Heavy Cavalry Redux

“Drive me closer! I want to hit them with my sword!”

no-one with a tank, ever

This is a recreation/reformulation/retcon of the original description of the Empire’s heavy cavalry legions, in light of both criticism received – and assistance to resolve it – and rethinking of my own. It should be considered as a replacement for the original post here, et. seq.

Let us proceed.


Making up the remaining one of every sixteen legions (i.e., one per three light cavalry or heavy infantry, and one per nine light infantry), we have the heavy cavalry. Direct-fire death on very large treads, which is to say, main battle tanks. The biggest of all the big sticks. Putting the “brute” into “brute force”.

For additional flexibility, the majority of Imperial MBTs are built off a common base platform, with a selection of swappable modules to provide specific functionality for specific cases. (Unlike many modular vehicle systems in this ‘verse, however, these aren’t hot-swappable; the need to remove and replace and integrate large and complex chunks of armor plate, etc., when doing it means that this requires some pretty major machine-shop type facilities. It’s not something you can do in the field, and indeed something only seen at the most well-developed remote operating bases.) Due to these functionality differences, MBTs are usually classified by the module.

So first we’ll talk about the capabilities of the base platform, and then we’ll talk about some of the more commonly seen modules:


Base Platform

The base platform of the Imperial MBT is a low-slung vehicle with all-around glacis design, designed to minimize its target profile and give it a low center of gravity. In dimensions, it is approximately 12 m (39 ft) long, 4 m (13 ft) wide, and 3 m (10 ft) high; its total mass (varying, of course, by module), however, is of the order of 60 short tons, due to the extensive use of lightweight composites.

8 m of the length and 3.5 m of the width at the front is the module socket; height of modules varies, but none take it much above the basic 3 m height. At the rear of the platform, an externally-opening compartment can be used to hold resupply, infantry needing transport, or a “hot soup” fuel pod to increase vehicle endurance.

Armament

The armament of the base platform (effectively the secondary weapons systems common to all tank classes) is fitted in four altazimuth ball mounts, located on either side of the vehicle, towards the front and rear.

These mounts’ field of fire extends 180 degrees vertically, and approximately 160 degrees horizontally at zero vertical, i.e., limited only by the occlusion of that side’s other mount. In effect, they maintain full coverage to the side, front, and rear of the tank, with only a small gap in coverage to the front for the rear mounts, and to the rear for the front mounts.

The front mounts include coaxial ortillery target designators and heavy (72 mm) mass drivers/micromissile launchers; the rear mounts only include medium (36 mm) mass drivers.

(While the latter do spend much of their time firing forward and to the flank, their special purpose in being mounted where they are is to give you something to pop the drone lining up to shoot you in the ass with so you don’t have to stop engaging your main target while you do it. In their battlefield environment, micro-AKVs are cheap and plentiful, so this happens a lot. If you had to slew the main gun around every time, you’d be taking your eye off the ball way too much – even if you could get it to reliably track something that small and fast-moving.)

See also Point Defense, below.

Armor

The armor of Imperial MBTs is relatively standard for Imperial armored units; there’s just a lot of it. The core structural frame is honeycomb-patterned diamondoid composite, covered with multiple slabs of interlinked refractory cerametal (i.e., a ceramic-metal composite formulated for both great physical strength and resistance to heat), electrical and thermal superconductor meshes, more cerametal, reactive-armor sections, and an outer anti-energetic ablative coating to sprayed on top of it all. Additional side plating shields the rollagons. A nanopaste-based self-healing system runs through channels in the armor, keeping damage patched up in the field.

The survivability specifications on all this armor is that the vehicle should be able to survive a near-miss with a tactical-range nuclear weapon or equivalent orbital kinetic strike.

Command and Control

An Imperial MBT nominally crews three: semi-specialized commander, driver, and gunner positions; in practice, this is rendered a mite fuzzy inasmuch as they’re both ably assisted by the vehicle’s internal synnoetic (i.e., designed to function integrated with another sophont mind) AI, and linked to each other by internal conflux hardware (i.e., functioning as a loose, mesh-topology temporary group mind for maximal efficiency, enabling coordination and multitasking by splitting off semi-autonomous agents).

Primary control is routed through the AI and direct neural links – the vehicle seats are virtuality chairs, connecting to the crew’s implanted laser-ports – but auxiliary/backup manual controls are also available.

