Aurora 4x
VB6 Aurora => Bureau of Ship Design => Topic started by: Iranon on January 25, 2016, 06:01:15 AM
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I thought it'd be neat to pool in on some little things that other players may have missed. I'll start off:
Subdivison. It's possible to make ships more resistant to damage by more extensive subdivison than the norm, as seen in many German designs during the world wars.
You can do this in Aurora by using smaller components that still have the same HTK, e.g. small engineering spaces or tiny fuel tanks. It's expensive compared to simply adding more armour, but doesn't add weight and helps against hits that would bypass armour, like shock damage or meson weapons.
I find this useful for very stressed designs that devote a high percentage to propulsion, with little room for mission tonnage or armour. Cool detail: Most relevant for fuel spaces as per the historical counterparts; WW1 arrangements incorporated coal bunkers into the protection scheme, WW2 designs used oil tanks as part of their torpedo protection system.
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Engineering;
A good number of engineering spaces to be mission effective for military ships is 1 per 1,000-1,500 tons of ship. If you plan on a 15,000 ton ship, plan 10-15 engineering spaces in. Plan on a 100,000 ton ship, plan 67-100 into the design. Despite making it seem there is an overabundance of maintenance life, it lets them have enough maintenance and damage control to perform field repairs of major systems in an enemy system without the need of a support ship (given that engineering will be damaged/destroyed in a fight as well).
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It can often be a good idea to make a size 1 engine (or size 0.1 for missiles), to help you sketch up a concept design with the right size engines for what speed you want. They are very cheap to research and Aurora got good tools for adding many of them if you need, so it prevents you from researching bigger engines only to find out they were too big/small to fit into your design.
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As I prefer large scale battle, I prefer the biggest engine I could build, 1 for 10kt each. The range and fuel efficient reason is much important for me. Lost one ship? I have five in production.
As showed in my last post, my ship rely on AMM as basic defence. They are easily blown up as I've seen size 100 explosion when engine is on fire, but NPR rarely get there.
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It is actually viable to tool a shipyard to produce both commercial geosurvey ships and military gravity survey ships, with a bit of trickery. This seems nearly impossible or quite inconvenient normally due to how calculating differences for necessary retool though: that being you need a percentage of "differences" to be lower than a certain amount per the cost of the vessel, "differences" being new components and hull changes.
So here's the secret strategy to make it so you can in fact build these two from one shipyard: You build a 'dummy' vessel like so:
Interim - Frame Blueprint: 315 Series class Science Vessel 4 900 tons 67 Crew 464.8 BP TCS 98 TH 180 EM 0
1836 km/s Armour 3-25 Shields 0-0 Sensors 6/6/1/1 Damage Control Rating 2 PPV 0
Maint Life 2.09 Years MSP 119 AFR 96% IFR 1.3% 1YR 37 5YR 548 Max Repair 100 MSP
Intended Deployment Time: 16 months Spare Berths 0
Cryogenic Berths 1000
180 EP-C Directional Ion-Pit Drive (1) Power 180 Fuel Use 1.97% Signature 180 Exp 3%
Fuel Capacity 50 000 Litres Range 93.2 billion km (587 days at full power)
CIWS-120 (1x4) Range 1000 km TS: 12000 km/s ROF 5 Base 50% To Hit
Active Search Sensor MR11-R81 (1) GPS 1701 Range 11.3m km Resolution 81
Thermal Sensor TH1-6 (1) Sensitivity 6 Detect Sig Strength 1000: 6m km
EM Detection Sensor EM1-6 (1) Sensitivity 6 Detect Sig Strength 1000: 6m km
Gravitational Survey Sensors (1) 1 Survey Points Per Hour
Geological Survey Sensors (1) 1 Survey Points Per Hour
This design is classed as a Military Vessel for maintenance purposes
It has all of the components that either the geosurvey or gravity survey vessel would have. This is what you tool your shipyard to, but not to build any of these. I included cryogenic berths for reasons you'll see in a second.
Once this design is made, copy it thrice, and design the following via subtraction, that is to say, only remove parts, don't add any (significant amount of) parts.
