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[coleslaw35]

I tend to SM in some minerals every once in a while. I don't like Sol becoming barren. I do wait a few centuries before doing it, though. So exploration is always faster than waiting around.

How do you manage to have your games last that long without turns taking literally 5-8 minutes to complete? I started a save in the in-game year of 2016 and got to about 2092 before the turn lengths were too horrid to handle.

[Dozebôm Lolumzalìs]

Autoturns, man. Just turn them on, click "30 days," leave a corner of the screen visible so you can see when the processing's done.

And I may have exaggerated just a little bit. More like 80-100 years rather than 200.

Also, turn off orbital motions, don't start with an NPR, don't let NPRs activate anything, that sort of stuff.

[QuakeIV]

I tend to limit games to one hundred systems or so and leave some active NPRs to play around out there and to eventually find me.  Makes things a lot more competitive.

[Ozyton]

Question: What power modifiers do you use on your ships? I have always assumed that the highest modifier gives the highest speed, but if you require the ships to have a given endurance (mine's 10b km or something), then the extremely large fuel tanks might slow it down so much that a smaller, slightly less powerful ship could be faster.

1) 40% of your engine tonnage in fuel is performance-optimal for fixed engine size, 32% if engine size is freely scaleable. Beyond this, you need so much fuel that using a higher power multiplier will cost you speed on set tonnage and range.
I prefer to err on the side of fuel efficiency for mainstream designs, 5% of engine tonnage is more likely unless I care very much about performance and compactness (carrier-bound craft, boarding vessels).

2) If I did the maths right, you re at your most fuel efficient if engines make up 60% of your mission tonnage (if we could ignore overhead like armour, bridge, engineering spaces). Below 1.0 power, you are at your most buildcost-efficient when engines make up 50% of our mission tonnage (above 1.0, the smaller and more stressed design is always cheaper to build).
50% engines of total tonnage is a reasonable simplification, personally I prefer a little more (1 size-50 engine for every 4500t, 0.9 as a standard power multiplier, e.g. 8000km/s at Magneto-Plasma).

I'm probably stupid, but... think this entire post went over my head. Are you saying if you want a 1000 ton engine you want to put 400 tons of fuel on the ship (40% of 1000) in order to be efficient? Is this just to get the most range and speed per liter of fuel because more fuel slows the ship down? What is fixed engine size compared to a "freely scaleable" one (last I checked once you made an engine it couldn't change size)...?

If 60% of your ship tonnage is just engines, and you add 40% of your engine tonnage as fuel, wouldn't that leave you with 84% of your ship made entirely out of fuel and engines, and only 16% of actual ship (before considering armor/crew)?

Or is all of this in relation to the actual power modifier versus engine size in some way?

Don't worry too much about answering, I'm probably just going to use the automatic engine designer thing anyways.

[Dozebôm Lolumzalìs]

Are you saying if you want a 1000 ton engine you want to put 400 tons of fuel on the ship (40% of 1000) in order to be efficient? Is this just to get the most range and speed per liter of fuel because more fuel slows the ship down?

I design engines for each set of parameters:

1. What size ship will this need to propel?
2. How fast will this ship need to go?
3. How long do I want that speed to be able to be maintained? i.e., how far should it be able to travel?

Then I fiddle. In the engine design window, leave it at your highest engine type (like nuclear pulse, ion, magnetoplasma, gas core antimatter) and best efficiency (50%, 30%, 90%). For now, leave the power/efficiency tradeoff bar at x1.00/x1.00. Now adjust the engine size until the EP is equal to:

Code: [Select]

EP = desiredSpeed*hullSpacesToCarry/1000 or desiredSpeed*tonsToCarry/50000
For instance, a 2000-ton ship going 5000 km/s would need an EP of 200.

Now take your desired range and speed, and determine the number of hours that you want the ship to be able to travel at maximum thrust.

Time = Distance/Speed, so

Code: [Select]

seconds = km/(km/s)
hours = km/(km/s * 3600)
Multiply the hours of travel by the fuel requirement per hour (not the fuel requirement per EP-hour, that's different) to get the liters of fuel required. Now divide that by 1000 to get the tons of fuel storage needed to hold that fuel.

