Not Even Their Final Form

The classical image of the aircraft carrier remains that set by the Third, Fourth, and even Fifth Oceanic Dominances - from the flush-deck carriers common at the start of the Third, to the V-deckers that dominated its ending, the Fourth, and into the Fifth, the romance of the flattop continues to dominate the popular imagination¹.

But these were not the last generation of carrier designs.

The last and latest generation of aircraft carrier, perhaps best typified by the Daiségei ("Great Whale")-class that began it, was a radical departure from everything that went before, as were the aircraft it carried. Having pushed prior technologies as far as they could go, the Imperial Navy convened its most radical maritime architects to produce a blank-sheet design for the new era. What they produced was extraordinary.

It all started with the catapults.

The development of the previous generations of carriers involved a roughly linear progression in methods of aircraft launch while methods of recovery stood, in essence, still. Designs progressed from STOBAR carriers (in which aircraft were expected to manage their own take-off from the flight deck, and landed to be caught by hook-and-cable arrest systems), through steam-powered catapult launches (CATOBAR), through electromagnetic catapult systems, using similar technologies to the coilgun-based weapons systems being fitted to contemporary battleships.

The Daiségei-class concept originated from one simple idea: what if we put the entire aircraft inside the coilgun²? This would do for recovery what the electromagnetic catapult did for launch, while avoiding the need to make solid dock with a captive cradle on touchdown - a prospect with little appeal to anyone, not least the pilots already familiar with the rigors of carrier landing.

Such a simple concept, at first, floated to simplify the deck machinery and recapture energy from landing aircraft during their deceleration. But one with so many implications.

The Aircraft

The very next step, of course, was to bring the aircraft designers in on the plan. Their joining in on the blank-slate design ushered in a new generation of naval-specific aircraft, whose key novel feature would be familiar to aficionados of modern UAVs and AKVs: replacing the aircraft's keel longeron with an electromagnetic frame running down the centerline at the bottom of the fuselage, made up of independent hybrid-excitation segments - to prevent quench propagation or other cascade failures - each composed of a solid permanent magnet core wrapped in actively-driven superconducting coils.

These coils, each following the well-established coilgun model in which each has an associated accumulator under photonic control, provide the means for the aircraft to couple to the launch/recovery accelerator not merely passively, but synchronously (at the cost of requiring telemetry interlock with the carrier), which in addition to allowing true regenerative operation rather than mere eddy-current braking, permits the accelerator to actively steer and center an incoming aircraft in a manner similar to, on a larger scale, that of maglev rail - allowing a much more flexible landing window, and operation in heavier seas than the original flattop design.

And the active magnetic system would be easy to integrate with the existing aircraft power subsystem, which already made use of radiothermal generation, supplemented by engine-power taps and buffered through multiple superconducting-loop accumulators, to support the aircraft's avionics and hotel load.

This was not without both cost and profit to the overall aircraft design, of course.

The most obvious cost was that it foreclosed on the option to make use of the - then-common in civilian designs - magnetoaerodynamic vortex-jet engines for such aircraft; the difficulties of reliably integrating two complex electromagnetic systems at two critical flight phases were deemed, if not beyond the technology of the time, at least not suitable for attempting at this point. Fortunately, the existing engine combination in use on military aircraft - a combined-cycle nuclear-electric propfan and variable-throat nuclear-thermal ramjet/scramjet remained superior in role, and was designed to be powered primarily by its own internal core, requiring no large additional fuselage powerplant.

A secondary limitation was the need for a continuous keel, which initially was thought to pose potential problems both for the main gear well, and for fuselage weapons bays. For the gear, especially given the reduced load mentioned below and the broad beam of most carriers, this was solved simply by displacing the main gear to the wing roots, conveniently also adjacent to the heaviest loading on, and thus most heavily reinforced part of, the airframe.

Weapons bays appeared more problematic, until on review it was noted that very few weapons of the time required the clean bottom drop called for by deadfall ordnance, and it was decided that the rare exceptions could be offloaded to external hardpoints or specialized vehicles. Actively-guided ordnance could - and in many cases already had, to serve the needs of stealth aircraft - be transitioned to side-bay ejection.

