Ahh! Aliens are real! And hostile! (Help!)

[Shadow]

So far I've used a squadron of seven Sussex-class frigates for anti-missile duties. They're rather old by now, however, and due to be replaced with a more advanced successor in the near future.

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)
GenCore Theta-class R300/20 Barriers (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

You don't need to keep up with their missile speed. Yes, turrets can get big, but put them on dedicated escorts like that and you're golden. 40k-ish km/s seems to be a common speed for Precursor anti-ship missiles, and with 16k km/s tracking (which means 4000 km/s beam fire control tech: not advanced at all), you have an easily achievable maximum accuracy of 40%. Per shot.

Each barrel would fire 4-5 shots (I think mine fired 3, though). Quadruple turrets therefore spit out four times that. So you end up firing, in my modest case, 12 shots per turret. 24 per frigate. 168 total shots in my squadron's case. 168 40% chances. An average of 67 missiles destroyed every five seconds. Forever.

I think one turret can only engage one salvo at a time, but with 14 platforms in my case, it'd be hard to be outnumbered in this regard.

The only time my point-defense bubble was overwhelmed was one time a Precursor AMM PDC engaged my battle group with a considerable number of 60-missile salvos. They were tiny, warhead 1 missiles, but flew at close to 70k km/s (68,700 km/s, I believe). I don't quite remember, but I think at least 15% of every salvo got through, but thankfully didn't cause much damage.

Sure, if those had been larger warheads, I would've been in a pickle. But so far I haven't encountered enemies with such capabilities. But even if I do, the new turrets (and associated FC modules) I've designed have a tracking speed of 32k km/s, and fire 5 shots instead of 3 every five seconds. Not only would they have better accuracy (45%) against hypothetical 70k km/s anti-ship missiles than the old turrets did against 40k km/s ones, but also fire 67% faster, meaning 67% more chances to score hits.

That said, and playing my own devil's advocate, considering you can fit around 20 size-1 AMMs in a single HS (depending on magazine technology), you could potentially have all the AMMs you'll ever need for a single engagment (launchers included) in the space a pair of quad Gauss turrets would otherwise take. With better range and maybe even better accuracy. This would come at the expense of limited ammo and more logistics considerations, of course, but that may or may not be a problem.

I wouldn't mind if it worked like that, because that would mean we have at least two perfectly valid alternatives for anti-missile defense. And multiple balanced options is what makes Aurora grand.


PS: Yes, a layered defense is also possible, but it's a logistics hassle and I've yet to find a threat that warrants the use of such a setup. And besides, such strategy implies compromising each method for the sake of the other, raising the question of whether fully focusing on a single option would've been just as effective. If not more.

EDIT: De-smilified my design.

[Brian Neumann]

Good analysis of the point defense problem.  My 1st choice is to have enough beam weapons to deal with any reasonable salvo size I might be seeing.  I then add a few amm launchers with lots of ammo to thin out big strikes, like those a fighter or gunboat swarm can spit out.  They thin out the combined alpha strike to the point my beam weapons can handle the remainder.  Even if I take some heavy hits, this approach tends to leave me with armour damage and not internals, and my shields rebuild for the next strike.  As long as the shields keep rebuilding they need a lot of extra damage to get through and it works.

Brian

[Ziusudra]

I just copied the design for my AMM ship and replaced all the missile components with two full size quad gauss turrets.

Some other things I noticed in favor of gauss turrets: Max Repair decreased by 58.2%, Est Time increased by 60.6%, Build Points decreased by 13.3%, Build Time decreased by 13.1% and PPV increased by 540%.

[Shadow]

I just copied the design for my AMM ship and replaced all the missile components with two full size quad gauss turrets.

Some other things I noticed in favor of gauss turrets: Max Repair decreased by 58.2%, Est Time increased by 60.6%, Build Points decreased by 13.3%, Build Time decreased by 13.1% and PPV increased by 540%.

