Ships of the Fleet

So, in today’s piece of worldbuilding, have an analysis and explication of the different classes – or the different types, rather – of military starships operated by the Imperial Navy. (The basis for the ternary plot I’m using is, of course, Winchell Chung’s analysis here, so you might want to go read that first if you’re not familiar with the concept, then come back here.)


shipgrid05The chart on the right illustrates the differences between the various types and classes of warship in common use by the Imperial Navy by their P/D/W ratio – i.e., the relative trade-off between propulsion, defenses, and weapons (i.e. offensive armament):

“in common use” should be read as “not counting all the weird-ass specialist ships we build for special cases”; also, it doesn’t include auxiliary vessels (oilers, hospital ships, etc.) since they’re not operated by the IN, but by the Stratarchy of Military Support and Logistics.

Battleships, Dreadnoughts and Superdreadnoughts

“I am an Imperial Mandate-class dreadnought, and you are within a million miles of me. Ergo, you continue to exist solely on my sufferance.”

an early experiment in AI captaincy

Battleships, dreadnoughts, and superdreadnoughts (B, D, S on the chart) are capital or supercapital ships mounting heavy long-range firepower as their primary function.

These types, the ships of the wall, are the kings of the outer engagement envelope, engaging each other with powerful weaponry at ranges of up to two light-minutes, and rarely closing beyond one to two light-seconds range (a zero/zero intercept at this residual range is considered a “set-piece” battle). They are the purest of all naval vessels in function, existing simply to counteract each other in the battlespace of major fleet actions, or to own the volume of space they can dominate if not opposed; the ultimate argument of star navies.

The principal difference between two of the three types is simply mass and volume; doctrinally, the majority of the ships of the wall of any given time should be of battleship classes, with their larger cousins the dreadnoughts providing heavier stiffening formations to the wall and occasional nasty surprises.

Because while it sure would be nice to build nothing except dreadnoughts, even nearly-post-scarcity economics doesn’t stretch to overbuilding everything just in case.

Superdreadnoughts, while sometimes referring to particularly large dreadnought classes, more typically refer to ships falling in the dreadnought type by mass, while using much of their internal volume for specialized systems: typical examples would include the command superdreadnought, the information-warfare superdreadnought, the anti-RKV superdreadnought, and so forth.

Mauler Superdreadnoughts

One example of this listed separately (L on the chart) since its P/D/W ratio moves it well outside the standard range is the mauler superdreadnought. In this case, the specialized systems in question are a very, very large mass driver or laser, with propulsion and defensive systems stripped back to accommodate it.

Mauler superdreadnoughts are not considered ships of the wall, but rather are specialized vessels used to attack specific hardened targets. Since their low speed and weak defenses render them vulnerable “glass cannons”, they are typically operated as part of a task force including close-in point-defense cruisers, and only brought up once opposing fleets and mobile defenses have been cleared away; however, in their specialty role of cracking hardened fixed bases, they’re unequalled.


The “hyperdreadnought” is a peculiarly unique version of the superdreadnought type, of which the Empire fields three, each unique within its class; Invictus, Imperiatrix, and God of War.  In order, they are the home of Admiralty Grand Fleet Operations, the Imperial Couple’s personal flagship, and the literal embodiment of the archai/eikone of war.  Any one of them turning up in the battlespace would have implications that, by and large, no-one wants to think about thinking about.

Battlecruisers and Cruisers

The backbone of the fleet, battlecruisers and cruisers (C on the chart) are middle-weight combatants, more heavily armed than destroyers and frigates, and yet more maneuverable than battleships and larger ships of the wall. Most cruisers also maintain limited AKV facilities. They are perhaps the best balanced (between operational aspects) of any of the Imperial Navy’s standard types. The distinction between cruisers and battlecruisers is simply one of mass and volume, with battlecruisers identifying the significantly larger and heavier classes of the type.

In fleet operations, battlecruisers and cruisers serve as screening elements and operate on the fringes of the close-in battlespace, maneuvering aggressively for advantage. For the most part, however, these middle-weight combatant types are intended for patrol operations and long-endurance “space control” missions, sometimes alone and sometimes in flotillas, as well as serving as the IN’s go-to types for independent missions of almost any type. In areas of heavy patrol activity, cruisers may lead destroyer or frigate flotillas into action.

