Star Wars Ship Design Technical Notes 1

posted in: Design notes | 25

1. Power generation is the most important metric for a warship. Power gets turned into weapons fire, acceleration, and shielding. Everything that a warship actively *does* depends on how much power it generates.

2. Volume is the most important ship dimension, because power depends on the volume of the reactor(s). Reactor volume is proportional to total volume, but this can be short circuited a bit by letting the reactor partially protrude in a bulb. A ship with a bulb devotes proportionately more of its volume to reactor than a ship with totally internal reactors, for a given overall wedge shape.

3. Mass is the second most important ship characteristic. The ratio of power to mass determines how well a ship moves.

4. Square-cube law still exists. Increasing length proportionally increases surface area by the square of the increase, and volume by the cube. An 8km ship the same basic shape as a 2km ship is not 4 times bigger, it is 64 times bigger.

5. Warships maximize the volume to surface area ratio. Surface area means more armor (and mass), and more shielding requirements. Combat ship design will trend towards increasing volume for power (see rule 1) and reducing surface area to concentrate armor and shielding.

6. Power is used. Weapons are energized by the reactor, and at full power draws most of the ships’ generating capacity. Not a hard and fast rule, but since combat designs trend to high power and low surface area, that means armament of such ships becomes more and more prominent. Big ships need to mount big (or at least more) guns, on proportionately less space.

7. It is easier to cut mass than add mass. People go the other direction. But in structures, higher mass needs special structural arrangements to handle higher stresses. Removing mass leaves a basic hull girder stronger than it needs to be, so it’s a simpler way to go. Doing so will increase agility because mass is removed, but engines and power remain the same.

8. Storage volume is cheap, protected volume is not. Fighters, troops, etc. need open air space inside the hull. That’s cheap. But if that volume needs to be covered with armor and shielding and structure to take heavy blows, then it becomes expensive. If the protected volume expansion for these things does not include more space for reactor, power to weight goes down, and the ship is for its size less able to fight. Carriers will suffer from this. You will see carriers being “cut out” from bigger ship designs, incidentally opening space for hangar apertures and improving their ability to run away. But you won’t see lightly built ships with light hangars up-armed into battleships, because they don’t have the structural strength or weight tolerance there to begin with.

9. Wedge shapes are used in universe because they offer clear fire arcs. Warships that are expected to maneuver tend to be that shape so that at least in one direction (forward or top usually), most of its guns can bear. A gun that can’t point onto the main target is extra weight and cost. The larger the ship, the more all-round arcs needed because it won’t be able to maneuver to keep more agile targets in firing arc, so they will have more guns on less efficient (line of sight to target uptime) positions. But a fast ship like a destroyer will have “blind spots” because it is expected to maneuver, and can’t absorb the weight and cost increase of having guns everywhere. Efficiency matters more as designs get smaller.


Because of all this, the nastier a ship gets vs other ships in a slugging match, the more compact it gets, and more of its surface area gets covered with guns. DUH right? Well, here’s the logical basis for that design outcome. Sleek ships are more aesthetic and more in line with something like Executor. But before you complain about how giant battleships look, consider that if you take a super sleek ship, and it’s probably proportionately underarmed, undershielded, and underpowered. Function over form, to a certain extent.

25 Responses

    • Fractalsponge

      I think these TIE tank ideas in general are rather stupid. Because you’d totally make ground vehicles the same way as something designed for multi-thousand g acceleration in vacuum… It’s like attaching tracks to an F-22. Pointless and probably far more expensive than you need for a self-propelled ground vehicle. This is one of those “concept design for concept design sake run amok” sort of design decisions.

      • gorkmalork

        I’d give the Mauler *slightly* more credit for traverse range that doesn’t involve zapping off its own treads, but agreed either variant makes AT-STs look all but tactically sound by comparison.
        *visualizes a super-bored walker squad playing Ultimate Soccer(C) with TIE-tank cockpit balls*

      • Spaceman 28

        I love the Tie Crawler though! Although that is probably just from the lego set.
        I just think it looks awesome. Despite the fact it would be very ineffective.

        • gorkmalork

          Could be an offbeat Sienar attempt to branch out for the civilian ATV market.

        • CRMcNeill

          I think the TIE Crawler would be a bit more effective with heavy gun sponsons on the outer edges of the treads, ala a WWI tank. And without the need to power repulsorlifts and the like, a lot of power could be diverted to pushing the weight of heavier armor, or even a magnetically sealed hull to give it better durability.

