Fighter Carriers

Fighters and Fighter Carriers

Fighters, if properly designed, are very powerful units. They are not aircraft equivalents but are more like late-19th/early20th century torpedo boats. Those with a historical bent will know it was common for large armoured ships before the 1892 adoption of the battleship type to carry torpedo boats. Eventually the TB got larger and more seaworthy, becoming the torpedo-boat destroyer. In all cases the torpedo was a "balls to the wall" short range weapon, like a submunition in 2300ad.

Now, our bigger ships carry fighters. There are two ways, and back in the 90's Wade Racine explored both. You can carry the fighters in a hangar bay, or you can place them in magnetic slings on "the deck".

The advantages of a hangar bay are:

1. Ease of maintenance
2. Ease of fueling and rearming, especially with nuclear weapons
3. Uses less surface area consumed - each bay consumes the same SA as a single fighter on the deck
4. Unlaunched fighters are protected in the hangar

The major disadvantage is the speed of launching an alpha strike (defined as launching all fighters) .

The deck is precisely the opposite in advantages and disadvantages; a fast alpha strike launch, but horrible handling problems.

Stutterwarp and Launching

Here we should consider how to launch and recover a fighters. This also applies to other objects, although few will be recovering missiles. This largely depends on your model of how stutterwarp works. What is known is that a stutterwarp field propagates by contact - all objects physically connected with a operating stutterwarp will be translocated with the drive. The level of contact required apparently goes down to any atom that is exchanging virtual particles with any object that is being warped. The upshot is that everything inside the ship, including the air, is in sufficient contact to be warped. Objects outside the can still be carried with it if they are undergoing virtual particle exchange with the ship, which in practice means either a very short distance outside it (a few cm or even less) or magnetically coupled to the ship.

We also know the stutterwarp is digital - that is an object is being warped or isn't. There is no "field edge" that will vaporise objects entering or leaving.

An unresolved question is how do stutterwarps interact. If I spin up a stutterwarp of a fighter or missile inside the carrier ship, what happens? What must not be ruled is that it functions normally, because it would break the universe. Consider taking a stock Kennedy; warp 4.812 with 150 MW supplied to a single drive. Now give it 2x 75 MW drives, each of which gives 3.820, or 7.639 summed. 3x 50 MW would give warp = 10.01 etc. So what alternatives are there? I see two:

1. Only one warp field can operate. A second operating drive causes a violation and the ship explodes, or maybe a breaker triggers and both drives instantaneously shut down (exploding if either is charged). Objects must be ejected in a non-warping state, and then spin up.
2. Warp drives destructively interfere with each other. Spinning up a second drive decreases the efficiency of the first, but both are warping the ship. This may produce odd movements of the ship.

Option (1) is simpler, but means care must be taken with all secondary drives carried aboard a ship. This is not much different to reality - igniting a rocket motor or jet engine in a wet ships magazine/ hangar isn't going to end well.

You can't all stop the carrier and warp objects off because the objects would pull the carrier with them. Besides, this would really alter Star Cruiser. The rule would change that ships have to be at all stop to launch missiles. That would add an interesting tactical wrinkle to the game, but it isn't how anyone's ever played it.

Now, how to launch a fighter (or missile). First you can't launch it "forward" whilst warping, because you'd run it over. You have to kick it off the side (at the broadest point of the ship, for the same reason) or off the aft. Ideally you'd keep it connected to the mothership by a wire until it's a little way from the mothership. The stutterwarp field would propagate down the wire, carrying the object with the mothership until the wire is cut. This is more important with submunitions, which are prettymuch a wire guided "missile" - cutting the physical connection makes communication and aiming difficult. It is not absolutely necessary for a missile or fighter (unlike a submunition).

The hangar bay exit probably looks more like a lift than an open hole of Battlestar Galactica. Launches are simply a vehicle pushing off the deck (hull) and then as the distance opens the mothership suddenly warps away the instant the stutterwarp field ceases to couple with the launched object. The launched object then starts spinning up its own stutterwarp.

Now, it would thus appear the more sensible arrangements would parallel real aircraft carriers. The Carrier has hangar(s) with lift(s), and on the deck (hull) of the carrier you could place a rail system to move fighters around on the deck. The flight deck should be clear of obstructions, especially aft. The lifts should be at the forward end of the flight deck rather than the aft, because fighters launch aft (i.e. against the motherships direction of travel). If the deck is loaded, then the aftmost fighters must launch first so not as to crash into others.