Cruisers are also the type within which most variation exists, and cruiser classes may wander quite far from the indicated P/D/W ratio. Of particular note here is the point-defense cruiser (“pd” on the chart), the one type which you might see as a ship-of-the-formation, stripped of most of its offensive armament in exchange for point-defense enhanced to the point of augmenting that of other ships, but many other specialized varieties exist: the assault cruiser (optimized for planetary assaults, i.e., heavy on the ship’s troops and capable of launching drop shuttles and drop pods into atmosphere; some of these are aerospace cruisers, which atmospheric interceptors can sortie from before there’s an orbithead established); the diplomatic cruiser (a big stick to transport the softly-speaking); and the interdictor cruiser (specializing in the volume-security mission, which is to say, to chase down, capture and board other starships).  The primary battlecruiser variants are the command battlecruiser (optimized to carry the admiral commanding a CC/BC task force) and the carrier-battlecruiser (which carries AKVs – see below – as well as its internal armament; this is the type of battlecruiser usually found operating alone, due to its significantly enhanced operational envelope and capabilities).

Due to their versatility, the IN maintains a greater tonnage of battlecruisers and cruisers in commission than starships of any other types.

Destroyers and Frigates

Destroyers and frigates (D, F on the chart) are small, fast, maneuverable ships used for screening larger vessels, as escorts, and for patrol work. On their own, their capacity is severely limited, for which reason they typically operate in flotillas assigned together.

As with the above two types, the most obvious difference between destroyers and frigates is their mass and volume. That said, the strict difference between these two types is that while a destroyer may possess very limited broadside armament, due to its limited volume, it does possess it. A frigate, however, possesses no broadside armament; its spaceframe is essentially constructed around its primary gun.

Like cruisers, destroyers and frigates are designed for the “close-in” battlespace – with the understanding that close-in, in space terms, means anything under one light-second of separation. Indeed, these types arguably dominate this battlespace, since they form the majority of the IN’s screening forces, whereas cruisers are largely incidental to “set-piece” naval engagements. In this area, they use their superior maneuverability to both engage each other with wolf-pack tactics and to swarm larger ships at close-in range. Their lesser defensive capabilities than their larger cousins reflects the intention that they should substitute speed and maneuverability, avoiding being hit, for the ability to withstand taking one.

Destroyers and frigates are also intended to serve in escort and patrol roles in relatively safe space, where antipiracy patrol is the main concern (a flotilla of destroyers or frigates is considered an effective counter to a single cruiser-class vessel, which would be a rare high-end encounter under such circumstances); and in small numbers and specialist classes as scouts, avoiding engagement entirely.

Some frigate classes, uniquely among naval vessels, are capable of atmospheric entry and landing. Such frigates occasionally serve an additional role with Imperial Naval Intelligence.

Autonomous Kill Vehicles (AKVs)

AKVs (A on the chart) – autonomous kill vehicles – are extremely smart multi-bus, multi-munition, multi-mission missiles. An AKV is, in effect, a small, stripped-down, AI-piloted starship – capable of much higher acceleration and greater maneuverability than a standard design, albeit with much less endurance – designed to act in multiple roles: as a mobile reconnaissance platform; as a “fighter craft” used to swarm and destroy larger starships from inside their own point-defense zones; or, when it loses all other fighting ability, as a kinetic energy weapon in its own right.

As indicated on the chart, AKVs have essentially no defensive weapons of their own; the intent is that they should substitute their vast advantage in speed and maneuverability for armor and point-defense.


A monitor (M on the chart), in essence, is a fixed base – an orbiting station or asteroid base – used for local defense. Their W/D ratio is skewed more towards defense than the ship-of-the-wall types, since unlike those, they lack even minimal maneuverability to avoid incoming fire or to retreat from the battlespace; on the other hand, their lack of concern for acceleration or other propulsive matters means that there is effectively no upper limit on the mass of the weapons or defenses that a monitor can mount, and asteroid-based monitors may make extensive use of the asteroid’s mass as armor and heatsink both.