      • Grand Admiral Declann

        A kid with a Nerf toy “Blaster” runs up to TIE/Crawler. Shoots dart at the cockpit, dart bounces off. TIE/Cr viewport shatters inward. “What are you DOING?!?!” The TIE/Cr Pilot screams out of his new Window. “This is an Imperial Armored Assault! Get out of here before you get hurt!!!”

      • CRMcNeill

        Considering TIE mass-production, the TIE Crawler could be an attempt to use available material (TIE cockpits) to make one of these:

        The concept from the WEG Imperial Sourcebook is a force multiplier that allows a single crewman to control a large area. It requires heavy droid-brain / automated support to function effectively, but it works fine against mid- to low-tech populations that lack the resources to jam the automated systems.

  1. StellarMagic

    While many guns are useful, each gun battery needs fire directors and when the bridge has a crew pit of thousands of fire directors trying to direct the fire of the ship as the captain commands them then… combat efficiency almost certainly begins to fall off.

    This is a very real and historic problem with warship design, with no real good solution besides trying to find the optimum number of guns for a ship that size with X number of fire controllers. When you start building ships in the multi-kilometer scale, there probably has to be dozens of gunnery officers to coordinate the fire directors as an additional layer of organization. Still, this only negates the issue to a degree.

    Perhaps this is why we see fewer visible guns on the largest of vessels? The decline in efficiency of coordinating that many guns made them less useful, with power instead being directed more toward shields and engines.

    • Fractalsponge

      In setting, astromech droids can plot hyperspace jumps. I think computing power in support is not really a problem. Manual gunnery direction I imagine is largely target prioritization. Batteries would be slaved to central control, and fire in linked volleys for large ships. There’s a limit for how well huge main batteries can be controlled, but for city-sized warships you could easily have 5 or 10 independent gunnery direction teams, separately controlling by quadrant or something.

      • StellarMagic

        There’s a lot of canonical visual evidence that Imperial starships use human gunners for most of their weapons, though most of it is from smaller gun positions. We even see a gun director make a critical mistake in ANH when he stops the guns from destroying C-3PO and Artoo in their escape pod, and individual two-man gun crews operating weapons both in ANH and Rogue One.

        On the flip side, there is evidence of centralized firing control from separatist starships, droids on the bridge of munificent class-frigates firing turrets on the bottom hull for example.

        Another possible reason for bigger ships to seem ‘underarmed’ is that bigger guns might need more heat dissipation in the form of cooling systems, capping the number of guns that could be fitted to a ship (heat generation goes up by volume, heat dissipation goes up by the radiator area). If they function as up-scale blaster weapons… they might also need a massive reservoir of blaster gas in addition to power from the reactor.

        • Fractalsponge

          Gun director in ANH my have been a battery direction center, not a single turret. In any event, control must be possible, or the thousands of individual weapons mentioned for the larger structures would be pointless.

          I’m not sure radiators are (purely) area based. The tech is supposed to be based on generating energetic neutrinos that exit the ship, being largely able to pass through most matter. At that point, radiators can be stacked.

          • StellarMagic

            Whoa… that’s an interesting piece of tech, converting thermal energy to energized neutrinos. I’ve never heard that before, neat.

            As for the large number of guns being coordinated by human officers and gunners… it can be done, but it’s a bit like coordinating an old fashioned artillery division. The lag from the order being given on the bridge to the gun crews receiving the order is probably quite large, as you’d need several layers of commanders and coordinating officers.

            Lets say we have a Imperial II-class Star Destroyer. Going with the legends armament we have…

            8x Octuple barbette turbolaser batteries
            20x Heavy ion cannons
            126x Turbolaser batteries (50 heavy, 76 other)

            Legends gives us a total number of 330 gunners for the Imperial-II, this works out to about 2.1 gunners per battery, which is consistent with the observed number of 2 gunners per gun in ANH and Rogue One. Since World War II, a battery usually refers to a single turret on a battleship… unlike on land where it could be a collection of individual guns. I think that in Star Wars both uses of the term may be correct, in which case its possible multiple gun turrets are slaved together to form batteries of the smaller guns, though the second usage is probably more used for smaller guns.

            To coordinate those guns from the bridge… you’d probably end up with an organization like this.