Against this could be set the ability to reduce fatigue in, and thus lighten, the overall airframe, since the load applied to them by the magnetic accelerator was distributed both across much of the fuselage and across a greater span of time. Similarly, the landing gear itself would bear less load, from milder decelerations and gentler touchdowns.

The Ship

But the greatest changes were to the carrier itself. As I have implied above, this generation of carriers were not accounted among the flattops, and for one simple reason: the "runway" of these carriers is not a flat strip, but a tunnel.

Field geometry dictates that you should have coil segments surrounding the aircraft's keel from above, below, and on both sides to avoid asymmetric-force problems and to let the field envelope center the aircraft for smooth acceleration. And the coil structures themselves are heavy; stability concerns dictates that they be low.

Daiségei and her sisters have a flight deck; it is the internal deck within which the tunnel rests, extending through the ship from bow portal to stern portal in a shallow "V", with the elevator system (and, on either side of them, the emergency arrest equipment) in the center. The shallow angles of the tunnel allow landing aircraft to descend on a comfortable glide slope directly into the capture envelope, and boost launching aircraft directly into their climb-out. (And since the tunnel extends all the way through the ship, should deceleration fail and they have a bolter on their hands, the accelerator can switch modes and accelerate them back to flight speed for their go-around.)

The Daiségei-class, designed as fleet carriers, had a pair of launch/recovery tunnels, balanced to each side of the ship's centerline. (Escort carries classes which followed usually made do with one.) In the course of normal operations, this let them launch through the bow portals, into the wind, and recover at the stern, using one tunnel for each for minimal risk; in less normal times, both could operate simultaneously.

The hangar, meanwhile, is buried deep within the hull, and treated to the full flexibility of modern automation: every aircraft stored within an individual cell in a three-dimensional rack, capable of being moved from there to either tunnel, or to maintenance or arming bays, or to a launch queue beneath the tunnel in the course of spotting a strike, as simply as punching in a tail number.

What is the most important thing the carrier gains from these changes?

Resilience.

On a classically designed flattop, the flight deck is both the single most operationally critical and is most vulnerable aspect; deck-penetrating hits, from gun, missile, or drone, can shut down flight ops for hours or longer even if the ship itself survives easily. In this generation of carrier, all the vulnerable equipment needed to arm, spot, and launch aircraft is buried deep within the hull, behind stout belt armor with only the relatively small bow and stern portals exposed. And even they are protected in the type design, with decklets below their emergence housing blast, FOD, and sea-tight doors to close this vulnerable access when not in active use, with accompanying CIWS to guard against enemy attempts to sneak a weapon by.

As for the rest of topside? Very little flat profile at all; Daiségei, true to its name, has an armored "whaleback", whose armor and profile combine to shrug off attempts at potentially-penetrating plunging hits. Since without a flattop's flight deck there is no need for an island, there's only a small superstructure forward to minimize visual and radar profile, followed by a pair of sensor masts, the auxiliary aircraft hangar - which houses the tilt-rotors and tilt-turbines used for resupply, scouting, and ASW and their small VTOL apron, all accompanied by a scatter of point-defense weapons and vertical-cell missile launchers for local defense.

Low-slung, whaleback-armored, weather-hardy, with minimal superstructure and no visible runway at all? They hardly seem like the classic image of a carrier at all, do they?

Yet it was with Daiségei and her sisters that the aircraft carrier design reached its apotheosis.

- The Last Carriers, Commodore Atélen Dallewyl-ith-Dallewyl

  1. Perhaps the brevity of the Eclipse War, which did not lend itself to fleet actions, was responsible for the greater prominence of the "fighting carriers" in mind and memory - ed.
  2. Future readers will recognize this as an early form of the system later used by spacefaring AKV carriers.