Interim - Geo: 315 Series class Geosurvey Ship 4 250 tons 50 Crew 320.2 BP TCS 85 TH 180 EM 0
2117 km/s Armour 3-23 Shields 0-0 Sensors 6/6/0/1 Damage Control Rating 1 PPV 0
MSP 47 Max Repair 100 MSP
Intended Deployment Time: 16 months Spare Berths 1
180 EP-C Directional Ion-Pit Drive (1) Power 180 Fuel Use 1.97% Signature 180 Exp 3%
Fuel Capacity 50 000 Litres Range 107.5 billion km (587 days at full power)
CIWS-120 (1x4) Range 1000 km TS: 12000 km/s ROF 5 Base 50% To Hit
Active Search Sensor MR11-R81 (1) GPS 1701 Range 11.3m km Resolution 81
Thermal Sensor TH1-6 (1) Sensitivity 6 Detect Sig Strength 1000: 6m km
EM Detection Sensor EM1-6 (1) Sensitivity 6 Detect Sig Strength 1000: 6m km
Geological Survey Sensors (1) 1 Survey Points Per Hour
This design is classed as a Commercial Vessel for maintenance purposes
Interim - Gravity: 315 Series class Gravitational Survey Vessel 4 300 tons 55 Crew 332.8 BP TCS 86 TH 180 EM 0
2093 km/s Armour 3-23 Shields 0-0 Sensors 6/6/1/0 Damage Control Rating 2 PPV 0
Maint Life 2.5 Years MSP 97 AFR 73% IFR 1% 1YR 22 5YR 324 Max Repair 100 MSP
Intended Deployment Time: 16 months Spare Berths 0
180 EP-C Directional Ion-Pit Drive (1) Power 180 Fuel Use 1.97% Signature 180 Exp 3%
Fuel Capacity 50 000 Litres Range 106.2 billion km (587 days at full power)
CIWS-120 (1x4) Range 1000 km TS: 12000 km/s ROF 5 Base 50% To Hit
Active Search Sensor MR11-R81 (1) GPS 1701 Range 11.3m km Resolution 81
Thermal Sensor TH1-6 (1) Sensitivity 6 Detect Sig Strength 1000: 6m km
EM Detection Sensor EM1-6 (1) Sensitivity 6 Detect Sig Strength 1000: 6m km
Gravitational Survey Sensors (1) 1 Survey Points Per Hour
This design is classed as a Military Vessel for maintenance purposes
Interim - Transport: 315 Series class Science Vessel 4 150 tons 42 Crew 226 BP TCS 83 TH 180 EM 0
2168 km/s Armour 3-23 Shields 0-0 Sensors 6/6/0/0 Damage Control Rating 1 PPV 0
MSP 34 Max Repair 34 MSP
Intended Deployment Time: 3 months Spare Berths 3
Cryogenic Berths 1000
180 EP-C Directional Ion-Pit Drive (1) Power 180 Fuel Use 1.97% Signature 180 Exp 3%
Fuel Capacity 50 000 Litres Range 110.1 billion km (587 days at full power)
CIWS-120 (1x4) Range 1000 km TS: 12000 km/s ROF 5 Base 50% To Hit
Active Search Sensor MR11-R81 (1) GPS 1701 Range 11.3m km Resolution 81
Thermal Sensor TH1-6 (1) Sensitivity 6 Detect Sig Strength 1000: 6m km
EM Detection Sensor EM1-6 (1) Sensitivity 6 Detect Sig Strength 1000: 6m km
This design is classed as a Commercial Vessel for maintenance purposes
If it was all done correctly, you will be able to retool a single naval shipyard with the frame blueprint design, and be able to build any of the three derivatives, like so:
(http://i.imgur.com/LfupuBL.png)
Very useful, in my opinion, particularly when just starting out, and you have decided against giving yourself survey vessels using Fast OOB (or said survey vessels get blown up).
You can probably get away with pulling this off with some other designs and whatnot, but this is the most dramatic and reliable instance I've noticed this tactic working.
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Dissimilar similar ships. If your freighters and colony ships share a common design, only switching out a Cargo Hold for 10x Cryogenic Transport, chances are at least one of the designs is inefficient.
