Fuel Harvestor Design

[AL (OP)]

In most of my games I have completely ignored the sorium harvester component and stuck with colony based refineries to maintain my fuel stockpiles. Recently I've been trying out Fuel Harvesters since in my current game the only sorium to be found in my home system is on a great big gas giant, so what I came up with was a
450 000 ton commercial rig with 170 harvester modules. If I recall correctly, at my current mining tech it makes about 5-6m fuel per annum but that still feels like it's too slow. So first question, what kind of size/number of modules do you build your fuel harvesters to?

Now considering my harvester was already a fairly decent size, I figured adding a few CIWS modules wouldn't hurt and I also slapped on 5 engines to allow it to propel itself (albeit at a measly speed of 230km/s, but enough in my case). So second question about fuel harvester design, do you tend to deck them out with all the gadgets, or add only harvester modules and fuel tanks?

Finally, does deployment time even matter for fuel harvesters? I suppose it would result in degraded to-hit chances for CIWS, but will morale affect mining rate too? If so, would the better approach be to increase deployment time to however long it takes to fill the tanks, or move a ship with a recreational module over to the gas giant?

[Mastik]

  My present harvesters are 75000T, 16 modules, 384,000 L/annum.  I use the most fuel efficient engines i can build.  Defenses are probably useless, but i include CIWS on my builds, along with basic thermal and EM detectors.  The defenses take so little space, so what the heck.  I have deployment set at 240 months, so i can basically forget about them.

[MarcAFK]

My harvesters usually have a few layers of armour, some CIWS and a pile of size 1 sensors, however when I'm seriously short on fuel AND duranium I'll trim all that off and most of the engines to maximise harvesting modules.
That said when you're talking about megaton sized harvesters they demand significant protection as they're far more vulnerable than ground refineries, and not as replaceable as light harvester swarms.

[Vandermeer]

I know you don't shy away from bigger designs, so from the Astral game I had this design, which is conform with what I normally use:

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Oracle Segment Astral class Fuel Harvester Base    1,400,000 tons     5163 Crew     52809.3999 BP      TCS 28000  TH 22400  EM 0
800 km/s     Armour 18-1114     Shields 0-0     Sensors 18/18/0/0     Damage Control Rating 18     PPV 0
MSP 424    Max Repair 200 MSP
Intended Deployment Time: 3 months    Spare Berths 2   
Fuel Harvester: 400 modules producing 28800000 litres per annum

800 EP "Blue Tide" Clean Fusion Drive (28)    Power 800    Fuel Use 2.21%    Signature 800    Exp 5%
Fuel Capacity 248,060,000 Litres    Range 1443.1 billion km   (20878 days at full power)

CIWS-500x10 (40x10)    Range 1000 km     TS: 50000 km/s     ROF 5       Base 50% To Hit
Ghoma Integrated Nervecluster (r.151m-5.5kt) (1)     GPS 8800     Range 151.0m km    Resolution 110
Impact Overseer (r.1568k) (1)     GPS 80     Range 14.4m km    MCR 1.6m km    Resolution 1
Thermal Wake Receiver TH-18 (1)     Sensitivity 18     Detect Sig Strength 1000:  18m km
EM Wake Receiver EM-18 (1)     Sensitivity 18     Detect Sig Strength 1000:  18m km

- The speed does not necessarily have to be that much. Around 30-60 would already be enough, because you would only need it to make the automated ultra short fuel deposit trips to nearby moons of those harvested giants.
- This ship is exactly of the size of one of the standard freighters (20 holds), tankers, terraformers and cryo ships that I normally use, making it possible to construct all of them with only 2 commercial yards.
- The base gets towed in place by one of the tanker/"infrastructure pusher" hybrid designs btw., so still relatively fast at only 1/2 of the usual tanker speed.
- The design is cut out to work as a team of a total of 8 of these harvester bases in one TG. You may remind that the fuel limit per TG is slightly more than 2 billion liters before error windows come, so I have this model*8 + one 300kt recreational base made in a way that they stay just below that. Then the rest to the 1.4mt is filled with harvesters (and the usual CIWS etc. shenanigans) to hopefully have it harvest around one tank per year. (I aim for "one tank per year" as a guideline, but of course the refining rate shifts with mining technology)

Of course you could have simply more TGs per giant for limitless extraction, but I usually stay with that for RP reasons, and also because there are usually more giants around that need attention, and would do nice as another haven in deep space to have.