Note the engine size in tons (click the "show sizes in tons" checkbox at the bottom of the engine design window if it's something like 20 HS instead of 1000 tons) and multiply that size by 0.40 to get the tons of fuel storage that should be paired with the engine in the engine-fuel composite.

If your fuel storage weight is greater than this number, move the power-efficiency tradeoff bar to a more efficient, less powerful setting. For instance, x0.80/x0.57. If the fuel storage is less than this number, move the power-efficiency bar to a more powerful, less efficient setting. For instance, x1.30/x1.93. Once you've changed the power-efficiency bar, change the engine size until the EP is once again the required amount for your ship size and speed.

Repeat this, recording the power-efficiency setting and total ton size for each attempt. Then once you've found a setting that seems to closely match the 40% rule, test the two surrounding settings (for instance, if x0.35 fit well, test x0.30 and x0.40). Then look at every test's total engine-fuel size in tons, and pick the setting that gives you the smallest total engine-fuel composite size.

An explanation of why this works:

There are many ways to move a given object a given distance with a given speed. You could use a giant engine with almost no power, but, hey, it just needs one drop of fuel! Or you could use the most powerful engine in the world, taking up only the mass of my hand - but it requires a skyscraper full of sorium every hour. Obviously, these aren't optimal. This technique finds the smallest engine-fuel composite (that is, the mass taken up by both the engine and the fuel storage) for a given ship, speed, and distance.

Now, there are of course exceptions, as well as times you might want to ignore this rule. Shields take up fuel, so you might want to add a little extra fuel storage to your ship even if it's suboptimal. However, going for a wanted distance of a few million km beyond your actual wanted distance achieves the same thing, only optimized a little better.

If you are low on sorium or want to conserve it, using a less-powerful, more efficient, much larger engine may be strategically important. This technique assumes that sorium supplies are not a problem, though it does produce more efficient than other designs.

An explanation of why longer distances need more efficient engines:

Look at this technique as multiplying and dividing the sizes of the two parts of the engine-fuel composite. When you only travel a few million kilometers, the fuel will take up a very small portion of the ship size, so dividing the engine by 1/2 and multiplying the needed fuel by 2 will produce a better composite and a better ship.

But when you're traveling many billions of kilometers, the fuel starts to become significant, and decreasing the needed fuel for a small increase in the engine size becomes optimal.

=========================================================================================================================

If 60% of your ship is just engines, and you add 40% of your engine tonnage as fuel, wouldn't that leave you with 84% of your ship made entirely out of fuel and engines, and only 16% of actual ship (before considering armor/crew)?

This is true. But when one remembers the current state of spaceships, this doesn't actually sound all that bad.

For spacecraft the payload fraction is often less than 1%, while the useful load fraction is perhaps 90%.

And perhaps the advice is bad. I don't design my ships around proportions, I design my ships around mission requirements. I need it to go this far, this fast. How much space do I need for engine-fuel composite? Let me calculate, etc.

==========================================================================================================================

Or is all of this in relation to the actual power modifier versus engine size in some way?

I do not understand, but I hope that the above explanation clears up this question.

======================================================================================================================

Don't worry too much about answering, I'm probably just going to use the automatic engine designer thing anyways.

Too late. Already wrote a thousand-word explanation. (That's a three-to-four pages double-spaced essay! Wish I showed this much effort for my actual assignments, heh.)

And what is this "automatic engine designer thing" you speak of?

[Flying Dice]

Contemporary spacecraft have that much engine+fuel to that much mission payload because we're still using chemical rocketry.

Again, this is a theorycraft vs. practice issue. That might be optimal from a pure drive efficiency standpoint, but a ship that has 84% of its tonnage devoted to the drive and fuel is going to be painfully useless for whatever it's supposed to be doing unless it's a tug (in which case the ratio should be higher) or boarding shuttle.