Why? Because cargo holds are very cheap, it's more economical to build more freighters than overengineer them. Cryogenic transport OTOH is reaonably expensive, pairing it with decent speed and cargo handling is more economical than building many barebones colony ships. Making use of this doesn't prevent one from building both ships in the same yard.
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I tried your suggested Frame Blueprint method and it worked great. (Once I figured out what it all meant)
I'm now able to build
Geosurvey Vessels, Grav Survey Vessels, & a basic small troop transport all from the same shipyard without the downtime and expense of continually refitting the yard. The small troop transport can also be used to drop seed colonists on a colony as well I'm thinking.
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In a game which is now long corrupted, I had my entire civilian shop line constructed from two shipyards. Miners, fuel harvesters, colony ships, troop transports, freighters, salvage shops, tankers, and a maintenance transport ship that had a bunch of maintenance spaces to carry MSP to forward deployed TGs. It took hours of fiddling, but I got it eventually. The secret I learned is, design from the maintenance ship and the colony ship. They are the big ticket items.
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I've been doing the colony/cargo ship thing for ages, but the frame thing is frankly genius. Thanks. I'll have to try it out.
One very valuable thing is to make sure that your warships have more than one engine. This improves their chances of making it home after damage.
For missiles, make sure you optimize your engines. Missile engines are almost free, so it makes sense to custom-tailor them for the job.
For unitary missile engines the optimum fuel fraction is .2391 and the engine is .7609 with a ratio of 3.182. All of this assumes that you can vary the engine power modifier infinitely, so they don't translate well to very high-speed missiles (or ships). However, it should be of some help for building slower, longer-range weapons.
So get as close to that as possible. It's usually worth 5-10%, which doesn't sound like much until you remember that it's half of the next fuel-efficiency tech.
Also, I've made fairly extensive use of two-stage missiles. This gives you long range and good speed for evading point defenses. And you can mix in some decoys to draw off AMMs and beam defenses. Have them split at the same time as the main warheads, and make them slightly faster. As small an increment faster as possible, in fact.
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For unitary missile engines the optimum fuel fraction is .2391 and the engine is .7609 with a ratio of 3.182. All of this assumes that you can vary the engine power modifier infinitely, so they don't translate well to very high-speed missiles (or ships). However, it should be of some help for building slower, longer-range weapons.
So get as close to that as possible. It's usually worth 5-10%, which doesn't sound like much until you remember that it's half of the next fuel-efficiency tech.
I keep reading this hoping that it will make sense. So perhaps an example will help me make sense of it. Assuming a size 6 engine with 1MSP dedicated to warhead, how big should my engine and my fuel be for your formula?
Also, I've made fairly extensive use of two-stage missiles. This gives you long range and good speed for evading point defenses. And you can mix in some decoys to draw off AMMs and beam defenses. Have them split at the same time as the main warheads, and make them slightly faster. As small an increment faster as possible, in fact.
What do you put on your decoys? I've never played with multi stage missle designs before, but that sounds interesting.
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Can't have too many things at once fixed.
If E is engine tonnage, S is size of the missile, A is Agility points per MSP.
Ideal fuel is 0.4E if using maximum-size engines already, 0.3182*E otherwise.
Ideal agility to maximise to hit chance on a given budget for engine and agility is E-10S/A (this requires fine-tuning to avoid losses to rounding, and ignores possible fuel savings by larger engines).
Subbing numbers for a size 6 missile with 1 MSP warhead (which I assume you meant), we put in the numbers of non-warhead space of 5:
5=2.3182E-60/A
If you have a missile agility tech of 80:
5=2.3182E-0.75, for an engine size of 2.4803, and corresponding fuel of 0.7892 and agility of 1.7304 with 1/10000 of a MSP lost in rounding
We don't care, as agility will need some adjusting to avoid rounding losses.
In practice, this beautiful precision is unnecessary to counterproductive as there may be other considerations:
I never have enough engine multiplier tech to hit the ideal without excessive range (if I do, I messed up research priorities). Also, bigger lower-power engine and less fuel is cheaper.
I usually want more engine and less agility than the theoretical optimum: faster to better evade PD, better range for free if we can increase engine size, and again usually cheaper.