Core sensors and communications include all the standard options: radio and whisker laser communications, access to the OTP-encrypted tactical mesh, threat identification systems, teamware and C3I systems integration, thermal imaging, remote sensor access, and all-around local sensors including pulsed-usage radar and lidar, T-ray high frequency snoopers, ground-penetrating radar, target-painter detection – and, of course, plain old electronic visual and sound transmission, since the interior of the MBT is fully sealed and includes no direct visual paths.

The MBT also includes a battle computer capable of functioning as a major node in the tactical mesh, and a full ECM suite.

Drones

As with all other units of the Imperial Legions, the heavy cavalry too has its drone accompaniments, with each MBT having a pair of WMH-12 Skyorca drones attached to it for close air support, along with a pair of heavy ground drones matching its own tactical function.

Internal Environment

To the delight of those legionaries who like a little comfort in their soldiering, the internal spaces of an Imperial MBT are a comfortable – albeit confined – shirt-sleeve environment. (Climate control, leather seats, the works…)

This is partially because given the expense of building one of these anyway, throwing in a few civilized comforts is barely a blip on the budget, and partially because – well, anything that successfully penetrates the armor tends to leave the crew as a hundred-yard-long red/blue/silver-white/etc. smear on the ground behind the exit hole anyway, so there’s no point in having them sit around in full combat armor. A padded jacket and helmet are sufficient to prevent accidents from concussion and rough terrain.

The interior is also a fully sealed and controlled life support environment for NBCN protection and exotic atmosphere/vacuum use. This also renders all tanks amphibious tanks by default: once you’ve covered all the various atmospheric compositions and pressures you might need to operate in and discarded thereby air-breathing engines and other systems, you’ve built a vehicle that can shrug off submergence, too.You could drive a modern Imperial MBT from continent to continent across the ocean floor, given a case of rat bars and a good reason to try it.

Point Defense

The MBT is equipped, as all else is, with a military-grade kinetic barrier system.

For active point defense, the base platform is equipped with a mix of mini-autocannons (in altazimuth ball mounts) and laser emitters, laid out to ensure all-around coverage, and capable of independently and automatically targeting all incoming fire and close-in soft units, subject to target identification and prioritization routines set by the crew.

Power

It seems a little inappropriate to say that the MBT is also powered by a micro-fission “hot soup” reactor, inasmuch as, well, it ain’t that micro. It is “mini”, perhaps, compared to standard-sized fission reactors, but it’s as large as the thorium molten-salt kind gets. The bigger ones all tend to be the safer “pebble-bed” design.

Naturally, this is buffered through a large set of superconducting-loop accumulators to handle immediate power draws and provide backup power in the event that you lose the power reactor – enough to make a fighting withdraw, anyway, although not enough to continue an engagement with.

Propulsion

The Imperial MBT moves on neither wheels nor treads; rather, it sits atop eight semi-squishy rollagons, near-spheres of a “smart fluid” rotated electromagnetically from within the sealed main hull, enabling it to move with equal facility in any direction, at speeds of up to 150 mph on a good, flat roadbed. Note that this is not a drivetrain developed specifically for military purposes: modern civilian ground-cars use similar technology.

The propulsion system also has considerable electromagnetic control over the shape of the rollagons; while they don’t have them normally, if you need spiked wheels or some other shape-variation to cross some tricky terrain, it can provide them on demand; if need be, they can even form “paddle-propellers” for amphibious operation.

A limited vector-control/impeller system permits the tank to apply vertical thrust to itself; this is used primarily downwards on light-gravity worlds to keep ground pressure high enough for the rollagons to be effective, occasionally upwards to reduce ground pressure where the ground is soft, and even more occasionally to lessen the severity of falls, ground collapses, or deliberate drops from low-flying transport aircraft.

(It would theoretically be possible, on light-gravity worlds, to use it to make “skips” over obstacles or other short vertical jumps, but this is generally considered an excellent way to become skeet.)

Stealth and Masquerade

The Imperial MBT, much like the heavy infantry, supports only the most basic chameleonic coating and signature reduction features; the nature of the battlefield environment of the time is such that any heavy unit has a signature (in terms of heat, reactor neutrinos, and the EM pulse accompanying weapons firing) that can’t be baffled worth a damn. As such, designers concentrated on designing a vehicle that could “tank” (sic) incoming fire in the process of executing shock and awesome.

It should however be noted that this does not preclude the use of external decoys, or the use of signature modification systems to confuse terminal guidance of incoming weapons, or indeed to masquerade as something else — but these systems have to work with the platform’s high signature, not try to conceal it.