Recovery is impossible if the mothership is warping. To land vehicles any ship must come to all stop, and the vehicles must all stop alongside and do a conventional docking. If docking to a rail system then it can be moved to a lift and brought into a hangar. For a non-carrier without a flight deck, just a lift, then the dock must be with the lift proper.

With "battleships" with a large fighter complement, they do not define the number of hangars, or how tightly packed the vehicles are. We don't know their launch rates etc., and I can find no errata to fill this in. Richelieu is listed as normally carrying 6 fighters (Martels as per SC) and 9 landers of similar size. The landers can easily be exchanged for fighters, which would give the Richelieu 15 fighters. This is probably what the writer of Invasion thought about when he had the Richelieu run a ferry mission transporting 15 fighters to Grosshiddenhafen.

If the fighters etc. are being carried at 6x volume, then the total hangar is 6 * 280 (m3) * 15 = 25,200 m3, or 12,600 m3 at 3x volume (with launch rate penalties). SotFA indicates the Richelieu commonly carries ca. MLv477 of small craft, which equates exactly to 15 Martels.  I am not convinced that the SotFA writer didn't mean sixteen fighters. Richelieu is stated to have multiple hangars (and hence lifts), but I guess the two on the Ship Status Sheet would suffice. The Richelieu would be distinguished from a carrier by the lack of a deck to park up a strike, leading to a low sortie rate.

Why Have a Dedicated Carrier

Now, a real dedicated fighter carrier doesn't seem to have that many advantages over a large "battleship", although the large fighter carriage is expensive in terms of mass and money. Think of the cost of armouring large hangars to BB standards.

However, a battleship is very sub-optimal for carrier operations. At least recovery of launched vehicles requires the mothership to "all stop". For a hybrid battleship-carrier this is fatal; the carrier must pull well out of the line-of-fire and conduct landing operations in a helpless state. Maybe there are advantages in launching from all stop. Being at all stop probably allows faster launching because deck and hangar operations are not complicated by the motherships stutterwarp. It may also allow the launched vessels to get their stutterwarps spun up sooner, because:

• They can be "pushed off" simultaneously, without crashing into each other as they are "dropped"
• They can warm up their stutterwarps on the deck without interfering with the motherships warp drive

Non-canonical Fighter Carrier examples


Graf Zeppelin

Contained in a non-canon publication, Michael Bolda's Graf Zeppelin was powered by a 100 MW fission reactor (fusion in text) and carried 8 Udet, 5 Wespe and 9 Gustav fighters. The Wespes and Gustavs were carried in two hangars (each 1/turn), whilst the Udets were all carried externally as fleet defence fighters. This is a relatively sensible arrangement, fitting the hangar/ flight deck split of a real carrier. It had 10 gun mounts for self-defence.

Ark Royal

The RSN Carrier, and is canonical that the RSN have at least one carrier. Wade Racine did a version  which featured 33 fighters (3 Donovans, 15 Wellingtons and 15 Harriers) all on the deck with a small maintenance hangar. The ship was armed and protected pretty well with full screens, armour 5, 20 missiles and 10 guns. There was no cargo which is problematic, not just because life support is only oxygen (food is in the cargo), but that means no spares or carriage of launched weapons.

Marian

Wade's French Carrier. She carried 50 fighters (15 Mistrals, 10 Bufers, 10 Riches and 15 Bonapartes) in 10 hangar bays.



Notes on WW2 Aircraft Complements and Spares

There is a serious issue with assessing carrier aircraft complements in WW2. First there is a doctrinal difference; the USN kept large complements of aircraft on deck rather than in the hangar. This created a large increase in the number of aircraft carried, but created handling problems. This was possible because (1) the USN operated mainly in the Pacific, as the weather conditions in the Atlantic quickly rendered deck parked planes unservicable, and (2) the threat of large land based airforces in the North Sea and Med meant that a deck full of aircraft was an extreme hazard (as happened to the Japs at Midway). It also meant the entire deck park was constant having to be shuffled around, because the deck park blocked either the forward deck (where planes launched) or the aft deck (where they landed).

Second, the USN complements included significant numbers of spare aircraft included in their complements. A standard 1941 US carrier was issued 4 sqns of 18, but none could operate more than 60-65 at once. They carried fewer pilots than planes until ca. 1939, because the objective was to get every available pilot in the air. The introduction of conscription vastly increased the pool of naval pilots, allowing a crew to every a/c (even spares) and eventually even spare crews.