Most commercial shipping cares more about low logistical cost and maximizing the functional space--cargo holds, cryo pods, terraforming/mining modules, &c. than about how quickly it gets from place to place, especially since everything spends weeks, months, or years parked around system bodies. Military ships even more so--their paramount concern is with their combat effectiveness. The primary tool for combat in Aurora is the missile, and you don't need to have a fast ship to plaster an enemy task group from 600m km away. Obviously speed matters to some degree, but not to the point where your ships are toothless paper-thin wastes of minerals.

Here's a couple examples of this at work:

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Refuge class Salvager 100000 tons     203 Crew     3126.125 BP      TCS 2000  TH 1562  EM 0
781 km/s     Armour 9-191     Shields 0-0     Sensors 24/24/0/0     Damage Control 1     PPV 0
Maintenance Capacity 20 MSP
Cargo 75000   Spare Berths -2    Cargo Handling Multiplier 5   
Salvager: 1 module(s) capable of salvaging 750 tons per day

Justinian-Stubbs Aerospace 312.5 EP Commercial Magnetic Fusion Drive (5)    Power 312.5    Fuel Use 3.98%    Armour 0    Exp 5%
Fuel Capacity 1,500,000 Litres    Range 67.8 billion km   (1005 days at full power)

Zoren & Ventris Techsystems CIWS-320 (3x10)    Range 1000 km     TS: 32000 km/s     ROF 5       Base 50% To Hit
Sotha-Hezekiah Thermal Sensor TH1-24 (1)     Sensitivity 24     Detect Signature 1000: 24m km
Sotha-Hezekiah EM Detection Sensor EM1-24 (1)     Sensitivity 24     Detect Strength 1000: 24m km
This is a combat-zone salvage ship. It's designed to go into contested systems and hoover up mountains of wreckage while potentially coming under attack. Thus, it's heavily armored by commercial standards and has substantial cargo space (so as to avoid risking more fragile freighters). By tonnage it's only 7.75% drive and fuel. That's because it is going to spend the vast majority of its time either in port or sitting on top of wrecks. It doesn't need to be fast, it just needs to survive and carry a shitload of recovered materials and modules. If this were 84% drive and fuel, it would need to be accompanied by easily-destroyed freighters, be exceptionally vulnerable itself, and be markedly less effective at its purpose to boot.

I only need one or two of these to clean up after a major fleet action. If I designed them according to your hypothetically optimal distribution, I'd need four or six times as many ships, drastically increasing costs both material and managerial, as well as making each more likely to be lost if something hostile slips past the screening force.

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Solemn Oath class Missile Cruiser    57,600 tons     1241 Crew     27142.55 BP      TCS 1152  TH 1382.4  EM 6000
10000 km/s     Armour 20-132     Shields 200-300     Sensors 24/24/0/0     Damage Control Rating 137     PPV 60
Maint Life 8.46 Years     MSP 31510    AFR 248%    IFR 3.4%    1YR 785    5YR 11773    Max Repair 1200 MSP
Intended Deployment Time: 120 months    Spare Berths 0   
Magazine 1408    Cryogenic Berths 200   

Adonai Drive Systems 960 EP Inertial Fusion Drive (12)    Power 960    Fuel Use 55.11%    Signature 115.2    Exp 15%
Fuel Capacity 15,000,000 Litres    Range 85.1 billion km   (98 days at full power)
Taurus Defence Industries Xi R300/360 Shields (40)   Total Fuel Cost  600 Litres per hour  (14,400 per day)

Barak Technology 52cm C6 Far X-Ray Laser (1)    Range 480,000km     TS: 10000 km/s     Power 71-6     RM 8    ROF 60        71 71 71 71 71 71 71 71 63 56
Endanor-Salvin Systems CIWS-320 (6x10)    Range 1000 km     TS: 32000 km/s     ROF 5       Base 50% To Hit
Valefar Incorporated Fire Control S06 240-24000 (1)    Max Range: 480,000 km   TS: 24000 km/s     98 96 94 92 90 88 85 83 81 79
Kalick-Endymion Magnetic Confinement Fusion Reactor Technology PB-1 (1)     Total Power Output 10    Armour 0    Exp 5%