In practice, 40% engines, 30% warhead+sensors, 20% agility, 10% fuel is my guideline for general-purpose missiles. If you're set on a different payload, the 4:2:1 ratio of engine to agility to fuel remains useful.
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I keep reading this hoping that it will make sense. So perhaps an example will help me make sense of it. Assuming a size 6 engine with 1MSP dedicated to warhead, how big should my engine and my fuel be for your formula?
Basically, you allocate a certain amount of propulsion space on the missile (P) which is equal to engine space (E) + fuel space (F). For the best speed/range (one is maximized while the other is fixed) E= .7609*P and F= .2391*P. So if you're allocating P=6, then E=4.57 and F=1.43.
The one caveat is that this assumes there is no cap on the power multiplier you can use. You may very well need more engine than these numbers would indicate, particularly for things like AMMs. The most important rule is that you shouldn't have a missile that doesn't have max-size engines and has more than a third of the engine space in fuel.
What do you put on your decoys? I've never played with multi stage missle designs before, but that sounds interesting.
My basic missiles are all size 1, and I have the tech to make this work. (In fairness, I was as concerned with getting missiles through really heavy defenses as I was with raw damage, which may not have been the absolute optimum.) The standard missile does about 150,000 km/s, and has a size-4 warhead with a range of 17 mkm, IIRC. I mount from 1 to 3 of them on a size 4 bus which has a much more efficient and less powerful engine, and then fire them at targets at ranges up to around 1,000 mkm. The bus doesn't need to go fast as it doesn't have to get through defenses. Each stage can be optimized for its own job. The decoys are set up to be very slightly faster than the actual warhead missiles, and are released at the same time. Each fire control has one tube of decoys and usually about 5 tubes of regular missiles. The decoys separate at the same time, and double the number of different targets, which helps saturate fire control on the receiving end. They're also a bit ahead of the regular missiles, so they get shot at first. As the difference in speed is usually 100 km/s, they normally arrive on the same increment as the attack missiles, and draw off all the beam PD.
The decoys have a slightly different (more powerful) engine than the regular missiles, fuel to have the same range, and everything else is armor.
Can't have too many things at once fixed.
If E is engine tonnage, S is size of the missile, A is Agility points per MSP.
Ideal fuel is 0.4E if using maximum-size engines already, 0.3182*E otherwise.
Ideal agility to maximise to hit chance on a given budget for engine and agility is E-10S/A (this requires fine-tuning to avoid losses to rounding, and ignores possible fuel savings by larger engines).
Subbing numbers for a size 6 missile with 1 MSP warhead (which I assume you meant), we put in the numbers of non-warhead space of 5:
5=2.3182E-60/A
If you have a missile agility tech of 80:
5=2.3182E-0.75, for an engine size of 2.4803, and corresponding fuel of 0.7892 and agility of 1.7304 with 1/10000 of a MSP lost in rounding
We don't care, as agility will need some adjusting to avoid rounding losses.
Something seems off with your math. I can't see where that equation comes from, and I definitely don't see a factor for engine power per MSP in there, which would be an important part of the trade. In some cases, making the missile faster is better than adding agility, because it has other benefits, too.
In practice, this beautiful precision is unnecessary to counterproductive as there may be other considerations:
I never have enough engine multiplier tech to hit the ideal without excessive range (if I do, I messed up research priorities).
This is pretty common, particularly for AMMs.
Also, bigger lower-power engine and less fuel is cheaper.
I'm not so sure about this. I may have to play with numbers.
I usually want more engine and less agility than the theoretical optimum: faster to better evade PD, better range for free if we can increase engine size, and again usually cheaper.
This I will agree with. My second stages have no agility at all, while the AMMs use the same engine and have a smaller warhead.
In practice, 40% engines, 30% warhead+sensors, 20% agility, 10% fuel is my guideline for general-purpose missiles. If you're set on a different payload, the 4:2:1 ratio of engine to agility to fuel remains useful.
That's going to give you about 95% of the efficiency of a proper optimum. Which is decent, but not perfect.
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I retract my earlier comment on your math not working. I worked through the same math, and got the same equation. It's beyond weird that the engine power drops out, but it does.