Module: Tactical Assault Tank (HV-10 Basher-class)

As close as it comes to a “standard” MBT design, the HV-10 Basher-class module loadout is similar to the V40 Ralihú IFV, scaled up; the Basher-class comes with a turreted super-heavy (144 mm) mass driver, but substitutes a bilateral quadbarrels with limited independent training for the Ralihú’s single coaxial quadbarrel.

(The heavy mass driver is also designed to function as a heavy micromissile launcher, if required, and as such is entirely capable of delivering large-diameter canister shot for anti-infantry work.)


Module: Long-Range Assault Tank (HV-12 Stormfall-class; also HV-12i Longeye-class)

The HV-12 Stormfall-class LRAT module is equipped with a turreted super-heavy (144 mm) mass driver intended to be capable of long-range indirect as well as direct fire, but substitutes the quadbarrels for bilateral “pop-out” missile pods, each capable of doing a simultaneous launch of up to 16 minimissiles, reloadable with a short cycle time from internal magazines. Just perfect for those days when you want to fight in the shade.

By changing the minimissile loadout of the Stormfall, it can also serve as an active air-defense platform.

Rarely seen is the HV-12i Longeye variant, which trades in both super-heavy mass driver and missile pods for a graser installation, suitable for direct fire only but capable of punching out even more heavily protected targets. Also, notably, the Longeye graser is often capable of penetrating the atmosphere and reaching targets in low planetary orbit.


Module: Drone Tank (HVC-14h Thunderbolt-class; also HVC-14l Stinger-class)

A drone tank, in legionary parlance, is the land-based miniature equivalent of an aircraft carrier. The HVC-14h Thunderbolt module contains nanoslurry and miniature drone components, which it uses to construct and deploy ad-hoc micro-AKVs to suit the requirements of the current battlespace, launching them into action as a centrally coordinated wing, for defense, reconnaissance, attack, or other functions.

(Or, to put it another way, it’s a self-propelled field factory that spews out custom drones and minimissiles on demand, simplifying your logistics and multiplying your options.)

The HVC-14l Stinger functions similarly, but substitutes swarm hives for the micro-AKV factory, and is thus able to saturate the local battlespace with microbot/nanobot swarms, be they the standard eyeballs, shrikes, gremlins, or balefire, or more specialized models.


Module: Tactical Arsonier (HV-10a Flammifer-class)

Used for cleaning up or eliminating nanoswarms (highly vulnerable to thermal overloading), area denial, reducing bunkers and dug-outs, and spreading pure terror, the Flammifer-class replaces the heavy mass driver of the Basher-class with a scaled-up nuclear-thermal flamer, while retaining the quadbarrels as-is.


Module: Command Tank (HV-10c Strategos-class)

The Strategos-class is a specialized vehicle for coordinating tank-squadron activities and close air support. The Strategos module doesn’t add any weapons systems; rather, it adds two more crew positions for squadron command, a specialized tactical/logistics C3I AI, and a nodal communications suite and its antennae.

A pair or triplet of Strategoi are usually assigned to a tank squadron made up of other classes for command/control functions.


Module: Pummel (HV-11 Pugnacious-class)

The pummel tank is a highly specialized variant, designed to rip apart buildings and fortifications. It carries sappers in its rear compartment, and is equipped with specialized demolitions equipment up front.


Module: Wrecker (HV-10w Trison-class)

Another highly specialized variant, the HW-10W Trison and other wreckers are logistics units, used to recover wrecked tanks and other heavy equipment off the battlefield for repair or for scrap.


Transportation

The Flapjack-class cavalry dropship was made specifically for this; apart from that, they mostly drive to wherever they’re needed, because only the biggest transport aircraft can carry them in useful numbers.

Worldbuilding: Sail Plans

Taking a brief moment to hand out a random factlet, let us turn from space navy to wet navy. Old school wet navy.

Did you know that the most widely used rig back in the days of sail, especially by the Alatian fleet, the largest both mercantile and military and which went on to form the core of the Imperial fleet, was a variation on what on Earth is called the junk rig?

(Well, no, you didn’t, because I’ve only just told you. It was a rhetorical question.)

Using bamboo battens and silk sailcloth, even, for a very Eastern flavor for the Earth reader.

The chief experimenters with alternate rigs and modifications to the standard junk rig were the actual Alatian Navy, principally because the major flaw in the junk rig is its difficulty in sailing close-hauled (i.e., close to into the wind), but in contrast, it’s exceedingly efficient at sailing with the wind, and requires – always a consideration – a rather smaller crew to manage it than a typical western rig.