This is a companion discussion topic for the original entry at https://eldraeverse.com/2026/08/24/not-even-their-final-form/

I think there’s a typo in this sentence—should it be “is both the single most operationally critical and the most vulnerable aspect"?

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How did they deal with the issue of the risk of crashing into the side of the ship if you missed the tunnel? With flattop aircraft carriers you can go-around if you have a bad approach even if you’re right about to touchdown, and with wire-based arresting gear you can be a bit off the center line and still catch the wire, while if you’re aiming for the tunnel and you’re off you go splat. Was the plan to just rely on pilots/autopilots being good enough to never miss the tunnel?

Edit: Actually after some further contemplation I feel the need to ask another question: namely, why bother with regenerative braking at all? I consulted Wolfram Alpha, a 50000 kg aircraft(heavier than any carrier fighter in real life) travelling at 343 meters/second(the speed of sound at sea level in real life on Earth and far beyond the actual expectable speed of any aircraft approaching an aircraft carrier) is 2.971 gigajoules (assuming perfect efficiency and no losses). 75 times that(the approximate amount of aircraft that an IRL Gerald R. Ford class carrier can carry) is 220.58 GJ. 220.58 GJ divided by 125 megawatts(the electrical(not thermal) output of one of the reactors on a Gerald R Ford class) is just under 30 minutes, and would be under 15 if both reactors are dedicated to the task. So I have to ask, what’s the point of regenerative braking and energy recovery given it would take only half an hour of a single IRL aricraft nuclear reactor to produce enough energy to equal all that could be recovered? Presumably Eldrae fission or fusion reactors at the time are more advanced than humanity’s reactors and could produce more energy. So why would they bother with regenerative braking and energy recovery when it’s such a small amount of energy compared to that that the aircraft carrier regularly produces? Why not just use eddy-current braking to decelerate when the amount of energy recoverable by regenerative braking is less than half a minute of a reactor’s electrical output per aircraft? Wouldn’t eliminating regenerative braking significantly simplify things in terms of complexity in both the aircraft carrier and its aircraft while only sacrificing a small amount of recoverable energy compared to that a nuclear aircraft carrier generates regularly?

In the approach phase, same way you deal with the risk of missing the deck or going into the island. You’re flying a nice, neat, computer-aided glide slope to and through the portal target, and if you can’t call the ball at the appropriate moment, you wave-off and go around.

But after that, this is actually one of the headline safety improvements of this design. As per this part…

…it’s not solely the pilot’s job to hit the narrow deck window that will allow hook to catch wire, with minimal assistance and margin for error. Once your glide path puts you in the capture envelope, the carrier-side hardware actively steers and centers you right down the bore. The aircraft will tell you to go around if you can’t capture the envelope from your current position and energy state.

This is a big reduction in pilot workload and maneuver difficulty at the most dangerous moment.

After capture, your big problem is if you can’t meet deceleration criteria enough to stop (the bolter case), and there things are also improved, because instead of having to manually hit TO/GA power and hope like hell you can hit flight speed before you fall off the other end of the ship, the other half of the tunnel provides you with the necessary attitude change and go-around boost.

This is of course all rather harder if your plane is all shot up at the time, and thus your fancy avionics and phase-locked keel are heavily degraded, but that’s why you train and keep current on the manual-landing-with-a-degraded-system worst-case scenario and the system does have a lot of fallbacks built into it (that’s why, for example, the keel is hybrid rather than pure-electromagnet) against situations just like that that I can get into if you like.

A few reasons:

  1. Entropy sucks.
  2. It’s something that falls automatically out of doing synchronous coupling, and synchronous coupling is what enables a whole lot of the other features of the system, like active guidance, shaping the acceleration envelope, and so forth, some of which are very much necessary to the design.
  3. That 3 gigajoules of energy - that’s 833 kWh, for those who like their old-fashioned figures - is going to end up somewhere, and if you don’t have a better plan for it, it’s going to end up somewhere as heat. (This is why passive eddy-current braking would be a lousy choice, because in it, the heat ends up in the magnetic keel and that much heat is something you don’t want loose in your airframe.) Even on the carrier, it’s an annoyance, and one that’s repeated every minute during active recovery operations.
  4. There is a certain elegance[1] to having that energy already sitting there in your coil accumulators to power the next launch rather than having to trickle-charge 'em off the main bus. Improves your cycle time, and every air boss loves that.
  5. While this is way out on the super-low-probability aspects of the decision tree, doing it this way lets you recover aircraft and maybe even continue limited air operations for a while after the carrier has lost not only main but also auxiliary power, i.e., is down to the emergency batteries.
  6. Entropy suuuuucks.

