This is my working map of the Craton’s interior. It’s a massive image, because I tried to make it all to scale as best I could in GIMP. One pixel is half a meter, approximately.

I wanted to share it, so I wrote out some of my thoughts on this.

You may notice some tiny little lines; those are scale markers, showing heights of 1 meter, 1.5 meters, and 2 meters. I hoped they would give some concept of the size of a human within the ship.

This is far from an exhaustive map; I’m sure many floors would be sectioned differently, extending up or down or otherwise conjoined. And of course this is 2D map of a 3D object, so a lot is lost that way! It’s more intended to get across some ideas.

I do try, when writing, to keep an idea of what decks are used for what. But this is a necessarily vague and messy thing.

Now.

1 – Front Cone
The frontal cone of the Craton is composed partially of ground-up bits of the original asteroid mixed into a concrete. This shield is massive and very heavy, but is important for defense, both in combat and in travel. A small object, traveling fast enough, will have the energy of a bomb, so you need something to protect from that.
I will admit something I have not calculated the optimal shape and size of the cone. I will have to do that sometime, and correct this image accordingly. Right now it’s just what I thought looked good.

2 – Coilguns
The Craton possesses three massive coilguns that are almost as long as the ship itself.
These weapons use electromagnetic coils to move objects to a very high speed and shoot them out. A railgun is similar, but by this point railguns would have fallen out of use, as they damage their own barrels by arcing electricity.
The Craton’s coilguns are extraordinarily efficient; perfect conductors and other advances in materials science has made these, while not wasteless (as that’s an impossibility), freakishly close. A tiny, tiny fraction of a percent of the energy is wasted in the form of heat.
However, the exact power of these railguns is something I’ve left fairly vague so far, though they can vary quite a bit; either doing a slow launch of a shuttle or shooting a bus-sized projectile to a fraction of c. They’re not only weapons.
The tip of the barrel of the three coilguns are covered at most times by very heavy slabs of the same material that the front cone is made from; there are several spots down the barrels that can close. This does create a slightly higher risk of failure, but is deemed wise since it’s a tube that runs down the heart of the ship.

3 – Cone Rim Defenses
Each of these dots show the location of one of the Craton’s Point-Defense Cannons. These are complex arrays that have banks of minigun-style weapons that spit out bullets as fast as possible. At the scales of ships like these, the damage they could do are minimal, but they are an essential tool against enemy missiles. Varying up your defensive options makes defending against both more difficult.
These are not the actual PDCs, incidentally – they are kept under protective shields most of the time and are lifted up and out to fire. This is a quick process, andd missiles can be detected from very far out, so this is not typically an issue.
Missile launchers are not shown here; they are on the main body of the hull, as the missiles can change course. Each missile battery can fire a variety of ordnance of various sizes and powers; warheads are small and nuclear in nature. Conventional explosives just have too little power.

4 – Fusion Reactor 1
The Craton has seven fusion tokamak-style reactors. I wanted to use this classic style, though we don’t know for sure if tokamaks will end up being the proper shape (they are by definition a toroid). I’ve heard of a lot of hopes about a peanut-shaped fusion reactor.
The plasma inside the Craton’s reactors reaches massive temperatures (over a hundred million degrees, probably many hundreds of millions). Obviously that’s pretty hot, but the materials science of the Sapient Union is extraordinary; perfect heat radiators are something they long-ago created, and simply take for granted.
They likely don’t use simple hydrogen fusion, as that produces a lot of neutron radiation. The fuel for their reactors are something rarer that is likely “mined” from gas giant planets and processed on the ship prior to use (similar to Ultra-Dense Deuterium). Any system possessing a gas giant would be stocked for extreme time – and most systems have gas giants.