Indirectly, you also have to keep in mind the resources saved otherwise spent building AMMs.

Also, theoretically, you could use half-size Gauss cannons on the quad turrets to considerably reduce the size of each emplacement. However, I'm not sure the size-related accuracy reduction comes before or after the cap imposed by tracking speed. If it's calculated before that, then it'd be a negligible disadvantage since base accuracy at point-blank is generally well over 100%. For example, imagine your base accuracy against a 40k km/s missile salvo at 10,000 km is 150%: halved by the half-size cannons is 75%, and capped by, say, 16k km/s tracking speed automatically reduces it to 40%. No actual loss.

Nevertheless, it would be a major issue if the penalty came in after the cap. You'd get a maximum accuracy of 20%.

Good analysis of the point defense problem.  My 1st choice is to have enough beam weapons to deal with any reasonable salvo size I might be seeing.  I then add a few amm launchers with lots of ammo to thin out big strikes, like those a fighter or gunboat swarm can spit out.  They thin out the combined alpha strike to the point my beam weapons can handle the remainder.  Even if I take some heavy hits, this approach tends to leave me with armour damage and not internals, and my shields rebuild for the next strike.  As long as the shields keep rebuilding they need a lot of extra damage to get through and it works.

Brian

Does the AI employ that kind of tactics?

[Brian Neumann]

I have seen npr's use gunboats with box launchers.  I have never seen them use fighters.  Gunboats (FAC's) have the advantage of range and they can pack in a lot of launchers.  Fighters can have even more launchers, but are usually much shorter ranged.

Brian

[Rastaman]

Indirectly, you also have to keep in mind the resources saved otherwise spent building AMMs.

On the other hand, you need to research a whole other line of technologies, while AMMs are just undersized ASMs. So if you're missile-heavy anyway, a turret PD is expensive in that regard.

[Ziusudra]

Nevertheless, it would be a major issue if the penalty came in after the cap. You'd get a maximum accuracy of 20%.

From looking at my logs, for the CIWS the base of 50% is modified by crew grade then tracking speed.

On the other hand, you need to research a whole other line of technologies, while AMMs are just undersized ASMs. So if you're missile-heavy anyway, a turret PD is expensive in that regard.

Absolutely. I wouldn't say one is inherently better. Starting tech, resources and scientists are all factors that could sway to one or the other ... or both.

On the other other hand, for missiles you've got all the missile, launcher and magazine techs in MK and all the drive, power and fuel techs in PP. For the gauss cannons, all you really need is turret tracking in EW, gauss cannon rate of fire in MK and fire control tracking speed in SF.

[dooots]

You also need some of the beam fire control range or else you only have a 50% chance to hit without increasing the size of the fire control.  You will also most likely want another weapon for anti-ship purposes and you may want another weapon for attacking planets.

At early techs missiles are the only weapon that can do all three.

[Giggle]

In my first campaign, I encountered an alien race which was using heavily armored missiles.

My gauss huns were overwhelmed because the missiles were fast (80K kms), but the main issue was that these incoming missiles were too tough for the damage of gauss guns which are always 1.
I don't know the mechanics of damage / missile armor, so I tried to boost the warhead of my AMMs, the result was not impressive, but at least it worked a little where the gauss guns were completly useless.

So I would say that gauss guns are effective, but sometimes, 1 damage is not enough.

[Charlie Beeler]

In my first campaign, I encountered an alien race which was using heavily armored missiles.

My gauss huns were overwhelmed because the missiles were fast (80K kms), but the main issue was that these incoming missiles were too tough for the damage of gauss guns which are always 1.
I don't know the mechanics of damage / missile armor, so I tried to boost the warhead of my AMMs, the result was not impressive, but at least it worked a little where the gauss guns were completly useless.

So I would say that gauss guns are effective, but sometimes, 1 damage is not enough.

Based on those stats I'd venture a guess that you faced Invader Plasma Torpedoes not missiles. 