Bale Armaments Company Size 4 Missile Launcher (50% Reduction) (22)    Missile Size 4    Rate of Fire 70
Eisenstein Technology Missile Fire Control FC460-R16 (2)     Range 460.8m km    Resolution 16
Javelin-4 III (352)  Speed: 40,000 km/s   End: 123.7m    Range: 296.8m km   WH: 16    Size: 4    TH: 386/232/116

Eisenstein Technology Active Search Sensor MR768-R16 (1)     GPS 12800     Range 768.0m km    Resolution 16
Sotha-Hezekiah Thermal Sensor TH1-24 (1)     Sensitivity 24     Detect Sig Strength 1000:  24m km
Sotha-Hezekiah EM Detection Sensor EM1-24 (1)     Sensitivity 24     Detect Sig Strength 1000:  24m km

ECCM-3 (2)         ECM 30
This is a military ship designed for limited independent action--long-term harassment of enemy operations, deep strikes into hostile territory, extended picket duty, hunter-killer operations on stray Precursor groups, periodically culling Swarm ships when I don't have the spare assets to kill the Queens, &c. It's much more drive-heavy; the drive+fuel component is slightly over 51% of its tonnage. That's primarily because it needs to be fast enough, despite its tonnage, to outrun just about anything that it can't outfight, with a few unfortunate exceptions.

What about a FAC, then?

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Foehammer class Fast Attack Craft    1,000 tons     29 Crew     552.2 BP      TCS 20  TH 512  EM 0
25600 km/s     Armour 1-8     Shields 0-0     Sensors 1/1/0/0     Damage Control Rating 0     PPV 2.4
Maint Life 4.18 Years     MSP 173    AFR 16%    IFR 0.2%    1YR 16    5YR 238    Max Repair 256 MSP
Intended Deployment Time: 12 months    Spare Berths 1   
Magazine 16   

Tridon Aero Engines 512 EP Inertial Fusion Drive (1)    Power 512    Fuel Use 130.11%    Signature 512    Exp 20%
Fuel Capacity 165,000 Litres    Range 22.8 billion km   (10 days at full power)

Adramelech Design Bureau X/O Rail-4 (4)    Missile Size 4    Hangar Reload 30 minutes    MF Reload 5 hours
Eisenstein Technology Missile Fire Control FC460-R16 (1)     Range 460.8m km    Resolution 16
Javelin-4 III (4)  Speed: 40,000 km/s   End: 123.7m    Range: 296.8m km   WH: 16    Size: 4    TH: 386/232/116

Compact ECCM-1 (1)         ECM 20
Still barely under 57% drive+fuel. And that leaves only enough space for four box launchers, a fire control system sufficient to future-proof it for coming iterations of its missile series and help offset enemy ECM, and a basic EW package.

--

So yeah. That's my point. A ship that's 84% fuel and drive is going to be woefully ineffective at whatever it's supposed to do. The only circumstances where anything even approaching that would be practical are very limited: tugs, which are just drives strapped to tractor beams anyways; boarding shuttles, which are drives strapped to drop pods; and gauss/reduced-size laser fighters, which both need extreme speed and have a very low-volume combat load.

It doesn't help that there's generally a cutoff where increased speed stops being useful in combat. In the vast majority of cases no enemy you encounter will exceed 15,000km/s. Most won't break 10,000km/s. Beyond either of those points the only real effects are: decreasing enemy CTH (in which case your volume would be better devoted to a higher grade of ECM or more PD equipment), and allowing E/KW ships to close more rapidly (in which case they also need to have good armor, a decent helping of shields, and enough weapons to decisively end the fight once they reach their range--without the first two they won't live long enough, without the third there's no point using them). All you ever really need is "enough" speed. That is, enough speed that you can catch enemy ships and they can't catch you. At low TLs that's just flat-out not possible, and at high TLs it's trivial.