With careful attention to hull design, too, the eventual junk-rigged clippers and windjammers of the Alatian merchant fleet ruled the ocean trade up to, and even into, the steam era: as their sailors would cheerfully point out, the trade winds were very reliable, and given that, that a good rig could deliver as much or more power than steam could, and also that it didn’t require all that fuel taking up space that could contain earning cargo kept the sailships in business, and in many cases those which carried steam engines used them as an auxiliary power source only, for when the wind failed.

(Why this digression into nautical history? I have no idea. But I found it an interesting piece of the universe, and so I wrote it down.)

On AKVs and Survivability

From the questions box:

Dear Gentlesoph,
Having been reading your posts, I have a question about AKVs such as the ‘Daggerfan’ and ‘Slasher’ classes. With high-powered lasers capable of doing damage at one light second, how do AKVs survive the 300,000km journey into single kilometer range? As stated in your ‘Nonstandard Starship Scuffles’ post, military vessels use armor woven through with thermal superconductors dumping heat into ‘thermal goo’. I assume this armor/thermal management system applies to AKVs as well, although you also state that point-defense lasers will shred a vessel unfortunate enough to get into very close range. How can an AKV survive at single kilometer ranges long enough to inflict damage on the target? Thank you for your time, I look forward to more posts!

Well, there are two parts to this: how do AKVs close to skin-dancing range, and how do they survive when they get there? I’ll take ’em one at a time.

On the first point: with great difficulty.

If you take a wing of AKVs and throw them at a fresh battleship, all you’re doing is providing its point-defense computers with skeet; they’ll be chaff and charnel before they get anywhere near the inside of the BB’s point-defense zone.

What you have to do is wear it down first. That’s is the job of the non-carriers on your side of the fight: throw a lot of kinetics at the enemy to make their PD work hard. That does three jobs: one, it keeps the PD grid busy in itself; two, any of it that gets through may just take out a chunk of the PD grid; but most importantly, three, by making them run their point-defenses, you’re building up heat in their ship. Your non-carriers also have the job of pumping heat into their ship directly with the big lasers.

That heat, in turn, is going to eat away at their PD efficiency in a variety of ways. Most simply, it’s going to have to cut back on its firing rate once the heat sinks start filling, because otherwise the crew will cook, but also the hardware becomes less efficient, processor error rates go up, and similar badness ensues.

That’s when you send in the AKVs, and you send in a lot of AKVs mingled with a lot of chaff and decoys, swamping the capabilities of the now-degraded PD grid. They won’t all get through – you plan for a lot of them not to – but once the grid’s sufficiently degraded, enough will to ruin the BB’s day.

As for when they’re there? Remember, they’re described as operating within the point-defense envelope, which is to say, inside its inner boundary, which is defined by the minimum effective range of the PD – set by a variety of factors, such as the range at which firing the PD will seriously damage your own ship, but of which probably the most important is the ability of the PD to track the target and slew to fire on it. At the sort of hug-the-hull sub-km range AKVs like to operate at, it doesn’t take much velocity to generate a huge traversal angle, and what you can’t track, you can’t reliably hit.

(And it’s hard for your screen to fire effectively at the AKVs ruining your day, ’cause even discounting the effects of the AKV exploding at point-blank range, every miss will hit you.)

All of which is to say: While there are some subtleties and complexities to the tactics (defense AKVs, screening vessels sharing PD, etc., etc.), the short answer is it takes a lot of work and losses to get an AKV force within range of a target, but once you do, that target is dead meat.

Heavy Cavalry: Fields of Fire

It seems there is a peck of confusion out there concerning exactly how the “base platform” weapons on Imperial heavy cavalry units actually function, and even are mounted (including at least one case of confusion so profound as to believe the rear/local defense guns were “sticking out the back of the turret”, in the style of anti-infantry defense MGs from early last century, despite the platform – without a module installed – not having a turret.).

Here is a diagram in my inimitably terrible style:

20181101_175819952_iOS

That’s your base platform, driving left to right. Green at the front are your cheek-mounted (i.e., in a three-axis gimbaled mount on the side of the vehicle) heavy mass drivers, target designators, and micromissile launchers. Purple at the rear are your cheek-mounted medium mass drivers for local defense. Both weapons are illustrated in their default rest position, i.e., forward-facing or rear-facing, respectively.

As can be seen from the shaded fields of fire, both can train sufficiently to hit anything on their side of the vehicle that doesn’t actually involve training through the platform body or the other weapon mount; i.e., the forward cheek-mounts can hit anything from directly forward (with a small blind spot directly in front of the vehicle) to not-quite-rear; and the rear cheek-mounts can hit anything from directly behind (with small blind spot directly behind the vehicle, likewise) to not-quite-directly forward.

