Phoenix Space Combat System for Dummies - Part Eight Armour

There are several different armour types out there with some (Light Plate) mainly used for fast ships not expecting to slug it out and others (Korondite Plate) mainly for stealth with much the same intention. We will not focus much on these as they are often attempts to avoid combat and we are concerning ourselves with a generic ship that slugs it out over several days.

For these sort of warships there are two armour types that are head and shoulders above the rest and these are Armour Plate and Ablative Armour Plate. 

Let us take each in turn. The most common is Armour Plate which is the workhorse of armour types and the most common you will (probably) have and encounter for major warships that are not toolkit smaller types designed for specific tasks. The basic Mark I armour provides a default armour depth of 80 and each mark increases this by 20 so Mark II = 100, Mark III = 120 and Mark IV (this is described as Advanced Heavy Armour on Battle reports) at 140. Since armour uses the standard 3D Probability engine for how much damage is blocked you can expect a mean of 40, 50, 60 and 70 per shot, dependant on Mark. These are all decent totals and means that for the highest Marks you are almost impervious to all but the highest mark Photon Guns and even Cannons would do limited damage. There is a second important factor to armour types and that lies in how is destroyed. A ship at full strength will contain an amount of armour plates and each of these can absorb a specific amount of damage before being destroyed. Until destroyed a plate functions at 100% (even if it is within 1 point of being destroyed). 

The standard plate absorption rates are also affected by the Mark of the armour as follows 

Mark I - Can absorb 1,000 points of damage
Mark II - Can absorb 1,250 points  of damage 
Mark III - Can absorb 1,500 points  of damage 
Mark IV - Can absorb 1,750 points  of damage 

This means that a single armour plate can take a huge amount of damage before disappearing and forcing the armour depth to drop.So even a ship being heavily battered my many opponents will still have armour protection deep into a battle. 

One further important consideration is that, just like shields, the above factors relate to Heavy Hulls only. If you put any armour on a normal hulled ship then the default armour depth is halved (so for Mark I would be 40 and Mark IV 70). This is because of the greater area the armour has to cover and (in my head at least) a weaker supporting hull structure. Try it on light hulls (and I am not sure why you would want to even if is possible and it would be worse still).  

This does tend to reinforce the dominance of heavy hulled warships. After all if you have two 200 hulled warships with one with normal hulls and one heavy and both with mark I armour. You then obtain (or make) enough Armour upgrades to get those ships to Mark IV armour then you logically do the heavy hull first as the end result will be a 140 armour depth. If you are fabulously rich you 'might' do so for normal hulled warships but all the cost only gets the armour depth up to less than half a heavy hull with Mark I armour. Much less bang for the buck. 

Battle Reports 

Battle reports have different ways to describe 'Armour Plate' dependant on the Mark and Hull type which may confuse some people. 

As an example Armor Plate Mark I on heavy hulls - Broadsword Class Heavy Cruiser [G] {Heavy Armour} 

The same on normal hulls would be - Patrol Cruiser Class Heavy Cruiser [G] {Medium Armour} 

Armour Plate Mark IV on heavy hulls is - Direwolf - Archaic Class Capital Ship {Advanced Heavy Armour} 

For the next common armour type we have ablative armour. This functions a bit like tank armour designed to protect against specialist shells 1  Ablative armour has a really high default armour depth 

So 

Mark I - 120
Mark II - 150
Mark III - 180
Mark IV - 210 

So that is a mean protection of 60, 75, 90 and 105!  The issue with ablative is that the armour plates only absorb a small amount of damage before being destroyed. Here is the Mark chart for ablative 

Mark I - 150
Mark II - 190
Mark III - 225
Mark IV - 260 

So assume a 200 heavy hull ship with Mark IV ablative armour is being attacked by a ship with 50 Photon Gun Mark IVs doing 95 damage each. We will 'assume' 25 of each shot is blocked by scintillators so 70 gets to the armour. Also don’t forget that each weapon is calculated individually which we will not be detailing here 

1 shot would pass around 70 to the armour and on average ALL the guns damage would be absorbed by the armour and nothing would get through to the hulls/internals. But after 50 shots around 3,500 damage would have been absorbed by the armour which would destroy about 13.4 plates and after a full days engagement against one ship around 53.84 plates would be gone (possibly less as when each plate is destroyed and the armour depth drops there will come a point when damage starts getting 'through' the armour meaning less is absorbed by the armour so less plates are destroyed). A 200 carries around 317 plates of armour and that rate of destruction that is around 16.71% of its armour destroyed - the armour depth at the end of the battle would be something around 178 at that point so 'slight' amounts of damage would start getting through. In the meantime this ship is creating merry hell of its own accord with no weapons/internals damaged but in any large action it is more likely that you will have 8 ships (probably) trying to take down one of equivalent size and if the battle lasts more than a day then ablative progressively gets to be a much worse proposition for combat.  