Japanese carriers carried spares, as they were limited in the number of naval pilots. On both Japanese and US carriers the spare a/c were partially disassembled.

RN carriers did not carry spares, and the number of a/c was equal to the number of operational a/c. This was due to several reasons, one of which was all RN carriers were trained in making night attacks, and that required a clear deck.Against the Japanese they indeed started carrying deck parks, but had to make deck redesigns was that, unlike USN deck parks, the carrier was fully capable of landing operations with planes on deck.

Now, we can agree that the US-Japanese practice of having large complements of spare a/c isn't going to happen, as we have limited no.s of fighters. A long-hulled Essex could only carry around 30 operational a/c in her hangar, plus 20 disassembled spares and 50 on the flight deck.

Using a rule of 3 WW2 a/c translates as 1 fighter, and dropping all spares, fighter group equivalents would be:

USN
Saratoga and Lexington: 18 fighters, 6 in hangar and 12 on deck
Yorktown type: 21 fighters: 9 in hangar and 12 on deck
Essex class: 28 fighters, 10 in hangar and 18 on deck

RN
Eagle and Hermes: both 6-8 fighters, all in hangar
Furious: 12 fighters, all in hangar
Courageous and Glorious:  16 fighters, all in the hangar
Ark Royal: capable of 24 in the hangar (3x volume), but only 18 carried for increased sortie rate
Illustrious etc.: 12 fighters, all in hangar in early war. Later 6 added as deck park.
Implacable and Indefatigable: 28 fighters, 16 in the hangar and a 12 fighter deck park

IJN
Kaga and Akagi: 24, all hangared
Rjujo: 16, all hangared
Soryu and Hiryu: 21, all hangared
Chitose and Chiyoda: 10, all hangared
Shokaku and Zuikaku: 24, all hangared
Hiyo, Taiho, Amagi and Unryu: 18, all hangared
Shinano: 16, all hangared

I generally think this is a good guide to complements for any Star Cruiser Fighter Carriers.


Building a Fighter Carrier

Fighters are a relatively recent phenomenon in 2300AD ship architecture. Assuming a misprint in the Donovan (which you have to, she's clearly not 2220's tech but rather 2270's) then the oldest fighter designs date to the 2270's. The British fighters are 2270's, and the oldest listed French design is 2280's. Hence any carriers must be relatively recent.

In a previous write-up I utilised the IRL examples of the RN Furious, Glorious etc. to provide a basis for a story, and had used a building Desarge 8860 as a basis of a carrier. The ship itself has two spin habitats (apparently); a large passenger habitat ca. 30,000 m3 in volume and a smaller forward crew habitat with the ships controls, sensors etc. Aft is the 180 MW fuser, the engineering, and I'd guess a small docking bay for spaceplanes etc.

The Desarge 8860, scanned from the Director's Guide

In a carrier conversion we could use the large hab ring as our deck. It is well clear of the general hull, allowing for ease of launch. The 30,000 m3 volume would, if used entirely for hangars, would house around 18 heavy fighters (280 m3) at 6x volume. The principle carrier based fighter is a Martel, which takes ca. 200 m3 of total volume (of which only ca. 140 m3 is interior volume). 30,000 m3 would make 25 fighters. Thus perhaps either 18 (3 sqns of 6) or 24 (3 sqns of 8) are appropriate.

Appendix: Nukes

All nuclear devices used in det-weapons must be pure fission devices. Fusion reactions don't produce X-rays but rather fast neutrons. In the modern H-bomb these neutrons are used to trigger a rather inefficient fission process. The "bomb-jiggle" makes this boosting basically impossible with a det-weapon. The 2 ton 10x2 device is approaching the size of the largest pure fission packages built in the 1950's, and the physics hasn't moved on that much. However, there is a catch.

The design of a det-weapon essentially precludes implosion type nuclear devices. The initial chemical explosion would destroy the lasing rods before they fired. Thus the det-weapon must be a gun-type device, with a slug of U-235 fired into a another mass of U-235 to achieve criticality. This rules out plutonium as our core, as it is impossible to make a plutonium gun-type device. With such a weapon we want the nuclear device to be at the rear of our det-weapon, to maximise the length of the rods and increase range. Gun-type devices are also safer; an implosion device can be initiated by an impact, whereas gun-types can't.

