The Diminishing Returns of "Big Ships are Better"

[nakorkren (OP)]

Everyone knows that bigger ships are more efficient in terms of what % of mass you have to spend on armor vs how much tonnage of useful internal components you can protect behind that armor. This occurs because the surface area of a solid grows more slowly than the volume of a solid. I decided to take a look at the actual numbers for this to figure out if there's a point of diminishing returns, using tonnage of armor divided by non-armor tonnage for two different amounts of armor (1 row and 10 rows) at a specific level of armor tech (laminate composite). My results are in the attached picture, but for the tech level I'm at, it seems that somewhere around 50 to 60k tons, the mass fraction has gotten pretty dang good and isn't going to get a whole lot better no matter how much bigger you go. As a result, this tells me it's not worth building ships much bigger than that unless you have a specific reason to do so, at least not to chase armor efficiency.

Side note, I usually run with around 6 to 7 rows of armor plus shielding equivalent to ~2 rows of additional armor, so for rows of armor less than 10, the point of diminishing returns is below 50k, maybe in the 40k range.

[nuclearslurpee]

There is a lot more to big-ship efficiency than just armor. In fact, probably the biggest benefit of large ships is efficient use of your most powerful officer bonuses as not only a ship captain but a subordinate commander in an auxiliary bridge, CIC, etc. has a bigger impact on a bigger ship, particularly since some of these bonuses are comparatively rare (personally I tend to see a dearth of Engineering and Tactical skilled officers for example). Bigger ships also provide the necessary rate of return to justify a "full set" of officer modules, whereas smaller ships are often better served by mounting an additional gun, engineering space, etc.

There are also numerous other component-based efficiencies. For example since a larger ship class will have fewer members, if you give each, e.g., a large active sensor then there is less replication of the same sensor capability across a fleet than if you had twice as many ships, half the size, with the same sensor. This means more tonnage dedicated to primary mission payload as well. Similar applies for components such as ECM, can apply for fire controls + ECCM depending on how you design the ship, etc. Engine efficiency is also potentially a consideration, as larger engines are more fuel-efficient and the largest engines are 400 HS (20,000 tons), if you mount multiple engines for redundancy then you can potentially make big gains in fuel efficiency and/or overall performance with ships on the order of 100,000+ tons.

That being said, bigger is not always strictly better and there are many cases where smaller ships will do the necessary work more efficiently. Smaller sensor ships or scouts are a common example. Another fairly common one is spinal lasers, as more (smaller) ships means more spinals and there is no other way to accomplish that. Ultimately, ship size is not as simple as "bigger is better" and it depends on what the mission profile and design + fleet doctrines are as well as what your race is capable of at any given point in the campaign.

[kilo]

@nuclear

You forgot to mention the component that gives you the largest benefit when using large ships. This is shield generators, as 4 ships with one generator each are far more vulnerable than one ship with 4 generators. There is no cost or displacement benefit involved here, but a large ship can use the full shield regeneration of all generators the moment it comes under fire. Compared to that, a fleet of smaller vessels would simply lose out on regeneration here.


@narkorkren

Larger ships are still generally better than smaller ones, the problem I see is the fact, that build times and cost go up and up. This limits you to having very few large vessels, which simply cannot cover an empire. On top of that they might be too expensive to be used against smaller fleets or even single vessels, as the fuel consumption of such an behemoth can be painful.

[Jorgen_CAB]

You don't just build you ships big because they are big... you do that so you get higher efficiency for the tonnage of ships that you can maintain in your fleet.

The size and how many ships you build should depend entirely on your need and capabilities. You can't split a 100kt ships in two so you need to be sure that a single ship is enough to do the job in one place... if you need to be in two places at once and 50kt would suffice then you should have a few smaller ships as well. But from a power projection point of view a single 100kt ship will always be much more efficient than ten 10kt ships mounting the same weaponry. The only thing that a bunch of smaller ship can have that a single large one can't are spinal lasers.

There also is the fact that some ships are more specialized than others so keeping them smaller means you can tailor a force a bit better and be more dynamic in that sense, this is where the different roles comes in. Such as escort, primary offensive ships or scouts.

