to assume it will operate inside a fleet most of the time, so CIWS are sub-optimal in using space compared to proper PD set to final defensive fire.

[SpikeTheHobbitMage]

The rules have changed in C# so you only need one BFC set to PD mode.  Each weapon/turret connected to it will then act as if it had its own PD mode BFC.

But will it be able to target multiple salvos? I was under impression that you can attach any number to guns/turrets to one BFC but in PD mode that will mean they all will target only one salvo of incoming missiles.

That was how it worked in VB.  Steve has changed the rules in C#.  Any individual weapon or turret can still only target one incoming salvo, but multiple weapons linked to a single PD mode BFC can now each target a different salvo.

1.  CIWS and in fact all PD weapons which are set to Final Defensive Fire (self or not) only engage missiles when they hit (or in the increment they would hit) 10,000 km from the platform.  So they only get to have one firing chance.  This means unless your ships are within 10,000 km (on top of each other as far as the game is concerned) it is very difficult for ships to provide supporting fire to their squadron mates using these settings.  For all practical purposes, they only protect the ship itself.  Area Defensive Fire is superior in every means for ships not travelling alone.

While FDF(self) only protects the ship it is mounted on, regular FDF protects any ship in the same task force.  It is supposed to protect any ship at the same location whether or not they are part of the same group, but I don't know if that bug has been fixed yet.  The last comment I remember about it was for VB.

ADF attacks any hostile missile within range, regardless of target, but it has never worked well.  It does not fire during the FDF phase, so not only does it take range penalties when it does fire, it can't defend against missiles that are fast enough to cross its firing envelope in a single tick.  It also completely ignores attacking missiles that are marked as neutral.  ADF's multiple attacks are only worth it if you have a major tech advantage, and even then they only apply to the first salvo of a barrage in most cases.

TL;DR Beam PD is very short range to start with and ADF takes range penalties on top of that, so if your task forces are close enough together for them to protect each other at all then you are better off co-locating and using FDF mode.

This is done by the gun, not the turret.

Incorrect.  A turret or CIWS mount counts as a single weapon, so can only attack a single volley.

[SpikeTheHobbitMage]

CIWS should really be left for ships operating alone/in pairs at most. Like carriers meant to be FAR away from the main fleet, or lone scouts meant to be spread alone in hot systems and never inside a fleet. And civilians. In any other situations, it's better to have normal PD if you can.

You never know how you might need to divide your fleets, what will happen in a battle, which ships in a fleet you will lose etc. But normal PD, be it gauss or even lasers or railgun, is preferrable because you will usually have moderate to large number of ships in a fleet and the number of PD guns tend to add up.

For a normal military ship, it's safe to assume it will operate inside a fleet most of the time, so CIWS are sub-optimal in using space compared to proper PD set to final defensive fire.

CIWS are more compact than any PD turret that you can build yourself, and (once the bug is fixed.  1.10?) work even when your sensors are down and during jump-shock, so they may still be worth it on high value warships.

[liveware (OP)]

So it seems to me that there exist two fundamentally different missile defense situations, not counting stationary targets like stations or planets.

First situation is that of a lone ship defending itself long enough to escape. In this situation the ship must reliably defeat as many missile salvos as might be expected given the strategic role of the ship. A scout, for example, would probably be a small and fast ship which should be able to outrun whatever hostile ships it encounters. In this case, the ship would only need to defend against a 'few' missile salvos while it runs away to beyond missile range. In this case I would expect that a CIWS system would be the way to go since there will be no supporting ships to assist with defense. However I would still be interested in doing a side by side CIWS vs gauss turret test for this use case in order to better quantify the differences between these two weapon systems.

Second situation would be that of a group of ships, with the ability to mutually support one another, attempting to close with an enemy in order to destroy it. Here is where I expect that gauss turrets would gain an advantage as a great many ships would be able to support a larger number of turrets, or alternatively a single dedicated missile defense ship could support the rest of the fleet. Obviously it would be important to keep the fleet tightly clustered for this to work, but this would allow for a larger volume of anti missile fire and presumably would be more successful than the lone small ship concept. More ships also means more targets for the enemy to shoot at which could lead to smaller individual salvos directed at each ship which should further improve the success of any antimissile fire.