The Astral game had all early fuel problems solved with one set of 8 of these, and had later for most of the game 3 giants mapped out. I found 2 more then after the bigger NPR war, just when it slowly turned that the 3 might not be enough to fuel the around 12 constant flying freighters of same size. The game was the most fuel expensive I had so far though, because all the freighters were "clipper" designs with maximum of 0.5 power factor and 50% engine tonnage, so pretty much as fast as a functional freighter can get on given tech level. That turned out to even challenge my usually quite opulent fuel mining policy, and normally a fraction of that is already enough. (For example, I remember having only 1 of these constellations in my Warhammer game, and then 2 in the Goa'uld one, and it netted me with tens of billions of liters reserves, so no problem)
In another test game I had simply one gargantuan fuel platform in Sol where Neptune turned out to be really nice. Since it was built with factories in the orbital habitat method, it would never get a refit, and so I tried my best to make it adequate by for example providing good armor despite early tech, which is easier when you make it even bigger. It alone had that 2 billion liter reserve, recreation, and a mining attuned to be at "one in a year" once the tech reached mining 30 or so, so at first only half of that I recon. Had some fancy name too, but I forgot. (large population start btw., which is why I could finance such a monster early)
The orbital habitat method is a nice alternative though, and 1.4mt is already fit for that too, but I just don't do it so I can later update what little improvement I make on those tiny sensors, and the armor.(and I have said large shipyards anyway)
My current EU game with 200m population and 24 labs start is just starting to build one of nearly 3mt and with 1000 harvesters after 25 years only, at ion age still, and with sparse resources (/most homeworld resource mined away by rival factions), so it is plausible.

Always produce masses of fuel. Always more than needed, and then double that.

[AL (OP)]

Thanks for the responses so far.
I do remember reading that fuel shortages are one of the main late-game problems that people face (or even early on from Steve's recent game), but I have yet to come close to a fuel shortage even in games lasting ~70 years (or does that still not count as late game?). So while it would still be fun overengineering the crap out of a fuel harvester, I always get the feeling that my efforts are somewhat wasted.

[MarcAFK]

I'm just starting to get out of a fuel crash that's gone on for half of the 12 years of my game, it was caused by the NPRs on earth draining all the resources while I was distracted making more factories.
I've built up a nice swarm of 16kton and 32kton harvesters from 2 yards, once I can afford the duranium and neutronium I'll refit my 90kton yard for harvesters. But it's likely within 5 years I'll get orbital habitats and start on some leviathans.
As a general rule I don't make platforms that take more than a few years to build, I'll probably make ones that cost 10k build points and use a bit over 30 % of industry for 3-4 years each.
Current swarm produces 4.5 million fuel, refineries on earth should be making 7 million except sorium shortage cuts it down to 2 million.
Planned 10k BP platform should make 5 million litres a year, move 300km/s (that'll get it to Barnards star in one year) , hold 2 years production and have 18 CIWS and 4 armour levels. 
Yeah it's nowhere near as well protected as yours but it's significantly cheaper, also a major FAC base will be installed at a moon of each location one of these will be placed at. Even so those extra 3 layers of armour cost 2000 duranium, It'll be more affordable with composite armour.

[GreatTuna]

Well, I find it hard to cause fuel shortage late-game. Engines tend to be extremely effective at this time, and since I don't use big designs (there's time you realize 30kton isn't big anymore), my ships' fuel consumption is very, very small.

Nonetheless I use harvester bases too.

