The Oblivion Class Corvette

[liveware (OP)]

I've been messing around with corvette designs because it's fun. I came up with the following two escort corvette designs using ion drive era tech and I'm going back and forth on which one I like better.

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Oblivion class Corvette      5,000 tons       123 Crew       573.4 BP       TCS 100    TH 500    EM 0
5000 km/s      Armour 4-26       Shields 0-0       HTK 35      Sensors 0/0/0/0      DCR 3      PPV 21
Maint Life 3.08 Years     MSP 255    AFR 67%    IFR 0.9%    1YR 40    5YR 604    Max Repair 125.00 MSP
Commander    Control Rating 1   BRG   
Intended Deployment Time: 12 months    Morale Check Required   

ARC 250MW SLIPS (Size Large Ionized Particle Stream) Drive System (2)    Power 500.0    Fuel Use 70.71%    Signature 250.00    Explosion 10%
Fuel Capacity 384,000 Litres    Range 19.6 billion km (45 days at full power)

ARC 300mm Plasma Cannon (1)    Range 48,000km     TS: 5,000 km/s     Power 24-3     RM 10,000 km    ROF 40        24 12 8 6 0 0 0 0 0 0
ARC M1 100mm Railgun (4x4)    Range 10,000km     TS: 5,000 km/s     Power 3-3     RM 10,000 km    ROF 5        1 0 0 0 0 0 0 0 0 0
ARC R48S5 Direct Fire Weapon Targeting Computer (1)     Max Range: 48,000 km   TS: 5,100 km/s     79 58 38 17 0 0 0 0 0 0
ARC 5MW HCGMFF (Helium Cooled Graphite Moderated Fast Fission) Reactor (3)     Total Power Output 15    Exp 5%

ARC M1 S5R1 Gravimeter (1)     GPS 1     Range 1.3m km    MCR 113.5k km    Resolution 1
ARC M1 S5 Electromagnetic Wave Detector (1)     Sensitivity 0.5     Detect Sig Strength 1000:  5.6m km
ARC M1 S5 Thermal Emission Detector (1)     Sensitivity 0.5     Detect Sig Strength 1000:  5.6m km

This design is classed as a Military Vessel for maintenance purposes


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Oblivion M2 class Corvette (P)      5,000 tons       111 Crew       616.7 BP       TCS 100    TH 625    EM 0
6250 km/s      Armour 4-26       Shields 0-0       HTK 31      Sensors 0/0/0/0      DCR 3      PPV 12
Maint Life 2.83 Years     MSP 331    AFR 67%    IFR 0.9%    1YR 60    5YR 904    Max Repair 156.25 MSP
Commander    Control Rating 1   BRG   
Intended Deployment Time: 12 months    Morale Check Required   

ARC 312MW SLIPS Drive System (2)    Power 625.0    Fuel Use 63.25%    Signature 312.50    Explosion 10%
Fuel Capacity 328,000 Litres    Range 18.7 billion km (34 days at full power)

ARC 300mm Plasma Cannon (1)    Range 144,000km     TS: 6,250 km/s     Power 24-3     RM 10,000 km    ROF 40        24 12 8 6 4 4 3 3 2 2
ARC M1 100mm Railgun (1x4)    Range 10,000km     TS: 6,250 km/s     Power 3-3     RM 10,000 km    ROF 5        1 0 0 0 0 0 0 0 0 0
ARC R144S6 Direct Fire Weapon Targeting Computer (1)     Max Range: 144,000 km   TS: 6,000 km/s     93 86 79 72 65 58 51 44 38 31
ARC 3MW HCGMFF Reactor (2)     Total Power Output 6    Exp 5%

ARC M1 S5R1 Gravimeter (1)     GPS 1     Range 1.3m km    MCR 113.5k km    Resolution 1
ARC M1 S5 Electromagnetic Wave Detector (1)     Sensitivity 0.5     Detect Sig Strength 1000:  5.6m km
ARC M1 S5 Thermal Emission Detector (1)     Sensitivity 0.5     Detect Sig Strength 1000:  5.6m km

This design is classed as a Military Vessel for maintenance purposes

Key technologies used:
Ion Drive Propulsion
Gas Cooled Fast Reactors
Capacitor Level 3
High Density Duranium Armor
BFC Speed 3k km/s
BFC Range 48k km
Level 1 sensor tech (both active and passive)

My goal is to build a relatively small escort that can provide point defense against missiles using it's railguns as well as providing some reasonable anti-armor capability via plasma carronades. The first ship is somewhat slower and has a worse BFC but packs 4x the number of railguns which I think is worth the reduced speed and BFC performance. 5k km/s is still reasonably fast for ion drive tech I think? 6k km/s is definitely better but with only a single railgun I'm not convinced the 6k km/s variant has enough firepower to justify the speed boost.

