Gauss Cannon

[Steve Walmsley (OP)]

I am introducing a new weapon to v2.6 called the Gauss Cannon. I still might fiddle with the stats a little but the weapon will be essentially as described below.

A Gauss Cannon, sometimes referred to a Coilgun, is a type of projectile accelerator that uses one or more electromagnetic coils to accelerate a magnetic projectile to high velocity. Gauss Cannon consist of one or more coils arranged along the barrel that are switched in sequence so as to ensure that the projectile is accelerated quickly along the barrel via magnetic forces. Although the damage from a single hit is limited (strength-1 hit), it can fire more rapidly than any other weapon except a railgun, and can even exceed the railgun's rate of fire on more advanced models.

There are three key pieces of technology involved in the creation of a Gauss Cannon. The first is the Rate of Fire, which determines how many projectiles can be fired in a 5 second period. A very basic Gauss Cannon has a rate of fire of one but models with a rate of fire of up to six projectiles per 5 second increment are possible. The second is the Launch Velocity. A basic Gauss Cannon only has a range of about 10,000 kilometers. With greater launch velocities this can be extended to as much as 60,000 kilometers. Finally, the size of the Gauss Cannon installation, which has a considerable impact on its accuracy. A full size installation of 300 tons (12 HS) has many highly adjustable coils that can react very quickly to translate information from an associated fire control system into adjustments in the speed and direction of its projectiles. Smaller versions of the Gauss Cannon are easy to construct but they become progressively less accurate due to fewer and smaller coils. The smallest version, at one twelfth normal size (0.5 HS) has just 8% of normal accuracy.

While the smaller, low accuracy versions of the Gauss Cannon are unlikely to be of much use on board full-size ships, they are useful for fighters that lack any other weapon of comparable size. Even their low chance to hit will eventually cause damage in an extended dogfight and it gives them a lightweight "beam" weapon capable of damaging thin-skinned ships and FACs.

Because the Gauss Cannon requires very little power to operate, the required power generation is built into the installation, removing any reliance on separate power reactors.

Throughout the fighter thread and during the design of this weapon system, I was concerned about creating something that would be a better anti-missile system than the 10cm laser. Eventually I decided that I would just let it happen because the weapon also has disadvantages over the laser in other ways. Lets compare a 10cm C3 Ultraviolet Laser to a 5 HS Gauss Cannon of comparable technology. Because they are different sizes, I'll match three lasers (9HS) and 2-3HS of reactor power against two gauss cannon.

10cm C3 Ultraviolet Laser
Damage Output 3     Rate of Fire: 5 seconds     Range Modifier: 4
Max Range 120,000 km     Laser Size: 3    Laser HTK: 1
Power Requirement: 3    Power Recharge per 5 Secs: 3
Cost: 20    Crew: 30

Gauss Cannon R3-100
Damage Output 1     Rate of Fire: 3 shots every 5 seconds   Range Modifier: 3
Max Range 30,000 km     Size: 6    HTK: 1
Cost: 36    Crew: 24

The three lasers will get 3 shots compared to the 6 shots of the two gauss cannon. On the surface this makes the gauss cannon appear to be twice as good. However, the lasers are also a very effective anti-ship weapon at close range while the gauss cannon are useless against a ship with even 1 point of armour. In addition, the lasers potentially have a range four times that of the gauss cannon so they may well get two shots at incomining missiles, albeit at much lower chance to hit, and they can be used in area point defence mode and against fighters at much longer ranges. Finally, investments in laser tech can be used for a variety of both offensive and defensive weapons while gauss technology is essentially for close-range missile defense and fighter weapons. Therefore I think the advantages and disadvantages cancel each other out reasonably well.

That said, I do think the potential for missile defence overall has been raised so given the concerns John has raised in the Fighter thread I am considering upping missile engine power by 25% to compensate for both the new fighter rules and the introduction of gauss cannon. I am open to comments on that idea though before I go ahead with it.

Steve

[Haegan2005]

Isn't this a lower power railgun?

[Steve Walmsley (OP)]

Isn't this a lower power railgun?

A little different. Quoting from Wiki...

