Armour and ShieldsThe general principle for armour remains the same in Newtonian Aurora, although the specifics have changed. Rather than the abstract nature of armour in standard Aurora, Newtonian Aurora measures armour thickness in centimeters and calculates the amount required based on the surface area of the hull. For the purposes of armour, shields and chance of weapon impact, the hull is assumed to be spherical and each ton of displacement is 10m3. So a ship of 5918 tons would have a volume of 59,180 m3, which is a sphere of approximately 48m in diamater. The surface area is 7344 m2 so a layer of armour 1 cm thick would mass 73.44 tons (rounded to 73). If the armour thickness is increased to 3cm, the hull volume is 60,690 m3 (including the armour), surface area is 7468 m2, sphere diameter is 49m and armour tonnage is 224. All this information is shown in the armour section of the class window. Each cm of armour means 1 row of armour boxes. The width of the armour is equal to the diameter of the sphere, which is 49 in the latter case. Armour is rated in the amount of megajoules required to destroy one box. For example, High Density Duranium Armour is rated at 80 MJ per box while Ceramic Composite Armour is 125 MJ.
The total amount of armour boxes in Newtonian Aurora is now greater for the same tonnage of armour in Standard Aurora but probably less than twice as much. So a ship that used to have 3 layers of armour would now have 5-6 layers for about the same tonnage. It's not an exact conversion though as Standard Aurora uses the concept of Armour Strength to require less tonnage for the same number of boxes at higher armour levels. That concept doesn't exist in Newtonian Aurora where you will always need the same tonnage of armour for the same number of boxes. Better armour in Newtonian Aurora is more resistant to damage though. Damage is rated in Megajoules rather than an abstract damage rating so 1 box will subtract a set number of megajoules from the total damage amount, rather than 1 box stops 1 damage.
The way in which damage is applied to armour is still basically armour boxes removed due to damage but the way in which the boxes are selected will change. Assume for the purposes of these example, there are no active shields. Lasers (which are totally different than standard Aurora and I will cover the details in a later post) will affect an area of armour depending on the diameter of the beam when it hits the target. The megajoule output of the laser will be divided between the number of armour boxes covered by the beam, which means once the beam widens to a certain amount, it will only warm up a large section of the armour rather than vapourising a smaller section. For example, if the armour is rated at 100 MJ and the laser output is 1200 MJ, it could penetrate 4 layers of armour by three columns if the beam is only 3 boxes wide, or penetrate two layers by six columns if the beam is 6 boxes wide, etc. If the beam is 13 or more boxes wide, it wouldn't damage the armour because the megajoule damage per box is less than 100. The width of the beam will depend on the range between firing ship and target and on the wavelength of the beam in nanometers (more on that in the forthcoming laser post). Lasers won't be able to affect more than half the width of the armour (one whole side of the ship) so any beam width beyond that will be wasted.
Kinetic weapons such as railguns will punch a hole one box wide straight through the armour. If they penetrate through the entire armour belt, they will damage a limited number of systems depending on the size of the ship and then potentially punch their way out again, damaging armour from the inside outwards. Of course, it will be much harder to hit with a railgun due to the speed of the projectile but the potential for damage is much greater, especially if the target ship is moving at high speed.
Nuclear weapons in Newtonian Aurora are area-based and missiles may be set for proximity detonation. If a ship is close enough to be within the blast radius, any damage that penetrates the shields will be applied to half the width of the armour, which will be the side of the ship facing the explosion. To determine the damage applied per box, the total MJ output of the explosion (which for 1 megaton would be 4,184,000,000 Megajoules - ouch!), is applied across the total surface area of a sphere with a radius equal to the range from the ship to the detonation point. The total energy output for 1 square metre of that explosion at the given range (or maybe 2 m2 - haven't decided yet) will be applied to each affected armour box. This isn't quite as bad as it sounds unless you are very close to the explosion because the rate at which damage falls off for nuclear detonations in space is far higher than in atmosphere.
For example, if you are 500 meters from a 200 kiloton detonation (which is a 1 ton warhead at tech level 3), the total damage applied per armour box will be 266 MJ. At 100 meters though it is 6659 MJ per box, which wouldn't be good. And yes, this means it is possible to take out a ship with a single missile if you get close enough, so I suggest anti-missile defence should be a priority
. I thought a lot about this but decided to go with the realistic option. Lets face it - if the Nimitz took a direct hit from a 200 KT nuke, it would be in some difficulty. Don't forget though that you can also use nuclear detonations defensively and a single small nuke could take out a lot of attacking missiles with a proximity detonation. Also missiles will generally be slower than in Standard Aurora. Targeting will be different too but I will cover that in another post.
Another example. A 1 megaton nuke would cause 83 MJ per box at 2000 meters, 332 MJ at 1000 meters, 1331 MJ at 500 meters and 5327 MJ at 250 meters. At 100 meters it would be 33,295 MJ per box!! Definitely need to keep the location of any fleet bases and shipyards a very closely guarded secret! In fact, I think dispersing shipyards may be a good idea. In a way, I am designing Newtonian Aurora without a really detailed idea of how the combat is going to play out. I am trying to create realistic systems and then I will see how everything interacts and how that drives tactics. It will be fun to find out
Other types of warhead will include laser heads and shrapnel heads, although I haven't designed those yet.
Shield UpdateAlthough I have already explained the basics of shields, the changes I have made to armour (see below) will slightly affect the details but not the general principles. Shield radius will now be equal to 1.25x armour radius, so shields will be much closer to the hull and will not make the ship significantly easier to hit. Shield Area is also now in square meters rather than the abstract size I used in my earlier post and the point strength is equal to total area divided by 200. In effect, I am assuming that the energy contained in 200m2 of the shields will be applied against any single kinetic strike.
Although the maximum strength that can be applied against a kinetic strike is the point strength, a laser strike with a beam diameter greater than one will affect a greater area of the shields and will require greater energy to penetrate. I'll cover this in the laser post. Against a nuclear detonation, the amount of energy that will strike the shields will be equal to the square meter damage at that range mutliplied by (armour width*0.625). This is because half the ship will be affected and the shields are 25% wider than the hull, so half the armour x 1.25, which is all the armour x 0.625.
Note: In reality, the damage to armour and shields would be greater because the ship has height as well as length. In effect I am assuming a strip of the ship 1 meter high is all that is hit by the blast. However, the game is 2D, it's complicated enough already and nuclear weapons don't really need the extra help so I am happy to live with that simplification. In addition, some parts of the ship would actually be slightly closer to the explosion than others so the damage should vary across the hull. I am not going to include that complication either.
Example of shield and armour calculationA ship of 4884 tons has 6cm thick armour and 72 GJ shields. The hull volume is 48,840 and the spherical diameter is 45 meters. The surface area is 6461m2, which is multiplied by 0.06 for 6cm of armour, giving 388 tons of armour. The armour is 6 layers by 45 columns and is Ceramic Composite with a strength of 125 MJ per box. The radius of the shields is 25% greater than for the armour, which gives a surface area of 10,096m2. The 72 GJ total shield strength (72,000 MJ) is divided by (10096/200), to give a point strength of 1426 MJ.
Steve