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Ashod II class Fuel Harvester Base    611 450 tons     2405 Crew     18830.0001 BP      TCS 12229  TH 5000  EM 0
408 km/s     Armour 10-641     Shields 0-0     Sensors 50/40/0/0     Damage Control Rating 50     PPV 0
MSP 962    Max Repair 80 MSP
Intended Deployment Time: 120 months    Spare Berths 0   
Fuel Harvester: 190 modules producing 19000000 litres per annum

Ivanov Aeroengineering 250 EP Commercial GCAMD (20)    Power 250    Fuel Use 0.03%    Signature 250    Exp 1%
Fuel Capacity 50 000 000 Litres    Range 48960.0 billion km   (1388888 days at full power)

Browning ASM Defence Mk. 3 (18x10)    Range 1000 km     TS: 50000 km/s     ROF 5       Base 50% To Hit
ExpAI Active Search Sensor MR123-R15 (1)     GPS 1200     Range 123.9m km    Resolution 15
Ratters Thermal Detector S50\Sz1 (1)     Sensitivity 50     Detect Sig Strength 1000:  50m km
Ratters EM Detector S40\Sz1 (1)     Sensitivity 40     Detect Sig Strength 1000:  40m km

This design is classed as a Commercial Vessel for maintenance purposes
One per system is enough (because everybody refuels at Zemlya anyway, where four of them are stationed), and it has some degree of protection, up to being able to survive two ramming attempts from ship weighing around ~38kton.

[Vandermeer]

As a general rule I don't make platforms that take more than a few years to build, I'll probably make ones that cost 10k build points and use a bit over 30 % of industry for 3-4 years each.

What kind of ship would that be, other than factory produced orbital habitats maybe? But since you speak of relatively small range still, it sounds like the old persistent misjudgement that large ships are slower to build.
They are not however, at least when still built in shipyards. In fact, depending on the complexity of components used, you will find that build time even goes down the larger the ship, which is especially noticeable with civil designs. The reason is that the build points per interval increase with shipyard size, and though the official formula I had seen on the wiki would indicate that build time steadily rises (at exponentially slower rates albeit), in praxis it does not happen for some reason I also don't quite understand.
(here some visual proof from the latest Astral game save)

Off-Topic: show

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(that would be 7 months and 17 days at uniform researched TL7, ~ but it was always like that)
(I always like to mention at this point: These 150mt civil modules of my fortresses? Built in 3-6 months each. :-P)

So the point is: In Aurora you cannot possibly create a fuel platform that takes multiple years to built, except maybe if you use some TL 12 engine without ever having leveled shipyard speed or something unlikely like that.
The ships with the longest build time are in my experience ironically the small facs and those towards 7k (..but maybe just because I can't keep my hands of the largest possible singular engines that I can fit in ...)

Planned 10k BP platform should make 5 million litres a year, move 300km/s (that'll get it to Barnards star in one year) , hold 2 years production and have 18 CIWS and 4 armour levels. 
Yeah it's nowhere near as well protected as yours but it's significantly cheaper, also a major FAC base will be installed at a moon of each location one of these will be placed at. Even so those extra 3 layers of armour cost 2000 duranium, It'll be more affordable with composite armour.

Yeah, the armor is actually just vanity. Well, I guess if you really can overcome a missile ship's magazine by tanking, then it is a win in the book. But a single beam weapon on any attacking ship will make you lose that station, because you cannot possibly get guards there fast enough to stop them. So unless you really bother to make a protective base close to it, these stations cannot really be protected under fire, so the armor is quite useless and wasteful.
The real way of protecting distant infrastructure is a good further out laying information grid, so jump point warning buoys or sensor outposts etc. . This way you don't have to divide your forces and make them weak, but they simply wait at their central haven and move or detach when danger encroaches, and before it can reach some place where damage might be done.
That is at least my approach if I wouldn't RP it.

Well, I find it hard to cause fuel shortage late-game. Engines tend to be extremely effective at this time, and since I don't use big designs (there's time you realize 30kton isn't big anymore), my ships' fuel consumption is very, very small.

What has bigness to do with fuel consumption though?(after the 50 HS engines are already used I mean)
Fleet tonnage is fleet tonnage, and shipping tonnage is shipping tonnage, no matter the "dosage" or increment, right?

[GreatTuna]

Bigger ships eat more fuel, duh.
I use smaller ships = I use less fuel. Simple _{yet insane} logic!

Okay, I use few smaller ships, move them around only when needed and generally don't use 2mt+ fuel guzzlers. Thus, low fuel consumption (and no fuel shortages).