5 – Outer Hull/Mantle
The cratonic asteroid that the Craton was made from was a very unusual rock.
While many asteroids are essentially mountains of pebbles weakly held together by gravity, cratonic asteroids are solid. They are composed mostly of nickel-iron, but with a third added ingredient, a kind of inert tenkionic matter that has a very high mass and forms extremely solid bonds. This form of matter is safe for mundane life to be around, even for long periods, and is found to be drawn towards zerospace.
For unknown reasons, cratonic asteroids are always found as geoids, despite their small mass. These asteroids are extremely ancient, possibly the first solid matter that formed in the young universe. One thought is that this time the tenkionic matter was more active with their form of radiation, kratonic radiation. In that time, the mass of the object would have been far higher, causing it to collapse into a geoid, almost regardless of size.
Cratonic rock is also extremely strong, and these two qualities have led to many of the cratonic asteroids that are found to be converted into ships.
Carving out the asteroid was extremely difficult, but in the process, ground cratonic rock slush was produced, which was mixed with a tough concrete to resurface parts of the finished ship. This mixture has a distinct appearance from the material of the frontal cone, appearing like the original asteroid, for aesthetic purposes.
Under this artificial layer is some of the original, unaltered asteroid – 50 meters of it. Even with the direct openings like the hangars and Equator Deck, which reach the surface, cratonic rock has been left behind and around them as much as possible.
This cratonic rock layer is a potent defense for the Craton, being harder than any other ship armor in wide use, and also serves to insulate the crew from radiation.
Because the cratonic rock is drawn to zerospace, the Craton is also able to enter that quasi-realm far easier than most ships of larger size.

6 – Equator Deck
The location of many scenes, the Equator Deck is angled differently than most of the decks. Artificial gravity is a requirement to allow people to walk on the “walls” and gaze out at space above them.
On a ship like the Craton, an area dedicated for recreation is a must, and so it was made a key feature of the vessel. Small businesses run by civilians of the ship provide many services, create luxury items, and . The Equator is the major hub of this, but other locations on the ship can be made impromptu art alleys or serve as small markets.
These small owners are not capitalists; the resource allocations for these shops are based on civilians applying for and demonstrating an understanding of certain skills, such as organization and of course the functions of the shop. They may then take on apprentices who earn Exchange Credits for their work. The owner and workers all earn their Ex based on their hours of work.
The Equator Ring has massive windows made of transparent titanium. These serve, through sheer thickness, of protecting people below from radiation, but are an incredibly resource-intensive product, being atomically perfect. There are shutters for them as well, which close before a zerospace jump.
Funny note about eating in this time; dishes are not washed and reused, but recycled and 3D-printed. The fusion generators of the Craton generate so much power that this is more efficient than wasting a lot of water with cleaning.
They probably would look back at us re-using dishes and think it gross and unsafe.

7 – Zerodrive Generator Ring
Zerodrives are large rings that are able to poke holes in reality as we know it. Through these holes, or portals, one enters zerospace. The zero, incidentally, is due to the common thought that this is the “zeroth” dimension.
The force of gravity is stronger in zerospace, and so a small amount of mass is able to do a lot.
The Craton is somewhat unique in being able to make zerospace jumps at such a small size*. Most vessels require 21+ very large reactors to generate enough power, but the Craton’s special nature allows it to do so far more energy-efficiently.
“Speed” is not a very useful term in zerospace, but it is known that velocity increases with time. Three days is the safe limit for time spent submerged, both for the crew’s mental health and for ease of return. If too much velocity is gained in zerospace, it cannot be safely shed to allow a return to realspace, which its harsh rules about going faster than the speed of light.
These engines also can create “thinnings” instead of breaches for a smaller fraction of the energy. This is how the Craton moves in realspace – by opening a portal that draws the ship towards it gravitationally. This means that, unlike most ships, more mass actually has benefit for the Craton in moving itself.
The acceleration is good, and both inertial dampeners (yes, that old scifi trope) that function off cratonic technology, and the nature of cratonic rock, the stresses are spread evenly across the ship’s cratonic structure, preventing it from pulling itself apart.
This behavior has led to conclusions that the cratonic matter behaves akin to a single atom, holding itself together with the strong nuclear force. And physics is left crying.
The extra gravitational energy produced by the zerodrive is called pseudogravity, as it does not propagate infinitely like true gravity does, but goes only a relatively small distance before somehow “sinking” back into zerospace.
Even the Craton’s inertia is subject to this, and over time, if the engines are not used, the ship will lose energy until it has left only the inertia it initially had! This could, theoretically, lead to strange situations like the ship beginning to drift in the opposite direction of its original direction of travel!
Thus, despite the ship being able to move itself, energy is ultimately conserved – yet another way that the Craton seems to defy physics.
In practice, the zerodrive always has thin white rings of lights that face towards the back (which is actually just a polite way of indicating to other vessels which way it’s going), and these would grow brighter as it activates, though it’s not particularly dramatic.
More positively, the ring is always active to some extent so long as there is power, making it hold itself together very well against damage. So they are a target, but not an easy target.