[Alastar]

1) 40% of your engine tonnage in fuel is performance-optimal for fixed engine size, 32% if engine size is freely scaleable. Beyond this, you need so much fuel that using a higher power multiplier will cost you speed on set tonnage and range.
I prefer to err on the side of fuel efficiency for mainstream designs, 5% of engine tonnage is more likely unless I care very much about performance and compactness (carrier-bound craft, boarding vessels).

2) If I did the maths right, you re at your most fuel efficient if engines make up 60% of your mission tonnage (if we could ignore overhead like armour, bridge, engineering spaces). Below 1.0 power, you are at your most buildcost-efficient when engines make up 50% of our mission tonnage (above 1.0, the smaller and more stressed design is always cheaper to build).
50% engines of total tonnage is a reasonable simplification, personally I prefer a little more (1 size-50 engine for every 4500t, 0.9 as a standard power multiplier, e.g. 8000km/s at Magneto-Plasma).

I'm probably stupid, but... think this entire post went over my head. Are you saying if you want a 1000 ton engine you want to put 400 tons of fuel on the ship (40% of 1000) in order to be efficient? Is this just to get the most range and speed per liter of fuel because more fuel slows the ship down? What is fixed engine size compared to a "freely scaleable" one (last I checked once you made an engine it couldn't change size)...?

If 60% of your ship tonnage is just engines, and you add 40% of your engine tonnage as fuel, wouldn't that leave you with 84% of your ship made entirely out of fuel and engines, and only 16% of actual ship (before considering armor/crew)?

Or is all of this in relation to the actual power modifier versus engine size in some way?

Don't worry too much about answering, I'm probably just going to use the automatic engine designer thing anyways.

Mostly, yes. If you have a propulsion budget of 1400t, and use multiple small engines of a given size, 1000t engines and 400t fuel maximises the range for any given speed. If you reduce engine tonnage to 800t and adjust power multiplier accordingly, 600t of fuel will give you shorter range.

If you want to use a single engine, this no longer applies cleanly because larger engines are more efficient. IIRC 100:32 is the most efficient split for missiles with a single engine smaller than the maximum. It's not fixed for ships because of how things scale, size-2 engines are only a little more efficient than size-1 engines while size-50 engines are considerably more efficient than size-25 ones.

*
 
No good design has 84% propulsion tonnage, unless it's a tanker or something very unusual with specific reasons. 40% fuel of engine tonnage is too much fuel unless you care only about compactness and not at all about efficiency. 60% engines of your mission tonnage (so less of total) implies you care only about fuel efficiency and not at all about compactness. They are upper bounds working at cross purposes, so you wouldn't combine them.
Many of my ships are around 55% engines though, with rather little fuel.

[Alastar]

@ Flying Dice:

If commercial vessels don't have to be fast, they may still be useful with a large propulsion plant: just lower the power multiplier even further, if you have the shipyard capacity for a larger vessel your salvager could be faster as well as cheaper with greatly reduced fuel use.
My only commercial vessels with 0.5 power engines are those that may limit my fleet speed, like tankers and jump ships.

Many of my commercial vessels apart from freighters consist mostly of engines. Why not freighters?
The above optimisation assumes fixed speed. Cargo holds are dirt cheap, so we shouldn't spend excessive resources on making them fast. This means we may not have low enough minimum power, and will hopelessly exceed our speed goal if we make them consist of 50% engines.
Even if we have that tech... freighters are cheap anyway, their highest true cost may be tying up shipyards rather than build or fuel costs, so making them much bulkier than they need to be in the name of cheapassery may be shooting ourselves in the foot.

[RAM]

 Also remember that tankers are a thing, so you can often get away with your ships only carrying enough fuel to do their on-site work because someone else is paying the transit costs. And every gram that you save on fuel tanks is less mass for a swifter ship.
 Either you are dealing with combat ships, in which case getting perfect space-efficiency is secondary to getting desired performance, so things like tankers and tugs and hangar-ships start becoming attractive options for transport and 40% fuel would just be a massive waste of engine power that never sees use. Or you are dealing with ships that do not want to see combat and generally perform a task that requires a vast amount of travel and the idea of valuing space-efficiency over fuel-efficiency would start to cost you too much Sorium and even if Soruum is limitless, the fuel processing facilities would start to be a hassle...