[Vandermeer]

But say you want to ship 200 auto mines to a distant outpost, so that is a 200 cargo hold order basically. -> It does not matter whether you ship that with 100 size 2 freighters, or just 10 size 20. When engine and design efficiency is eliminated as a factor (because engines are of same power+size+tech, and the designs use same engine percentage), then fuel cost is determined by how much tonnage of ships in total you have to move around, not the size of any individual unit.
Or if you say that you simply don't have these 200 cargo holds ready in your fleet, but maybe just 50 in total, so shipping takes longer, and the fuel production can keep up... ; Well, that is just saying that the fleet as a whole is smaller and uses thus less fuel, and has again nothing to do with individual ship size and their consumption.

Otherwise, 100 size 2 freighters consume exactly as much as 10 size 20 ones when all in flight.

[GreatTuna]

B-but smaller ship uses less fuel when it flies, because it needs less engine power to maintain the same speed as larger ship (assuming they have equal speed) and move around.

As for shipping, I use commercial civilian, duh freighters for that. They don't consume fuel, they consume money, and I've got that covered.

Besides, I already said that I use small fleets, didn't I? _{Okay, I didn't, but you could figure it out.} And my fuel production goes beyond consumption, and if I need even more, I can make more harvesters. I am close to gallicite shortage though, all that engines are really eating my stockpile. But fuel, no shortage, I have 1 billion units and that's enough for me.

[MarcAFK]

I did mention I was using industry to make the platforms, but I should have specified factories rather than shipyards.
As a reference at my current production levels 12 years in, warships are 8k tons costing 1200 BP , commercial 90k tons costing 1-4k BP (damn expensive colony ships), shipyards have build rate of 600 and my total factory production on earth is 7500 with a 30% bonus governer.
So the 780,000 ton 11k build point harvesting platforms are a major investment, but keep in mind the 160 ground based refineries that would produce the same fuel quantity would cost 19k duranium which I'm in seriously short supply of.
The platform however costs 5700 duranium which is half armour, 4000 boronide, 600 mercassium, 200 vendarite,  240 uridium and 625 gallicite. I have enough boronide for 3 platforms, but I'm still running short of duranium even now with manned mines making 3000 a year on Europa.
Edit: in reference to the discussion of fuel consumption , the crippling fuel shortages I've been running has made me consider efficiency a little more than I usually would.
Ignoring power multiplier for a moment, if my commercial fleet is all 30% power level then Fuel consumption for a ship is based entirely on power level, no matter how many engines I pile into a ship the increased speed just means higher consumption, or vice versa. So in theory when the ship arrives at the destination Fuel use is the same right?
But taking into consideration the actual payload capacity of the ship can give greater efficiency.
I'll post an example.
Heres my current small tanker with the engine replaced with a stack of size 1's for consistency:

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Zippo - A class Tanker    1,000 tons     8 Crew     132 BP      TCS 20  TH 30  EM 0
1500 km/s     Armour 1-8     Shields 0-0     Sensors 1/1/0/0     Damage Control Rating 0     PPV 0
Maint Life 12.04 Years     MSP 41    AFR 16%    IFR 0.2%    1YR 1    5YR 8    Max Repair 6 MSP
Intended Deployment Time: 12 months    Spare Berths 0   

6 EP Ion Drive (5)    Power 6    Fuel Use 15.75%    Signature 6    Exp 5%
Fuel Capacity 630,000 Litres    Range 720.0 billion km   (5555 days at full power)

This design is classed as a Military Vessel for maintenance purposesRemoving 3 of the engines gives this:

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Zippo - B class Tanker    1,000 tons     5 Crew     146 BP      TCS 20  TH 12  EM 0
600 km/s     Armour 1-8     Shields 0-0     Sensors 1/1/0/0     Damage Control Rating 0     PPV 0
Maint Life 14.35 Years     MSP 46    AFR 16%    IFR 0.2%    1YR 0    5YR 6    Max Repair 6 MSP
Intended Deployment Time: 12 months    Spare Berths 1   

6 EP Ion Drive (2)    Power 6    Fuel Use 15.75%    Signature 6    Exp 5%
Fuel Capacity 780,000 Litres    Range 891.4 billion km   (17195 days at full power)

This design is classed as a Military Vessel for maintenance purposesNow, Zippo B takes 2.5 times as long to get anywhere, but uses only 40% as much fuel. .4 fuel consumption times 2.5 times as long = 100%
So fuel consumption is the same no matter how fast the ship is.
But design B holds 24 % more fuel giving greater fuel efficiency.