            > Main Battery – Commanded by a gunnery officer on the bridge.
            >> 2 Fire Controllers/Directors each commanding:
            >>> 4 Octuple barbette turbolasers

            > Secondary Battery – Commanded by a gunnery officer on the bridge.
            >> 2 Fire Directors each commanding:
            >>> 3-4 Fire Controllers each commanding:
            >>>> 3-4 Heavy turbolaser batteries

            > Tertiary Battery – Commanded by a gunnery officer on the bridge.
            >> 4 Fire Directors each commanding:
            >>> 4 Fire Controllers each commanding:
            >>>> 4-5 Turbolaser batteries

            > Ion Battery – Commanded by a gunnery officer on the bridge.
            >> 4 Fire Controllers/Directors each commanding:
            >>> 5 Heavy Ion Cannons

            > Tractor Beam Battery – Commanded by a gunnery officer on the bridge.
            >> 3 Fire Controllers/Directors each commanding:
            >>> 3-4 Tractor Beam Projectors

            This is manageable, it’s roughly the same level of organizational complexity as you’d see with a modern artillery battalion, whereas larger ships would have larger organizational structures. Like this for an Executor-class Star Dreadnought.

            > Main Battery – Commanded by a gunnery officer on the bridge.
            >> 2 Fire Zone Coordinators commanding:
            >>> 5 Fire Directors commanding:
            >>>> 5 Fire Controllers commanding:
            >>>>> 5 Battery Directors controlling:
            >>>>>> 8 Heavy turbolasers – Slaved to the battery director.

            > Secondary Battery – Commanded by a gunnery officer on the bridge.
            >> 2 Fire Zone Coordinators commanding:
            >>> 5 Fire Directors commanding:
            >>>> 5 Fire Controllers commanding:
            >>>>> 5 Battery Directors controlling:
            >>>>>> 8 Turbolasers – Slaved to the battery director.

            > Concussion Missile Battery – Commanded by a gunnery officer on the bridge.
            >> 2 Fire Zone Coordinators commanding:
            >>> 5 Fire Directors commanding:
            >>>> 5 Fire Controllers commanding:
            >>>>> 5 Heavy concussion missile tubes

            > Heavy Ion Battery – Commanded by a gunnery officer on the bridge.
            >> 2 Fire Zone Coordinators commanding:
            >>> 5 Fire Directors commanding:
            >>>> 5 Fire Controllers commanding:
            >>>>> 5 Heavy ion cannons

            > Tractor Beam Battery – Commanded by a gunner officer on the bridge.
            >> 2 Fire Directors commanding:
            >>> 5 Fire Controllers commanding:
            >>>> 4 Tractor beam projectors

            > Point Defense Battery – Commanded by a gunnery officer on the bridge.
            >> 4 Fire Zone Coordinators commanding:
            >>> 5 Fire Directors commanding:
            >>>> 5 Fire Controllers commanding:
            >>>>> 5 Point-defense laser cannons

            This is also manageable, but also quite a bit more unwieldy. Increasing the armament beyond this would require even more layers of coordination and control… You’d end up with regional gunnery command centers like what the Death Stars had to manage the firepower.

  2. Anonymous

    Would you consider redesigning the Executor so that it would not look so underarmed? I know the ship is supposed to have over 5,000 weapons but it has so much barren space as well. If equipped with two or more reactor domes on the bottom it could wield more guns and better shielding. Plus, it would be cool to see the superstructure up close to see all the details and gun mounts.

    • gorkmalork

      Fractal doesn’t exactly seem short on projects as it is, and that one (appealing though I find it) sounds like too much tinkering *not* to get amply compensated for. ‘Sides, the whole ‘barren space’ thing seems as much an SFX limit for the original model as anything-with a ship that size, most shots containing all or even a fair portion of it just won’t be close enough for visible Impstar-scale batteries, barring a handful of TESB & ROTJ frames, and the modelmakers who slapped it together probably didn’t have our flavor of retroactive design discussion in mind.

      That said, I did waste some time doodling a ridiculous hypothetical Executor refit for one of the Legends!New Republic’s captured examples; at the moment all I have is a crap-tastic pen-doodled broadside shot, but I might have to see if a few more perspectives turn out any better.

  3. Anonymous

    So since this is the first notes how many more notes are you going to make later?

    • Fractalsponge

      As many as I can think of/have time to make. It’ll be a series of posts, but not sure how many yet.

Leave a Reply