[chrislocke2000]

What are the tech levels you were using to build the guns and associated fire controls and turrets in the frigate? Would be interested to know how much effort it would be for me to get some similar ships to those in my fleets.

Went up against a couple of 15k ton AMM beast NPRs last night with pretty dire consequences. Am 15 years into the game with a std staert and 500m pop. Had 8*8k anti ship missile ships, 12*6k anti ship missile ships, 6*6 AMM ships plus 6*6k jump ships with sensors and 2*8k jump ships with sensors (I hate the idea of ferrying ships back and forth across JPs so just role play that you can't do - squadron jumps all the way!).

From a previous visit to the system I knew there were 5 NPRs sat in orbit at one planet and their AMMs were more than capable of defeating my previous waves of 72 missiles but some of the AMM ships would move to another moon to presumably reload once they had fired odd some stocks of missiles. This time roun therefore I sat my fleet on an intercept point between the planet and the moon and fired off a small salvo to try and get the two AMM hostiles to break from the planet and the mutual support they were getting from the other ship.

Once away I fired off some full salvos to engage the hostiles. Salvos were now at 136 missiles but these were still going down to just 4 or 5 hits per salvo with the hostiles coming straight at me.

Was feeling comfortable that I would be able to wear them down before they could restock when I get hostile missiles detected - waves of 43 size 1 missiles doing over 40k whislt the hostile ships was still about 25 mil from my position which gave their AMMs some 5 times the range of mine! My own AMMs went into action but even with a 3-1 fire rate and several goes 15 or so missiles were getting through - thank god they were only strength 1 warheads. Things seemed to be going ok for the first few rounds but then my AMMS got behind on the sucessive waves which meant that between targetting and launching my own AMMS the hostile missiles were closing and hitting their targets beofre mine could actually intercept which left my ships taking 43 volley hits every ten seconds or so. My jump ships have more armour then my missile ships so were weathering the storm slightly better but I soon had a stream of heavily damaged 8k missile ships dragging behind the fleet and several that were destroyed out right.

Thankfully I think the NPR that was in the lead had expended almost all of its AMMs on my ships as when my own ASMs finally reached them there was little defensive fire and they finally bit the dust. With 4 more volleys of hostile AMMS incomming to my own fleet it wasn't a moment too soon!

The fleet is now limping back home with repairs ongoing but with serious damage to many and with large numbers of the heavy ships having basically no armour left. Now all I have to do is work out how to try and take on the last three NPRs....

I guess one question on this is would the above tech gaus cannons actually have helped given that the hostile missles moved at just over 200k km per increment and were therefore moving from outside target range to hit in one step?

[Narmio]

Well, turrets in Final Fire mode would always get one shot off just before impact, so there's no chance of them not firing because the incoming missiles were too fast.  The problem is that against waves of 43 missiles it's next to impossible to have enough turrets to pop them all.

[Charlie Beeler]

since base accuracy at point-blank is generally well over 100%

If you’re talking about beam fire control this is blatantly false.  The best I've ever seen is 99% before modifiers.  

Let's face it, it's all about overwhelming the defenses.  The average NPR missile destroyer is packing at least 10 offensive launchers.  Average anti-ship missile speed, that I've been facing since v5.0 came out, is 40k kps.  

Let's use the above Sussex.  The fire control and turret are matched is tracking speed (Good) at 16K kps (not so good) with a 10k accuracy of 94% (Good).  2 turrets of 12 rounds each (Good) and 2 fire controls (Good).  Against 16k/kps missiles this is more than adequate (11 out of 12 hits).  But against 40k/kps the percentage is adjusted to 37.6% (94% * (16k/40k)) that’s only 4 hits per turret.

But there are 7 frigates in the TG!  You’re also facing 4 or more ships throwing missiles at you.  In theory those 7 FG’s should intercept 56 40k/kps missiles.  If the NPR has 2 more ships that’s at least 4 leakers.  At this point it’s nominally acceptable.  I’ve faced NPR’s who’s missiles are 50-60k/kps and that is where having the ability to thin the incoming salvos becomes necessary.