I'm wondering what others think? Feedback is appreciated!

EDIT: Forget to transliterate my acronyms

[nuclearslurpee]

I'd say the first ship is probably better. The overall design is neater and 5000 km/s is a decent speed while 6250 km/s is excessive and costs you a lot of weapon payload. However I don't like the undersized BFC which will have accuracy problems due to low max range. Especially with that plasma cannon you really want to get in to 10k km and land the hit, otherwise you're losing a lot of alpha damage.

You might consider dropping a layer of armor and using the tonnage for a longer-ranged BFC. If you have a couple HS left over bumping up the engine size can't hurt, every 1 HS more engine size is going to get you +250 km/s to help close ranges.

[brondi00]

I agree.  At magneto plasma you can up speed to 6250.

[Jorgen_CAB]

I would probably also choose the first ship, but that is entirely depending on how important speed is. The fire-control probably also would need to be replaced at some point as well, that one is really underwhelming for it's purpose.

I also find that the ship probably have too weak passive sensors as I figure this ship should be able to operate on their own as scouts. Scouts should always have decent passive sensors. You also could add the smallest type of hangar and fit a couple of really small active fast scouts as well... you can get decent small fast active sensor scouts at about 20-25t apiece. This way the ship itself only need to have a resolution 1 active and can use its fast scouts to fix any potential enemy at a longer range and don't have to endanger the ship itself.

Ships of this scale usually have too weak armour to be good beam ships so the weapons should mainly be considered for self defence or used against civilian ships. Being able to avoid the enemy should otherwise be their doctrine. They also can act as point defence for capital or support squadron as a secondary role. But PD perhaps is the ships primary role and then I think all is fine in general.

[liveware (OP)]

I'd say the first ship is probably better. The overall design is neater and 5000 km/s is a decent speed while 6250 km/s is excessive and costs you a lot of weapon payload. However I don't like the undersized BFC which will have accuracy problems due to low max range. Especially with that plasma cannon you really want to get in to 10k km and land the hit, otherwise you're losing a lot of alpha damage.

You might consider dropping a layer of armor and using the tonnage for a longer-ranged BFC. If you have a couple HS left over bumping up the engine size can't hurt, every 1 HS more engine size is going to get you +250 km/s to help close ranges.

The original Oblivion had 3 layers of armor and a better BFC... I might go back to that.

[liveware (OP)]

I would probably also choose the first ship, but that is entirely depending on how important speed is. The fire-control probably also would need to be replaced at some point as well, that one is really underwhelming for it's purpose.

I also find that the ship probably have too weak passive sensors as I figure this ship should be able to operate on their own as scouts. Scouts should always have decent passive sensors. You also could add the smallest type of hangar and fit a couple of really small active fast scouts as well... you can get decent small fast active sensor scouts at about 20-25t apiece. This way the ship itself only need to have a resolution 1 active and can use its fast scouts to fix any potential enemy at a longer range and don't have to endanger the ship itself.

Ships of this scale usually have too weak armour to be good beam ships so the weapons should mainly be considered for self defence or used against civilian ships. Being able to avoid the enemy should otherwise be their doctrine. They also can act as point defence for capital or support squadron as a secondary role. But PD perhaps is the ships primary role and then I think all is fine in general.

I have a separate dedicated scout corvette with 500ton passives and the same speed/range as the Oblivion. Normal JP scout corvette squadron will be 2x PD corvettes (Oblivion class), 1x scout, and 1x jump corvette. General patrol squadron will be 3x Oblivions and 1x scouts.

I might see what I can up with using 3 armor layers instead of 4. Small scout craft are definitely useful...

[nuclearslurpee]

I'd say the first ship is probably better. The overall design is neater and 5000 km/s is a decent speed while 6250 km/s is excessive and costs you a lot of weapon payload. However I don't like the undersized BFC which will have accuracy problems due to low max range. Especially with that plasma cannon you really want to get in to 10k km and land the hit, otherwise you're losing a lot of alpha damage.