Carriers (V on the chart) are battleship or dreadnought-sized vessels which eschew armament of their own in exchange for carrying a large number of AKVs, along with AKV replenishment supplies, strap-on AKV thruster packs, observation platforms, etc. Since they are not generally maneuverable enough or well enough protected (the massive flight deck of a carrier is essentially a corridor through the armor into the heart of the vessel) to survive heavy attack, they are usually held back from engagements, and as such their designs heavily emphasize point- and local-space defense over additional propulsion.

Assault carriers

Assault carriers – i.e., those carrying dropships rather than AKVs – also fall into this category. The same general operational rules apply; they are held well back from any engagements, and do not move in to the target area until the high orbitals have already been cleared of the enemy.

Starfighters / Scouts

Starfighters (“sf” on the chart) are not manned fighter-class vessels. (The intersecting rules of physics, economics, and tactical effectiveness do not, in the general case, support a fighter-class of spacecraft in direct analogy to fighter aircraft. Rather, such craft can be replaced trivially by an equivalent vessel removing the biosapient pilot, their life support, and the ensuing limitations on maneuverability, acceleration, and computational performance, and replacing them with a computronium block; in effect, converting the spacecraft into an unmanned AKV.)

Rather, starfighters and scouts are essentially mini-carriers, suitable for operation by a very small crew, or even on occasion a single sophont, dedicated to the special operations and reconnaissance roles. They are small, no-frills starships designed to carry a limited, but still useful, number of AKVs or observation probes in exterior clamps. On arrival at their target, the AKVs or probes are then released to carry out the mission, while the starfighter itself serves as a command post, repair and replenishment depot, and coordination node in the tactical ‘mesh.


Couriers (“o” on the chart) are simply militarized (in construction standard) versions of the equivalent civilian type. While remaining, for the most part, “all engine”, military couriers add limited defensive and extremely limited offensive capability to give them at least minimal survivability in the event that they must pass through an engagement envelope; doctrine, on the other hand, demands that couriers should avoid engagement at all costs utilizing their superior acceleration and maneuverability to any other warship type.

Trope-a-Day: Human Subspecies

Human Subspecies: Okay, no, since there are no humans.  (Or, at least, none worth speaking of.)  However, once the genetic engineers really got working, there are literally thousands of eldrae subspecies, galari subspecies, myneni subspecies, kaeth subspecies, esseli subspecies – although, with the esseli, it’s proceeded almost to the point that each individual is his very own species – and so on and so forth.  People adapted to space, to alien planets, to some social ideal, to live underwater, to stand up under high gravity, to photosynthesize, to reproduce parthenogenically, to fly with their own set of wings, to breathe different atmospheres, to dwell in solar coronas, to… well, it’s a really long list.

The Emperor’s Sword: Heavy Infantry

“Heavies! What is your profession?”

“Bein’ the chewy meat center in a vanadium-plated god of war, SIR!!”

– apocryphal

Making up three of every sixteen legions (i.e., one for every three light infantry legions) – again, not counting the various specialized legions built off a heavy infantry platform – are the heavy infantry legions. They’re the tip of the spear, the claw on the paw, the hard-strikin’ leading edge of the attack – if the light infantry are the backbone of the Imperial Legions, one might say that the heavy infantry is the bloody great horn on the end that the animal’s charge rams into its enemy with great force and vigor. But the important thing to understand about the heavy legionaries is the nature of their combat environment, and how it makes them infantry – at least partially – by courtesy alone. They’re not just big, tough legionaries in armor; the light infantry have that covered.

So let’s talk about the M70 Havoc combat exoskeleton, the current standard wear of the Heavy Legions. (Which is a combat exoskeleton because it’s descended from a long line of ancestors including, up front, civilian models used for construction, rescue, and so forth. It’s also fully-sealed powered armor, but then, so’s the N45 Garrex.)

Well, it’s big. It looks like a giant, stocky, barrel-bodied, dome-headed, no-necked humanoid with a back-sized hump, with weapons to match strapped to it. (And sort of as if it might overbalance backwards; it won’t, the gearing is much better than that and the armor is heavier in front to counterbalance, but the size of the powerplant and the auxiliary systems it’s carrying back there do create that impression, somewhat.) What it is, is basically a walking tank with interchangeable modular heavy-weapon packs that let it blast away on the battlefield, punch out small buildings, throw respectably-sized vehicles, dance a merry jig amid venting plasma, and toss around nuclear grenades at close range.