Against AMM’s this gets much worse.  They start at 50k/kps, and I’ve faced 70k/kps, which drops  the intercepts to 30% vs 50k/kps (per turret intercept of 3 missiles) and 21.5% vs 70k/kps (per turret intercept of 2 missiles).  

Reduced size gauss cannons are not a good idea in this environment.  That half size 50% cannon would mean that starting base 94% is a base 47% which then works out to 18.8% against 40k/kps missiles.  

These figures are before crew grade modifiers are applied.  

There is something that can help.  Max Tracking Time Bonus vs Missiles.  The percentage researched it the best offset vs speed penalty.  If I recall correctly, this is in 4% increments per 5 seconds of tracking on active sensors.  


Before facing NPR's I use my own missile ships as a benchmark.  Your own Percival with salvos of 12 missiles at 70k/kps (wh16) will overwelm your Sussex.  The Bellerophon's alphastrike of 20 50k/kps (wh100!!) would not even be a contest.

Yes, you can pack A high density of turrets to offset the lack of ranged intercept.  But it does come at a cost vs offensive ability.  

A program of requiring at least a single PD turret, and basic fire control, (not CIWS) on each combat ship for mutual defense and escorts with a quad turret (also for mutual defense) and suites of 5 AMM (w missile fire control) for area defense works in practice better than depending on turret only escort for fleet defense.

Yes, this is just my opinion.

[Shadow]

If you’re talking about beam fire control this is blatantly false.  The best I've ever seen is 99% before modifiers.  

I apologize. I was quite imprecise there. By base accuracy I meant the combined accuracy you get before it's chopped by the tracking speed limitation. That means a base of 94%, in my case, plus the crew rating bonus and possibly other things that push it over 100%. I'm guessing the tracking time bonus (I've invested some research on that) applies at some point, but I'm not sure where.

Now, a couple of things.

I did mention the Sussex class is reasonably old by now, and due for replacement by a future frigate with 5-shot (+67%) quad turrets and 32,000 km/s tracking speed. The Percivals are a different, newer generation of warships, so they've expectedly better performance than the older escort frigates. That said, admittedly I haven't really gauged against my own vessels, but rather those of my most common enemy: Precursors. They have good tech but aren't really numerous. I know there's technically NPRs out there, but unfortunately I haven't encountered them yet, 39 years into the game and 50-ish systems explored (out of 1000).

If I encounter aliens with technology such as what you described, I'll likely expedite the upgrade of my current escort frigates and probably build at least six more (having refitted the seven Sussex). Yes, that will naturally come at a cost, but I doubt it'll put a meaningful dent in my offensive ability. If the enemy is all about missiles, if you have a solid AM shield, you have all the time in the world to blast them to bits. And those that try to flee would be promptly run down by my Rheinland-class strike cruisers.

I'll likely be trying out your proposed single Gauss turrets sometime soon, since they do look superior than the CIWS alternative. However, while I do believe your fleet defense setup is probably just as effective as mine, it's very hard to determine, all things considered, whether the former's measurably better than the latter.

Fun Facts

• During their debut, I found out my Rheinlands can provide surprisingly effective long range (for direct fire weapons) area defense with their main railguns. They're obviously less efficient than dedicated Gauss turrets, but they thin out salvos quite nicely. Nonetheless, they do need to stay within the bubble of the escort frigates' resolution-1 sensors to be able to actually target (not to mention see) the incoming warheads. I might put them through a sensor refit soon, because of this.
• The primary mission of the Bellerophon-class stealth missile frigates is to slay their Chimeras: they are proven Star Swarm hiveship killers. While they can be employed against more common foes, that would likely result in wasteful overkill. A successor of the huge SLM-190 Excalibur would have integrated sensors, and that may make large salvos of them whole fleet killers.