Smaller ships are allot more stealthy so they go faster without being detected by thermal sensors.

In my opinion you probably want a mix of small, medium and large ships in any fleet... the amount of each type should simply depend on your doctrine.

I have rarely encountered production speed to be a problem with larger ships as it is quite easy to have enough yards to produce far more ships than you can afford most of the time, especially if you produce allot of small ships. I also have never really seen larger ships being more expensive than smaller ships in general... I would say that it mostly is the other way around if you calculate cost per tonnage. Also, as noted above... capitalize on good officers and concentrate them on larger ships is quite important too.

Another thing that might be important is the number of ships that may operate independently with a jump tender or squadron leader. If the jump tender is designed as a leader in a squadron and it may jump four ships you might design that squadron of ships as an independent group working as one unit. This is generally good for advanced scouting forces when scouting in strength. I usually group my escorts into squadron like this so they generally are smaller than primary offensive ships for that reason as they never really operate on their own when far from a base of operation. They might deploy on their own in a scouting capacity within a certain system but they rarely jump into a system on their own or in smaller numbers than the squadron size.

So... there is no real good answer to if the size of a ship you should build. It should come down to what capabilities you have for building them and the overall needs for being in many different places. Both in terms of strategic and/or tactical deployments.

Personally I often build my primary offensive ships as large as I can and with commercial engines to keep logistical costs down, my escort then are as big as I can make them with military engines supported with a military jump tender in a squadron formation. I then have fleet scouts which usually are quite small who are the main eyes of the fleet in addition to a plethora of small crafts that do all manner of stuff. The escort are my main patrol and reaction force within my borders and the really large ships simply are my space superiority assets I bring forth when I need real serious military fire power.

[nuclearslurpee]

@nuclear

You forgot to mention the component that gives you the largest benefit when using large ships. This is shield generators, as 4 ships with one generator each are far more vulnerable than one ship with 4 generators. There is no cost or displacement benefit involved here, but a large ship can use the full shield regeneration of all generators the moment it comes under fire. Compared to that, a fleet of smaller vessels would simply lose out on regeneration here.

This applies to a point, but the OP is talking about ships which are already quite large and arguing that the benefits of going even larger are quite marginal. This size is generally I would say large enough that you will be using the maximum shield generator size either way. Even at MaxTech the largest generator size is 50 HS (2,500 tons) which will be used whether a ship is 50,000 tons or 500,000 tons, and of course we are not necessarily using MaxTech here in which case the largest available generator will be even smaller.

[Jorgen_CAB]

Another thing that you might not consider is the overhead cost of retooling and serial production. How many ships do you expect to produce of a certain class. Smaller ships usually probably have a slightly less overhead cost in terms of retooling as they usually build in larger series for the same tonnage as they need less yard space to produce the same amount of tonnage so they can benefit from serial production more efficiently than larger ships. I think that is more important than higher production capacity for smaller ships.

I also think you come to a point where larger ships becomes logistically problematic and it might not be worth the time and effort. Where this limit is hit is hard to say though, probably depend on the size and productivity of your civilization.

[nakorkren (OP)]

As nuclearslurpee said, I am really looking at the marginal improvement of going bigger than~50k tons, and at that point the increases in efficiency is fairly small, whether you're looking at engines, shields, command modules or even officers. I'm thinking 50 to 60k is big enough to get excellent size efficiency without being so big you can't meaningfully divide your fleet.

[Jorgen_CAB]

The only ships that I usually build that are really large like 100kt or more are super carriers who use commercial engines which reduce both logistics and cost of your overall fleet without sacrificing firepower. These ships are super difficult to destroy by any means without needing as much internal space for defense as other "big" ships. You also can produce them relatively quickly so only need one yard with one or maybe two slipways. The engine is otherwise a huge cost of ships, you also get away with low cost for engine research. Carriers also can operate at slower speeds than other ships and still be very effective. I also often find that thermally reduced super carriers can operate at decent speeds without being detected by passive thermal sensors and will not need to pay through their nose for those engines.