If you take your nominal average wearer as being, oh, 7′ x 2′ x 1′, then while light infantry armor makes ’em bigger, it doesn’t make ’em so much bigger that they can no longer fit through doors, and so forth. The Havoc, contrariwise, makes its wearer more like 12′ x 4′ x 4′, and weighing something close to, maybe even on the far side of, a ton. There’s a reason military bases aren’t built to normal scale, and indeed, why you usually use the light infantry if you need to do the kind of building-clearing where it’s important that you’re left with an intact building afterward. Chap in a Havoc runs into your average suburban house hereabouts, he comes out the other side without noticing much of a stop, and it basically implodes. So it goes.


The wearer/operator goes in the front. The whole body opens up at the front, hydraulically, forward and up; the legionary climbs in backwards, then sticks his head up into the helmet and arms into the sleeves; then it closes again. The sleeves are internal to the body, not inside the arms of the suit; you can’t wear a suit that much bigger than you without risking tearing your arms off with every maneuver. Technically, when you’re fighting in a Havoc, you’re doing so with your arms at your sides, slightly bent, resting on the emergency hand controllers and keypads.

Those are only for emergency backup control, though. For primary control – if you’re wearing the suit right, the command torc built into the base of the helmet is resting right up against the back of your neck and the virtuality laser-port they installed in there, if you didn’t have one already, about halfway through basic, and has already established a high-bandwidth data connection with your brain. The moment you go active, you’re no longer wearing the suit and moving it about like a marionette; you are the suit, and moving it like your own body.

(Given its radically different capabilities, of course, this can be tricky to learn. That’s why they spend months teaching you Piston-Driven Fist Style martial arts, designed for these things, before letting you get anywhere near a combat exoskeleton for real; it’s also why an active-service heavy legionary is easy to spot on the street, because his gait will always be that little bit off.)

What they’re wearing in there is a very similar silk organza-type body glove to the one worn under regular combat armor; and exactly like its counterpart, it’s woven through with internal networking and environmental control and medical systems, capable of self-sealing, closing wounds, dispensing emergency pharmaceuticals, and covering everything in NBCN decontamination foam if penetrations are detected. The main difference here is that it can get hot in there; the Havoc bodysuit includes sweat-removal facilities (which filter water removed for the drinking reservoir) and Peltier cooling, run off the main power systems. This, and the legionary wearing it, fit tightly into the suit’s internal gel-filled padded sleeve that cushions them against acceleration and shock.


Naturally, all of this uses a lot of power. A lot of power. This is buffered through distributed superconducting-loop accumulators throughout the exoskeleton, but while they do provide enough power to let you keep moving for a while if you lose the main power plant, they aren’t really enough to actually fight it. For that, you need something that can generate the necessary power.

Ordinarily, they might solve that problem with an antimatter (except that’s not good stuff to keep around where people might be shooting at it) or fusion reactor (except they involve lots of auxiliary machinery to keep the reaction sustained, which also makes it stop working fairly readily when people shoot at it). To bypass those problems, they reached back a little in history, and what’s under the small of this suit’s back is a good old-fashioned micro-fission reactor, of the thorium molten-salt design (which is to say, tasty “hot soup”). This is much more resilient under fire – although if someone does manage to penetrate the armor and crack the flask, it does have the minor disadvantage of spraying highly radioactive heavy-metal fluoride vapor over the landscape. But you can’t have everything.

Sensors and Communications

Core sensors and communications are essentially identical to light-legionary combat armor; radio and whisker laser communications, access to the OTP-encrypted military mesh, threat identification systems, teamware and C3I systems integration, thermal imaging, remote sensor access, 360 degree sensing, etc., etc. It also incorporates the sound transmission and imaging systems, which are even more important in the case of the Havoc, since its “helmet” is a sealed armor-dome with no direct vision possible; all internal displays are produced by the battle computer. The internal computer is rather more powerful than that included in, say, the N45 Garrex, both to run the more complicated systems and to act as a more major node in the battle ‘mesh.