The equation I got is P=5S/A+C/2 where P is the space allotted to propulsion, S is the size of the missile, A is agility per MSP, and C is the space allotted to (propulsion+agility).
This is a tremendously useful equation for designing AMMs, and probably fairly useless for everything else. Thanks.
I should include the standard caveats. First, this was derived under the assumption that speed is directly proportional to the propulsion fraction. This is probably not a good assumption in most design cases. If you're building an AMM, you probably have a certain range you want, and then you want as high a hit possibility as possible at that range. A first approximation would be to include fuel in the (S-C) space, normally allocated to warhead. This assumes that fuel consumption remains constant, but bigger engines will need less fuel. I'm not sure there's a good way to deal with this analytically.
I'm currently looking into quantifying the performance advantage of these optimized missiles over the significantly faster missiles I've been using to date.
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I've done some poking around, and the only case in which faster-than-optimum missiles seem to work is when you're operating in shoot-look-shoot mode, and the faster missiles get more opportunities to shoot. A 20-25% above-optimum speed missile seems to work well here. In cases where you're limited by magazine size or launcher ROF, the missile with the highest chance to hit is the best choice.
(And this probably isn't that useful. 1v1 is only a good idea when you have high odds of a hit. Going from 1.5% chance of a given leaker to a 1% chance isn't a big improvement, particularly when it means you need to fire more missiles overall. Have one ship in your fleet set its fire control for short range and go 2v1 there.)
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if enemy missiles are faster than your AMMs this can end up being a problem for several reasons. Most notably, offset AMM escort tactics and last-ditch AMM salvos will not work very well.
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On the other hand, if missile range is your limiting factor, slower missiles of the same range actually means you can start shooting sooner, and thus get more missiles out overall.
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Then less missiles would hit because either hit chance is to low or they were slow enough to be taken out by anti-missile fire.
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Then less missiles would hit because either hit chance is to low or they were slow enough to be taken out by anti-missile fire.
Neither point is true. First, I should clarify that I was talking about AMMs, not regular missiles, so the issue of AMM fire is largely moot. Second, Iranon demonstrated (and I subsequently confirmed, both mathematically and in-game) that there is an optimum speed for AMMs, and it's certainly slower than I was building my AMMs. I cut speed about 40%, and got 10-ish percent improvement in hit chance.
The math behind this is fairly simple. I have two missiles with similar hit chances, one with a speed of 140,000 km/s and the other with 100,000 km/s, and both having a range of 14 mkm. Obviously, it takes Missile 1 100 seconds to reach max range and Missile 2 140 seconds. Assume my limiting factors are missile range and number of launchers/launch cycles, not magazine space or fire control. For the first missile, I can begin engaging when the enemy missile hits 19 mkm (380 seconds out), while the second lets me start at 21 mkm (420 seconds out.)
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Some might disagree - but I learned to love to build a single survey vessel class, putting a Geo and Grav sensor on it. The flexibility makes it much simpler to just survey out a system. That and I can pump them out constantly and have a easy to manage survey fleet that only gets upgraded (Sometimes) with new engine technology, as I scrap out older designs with my fuel efficient designs, those surplus engines end up in the survey fleet.
Most games my survey fleet consists of two classes - A jump scout with a jump drive and some passive sensors that does the first look inside systems, and then the grav-Geo scanning ships.
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Some might disagree - but I learned to love to build a single survey vessel class, putting a Geo and Grav sensor on it. The flexibility makes it much simpler to just survey out a system. That and I can pump them out constantly and have a easy to manage survey fleet that only gets upgraded (Sometimes) with new engine technology, as I scrap out older designs with my fuel efficient designs, those surplus engines end up in the survey fleet.
Most games my survey fleet consists of two classes - A jump scout with a jump drive and some passive sensors that does the first look inside systems, and then the grav-Geo scanning ships.
I've long been a fan of having specialised grav and geo survey ships. However, with so many races in my current campaign I decided to experiment and I have been pretty happy with the flexibility of the joint geo/grav designs.
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These days I put commercial engines on grav survey ships. I used to use regular military engines favouring fuel efficiency over speed but after a certain point I find it's just easier to cut down on the number of foreward fuel depots I have to set up to support exploration efforts.