I would argue that cargo being dirt-cheap is a good argument to make the rest of the freighter dirt-cheap to match...

[Flying Dice]

@ Flying Dice:

If commercial vessels don't have to be fast, they may still be useful with a large propulsion plant: just lower the power multiplier even further, if you have the shipyard capacity for a larger vessel your salvager could be faster as well as cheaper with greatly reduced fuel use.
My only commercial vessels with 0.5 power engines are those that may limit my fleet speed, like tankers and jump ships.

Many of my commercial vessels apart from freighters consist mostly of engines. Why not freighters?
The above optimisation assumes fixed speed. Cargo holds are dirt cheap, so we shouldn't spend excessive resources on making them fast. This means we may not have low enough minimum power, and will hopelessly exceed our speed goal if we make them consist of 50% engines.
Even if we have that tech... freighters are cheap anyway, their highest true cost may be tying up shipyards rather than build or fuel costs, so making them much bulkier than they need to be in the name of cheapassery may be shooting ourselves in the foot.

Why do the vast majority of human aircraft, trains, &c. still travel at subsonic speeds when we can make them supersonic?

Same answer here: the potential benefits are vastly outweighed by the cost. When I make a cheapo freighter I want a disposable means of transporting stuff that I can crank out fast, easy, and at little cost, not an overengineered piece of crap.

Here's a dinky one-hold freighter with my current tech:

Code: [Select]

Atlas II class Freighter    32,000 tons     107 Crew     871.8 BP      TCS 640  TH 1600  EM 0
2500 km/s     Armour 1-89     Shields 0-0     Sensors 24/24/0/0     Damage Control Rating 7     PPV 0
MSP 119    Max Repair 200 MSP
Intended Deployment Time: 60 months    Spare Berths 0   
Cargo 25000   

Nerrak-Samuel 800 EP Commercial Inertial Fusion Drive (2)    Power 800    Fuel Use 2.21%    Signature 800    Exp 5%
Fuel Capacity 500,000 Litres    Range 127.3 billion km   (589 days at full power)

Endanor-Salvin Systems CIWS-320 (1x10)    Range 1000 km     TS: 32000 km/s     ROF 5       Base 50% To Hit
Sotha-Hezekiah Thermal Sensor TH1-24 (1)     Sensitivity 24     Detect Sig Strength 1000:  24m km
Sotha-Hezekiah EM Detection Sensor EM1-24 (1)     Sensitivity 24     Detect Sig Strength 1000:  24m km
It's not particularly large, it's not particularly fast, and it'll die if anything looks at it funny. It's only 17% drive/fuel by volume.

And each of my commercial slipways can crank out close to three of them each year. And they cost this to make:

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400 Gallicite
235 Duranium
67 Uridium
63 Mercassium
39 Neutronium
30 Boronide
25 Vendarite
12 Corbomite
So let's say I want it to be a bit faster. I double the drives and fuel storage. Now it's 29% drive/fuel by volume. Hey, now I can't even build two a year per slipway, and now they cost this:

Code: [Select]

800 Gallicite
281 Duranium
67 Uridium
92 Mercassium
43 Neutronium
60 Boronide
25 Vendarite
12 Corbomite
That's a substantial decrease in their rate of production and a substantial increase in their cost-double the Gallicite and Boronide, 50% again on the Mercassium! And all you get is a 1,600km/s speed increase. On your tiny junk freighters. Which you need... why, exactly? These are the workhorses that are going to be spending decades ferrying random shit all over. You're going to be setting them into five-hundred loop order chains while you burn 30 day ticks waiting for research to complete. If they do their job slightly faster, great, that means that they spend more time sitting in port waiting for something else to need transport.

