Mars Pattern Macrocannons



The most common macrobattery, these are reliable, hard-hitting weapons firing kilo-tonne ordinance, mounted along the vessel's dorsal ridge or in broadside.



Mars Pattern Macrocannon Broadside



The most common macrobattery, these are reliable, hard-hitting weapons firing kilo-tonne ordinance, mounted along the vessel's dorsal ridge or in broadside.

Broadside: These weapons must occupy a Port or Starboard Weapon Capacity slot.

-Rogue Trader Core Rulebook, Page 202 Click to expand... Click to shrink...

Macrobatteries form the main armament of most ships, filling the broadsides of vessels with rank upon rank of gigantic weapons. Each requires crew of dozens, if not hundreds, to operate. Whether they fling kilo-tonne warheads across the void or roast their targets with high-intensity energy, macobatteries fire in volley. Their salvos are designed to blanket the space around a target, hopefully catching it in a maelstrom of destruction and overwhelm their defenses by the sheer number of shots.

-Rogue Trader Core Rulebook, page 218. Click to expand... Click to shrink...

In Rogue Trader, the weapons on starships are Supplemental Components. Each Weapon Component does not necessarily consists of one weapon - a single macro battery, for example, can have dozens of individual macrocannons arrayed in broadside.

-Rogue Trader Core Rulebook, page 219 Click to expand... Click to shrink...

When firing a macrobattery, a successful roll scores one hit, plus an additional hit for each degree of suvvess, to a maximum of the macrobattery's strength. Essentially, a more accurate hit means the character was able to land more shots on the enemy ship.

-Rogue Trader Core Rulebook, page 220 Click to expand... Click to shrink...

In the shooting phase, your ships get to unleash their weaponry against the enemy. The attacks that ships make are divided into two sort; direct firing and ordnance attacks. Direct fire attacks include weapons such as lasers, fusion beams and plasma launchers which when fired hit almost immediately, even across tens of thousands of kilometers. Ordnance attacks include torpedoes and fighters, which are launched during the shooting phase but are not resolved until they hit their target in a subsequent ordnance phase.

-Battle Fleet Gothic Rulebook, page 18 Click to expand... Click to shrink...

Weapons batteries form the main armament for most warships, ensuring that much of their hull is pock-marked by gun ports and weapon housings. Each battery consists of rank upon rank of weapons; plasma weapons; plasma projectors, laser cannons, missiles launchers, rail guns, fusion beamers and graviton pulsars. Weapons batteries fire by salvos, using co-ordinated pattern of shots to catch the target in the middle of a maelstrom of destruction.

-Battle Fleet Gothic Rulebook, page 20 Click to expand... Click to shrink...

So, I'm personally a supporter of BIGGATONS for 40k.But I've been realizing, no one really did the calcs for the macro cannon, one of the most common weapons in the Imperial Navy used on broadsides and as weapon batteries.So, after reading somethings from Rogue Trader and BFG, I've decided to do the calcs.First of all, the quotes.So what can we get about the macro cannon from those quotes?1. One macrocannon usually fire kilo-tonne shells.2. A Macrocannon battery consists of more than one macrocannon, up to a dozen or more.3. The Shells are fast enough to be considered 'Direct fire weapons' that hit 'almost instantly', and unable to be brought down by Point-defense turrets, and also fast enough to trigger the void shields.4. A Macrocannon broadside is made up of around 6 or so macrocannon batteries(from the graph).So, here comes the calcs.Premise:A kilo-ton is 1000 tons of mass, which translates into a million kilograms.Since macrocannons are Direct fire weapons, they have to beas fast as the torpedoes, and in order for them to NOT be considered ordnance weapons and 'hit almost instantly', we can safely presume they are several orders of magnitudes faster than torpedoes, perhaps even a significant fraction of the Speed of light(!).All that taken into account, let's assume the shells are 100 times faster than 40k torpedoes. A 40k torpedo goes 10 Void Units(One VU being around 10,000 kms) every strategic turn, and if you read the Starship section of the rulebook carefully you can see it is clearly stated a turn equals around 30 minutes IC.A little bit of calc-ing your self and you will discover torpedoes travel 56km/s.Calcs:So, since a torpedo travels around 56km/s, our macro cannon shell will travel 5600km/s, or to be exact, 5,600,000m/s.A million kilograms traveling at 5,600,000m/s , using the infamous ½mv^2, has around 1.568e+19 Joules of energy.That, in the TNT equivalent scale, isof energy, an averaged, slightly conservative figure.So that's is amacro cannon firing....As quoted above, a macro battery can have around 12 individual macro cannons, so a single macro battery will have around 44 gigatons of kinetic energy per salvo.That, arranged in a broadside(which apparently has 6 macro batteries, looking at the supplementary equipment chart), will haveIt is also worth mentioning that most cruisers has 2 weapon component slots for the port and starboard slot via game mechanics. If this has any relations to the fluff, it means that a single Macro cannon broadside from a Lunar class cruiser will have aroundcoming your way. That is on the assumption all the shells hit. It should also be noted that the accuracy of the macro cannon seems to be poor, so not all of that energy will be delivered to the target.Now for the maximum calcs, if we take the 'hit almost instantly' quote, we can also assume that macro cannon shells travel at a significant fraction of c. If we were to assume a macro cannon shell travels at 0.5c, using the atomic rockets page's relativistic kinetic energy equation, we get around 1.3923048454132637611646780490352e+22 joules.Round that up to 2 significant figure we have 1.4e+22 Joules of kinetic energy. In TNT equivalent that is 3,346,080,305,927 orRepeat the process for getting the broadside above and we get maximumfrom the broadside of a Lunar-class Cruiser. Again, the accuracy has been left out because that creates headaches.Evaluation and constructive criticism would be welcomed.