Otherwise I probably agree that around 50kt is about optimal for most other capital ships. It is large enough to capitalize on the most efficient ship components and having strong defenses and utilize officers relatively well. Whether you draw the line at 40kt or 70kt is more a matter of taste and need in my opinion.

Having options of both really big ships and smaller or medium sized ones should not be underestimated. I really don't see either extreme to be very good in general even if they can work.

[misanthropope]

im increasingly a fan of the "24 ship doctrine".  the total battle line meat of starfleet is 24 ships, however large that requires them to be.  often... charmingly large. 

the granularity is sufficient to allocate force among fronts, and by golly you don't waste precious naming effort on a ship that won't be significant to the plot.  "player" is as scarce a resource as any other....

[Demetrious]

Everyone knows that bigger ships are more efficient in terms of what % of mass you have to spend on armor vs how much tonnage of useful internal components you can protect behind that armor. This occurs because the surface area of a solid grows more slowly than the volume of a solid. I decided to take a look at the actual numbers for this to figure out if there's a point of diminishing returns, using tonnage of armor divided by non-armor tonnage for two different amounts of armor (1 row and 10 rows) at a specific level of armor tech (laminate composite). My results are in the attached picture, but for the tech level I'm at, it seems that somewhere around 50 to 60k tons, the mass fraction has gotten pretty dang good and isn't going to get a whole lot better no matter how much bigger you go. As a result, this tells me it's not worth building ships much bigger than that unless you have a specific reason to do so, at least not to chase armor efficiency.

Side note, I usually run with around 6 to 7 rows of armor plus shielding equivalent to ~2 rows of additional armor, so for rows of armor less than 10, the point of diminishing returns is below 50k, maybe in the 40k range.

This kind of work and these kinds of discussion threads are what make me really love this community. The mathematical hivemind that it can bring to bear on any discussion of balance or numbers far exceeds what even a small team of mathematically adroit devs could do.

Given that Steve has been proactive in his efforts to benefit smaller ships of late (single-weapon fire controls, fewer-shot railguns etc.) I'd say the tonnage economies innate to concentrating functions in fewer hulls definitely bites fighters/FACs less. The exception would be mid-range ships. Putting aside Jorgen's (good) point about specialization - is it perhaps possible that mid-range ships don't need to be good? Steve's latest British Empire AAR where he jumps from 18,000-20,000 ton warships right to 60,000 ton "Dreadnaughts," mirroring the real life jump from pre-dread battleships to dreadnought-style warships does make me wonder. Destroyers, as well, started as 600-1000 ton glorified torpedo boats and eventually ended up as the modern 2,000 ton, fast, powerful well armed thoroughbreds that came to define the word "destroyer" in WWII and beyond. (An Arleigh-Burke is not a destroyer.  A 10,000 ton ship with a dual-purpose main weapon system, capable of escort and independent ops, and operating two ASW aircraft from hangars is the definition of a heavy cruiser. Don't @ me!) It might be okay for ships under that point of diminishing returns to eventually be disfavored except for specialized roles simply because the maximum size of warship is determined more by technological/industrial limitations at the time than inherent feedback loops of engineering and efficiency.

Also, how does shock damage (which is supposed to be the great equalizer here in many respects, if I recall correctly) factor into the efficiency vs. redundancy conversation? Obviously, the more shields a ship can carry the less it fears shock damage, but I do not a lot of players (myself included) prefer to go skimpy on shields and rely on armor for protection for sheer tonnage efficiency anyways.

That might be a mistake with larger ships, with the threshold of "mistake" something we could probably chart on a graph comparing shield generator efficiency against armor efficiency...

"player" is as scarce a resource as any other....

Quoted for truth.

[nuclearslurpee]

Given that Steve has been proactive in his efforts to benefit smaller ships of late (single-weapon fire controls, fewer-shot railguns etc.) I'd say the tonnage economies innate to concentrating functions in fewer hulls definitely bites fighters/FACs less. The exception would be mid-range ships. Putting aside Jorgen's (good) point about specialization - is it perhaps possible that mid-range ships don't need to be good?