You might consider dropping a layer of armor and using the tonnage for a longer-ranged BFC. If you have a couple HS left over bumping up the engine size can't hurt, every 1 HS more engine size is going to get you +250 km/s to help close ranges.

The original Oblivion had 3 layers of armor and a better BFC... I might go back to that.

That's what I would have done, however with railgun and plasma ships I'm always loathe to suggest removing armor because you take a lot of hits when closing the range.

[liveware (OP)]

I'd say the first ship is probably better. The overall design is neater and 5000 km/s is a decent speed while 6250 km/s is excessive and costs you a lot of weapon payload. However I don't like the undersized BFC which will have accuracy problems due to low max range. Especially with that plasma cannon you really want to get in to 10k km and land the hit, otherwise you're losing a lot of alpha damage.

You might consider dropping a layer of armor and using the tonnage for a longer-ranged BFC. If you have a couple HS left over bumping up the engine size can't hurt, every 1 HS more engine size is going to get you +250 km/s to help close ranges.

The original Oblivion had 3 layers of armor and a better BFC... I might go back to that.

That's what I would have done, however with railgun and plasma ships I'm always loathe to suggest removing armor because you take a lot of hits when closing the range.

There is a trade-off between PD capability and armor... I've run the numbers before but not for this specific ship (I probably should). Basically there is a point at which adding additional weapons reduces the amount of missile damage one would expect to take provides better damage reduction than an equivalent displacement of armour. At my existing tech level, one extra layer of armour is about 200-300 tons which is about 1 rail gun. The same argument is true of engines... at some point it is better to be fast than durable.

[liveware (OP)]

I decided to strip an armor layer off of the Oblivion M1:

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Oblivion M3 class Corvette (P)      5,000 tons       134 Crew       584.3 BP       TCS 100    TH 500    EM 0
5000 km/s      Armour 3-26       Shields 0-0       HTK 40      Sensors 5/5/0/0      DCR 3      PPV 21
Maint Life 3.11 Years     MSP 259    AFR 67%    IFR 0.9%    1YR 40    5YR 603    Max Repair 125.00 MSP
Commander    Control Rating 1   BRG   
Intended Deployment Time: 12 months    Morale Check Required   

ARC 250MW SLIPS Drive System (2)    Power 500.0    Fuel Use 70.71%    Signature 250.00    Explosion 10%
Fuel Capacity 401,000 Litres    Range 20.4 billion km (47 days at full power)

ARC 300mm Plasma Cannon (1)    Range 144,000km     TS: 5,000 km/s     Power 24-3     RM 10,000 km    ROF 40        24 12 8 6 4 4 3 3 2 2
ARC M1 100mm Railgun (4x4)    Range 10,000km     TS: 5,000 km/s     Power 3-3     RM 10,000 km    ROF 5        1 0 0 0 0 0 0 0 0 0
ARC Beam Fire Control R144-TS5100 (1)     Max Range: 144,000 km   TS: 5,100 km/s     93 86 79 72 65 58 51 44 38 31
ARC 5MW HCGMFF Reactor (3)     Total Power Output 15    Exp 5%

ARC M1 S5R1 Gravimeter (1)     GPS 1     Range 1.3m km    MCR 113.5k km    Resolution 1
ARC Thermal Sensor TH1.0-5.0 (1)     Sensitivity 5.0     Detect Sig Strength 1000:  17.7m km
ARC EM Sensor EM1.0-5.0 (1)     Sensitivity 5.0     Detect Sig Strength 1000:  17.7m km

This design is classed as a Military Vessel for maintenance purposes

This has a better BFC and better passive sensors. My hope is that the improved passives will allow squadrons of 4x Oblivions to operate independently but my concern is that they lack the armor to engage missile armed opponents.

[nuclearslurpee]

I decided to strip an armor layer off of the Oblivion M1:

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Oblivion M3 class Corvette (P)      5,000 tons       134 Crew       584.3 BP       TCS 100    TH 500    EM 0
5000 km/s      Armour 3-26       Shields 0-0       HTK 40      Sensors 5/5/0/0      DCR 3      PPV 21
Maint Life 3.11 Years     MSP 259    AFR 67%    IFR 0.9%    1YR 40    5YR 603    Max Repair 125.00 MSP
Commander    Control Rating 1   BRG   
Intended Deployment Time: 12 months    Morale Check Required   

ARC 250MW SLIPS Drive System (2)    Power 500.0    Fuel Use 70.71%    Signature 250.00    Explosion 10%
Fuel Capacity 401,000 Litres    Range 20.4 billion km (47 days at full power)