Slower ships, but whenever a hostile NPR or spoilers found my grav ships they died. So it's not like survivability has been effected.
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These days I put commercial engines on grav survey ships. I used to use regular military engines favouring fuel efficiency over speed but after a certain point I find it's just easier to cut down on the number of foreward fuel depots I have to set up to support exploration efforts.
Slower ships, but whenever a hostile NPR or spoilers found my grav ships they died. So it's not like survivability has been effected.
Another idea to help preserve the maintenance cost of your exploration survey fleet: put the military jump drives on your commercial geological ships instead. Or at least have a commercial geo ship that accepts it. Makes it a lot easier to deal with maintenance, as that's tonnage that doesn't need to be maintained due to being a commercial component on a commercial ship. Before you ask, yes, military jump drives are commercial components, and can transit both commercial and military vessels.
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Another idea to help preserve the maintenance cost of your exploration survey fleet: put the military jump drives on your commercial geological ships instead. Or at least have a commercial geo ship that accepts it. Makes it a lot easier to deal with maintenance, as that's tonnage that doesn't need to be maintained due to being a commercial component on a commercial ship. Before you ask, yes, military jump drives are commercial components, and can transit both commercial and military vessels.
If you are aiming for efficiency in maintenance for survey vessels I always feel it works best to use survey carriers. You have a main vessel that has a long deployment life and plenty of MSP, then design survey work craft that have little else other than a high efficiency commercial drive, and the required sensor type. The survey craft never suffer any failures due to only being out a few months or so, and the carrier can be designed to go for a good few years with no issues and have enough MSP to solve any possible problems. In addition you get to survey systems fast and with a few clicks using subordinate TG's.
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If you are aiming for efficiency in maintenance for survey vessels I always feel it works best to use survey carriers. You have a main vessel that has a long deployment life and plenty of MSP, then design survey work craft that have little else other than a high efficiency commercial drive, and the required sensor type. The survey craft never suffer any failures due to only being out a few months or so, and the carrier can be designed to go for a good few years with no issues and have enough MSP to solve any possible problems. In addition you get to survey systems fast and with a few clicks using subordinate TG's.
Though, it's worth noting that putting a jump drive on any military design incurs extra cost due to maintenance, it may be negligible due to the lack of mass-production of said vessel.
Though, in that vein, it reminds me of an idea I played around with, the hangar vessel as you mentioned, but rather than make gravity survey ships at all, make "Gravity Sensor Modules", which are designed essentially like so.
Tone class Sensor Platform 282 tons 2 Crew 104 BP TCS 5.64 TH 0 EM 0
1 km/s Armour 1-3 Shields 0-0 Sensors 1/1/1/0 Damage Control Rating 0 PPV 0
Maint Life 0 Years MSP 0 AFR 56% IFR 0.8% 1YR 47 5YR 705 Max Repair 100 MSP
Intended Deployment Time: 0.1 months Spare Berths 2
Gravitational Survey Sensors (1) 1 Survey Points Per Hour
This design is classed as a Fighter for production, combat and maintenance purposes
The reason being for this is that you can load them in to the hangars of the vessel and:
-They won't contribute to the maintenance cost via their huge-expense sensors.
-They will contribute to the task group's gravity survey capabilities and speed.
-They are easier to build, in the sense that you shift the cost of one of the most expensive components of a ship into fighter factories.
The only particular downsides I see is potential problems with nested-parasite management, and decreased flexibility in the sense that you can't split the task group to scan multiple points simultaneously, though you will be able to use more efficient engines, at least.
That said, in general, I tend to avoid putting jump engines on military designs unless they're specifically designed as some form of assault craft.
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Another idea to help preserve the maintenance cost of your exploration survey fleet: put the military jump drives on your commercial geological ships instead. Or at least have a commercial geo ship that accepts it. Makes it a lot easier to deal with maintenance, as that's tonnage that doesn't need to be maintained due to being a commercial component on a commercial ship. Before you ask, yes, military jump drives are commercial components, and can transit both commercial and military vessels.
That's pretty damn amazing! I'll have to try that! Thanks.