I would say that this is generally a correct and insightful observation. Really the point of the "mid-range" in practice tends to be "this is how big my shipyard is" at least in Aurora. You generally observe something similar in the last century or so of wet naval practice with the capital/escort dichotomy, both in the battleship era (the WWII heavy cruiser classes were broadly considered the least useful hulls and most naval powers transitioned to building mostly or entirely CLs by wartime) and the modern carrier task force era (10,000 to 15,000 ton escorts plus 100,000+ ton supercarriers, in the USN), an order of magnitude difference between capital and escort tonnage is pretty typical and the midrange tends to be filled by stopgap, treaty, etc. classes which are not generally considered optimal even if the designs are sound enough.

An interesting phenomenon with Aurora is that you generally will see the tonnage scale for both capital and escort/small ship designs increase over the course of a campaign, for capital ships this tends to be driven by shipyard sizes but this also holds true for smaller classes as new technologies and components are introduced and in some cases as components get bigger and require a larger ship to be used effectively. Your early PD ships might mount a battery of 10cm railguns and be 8,000 to 10,000 tons, but later designs may creep up to 15,000 tons to mount ECM/ECCM, CIC, more fuel or bigger engines with lower boost for longer range, and so on. Another example is the classic small ship for JP defense which in the early game could be a FAC sporting a 30cm plasma cannon, but later on may need to be a 3,000-tonner with a 60cm spinal laser with attendant ECCM module. This is yet another nuance we don't really see from the NPRs who tend to deploy the same size of ships at any tech level (in the same undersized fleets to boot), but for player races it is an interesting and organic evolutionary process.

[Demetrious]

An interesting phenomenon with Aurora is that you generally will see the tonnage scale for both capital and escort/small ship designs increase over the course of a campaign, for capital ships this tends to be driven by shipyard sizes but this also holds true for smaller classes as new technologies and components are introduced and in some cases as components get bigger and require a larger ship to be used effectively. Your early PD ships might mount a battery of 10cm railguns and be 8,000 to 10,000 tons, but later designs may creep up to 15,000 tons to mount ECM/ECCM, CIC, more fuel or bigger engines with lower boost for longer range, and so on. Another example is the classic small ship for JP defense which in the early game could be a FAC sporting a 30cm plasma cannon, but later on may need to be a 3,000-tonner with a 60cm spinal laser with attendant ECCM module. This is yet another nuance we don't really see from the NPRs who tend to deploy the same size of ships at any tech level (in the same undersized fleets to boot), but for player races it is an interesting and organic evolutionary process.

Indeed. I sometimes see this in reverse as well, especially for smaller ships, and I often think back to the US's inter-war submarine experiments, where they experimented with concepts such as large "cruiser" submarines and smaller S-boats. The eventual optimal was reached in the WWII fleet boats like the Sargo and Gato classes, which were of intermediate size between the prior attempts, and outperformed them both. It's simply because the technology required to reach that optimal balance was finally achieved, whereas prior attempts were bumping up against inherent limits that forced various engineering trade-offs. You see much the same with tank development; where the entire doctrine of light/medium/heavy tanks was eventually devoured by the Main Battle Tank; larger than some predecessors and smaller than others.

[Jorgen_CAB]

Also, how does shock damage (which is supposed to be the great equalizer here in many respects, if I recall correctly) factor into the efficiency vs. redundancy conversation? Obviously, the more shields a ship can carry the less it fears shock damage, but I do not a lot of players (myself included) prefer to go skimpy on shields and rely on armor for protection for sheer tonnage efficiency anyways.

That might be a mistake with larger ships, with the threshold of "mistake" something we could probably chart on a graph comparing shield generator efficiency against armor efficiency...

It is very difficult to calculate the value of shields as there are no mathematical way to know how important protection against chock and the regeneration effect of shields will impact the overall efficiency.

The only thing I know is that shields is a very powerful tool in most real practical situations that I have used them. I usually see them as a force multiplier in terms of defensive power. Shields obviously have less hit points than the total armour points on a ship on a ton for ton comparison. If shields did not have that they would be seriously over powered.