ARC 300mm Plasma Cannon (1)    Range 144,000km     TS: 5,000 km/s     Power 24-3     RM 10,000 km    ROF 40        24 12 8 6 4 4 3 3 2 2
ARC M1 100mm Railgun (4x4)    Range 10,000km     TS: 5,000 km/s     Power 3-3     RM 10,000 km    ROF 5        1 0 0 0 0 0 0 0 0 0
ARC Beam Fire Control R144-TS5100 (1)     Max Range: 144,000 km   TS: 5,100 km/s     93 86 79 72 65 58 51 44 38 31
ARC 5MW HCGMFF Reactor (3)     Total Power Output 15    Exp 5%

ARC M1 S5R1 Gravimeter (1)     GPS 1     Range 1.3m km    MCR 113.5k km    Resolution 1
ARC Thermal Sensor TH1.0-5.0 (1)     Sensitivity 5.0     Detect Sig Strength 1000:  17.7m km
ARC EM Sensor EM1.0-5.0 (1)     Sensitivity 5.0     Detect Sig Strength 1000:  17.7m km

This design is classed as a Military Vessel for maintenance purposes

This has a better BFC and better passive sensors. My hope is that the improved passives will allow squadrons of 4x Oblivions to operate independently but my concern is that they lack the armor to engage missile armed opponents.

This definitely looks a lot better overall despite the armor reduction. At 5000 tons we always have to make compromises after all.

A squadron of four of these can pretty comfortably defeat a "typical" ion tech ASM salvo of 10 missiles at 25,000 km/s, which isn't too bad for a 20,000-ton flotilla splitting its weapons between railguns and plasma (for comparison, I can get a 10,000-ton destroyer to mount 16x 10cm railguns at ion tech, and presumably another 10,000-ton ship could mount four or so 30cm plasma cannons but I haven't tried that). Against a heavy missile-armed opponent a single squadron of these should probably turn tail and run but for patrol work it should be good.

[Jorgen_CAB]

In regards of sensors I think that on a ship like this the most important thing is to detect EM radiation from enemy actives to know if you have been detected and are in the envelope of their active sensors. A size 1 (50t) EM will roughly detect a resolution 100 sensor at the same range it will detect you if you have the same sensitivity level. So if it operate alone (or the scout are disabled or elsewhere) that probably is most important.
Thermal sensors are more difficult... but you can look at what range you want to detect something versus the speed and thermal radiation you put out during scouting missions. This is probably why you generally want small passive thermal scouts in front of your ship/squadron to detect something before they detect your main ships thermal.

Ships this size in general make poor scouts unless dedicated to it and retaining their PD capabilities at the same time.

I probably would not really expect these ships to be good in an independent capacity and since each squadron already have a dedicated scout attached I would add a small hangar to that ship and then fit it with a bunch of small 20-25t passive and active crafts.

I usually find that the best ability to survive is to find the opponent first and able to know their strength and you can retreat or engage on your terms.

[liveware (OP)]

In regards of sensors I think that on a ship like this the most important thing is to detect EM radiation from enemy actives to know if you have been detected and are in the envelope of their active sensors. A size 1 (50t) EM will roughly detect a resolution 100 sensor at the same range it will detect you if you have the same sensitivity level. So if it operate alone (or the scout are disabled or elsewhere) that probably is most important.
Thermal sensors are more difficult... but you can look at what range you want to detect something versus the speed and thermal radiation you put out during scouting missions. This is probably why you generally want small passive thermal scouts in front of your ship/squadron to detect something before they detect your main ships thermal.

Ships this size in general make poor scouts unless dedicated to it and retaining their PD capabilities at the same time.

I probably would not really expect these ships to be good in an independent capacity and since each squadron already have a dedicated scout attached I would add a small hangar to that ship and then fit it with a bunch of small 20-25t passive and active crafts.

I usually find that the best ability to survive is to find the opponent first and able to know their strength and you can retreat or engage on your terms.

Instead of larger passives I considered slightly larger engines. I agree with your assessment that 50 ton tech 1 passives probably do not provide adequate detection range to keep these ships out of trouble. Larger engines would provide faster closing speed and hence reduced damage during closing, so that is probably a better option than larger passives.