You can see the advantages though and it can also impact targeting decisions 2 

Example 

Let's move back to our example ship action and its defence against two Photon Gun Ivs. Let us assume this Heavy Hulled ship has Mark I armour so has an armour depth at start of 80. 

Round 1 Shot 1 - the scintillators and shields between them have blocked 32 damage so far so 52 now hits the armour which does better than average and actually absorbs 45 damage. This '45' is added to the plates damage total. It is well below the plates damage total of 1000 so nothing is destroyed (note this is not direction specific the damage is cumulative until it breaches 1,000 and at that point destroys onw plate. You don’t have a 'plate A at 450 damage and Plate B at 900' type of situation… This means only 7 damage gets through to hit the hulls/internals.

Round 2 Shot 2 - this round the scintillators and shields stopped 30 damage so 60 now hits the armour. This does worse much worse than average and absorbs only 25 damage. 25 gets added to the 45 already done totalling 70 which is still much less than 1000 so again no plates are destroyed and 35 damage gets through to the hulls and internals. 

Our battle report would now read 

Round 1: 2 Photon Gun Ivs - 2 Hits - 42 (50) 180 - 100% 

Scintillators and armour damage is removed from the first number (so you remove the shields (50) and the damage to internals (112) from the total possible damage (180) and the number left is the total damage blocked by scintillators AND armour so says 88 damage was blocked by armour AND scintillators. 

Be aware that as most warships carry multiple amounts of weaponry that the mean damage taken will get closer to average the more weapons firing covered by one line. 

We are almost done with our defensive description so will move to what happens when damage hits its actual target (hulls and internals) with an emphasis on hulls. 

1 Tanks in WW2 initially had a very thin layer of armour which gradually thickened during the war (as engines chassis etc grew to 'cope' with the weight) initial armour piercing rounds were simple kinetic rounds with (sometimes) hardened heads that basically were intended to burst through the armour and then ricochet metal around the tanks innards or hit something explosive/flammable. Eventually armour thickness grew very thick (and clever angling of the armour helped ricochet these shots 'off' the tank) so equally clever methods of breaking the tanks armour was designed such APCR  and other such rounds. These included rounds that had an internal explosive shell that fired when the outside casing hit the shell. This then burnt through the plate. To counter this tank designers started hanging (almost) loose plates on the outside (they sometimes used wooden tree trunks) and eventually a layer of armour separated from the tank itself. The idea here as that these specialist shells would hit this 'throwaway' armour section and start their specialist operation but this would soak up the force of the shell before it reached the standard armour.  Some more modern tanks even have armour that is designed to explode itself on contact with that explosion basically countering the force of the incoming.

2 years ago now most of the militant human affiliations in the universe banded together to attempt to beat the then dominant affiliation - the DTR (this meant around 7 to 1 odds and even with those it was a close war). The DTR had no real answer to the Imperial Ground Party unless they could beat and defeat the combined human fleet. If they did this then the ground party could not safely attack DTR worlds. This lead eventually to an enormous fleet battle. The DTR fleet commander when targeting had a wide range of choices and decided to focus on the weaker/lower armoured ships under the intention that if they destroyed a large proportion of these then the Imperial fleet would have less hitting power leading to victory. It just so happened that the majority of these were CNF ships whose design philosophy at the time was somewhat similar to WW2 Russia in being 'quantity not quality' or 'God is on the side of the big battalions'. Most of the DTR ships were the highest mark armour/weapons so the Imperials did not have the same choice. The DTR certainly blew up huge amounts of low mark 200 hh CNF ships - which pleased them as the CNF had been recent allies and had changed sides but did not fire on the much higher mark IMP and GTT warships. The problem was that the best weapons were also in the best IMP and GTT ships so it did not reduce the Empires ability to hurt the DTR as much as they had hoped and the Empire meanwhile was destroying a large amount of advanced DTR warships, The end result was a DTR defeat and a huge strategic victory for the Empire and ever since the DTR have been extremely loath to get involved in military power politics whereas the Empire has been scared of nobody. One of the strategic discussions by the DTR post battle was that this targeting choice was a mistake and they should have focused on the most dangerous ships regardless as to the strength of their armour (which would have been IMP and GTT). I will cover other targeting implications in the blog post on fleet actions.