A Gauss gun is a type of projectile accelerator that uses one or more electromagnetic coils to accelerate a magnetic projectile to high velocity. Gauss guns accelerate the projectile using contactless means. Gauss guns consist of one or more coils arranged along the barrel that are switched in sequence so as to ensure that the projectile is accelerated quickly along the barrel via magnetic forces.

A railgun is a form of purely electrical gun that accelerates a conductive projectile along a pair of metal rails. Railguns use two sliding contacts that permit a large electric current to pass through the projectile. This current interacts with the strong magnetic fields generated by the rails and this accelerates the projectile.

I don't mind changing the name of the weapon to something else to avoid confusion but the mechanics are very different from the Aurora Railgun. Railguns are relatively slow-firing and fire a set number of larger projectiles (that get larger with higher tech), rather than an increasing number of small projectiles. Railguns also have a power requirement and you can't create smaller, less accurate versions. You also can't put railguns in turrets.

Steve

[Steve Walmsley (OP)]

Here is an fighter mounting a pair of R3-10 Gauss Cannon. This allows a total of six shots every 5 seconds with each shot being at 10% of normal accuracy The 0.6HS version of the GC allows 10%, compared to 8% at 0.5HS, 12.5% at 0.75 HS and 17% at 1 HS. In this case the 10% accuracy modifier means shots at 10,000 km will be at 5.8% each, which is the 58% of the fire control for that range modified by the 10% accuracy modifier. With 6 shots, the chance of getting at least one hit during the 5 second increment is 30%.

Code: [Select]

X-22 class Interceptor    175 tons     13 Crew     30.7 BP      TCS 3.5  TH 36  EM 0
10285 km/s     Armour 1     Shields 0-0     Sensors 1/0/0/0     Damage Control 0-0     PPV 1.2

Fighter Ion Engine (1)    Power 36    Efficiency 100.00    Signature 36    Armour 0    Exp 25%
Fuel Capacity 10,000 Litres    Range 2.5 billion km   (2 days at full power)

Gauss Cannon R3-10 (2x3)    Range 24,000km     TS: 10285 km/s     Accuracy Modifier 10%     RM 3    ROF 5        1 1 0 0 0
Fighter Fire Control (1)    Max Range: 24,000 km   TS: 12800 km/s     58 17 0 0 0
Steve

[MWadwell]

I am introducing a new weapon to v2.6 called the Gauss Cannon. I still might fiddle with the stats a little but the weapon will be essentially as described below.

(SNIP)

Although the damage from a single hit is limited (strength-1 hit), it can fire more rapidly than any other weapon except a railgun, and can even exceed the railgun's rate of fire on more advanced models.

How will armour on missiles affect the anti-missile abilty of a gauss cannon? (i.e. will it eliminate the anti-missile capability of a gauss cannon?)

[Steve Walmsley (OP)]

Although the damage from a single hit is limited (strength-1 hit), it can fire more rapidly than any other weapon except a railgun, and can even exceed the railgun's rate of fire on more advanced models.

How will armour on missiles affect the anti-missile abilty of a gauss cannon? (i.e. will it eliminate the anti-missile capability of a gauss cannon?)

The damage from gauss cannon will be treated as any other damage so it will be same as if a laser hit a missile for one point of damage. The formula for determining the chance of damage vs an armoured missile is Damage / (Armour+Damage) so 1 point of damage vs a missile with 1 armour has a 50% chance of destroying the missile. That means that lasers will be more effective against armoured missiles at close range because of their higher damage.

Steve

[Erik L]

Are Gauss Cannon turretable?

[Steve Walmsley (OP)]

Are Gauss Cannon turretable?

Yes, they will be when I add the necessary code to the Turret Design window.

Steve

[Steve Walmsley (OP)]

Are Gauss Cannon turretable?

Yes, they will be when I add the necessary code to the Turret Design window.

Which is now . Here is an example of a quad turret capable of tracking at 12800 km/s. Twelve shots will provide a formidable point blank missile defence but will be completely useless against warships and can provide no area defence mode.