The largest gun-type weapons were in the 20-30 kT range. This is essentially the practical limit for U-235 gun-types. Thus our 10x2 is likely a 20 kT device, and the Kafer 14x2 is essentially approaching the maxima for this technology.

Thus, is used simply as an explosive in the atmosphere, for every damage point make it 10,000 explosion points. A 10x2 would detonate as an EP = 200,000 explosion. The contact damage should decrease with range^2, and a 10x2 20 kT explosion would only penetrate an armour-10 hull is the detonation is within 20 m of the hull, and about 40 m for a civilian spec hull. However, if you detonated a nuke really "in contact" then an area 20-40 m from the device will be vaporised.

That's how I also played. Once you'd kicked a target out of stutterwarp then the next missile could forego the det-pulse and simply explode "on impact". In a practical sense the fuse will likely be the engine, which will couple to the mass of the ship in the last cycle before impact and the increased load be trigger the nuke.

As an aside, det-weapons are still "melee" weapons on a Star Cruiser board. The effective range of the incoherent, collimated beams (which are not laser beams) is in the 10's or a few 100 km. Det-weapons can't be realistically fired beyond the same hex.

Appendix: Bombs

In the pictures several fighters are shown carrying long, thin objects under their wings, and in the Bufer picture these objects being launched with chemical rockets. These fit large, single submunitions better than stutterwarp equipped missiles. Such a weapons system would suit the fighter much better.

Submunitions dispensers took 6x the volume of their warheads, except those whose masses were added in errata, where the number was only 4.5x.  In these latter cases it could be argued that a decreased rate of fire (i.e. every other turn) might be appropriate.

Externally carried vehicles (including ordnance) has no restrictions on launching, and all can be launched in a single turn. There is an issue regarding control of multiple submunitions, but as long as there is a fire control system then all can fire (against a single target) in a single turn.

The upshot is that if, say a Buffer, had 4 10x2 "bombs" instead of missiles then it could make a close approach to an enemy ship and simultaneously drop all 4 bombs against the target. Each would make their own attack roll, but there would be no point defence rolls. Such an attack is potentially far more devastating than a missile strike, especially if fighters attack in squadrons. A solid cruiser or battleship may easily be wrecked by such a strike.

Each bomb would be a warhead package (mass in tons = no. of strikes * damage per strike/10), and a simple navigation package (.1 tons). This assumes no rocket. However, if the submunitions dispensers extra mass/volume over a missile tube (2x volume of missile) is the chemical rocket then it's a hell of a rocket - a 67% fuel fraction is enough for a surface to orbit launch. Rather I suspect this is the extra mass of having a trainable launcher. If a "bomb" is a fixed single arc (i.e. shoots straight forward) then the train is avoidable.

I thus propose the following "bombs" in the French inventories

Bombe, légère, modèle 2 (L-2): an older weapon still in use due to large stockpiles. Now only carried by Martels due to the installation of a trainable launcher for this ordnance (LL-2). Warhead = 3x1, mass = 400 kg, cost = Lv55,000
L-6: the replacement for the L-2 is a significantly larger weapon designed to maximise the surface damage to a ship. Typical weapon for attack on lightly armoured targets or to destroy the sensors and weapons systems on armoured targets. Warhead = 6x1, mass = 700 kg, cost = Lv80,000
Bombe, antiblindage, modèle 3 (AB-3): the standard anti-warship bomb employed during the CAW and early WoGR. Licenced copies still in production as the standard ASF anti-ship weapon. Warhead = 5x2, mass = 1,100 kg, Cost = 210,000
AB-5: The heaviest warhead currently produced by France. It is the current standard anti-ship weapon equipping front line fighter units. Warhead = 10x2, mass = 2,100 kg, cost = Lv405,000




Appendix: Volumes for French Fighter Carriage

The following is a list of external volumes for fighter carriage:

Martel: 200 m3
Mistral: 140 m3, exclusive of slung ordnance (Note: backengineering shows the omitted armour rating is 7. Streamlined as spaceplane)
Riche: 100 m3, exclusive of slung ordnance
Bufer: 120 m3, exclusive of slung ordnance
Bonaparte: 220 m2

External stores for the Mistral, Riche and Bufer should be added.

The Bonaparte has an internal launched weapons store. In practical terms it's around 50 m3, so maybe 4 10x2 with all angle firing.