[liveware (OP)]

After 30 years of game progress and some live fire testing against my resident Precursor foes, I came up with a next generation model of the Oblivion:

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Oblivion II class Corvette (P)      5,000 tons       137 Crew       621.7 BP       TCS 100    TH 500    EM 0
5000 km/s      Armour 4-26       Shields 0-0       HTK 39      Sensors 1/5/0/0      DCR 3      PPV 21
Maint Life 3.24 Years     MSP 273    AFR 67%    IFR 0.9%    1YR 39    5YR 588    Max Repair 125 MSP
Commander    Control Rating 1   BRG   
Intended Deployment Time: 12 months    Morale Check Required   

ARC M1 250MW SLIPS Drive System (2)    Power 500    Fuel Use 70.71%    Signature 250    Explosion 10%
Fuel Capacity 383,000 Litres    Range 19.5 billion km (45 days at full power)

ARC M1 300mm Plasma Cannon (1)    Range 96,000km     TS: 5,000 km/s     Power 24-3     RM 10,000 km    ROF 40       
ARC M1 100mm Railgun (4x4)    Range 10,000km     TS: 5,000 km/s     Power 3-3     RM 10,000 km    ROF 5       
ARC M2 SRDFWS Targeting Computer (2)     Max Range: 96,000 km   TS: 5,100 km/s     90 79 69 58 48 38 27 17 6 0
ARC M1 5MW HCGMFF Reactor (3)     Total Power Output 15    Exp 5%

ARC M1 S10R1 Gravimeter (1)     GPS 2     Range 1.8m km    MCR 160.6k km    Resolution 1
ARC M1 S15R1 Thermal Emission Detector (1)     Sensitivity 1.5     Detect Sig Strength 1000:  9.7m km
ARC M1 S50R5 Electromagnetic Wave Detector (1)     Sensitivity 5     Detect Sig Strength 1000:  17.7m km

This design is classed as a Military Vessel for maintenance purposes

Notable improvements:

- Improved armor (composite instead of high density duranium, allowing for 4x layers instead of 3x)
- New BFCs (lower range but only 5% worse than max possible accuracy, and having 2x BFCs allows for the carronade and railguns to target independently which is hugely useful)


It seems that I will need to rely on large numbers of these craft if I wish to overwhelm my current opponents in the near term. I have 25% research mod in this game so researching new engine tech is hard, same for better armor and weapons. Shields are under development but are still a few years out.

What I have found is that a squad of 8x Oblivions has fairly good PD capability against the 30k km/s ASMs my foes like to use, but they get sandpapered to death by their AMMs at close range. My maths tell me that about 50x Oblivion IIs would be able to close the range, but that's a sizeable resource commitment and I'm still on the fence about whether that is the best option or if a new, larger ship would better.

[nuclearslurpee]

What I have found is that a squad of 8x Oblivions has fairly good PD capability against the 30k km/s ASMs my foes like to use, but they get sandpapered to death by their AMMs at close range. My maths tell me that about 50x Oblivion IIs would be able to close the range, but that's a sizeable resource commitment and I'm still on the fence about whether that is the best option or if a new, larger ship would better.

Just don't do what I do and accidentally calculate your PD requirement using Gauss Cannon BFCs in your spreadsheet when your fleet has Railguns... 

[liveware (OP)]

What I have found is that a squad of 8x Oblivions has fairly good PD capability against the 30k km/s ASMs my foes like to use, but they get sandpapered to death by their AMMs at close range. My maths tell me that about 50x Oblivion IIs would be able to close the range, but that's a sizeable resource commitment and I'm still on the fence about whether that is the best option or if a new, larger ship would better.

Just don't do what I do and accidentally calculate your PD requirement using Gauss Cannon BFCs in your spreadsheet when your fleet has Railguns... 

Nope, I am too lazy to do a spreadsheet for that. I use:

expected accuracy = tracking speed / missile speed

Which in my case yields accuracy = 0.07 (approx)

Then I have:

missiles destroyed = expected accuracy * number of shots per ship

Which in my case yields 0.07 * 16 = 1.12.

Missile volleys I am struggling with are about 50 missiles each with 70k km/s missiles. So I need about 50x Oblivions to counter that.

All of which I can easily calculate using my standards approved TI-30x non-graphing calculator! (which I hate... my TI-89 is so much more better)

EDIT: I neglected to include the effect of my BFC which imparts a 0.9 accuracy modifier on my 1.12. But that's not that important really since I need at least 50 Oblivions which is a huge investment to begin with. 60 would not be that much more. 75 is probably a better "safe" number.