Quad Gauss Cannon R3-100 Turret
Damage Output 1x12      Rate of Fire: 5 seconds     Range Modifier: 3
Max Range 30,000 km    Turret Size: 32    Armour: 0    Turret HTK: 4
Cost: 184    Crew: 96
Maximum Tracking Speed: 12800km/s
Materials Required: 40x Duranium  144x Vendarite  
Development Cost for Project: 1840RP

Steve

[Charlie Beeler]

Excellent!!  This with the new missile rails looks promising.

[kdstubbs]

Steve,
      I noticed you said the rail gun fired heavy projectiles and was slow firing.  Back in the 80s the US was experimenting with rail guns firing lexan pellets 7 grammes in mass.  They were accelerated to something approaching 10-25 KPS.  When the mass hit a test ingot, it cut a two foot deep hole in a Aluminum ingot.  The hole was over six inches in diameter.  Theoretically, the limiting factor for the rail gun was friction along the rails.  The coil gun may eliminate that problem especially when fired in a vacuum.  velocities will have to increase for really massive damage potential.  But assuming a one shell per second rate of fire, with each mass weighing one kilogram, at a velocity of 1000 kps, I will let you do the math.  So 1 point of damage may be low.

However, this will be dependent upon how strong your armor might be compared to the Kinetic gauss gun projectile.  Problem is projectiles continue until they hit something.  During fleet actions this could present some interesting tactical possibilities.

I like what your doing with the game, will be interest to play around with the possible ramifications of the new weapon.

Kevin

[Erik L]

The discussion here on gauss cannon vs armor was based in 2.6, prior to the new armor model. I've yet to fight a battle with the new weapons and armor, so does it still hold true that GC are not very effective against armor?

[Michael Sandy]

How is missile leakage handled?

If there are 5 missiles incoming, and 10 point defense shots, in a real world situation you would have 2 point defense shots assigned per target.  The less accurate your point defense, the more leaks you get.

For example, 20 missiles vs 40 point defense with 50% kill chance means each missile has a 75% chance of being killed, resulting in 5 leaks.  Unless you have multiple point defense phases.

If you have 20 missiles vs 100 point defense with 20% kill chance, you have a leak chance of .8^5 or about 32% leak, so 6 or 7 missiles would leak.

For area point defense, getting a lot of shots that thin the wave before the final impact is more important.  But when you are trying to kill all the missiles, for example protecting a planet from bombardment, you want the last ditch point defense to be very, very reliable.

[Steve Walmsley (OP)]

How is missile leakage handled?

If there are 5 missiles incoming, and 10 point defense shots, in a real world situation you would have 2 point defense shots assigned per target.  The less accurate your point defense, the more leaks you get.

For example, 20 missiles vs 40 point defense with 50% kill chance means each missile has a 75% chance of being killed, resulting in 5 leaks.  Unless you have multiple point defense phases.

If you have 20 missiles vs 100 point defense with 20% kill chance, you have a leak chance of .8^5 or about 32% leak, so 6 or 7 missiles would leak.

For area point defense, getting a lot of shots that thin the wave before the final impact is more important.  But when you are trying to kill all the missiles, for example protecting a planet from bombardment, you want the last ditch point defense to be very, very reliable.

For both area and point-blank PD fire, each fire control system is assigned a target salvo and fires all weapons at that salvo. The total number of hits is calculated and that number of missiles are removed. This can lead to overkill if there are more hits than missiles but those hits are not carried over to another salvo. Its a good idea to have multiple fire controls so you can fire at multiple salvos.

This is a little more efficient defence-wise because you don't get two successful shots at one missile while missing a second. However, this is compensated for in two ways. The fact that a fire control can only shoot at one salvo means you can overkill at a salvo level rather than at an individual missile level and this inherent efficiency is already factored into missile defence. If I change the mechanics so that each weapon targets an individual missile within a salvo, I would probably have to improve missile defence to compensate for it.

In any event, five seconds is a long time in close range beam combat. With computer controlled targeting, there would probably be time to fire at every missile with a single shot, if you have more weapons than missiles, then follow up with second and third shots at the leakers using unused weapons. So the current method may well reflect the likely reality anyway.

Steve