*I have, in the story, mentioned a few examples of other small ships that can do this; special scout ships that are basically all just reactors, and very, very expensive massive capacitors that allow a vessel to store enough charge for a jump or two.
It’s also possible for a ship to

8 – Command Center
At the heart of the Craton, the Command Center is where much of the action in the stories takes place. It is not literally in the center, both because of the coilguns and because it’s never a good idea to make your ship’s brain’s location be too predictable.
The Command Center’s layout has been described, but I really want to do an image like this for that specifically, so I won’t go too much in it.
The Command Center is actually heavily isolated from the rest of the ship in terms of personnel access. It has an attendant section of offices and support rooms, with limited access to other personnel. All traffic in and out is monitored and screened (which is really true on the entire ship, but nowhere moreso than here).
The main center itself has only two entrances on two different decks, and their layout is designed for defense. This makes attempts to capture the ship more difficult.

9 – Main Hangars
The largets hangars on the Craton, they are 70 meters wide and 45 meters tall, and extend nearly 100 meters into the ship. These are specialized for use for accomodating larger vessels, and the ship has other airlocks and several smaller hangars.
These large hangars do have decks within, but these only extend part of the distance from the wall, and can be retracted if need be, though “curtains” of strong material can also be used to cordone off areas, and the doors can open in sections.
Several large wall offices are also visible that are for hangar personnel.
There are no magic forcefields; when the hangar doors are opened they are open directly to the vacuum. Very tricky techniques are needed to get as much oxygen as possible out in case they do need to be opened.
The doors have blocks of transparent titanium embedded in them, usually covered with armored shutters. These can be iris opened and so the hangar is more often used as a grand observatory than its intended purpose.

10 – Coilgun Base
You may remember this from when Jaya oversaw the manual loading of a coilgun shell in a drill, the seven-ton projectile fell to the floor, and a crewman was almost crushed.
The coilguns don’t extend fully to the aft of the ship, and Reactor 7 below it is its primary power source, though any of the reactors can be used for this task if necessary. Reactor Seven is slightly offset in a different axis than we see here, just in case.
Coilgun shells can range from small, accelerated to massive speeds, to bus-sized shells of tungsten alloy that achieve only modest velocity, but will transfer more of their energy to the target.

11 – Radiator Fins
The Craton’s fusion reactors create a lot of waste heat. Getting rid of that so the ship does not melt itself into a glowing orb is very important, so the ship possesses massive radiator fins. The consist of a heavy, solid matrix filled with channels of heat-transferring conductors.
These would glow a dull red most of the time with heat, and may turn even brighter as the ship does more.
The ship also probably takes advantages of more exotic heat regulation, like stringing heated magnetic beads along electromagnetic lines, cyling them in and out of the ship to increase their heat-dissipating surface area.
The fins are thick so that they can also be something of a heat sink in an emergency.

12 – Navigation Laser Tower
The most common threat the Craton may encounter is flying space debris. This can be tiny, something that is just absorbed by the front cone, or could be big and fast enough to be dangerous.
The Navigation Lasers are tasked with destroying small debris before it hits the Craton. They are placed at intervals on 450-meter tall towers, to give them a clear line-of-sight on incoming debris, along with sensors – both those related to their command and control and other, general-use sensors.
As lasers travel at the speed of light, they are the first line of defense of the ship after an incoming threat has been detected. Outside of maintenance, they are always active and watching in all directions.
In times of combat, these lasers are effective against incoming enemy missiles, drones, or small ships. While very powerful, against large ships they are only going to deal small pin-points of damage, thus in such cases are only good for targeting specific weakpoints.
The mix of Point-Defense Cannons and Lasers is considered to be important, as it makes enemy missile designers have to contend with multiple avenues of threat.

Hope this was an interesting read for you. In this series, I have always wanted to respect physics, and allow only for the limited use of a specific family of technologies to break that for writing convenience. I also wanted my non-physics technology to come with its own drawbacks, limitations, and caveats so that as little as possible had to be handwaved.

I will be posting about upcoming stories more soon! I’ve had a long and unpleasant bout of covid, and the long-term symptoms have caused me a lot of issue. This, along with my co-writer having some issues has slowed things down.

But I will bring some positive news soon, I promise!