On top of this, the Havoc adds pulsed-usage radar and lidar systems, plus integral T-ray high-frequency snoopers, powered by its greater reactor capacity, and a full ECM suite.

Structure, Strength and Armor

In construction terms, outside the padded sleeve is the diamondoid-composite skeleton of the suit, a honeycomb-patterned framework to provide the basic structural strength of the armor. This includes the attachment points and channels for the “muscles” – pseudo-organic structures capable of changing length on electrical signal – which power the suit. (In conjunction, yes, with the stabilization gyros.) They’re calibrated for high strength, speed, and flexibility; a Havoc is designed to let its wearer run at 54 mph and lift over a ton within safe tolerances – while still being able to dance a jig and pick up an egg without breaking it.

This skeleton is environmentally sealed and environment-controlled, for NBCN protection and exotic atmosphere/vacuum use, able to withstand and operate within several hundred atmospheres of pressure and extreme temperatures. Also at this level, all the working portions of suit equipment (computers, sensors, life support, medical support, power distribution, etc.) are located and secured in place. All of these systems are spread out throughout the skeleton, constructed from highly redundant circuitry with automatic re-routing, so that even with heavy damage, it can still function. It also includes mounting voids for heavier subsystems, such as the power reactor, external hives, and modular weapons pack.

The armor on top of this is qualitatively similar to light infantry armor – a sandwich of interlinked, highly corrosion-resistant and refractory cerametal composite armor plates around electrical and thermal superconductor meshes, with an outer anti-energetic ablative layer sprayed atop it. There’s just a lot more of it, quantitatively speaking, in thick, overlapping slabs. Likewise, the Havoc comes with rather more kinetic barrier emitters than light legionary armor, and thanks to its thorium reactor, has a lot more power available to back them up with. Finally, some portions of the armor include reactive sections, capable of exploding outward to neutralize force from external explosions or impacting projectiles (or, occasionally, long drops), in deference to the fact that large anti-materiel weapons are fired at heavy legionaries with depressing regularity.

There are, generally, no chameleonic or “stealth” features included – and the heavy legionary exoskeleton does not come in any “scout” variants – since the thermal – heat has to be radiated! –  et. al., signature produced by the reactor and other exoskeletal systems are more than enough to vitiate attempts at stealth. On the other hand, it is equipped with the abovementioned ECM and signature-scrambling systems to confuse incoming guided missiles out of perfect target locks.


The Havoc can also fly, at up to several hundred mph depending on local conditions, using a combination of the same vector-control trickery used in standard combat armor, and of using its power reactor to provide the working heat to nuclear-thermal thrusters. (This is normally only an option in atmosphere, which functions as the supply of working fluid; in vacuum, it requires carting a big clip-on tank of remass around with you, which is less than convenient most of the time.) As in the former case, using this for extended flight is discouraged since it makes you an easy kill for air vehicles; on the other hand, it’s great for attaining position, making short skips, and so forth, not to mention extended low ground-skims. Attempting combat parkour with it is possible, but do bear in mind the strength of whatever it is you plan to bounce off of in the process; smashing right through it is often tactically awkward in combat situations.

Integral Weapons & Point Defense

In addition to weapons supplied by the modular pack, the Havoc possesses four integral weapons systems. Two of these are inbuilt to the arms of the suit: on the right, a heavy carbine equivalent to a tribarrel version of the IL-15i Battlesystem‘s carbine section, for routine anti-personnel and light anti-materiel use, and on the left, the KF-15 Dragonspume anti-nanitic/area-denial flamer, serving essentially the same purposes as they do for the light legionary only more so. The EI-12d Valkyrie target designator is built into the helmet section of the Havoc, for use in designating targets for the tactical net and ortillery, etc.

The fourth is a collection of defensive weaponry: each shoulder bears a point-defense pack, consisting of a pair of short-range lasers (designed to cause spontaneous explosion or vaporization-induced deflection) and a pair of short-range autocannon, independently and automatically targeting incoming fire for destruction.

The Havoc also carries an exoskeleton combat knife, which resembles a large hanrian – too heavy for unaugmented sophonts to use – scaled to the exoskeleton, which can be picked up and wielded by its manipulators for use primarily as a utility blade, although melee combat usage isn’t entirely unknown.