  1. And if you don’t find the phrase “a certain elegance” sufficiently compelling in its own right, you’re deeply out of sync with the culture of basically every Imperial engineering school. ↩︎

Fair enough especially regarding points 1 and 6(the only times entropy doesn’t suck is when it blows and when it blows you’ll almost wish it merely sucked). I hadn’t fully considered the heat thing, that may very well be a good justification for regenerative braking, even if you have the reactors at full power and all the batteries and capacitors are full you could at least transfer the energy to a bank of resistors close to the hull and the ocean, so the heat will be quickly absorbed by the colossal amount of water in the sea as opposed to existing in the very much limited mass that composes the braking magnets for aircraft. Although it probably won’t be remotely near 3 gigajoules of energy recovered, the value I gave was an intentionally high amount of mass and velocity to try and emphasize how little energy could be recovered even with perfect efficiency even in an ideal scenario.

Additionally I don’t think the comment about pilots having to manually hit TOGA power is actually a significant factor in practice, in real life navy pilots already push their throttle to full the moment they feel the aircraft hit the deck, if the arresting gear works properly it can still handle the force of a fighter at full throttle for a handful of seconds, if for whatever reason the wire snaps or the hook doesn’t properly engage with the wire the planes is already at full throttle and can easily go-around for another attempt as opposed to diving into the sea. So the bit about not having to manually apply TOGA power with a bad landing would only be useful in a scenario where the pilot didn’t already hit TOGA power reflexively during landing which would be rare among human pilots and presumably would be even rarer for Eldrae pilots.

Also now that I think about it there’s one additional reason you haven’t mentioned and likely haven’t thought of as to why regenerative breaking would be a good thing. Let’s imagine(with an emphasis on imagine because the scenario I’m about to propose is highly unlikely in any world that obeys realistic standards of probability and thus almost certainly would only occur in fiction) a case where the backup fission reactor is disabled, the chemical fuel power cells are disabled, the emergency batteries are nearly out of power, the primary fusion reactor is intact but was knocked out in a prior hit and could technically be restarted but kickstarting it requires more energy than is currently available in the batteries. All is doomed. Except what’s that, Pilot McFighterpilot, the protagonist of the story, hasn’t yet landed unlike the rest of his fellow comrades for whatever narrative reason and who if he dives into the deceleration tunnel at dangerously high velocity could provide enough energy to kickstart the fusion reactor and save the day is still in the air and could save the day? And then he does that and the day is saved and all is well? And the audience reading this story forgives the extreme improbability of such a scenario happening because it’s a necessary conceit for permitting the existence of an awesome moment which justifies itself because it’s an awesome moment of being awesome by a character who is full of awesomeness. At least that’s how I think an eldraeic viewer would perceive and accept such a fictional scenario anyway. Or at least that’s how I’d view and process such a thing myself personally, I like awesome things if they are awesome enough to overcome my difficulties regarding suspension of disbelief in improbable scenarios, if there is any silver lining to entropy, as generally horrible as it is, it’s that it allows for the opportunity for people to be awesome by defeating it.

Reason 3 is honestly the biggest one.

Improving the cycle time is vastly underrated by most people, yet every class of carrier has attempted to do just that. The Ford-class is up something like 20% over the Nimitz class in sorties per day, though part of that is by fewer alpha-strike setups** and more evenly spread out launches, plus being able to turn around each aircraft faster.

** A strike package consisting of pretty much all the avilable aircraft attacking at once.