It's shit like this and slapping thermal reduction on every single drive that makes me think a lot of people either cheat in a ton of minerals or play it as gamily as possible. Nobody sane would drastically increase cost and time of construction on cheap, simple ships for the sake of unnecessary over-engineering. These aren't packet boats or smuggling ships, they're the closest we have to tramp freighters, and they're government built, owned, and operated. It doesn't matter if they take five months or seven to move a terraforming facility to Mars when the actual terraforming process is going to take decades. Or if they take two years instead of one and a half to transfer a load of automines to a planet with a few million tons of low-accessibility minerals. If you use a fast freighter to pick up loads of minerals from distant mining colonies on a looped order you're going to be wasting fuel since it'll retrieve a smaller load each trip than a slow freighter. Shit like that.

Same reason I don't put cargo transfer modules on a lot of my freighters and such: without them, every stopover to load or unload will completely reset crew morale. It's slower, but it's also more efficient and more realistic.

Hell, with the lower cost of production and faster production speed, you can just crank out a bit less than twice as many, and you're at roughly the same cost while still moving sets of installations around faster.

[Alastar]

You may be missing my point, 0.5 power engines is what I'd consider "overengineered crap" for a humble freighter.
What if you triple the number of drives, but reduce power multiplier to 0.25?

[Flying Dice]

You may be missing my point, 0.5 power engines is what I'd consider "overengineered crap" for a humble freighter.
What if you triple the number of drives, but reduce power multiplier to 0.25?

Here's a dinky one-hold freighter with my current tech:

current tech

When I pull examples of ship designs, I'm pulling them from actual functioning campaigns, not test games where I've SMed in all of everything to build paper ships that aren't actually going to see play. Hence the occasional disparity in tech level, since real campaigns throw up different sets of researcher specializations and different circumstances dictate different tech routes. Obviously you decrease the power multiplier further as you research the relevant techs (and the opposite for fighters); I wouldn't ask someone posting a freighter from a fresh conventional start why they're using 1.00 power nuclear pulse drives, either.

[Alastar]

I would, because 0.5 is also available and a non-commercial freighter sounds terrible.

Inertial Confinement Fusion is a 90k tech.
Minimum Power 0.25 is a 4k tech of the same field, so "don't have the right specialist" holds little water... surely you could at least spare the 3-6k total for the first 2 or 3 techs.
Of course there may be overarching roleplaying considerations, but that seems horribly mismatched research... especially since you agree that you'd "obviously" use lower power multiplier when available.

[Azated]

I've played several games lasting a good few hundred years using large, fast, thermally reduced freighters with no fuel or resource issues since I first started playing. I don't even build tankers or sorium harvesters any more.

I'm not sure if I just play well in regards to resource output but It's really not that much of a problem to over-engineer something that could run on obsolete tech from a hundred years ago but instead uses better equipment than my military.

[Dozebôm Lolumzalìs]

A response to conversation:

It is agreed that "a ship that has 84% of its tonnage devoted to the drive and fuel is going to be painfully useless for whatever it's supposed to be doing." As I stated, ships should (mostly) be designed around what they're supposed to do.

With that in mind, a response to this:

Most commercial shipping cares more about low logistical cost and maximizing the functional space--cargo holds, cryo pods, terraforming/mining modules, &c. than about how quickly it gets from place to place, especially since everything spends weeks, months, or years parked around system bodies. Military ships even more so--their paramount concern is with their combat effectiveness. The primary tool for combat in Aurora is the missile, and you don't need to have a fast ship to plaster an enemy task group from 600m km away. Obviously speed matters to some degree, but not to the point where your ships are toothless paper-thin wastes of minerals.

A potential misconception is that "my" algorithm decrees that a certain proportion of the ship should be used for engines, or that speed should be prioritized. That is far from its functionality.

My algorithm takes three things: the size of your ship, the wanted speed of your ship, and the distance that ship should go. It always produces the engine-fuel composite system that is the most space-efficient, and frequently produces a fuel-efficient design - unless you want a high speed and a short distance! Even then, its solutions tend to err on the side of fuel-efficiency.

Thus, both of your example ships would benefit from the use of Dozebom's Algorithm. (I won't let it get to my head I promise )