Swarms and their Hives

The Havoc also comes with swarm hives, both internal and external, housing microbot/nanobot swarms. The internal hive(s) are integrated into the structural honeycomb, housing repair and medical ‘bots whose purpose is to crawl around the interior of the suit ensuring that it self-repairs, and even more importantly, it keeps its operator in good repair.

The external hives, on the other hand, are a reflection of the Legions’ belief in really close air support. The exact mix can be varied by pre-mission module swap-outs, but a typical default mix for the external hives (the M-823 Horde) is a roughly equal mix of eyeballs, shrikes, gremlins, and balefire – which is to say, of expendable recon assets, counter-swarm swarms, anti-machinery swarms, and anti-personnel/area-denial carbon-devourer swarms.

Modular Weapons Pack

The primary weapons of the heavy legionary, however, are those supplied by the modular weapons pack: again, selected according to mission. The modular weapons pack fits onto the upper rear of the exoskeleton, beneath the armor and behind the helmet, with hardened lines running to extended firing packages which clamp onto the suit’s arms. A typical “mixed-mission” modular weapons pack would be the BP-400 Conflagration, which adds to the integrated loadout the following:

  • An arm-mounted heavy tribarrel sluggun, a larger-bore version of that included in the IL-15i Battlesystem, capable of firing larger (1.5″) versions of all its different ammo types: anti-materiel spikes, flechette canister shot, bore-compatible grenades, or gyroc micromissiles, the latter of which can include as their payload exploding shells, incendiaries and napalm, cryoburn shells, nanoweapons (if someone’s set up a microwave power system for them), chemical/gas dispensers, cyberswarm dispensers, network node – or spy dust – dispensers, injector needles (at low power), restraint nanoglop, electroshock “stunner” shells, acid globs, anti-electronic fiberdust, mollynet, antimatter nuke-in-a-bullets, etc., etc. Naturally, the weapons pack can store plentiful supplies of multiple types, and switch between them on the fly. (One that they’re particularly fond of is the infamous “backscratcher”, which travels a short distance and then blasts flechettes back down at the firer, rattling harmlessly off the heavy armor but making a real mess out of any lighter infantry trying to attack it close up.)
  • A chemical/nanoweapons dispensing system, with storage tanks for same.
  • A backpack vertical-launch system for a half-dozen minimissiles, usually supplied with 0.1 kt microfusion warheads.


Like the light legionary, the heavy legionary is accompanied by and acting as the command nexus for a half-dozen AI combat drones, in this case usually mixed from the WMH-4 Octoscorp, the WMH-7 Grizzly, and the WMH-12 Skyorca, depending on mission parameters, each heavily armed in its own right. When not commanded otherwise, these too default to acting as defense platforms – but the best defense is a good offense, right?


Like the light infantry, the heavy infantry is usually delivered to the field by the G5-TT Corvee tactical transport, fulfilling its multipurpose role. The module used for heavy legionary transport, however, is somewhat different – it’s an open frame, and the legionaries ride on the outside, held in by suit-controlled magnetic clamps, the Havoc already being heavily armored enough. The weight savings permit systems to let them refuel and rearm in flight to be added instead of all that wasteful hull.

They don’t generally use IFVs/APCs to get around on the battlefield. A platform like this doesn’t need ’em.


– rookie heavy-legionary

“Heh. Heheheheh. Here’s a taltis, kid…”

– commander of Basher-class heavy armored vehicle

Trope-a-Day: Human Mail

Human Mail: This is what “steerage-class” transportation is.  In the old days they’d freeze you down (Human Popsiclestyle), and in the new days they put you into nanostasis, but either way, at the sophont shipping center they pack you into a body pod, stack them three by three by two into a powered (“reefer”) shipping container, and send the result off as freight to the sophont receiving center on your planet of destination, where they revive you. (Unless something goes wrong and you end up at the lost sophont office, but that hardly ever happens.)

In addition to being the favored transportation method of the poor and near-poor (because it’s obviously much cheaper to ship a corpsicle than something that needs life support), it’s also widely used for bulk personnel movements, like prisoner transfers, colonization ships, and troop transports.