[nuclearslurpee]

Also, how does shock damage (which is supposed to be the great equalizer here in many respects, if I recall correctly) factor into the efficiency vs. redundancy conversation? Obviously, the more shields a ship can carry the less it fears shock damage, but I do not a lot of players (myself included) prefer to go skimpy on shields and rely on armor for protection for sheer tonnage efficiency anyways.

That might be a mistake with larger ships, with the threshold of "mistake" something we could probably chart on a graph comparing shield generator efficiency against armor efficiency...

It is very difficult to calculate the value of shields as there are no mathematical way to know how important protection against chock and the regeneration effect of shields will impact the overall efficiency.

The only thing I know is that shields is a very powerful tool in most real practical situations that I have used them. I usually see them as a force multiplier in terms of defensive power. Shields obviously have less hit points than the total armour points on a ship on a ton for ton comparison. If shields did not have that they would be seriously over powered.

I honestly wonder if shields are possibly too strong after the early to mid tech levels, since they do not scale linearly, but given that for armor a practical rule of thumb is that it takes eroding ~50% of a ship's armor before internal damage becomes frequent and catastrophic - a very approximate rule, but sensible in general - if shields are even "only" 50% as size-efficient as armor at typical tech levels this would make them in practice just as good, and then better because of the additional advantages of shields (ignore weapon damage profiles, recharge vs repair, corbomite vs duranium to build, etc.). I would guess that probably to be reasonably balanced one would expect shields to be roughly ~33% as efficient as armor per ton, somewhere in that 25-40% range is probably reasonable.

For example the following Epsilon-level (15k RP) shield:

    Shield Strength 119
    Recharge Rate 75     Recharge Time 476
    Cost 194    Crew 25      HTK 5
    Size 25 HS  (1,250 tons)Development Cost 984 RP

    Materials Required
    Corbomite  194

has an efficiency of 4.76 points per HS, which compares to roughly Laminate Composite Armour (20k RP) which has 12 points per HS, so the shield is just under 40% as efficient as armor at the same tech level, which is pushing the upper bounds of "balanced". The efficiency can only get better since shield strength scales with generator size to the (3/2) power, and size maxes out at 50 so the tonnage efficiency of shields will eventually exceed 50% that of armor. So probably around the point where you start talking six digits for tech costs I'd be willing to bet that shields become basically superior in nearly all cases, at least for military ships.

This is probably a bit exacerbated by the fact that there is no real anti-shield weapon in the game. The bonus damage HPMs have is not really that much in raw damage per increment, and while railguns are fairly effective against shields compared to lasers, lances, etc. this is not saying a lot as the latter weapons are just countered strongly by shields.

...

Also, as an aside: when speaking of shock damage it may be useful to note that a chock is something rather different. 

[nakorkren (OP)]

This is probably retreading old ground for most of you, but I'll state it here both because I "talk to think" and in case it's helpful for anyone less seasoned.

Purely tactically, shields negate the shock from the first, "alpha strike". That's pretty important against an enemy which favors that, and useless against enemy designs that favor DPS and/or the sandpaper approach. The DPS approach includes railguns (yes, even large caliber ones), ASMs(because anyone making really large missiles isn't throwing as many of them, and in that case your PD can handle them), and the annoying AMM spam. For those enemies, armor is, tactically speaking, much better ton for ton than shields. However...

Strategically,  unless you expect to fight only one time and then go back to repair armor at a shipyard, some level of shield on top of a few layers of armor will be better than just armor every time. If you just have armor, and you go through multiple engagements, even if you only take a few hits each time, you accumulate damage. Unless you have such a technological advantage that you expect to win multiple fights in a row without taking any damage (which is ideal in the real world but sounds boring in a game), shields are your friend.

That means that assaulting a defended jump point with specialist brawling cruisers may be a great place to use all-armor, still depending on what weapons they're bringing to the party.

All-in-all, the gameplay balance between the utility of shields and armor is quite good.