In short, there are plenty of things for them all to shoot at.

 

Question: Useless Machines

Specialist290 asks:

So what do the eldrae make of the idea of “useless machines”?

The most famous example, of course, being the machine whose sole purpose, once turned on, is to turn itself back off. (Like so: https://www.youtube.com/watch?v=Z86V_ICUCD4 )

Insert usual disclaimer about the reliability of capsule summaries of the opinions of over a trillion sophonts.

Well, for a start, they aren’t “useless machines”. Useless machines manifestly fail to work properly. These are “amusing mechanical follies”, like Rube Goldberg designs, which are… amusing. Also decorative.

(The ur-example of the class *there* is actually a Precursor artifact, nicknamed “The Uncrater”, a black-box widget whose sole function appears to be declining to be packaged up in the current local language, then quietly disintegrating any packaging material used to attempt to do so.

You’ll find it indexed under “Amusing Mechanical Follies”. Also under “Suspected Precursor Practical Jokes”, and “Seriously, Guys, What The Hell?”)

 

Question: Marlinspike

Phineas Imhoff asks:

I have heard mention of the “spacers marlinspike” several times, I am curious what exactly is it for? Does it serve the same role as a traditional marlinspike, just recycled in space. Or is it something else?

It’s essentially the same tool, albeit with some minor microgravity adaptations. While there isn’t quite so much rope involved in celestime sailing vis-à-vis maritime, there’s more than enough to make such a tool useful (especially in the cargo department, for lashing of breakbulk), and that’s before you get to its handy secondary uses for poking suspicious-looking objects and rapping miscreants soundly across the base of the skull.

 

You’ll Want Us High and Clear

ICED FIRE-CLASS ANTIMATTER TRANSPORT

Operated by: Extropa Energy, ICC
Type: Antimatter Transport
Construction: Islien Yards, ICC

Length: 1,600 km (overall)
Beam: 3,200 km
Dry mass: 39,200 tons (not including cryocels)

Gravity-well capable: No; not even low-orbit capable.
Atmosphere capable: No.

Personnel: 31

  • Flight Commander
  • 3 x Flight Executive/Administrator
  • 3 x Flight Director
  • 3 x Flight Engineer
  • 3 x Propulsion Engineer
  • 3 x Cargomaster
  • 3 x general technicians
  • 2 x riggers/EVA specialists
  • Thinker-class AI

Drives:

  •  3 x Nucleodyne Thrust Applications 1×1 “Sunheart V” fusion torch

Propellant: Deuterium/helium-3 blend
Cruising (sustainable) thrust: 3.5 standard gravities (3.3 Earth G) at nominal load
Maximum velocity: 0.3 c unloaded, 0.1 c loaded (based on particle shielding)

Drones:

  • 3 x general-purpose maintenance drones
  • 3 x tether-climbing rigger drones

Sensors:

  • 1 x standard navigational sensor suite, Islien Yards

Other Systems:

  • 2 x Islien Yards boosted commercial kinetic barrier system
  • Biogenesis Technologies Mark VII regenerative life support
  • 2 x Bright Shadow EC-780 information furnace data system
  • Islien Yards custom dual vector-control core and associated technologies
  • Systemic Integrated Technologies dual-mode radiator system

Small craft:

  • 1 x Élyn-class microcutter
  • 1 x Adhaïc-class workpod

The standard vehicle for ferrying antimatter from the Cirys bubble at Esilmúr to its various places of use, the Iced Fire-class is a starship designed around one core principle, commonly adhered to when dealing with antimatter:

Don’t get any on you.

The core hull itself is much smaller than the dimensions above suggest; a blunted cylinder a mere 252 m in length, including bunkerage. This houses the entire livable volume of the starship, including a dock for the Élyn-class microcutter at the bow, and a bay housing for the workpod. Rather than the typical stern mounting, the three Sunheart V fusion torches are located in nacelles set off from the hull on radiator pylons amidships, located 120 degrees apart; these nacelles are fully vectorable for maximum maneuverability.

The stern of the core hull instead contains the attachment points and winches for a 1,600 km tether, at whose fully extended end is in turn attached the spinhub. This is a simple unit containing monitoring equipment and a centrifugal ring, to which in turn are mounted eight further attachment points and associated tethers, terminating in heavy couplings. It is to these couplings that antimatter cryocels are mounted during loading, and dismounted upon arrival. In flight, the action of the centrifugal ring maintains appropriate safe distance between the core hull and the cryocels, and between the cryocels themselves, while also ensuring that jettisoned cryocels will move away from the main body of the starship in the event of containment failure.