[Rich.h]

Something I noticed with these designs is that they tend to have reasonably large fuel tanks on board. I am guessing they are being used as refueling points as well as collectors. For my games I always work on the idea that the fuel needs some "refinement" and this is always done at a colony. So I find my gas giant to harvest then pick the closest other body to act as a fuel depot, my harvesters slowly grow in size jumps of 50kt as my other ships grow in size/numbers. The harvester design is usually set with the most efficient engines I can manage at the time, enough fuel to travel 20b km or so and then stocked up with as many harvesters as possible. This creates a constant flow of fuel to the depot and allows my reserves to grow at a happy rate where I never have any issues. It also lets me forget about things like fuel tankers to transport the stuff around as almost every system will have a depot somewhere on hand.

[MarcAFK]

I usually collect fuel by sending a small low powered tanker to collect from the group then dump it to nearest minor colony.
I'll set the tankers speed even lower than it's capable to give the harvesters time to build up a stockpile. On occasion I'll check if the harvesters are starting to build up a lot, then I'll raise the speed somewhat.
Large tankers I generally use for collecting from minor colonies to take to fleet bases or anywhere needing a significant quantity. Or for shipping large amounts between systems, or I'll send the ship to support fleet operations .

[Vandermeer]

The fuel tanks on the designs may seem large, but in comparison to the gargantuan harvester components, it still comes down to a tiny percentage of the designs, so it is not bad to have a year ration or so on board.
Normally I just use the default fuel deposit order and have the nearest moon at the gas giant made into a colony for that purpose only. This means that the trips are really short, and it avoids having any harvester fly to random colonies from system spin or civil mining site opening etc., which annoyed me in the past. From that colony I can abduct fuel after my own calendar - whenever it is needed or I think of it.

However, I also had the situation where my first found good gas giant didn't have any moons, and neither was there a close enough body in the system that could have served as substitute. In such case, it is good that you don't have to change the design for more fuel storage, because you can still let it work for a year, then send a tanker with saved order template once the log starts complaining.

Edit: in reference to the discussion of fuel consumption , the crippling fuel shortages I've been running has made me consider efficiency a little more than I usually would.
Ignoring power multiplier for a moment, if my commercial fleet is all 30% power level then Fuel consumption for a ship is based entirely on power level, no matter how many engines I pile into a ship the increased speed just means higher consumption, or vice versa. So in theory when the ship arrives at the destination Fuel use is the same right?
But taking into consideration the actual payload capacity of the ship can give greater efficiency.

Like here:

When engine and design efficiency is eliminated as a factor (because engines are of same power+size+tech, and the designs use same engine percentage), then fuel cost is determined by how much tonnage of ships in total you have to move around, not the size of any individual unit.

You can analyze it as this:
1. The more engine percentage you use, the less is there for actual "mission" tonnage.(can also be shipping I guess)
2. You thus need a larger ship to ferry around the same amount of cargo holds(/or whatever equipment).
3. A larger ship means more tonnage in total to propel around, and thus steeper fuel cost despite same amount of holds.

E.g.: A 20 holds freighter with 40% engine dedication is pretty much exactly 1 megaton large (400kt being engines). With 50% engines, it grows to 1.2mt (600kt engines), so you pay 20% more fuel for the same accomplishment of 20 holds material shipment.
..But wait, it is also 25% faster, so given you have an open ended order and the freighter constantly flying, you actually end up paying 1.25*1.2= 50% more fuel on the same time scale, and that for just 25% more speed/availability.
Large engine dedication is hugely costly. You really have to think if it is worth it.

If you are interested, I once researched the rule that lays behind this, which is this:

e2 an e1 being the engine dedication factors, like 0.4 for 40%. t2 and t1 are then tonnages of course.
Calculation example: You want to upgrade your 6kt and 33% engine percentage destroyer towards using whooping 50% as it is your only way to match a new enemies' speed. This fills into the equation as (1-1/3 / 1-1/2)= 4/3, so 33% more mass (8kt) if you want to keep the equipment constant.

You can then get fuel efficiency difference by calculating t2/t1 * e2/e1, which in this case would mean exactly double the fuel cost despite only bringing the same amount of weapons into the fight.(a little more armor though)