When I designed my ships I decided I wanted 50HS engines to maximize fuel efficiency, and at least two of them to ensure some redundancy in the face of combat damage. I also wanted 5,000 km/s speed to give me a better shot at controlling the range. While I have 1.75x engine tech I could not make a design that looked good to me at that rate of fuel use, so I settled on 1.5x and 18,000 tons. But as many here have pointed out my empire may not be able to sustain enough 1.5x fuel use ships to be effective.
So I went back to the drawing board and based a new set of 12,000 ton ships based on 1.0x engines, as I already had one of those researched. I lack any Power/Propulsion scientists so I'd rather not take the time to make a 50HS 1.25x engine. I'd consider these destroyers as they are individually much less capable than my cruiser designs, but I should be able to operate these without bankrupting my empire. As I am about halfway through the process of researching Stellerator tech I may not build these, but I thought I should share the designs for those who may be interested.
First up: the Memnon class PD destroyer. I could not bring myself to go full railgun, so this is a hybrid railgun/Gauss design. It also packs two lasers for finishing off cripples.
Memnon class Destroyer Escort 12,000 tons 316 Crew 1858 BP TCS 240 TH 1200 EM 450
5000 km/s Armour 4-46 Shields 15-300 Sensors 8/1/0/0 Damage Control Rating 7 PPV 62.12
Maint Life 1.82 Years MSP 677 AFR 164% IFR 2.3% 1YR 256 5YR 3844 Max Repair 300 MSP
Intended Deployment Time: 15 months Spare Berths 0
600 EP Ion Drive (2) Power 600 Fuel Use 30% Signature 600 Exp 10%
Fuel Capacity 750,000 Litres Range 37.5 billion km (86 days at full power)
Delta R300/360 Shields (6) Total Fuel Cost 90 Litres per hour (2,160 per day)
20cm C4 UV Laser (1) Range 256,000km TS: 5000 km/s Power 10-4 RM 4 ROF 15 10 10 10 10 8 6 5 5 4 4
25cm C4 Spinal UV Laser (1) Range 256,000km TS: 5000 km/s Power 16-4 RM 4 ROF 20 16 16 16 16 12 10 9 8 7 6
Twin Gauss 16K R3-85 Turret (3x6) Range 30,000km TS: 16000 km/s Power 0-0 RM 3 ROF 5 1 1 1 0 0 0 0 0 0 0
10cm Railgun V3/C3 5s (3x4) Range 30,000km TS: 5000 km/s Power 3-3 RM 3 ROF 5 1 1 1 0 0 0 0 0 0 0
PD Fire Control S03 48-16000 (1) Max Range: 96,000 km TS: 16000 km/s 90 79 69 58 48 38 27 17 6 0
Laser Fire Control S02.5 128-5000 (1) Max Range: 256,000 km TS: 5000 km/s 96 92 88 84 80 77 73 69 65 61
Gas-Cooled 1HS PB-1 (4) Total Power Output 18 Armour 0 Exp 5%
Active Search MR1/191K R1 (1) GPS 16 Range 1.8m km MCR 192k km Resolution 1
Thermal Sensor TH1-8 (1) Sensitivity 8 Detect Sig Strength 1000: 8m km
ECM 10
This design is classed as a Military Vessel for maintenance purposes
Next is the Penthesilea AMM destroyer. I realized that going with reduced-size launchers on an AMM ship was a mistake - if you have enough range for follow-up shots volley size doesn't matter, sustained fire rate does. Search and fire control range vs. size 6 missiles is 1.15M
Penthesilea class AMM Destroyer 12,000 tons 251 Crew 1715 BP TCS 240 TH 1200 EM 360
5000 km/s Armour 3-46 Shields 12-300 Sensors 8/1/0/0 Damage Control Rating 7 PPV 15
Maint Life 1.69 Years MSP 625 AFR 164% IFR 2.3% 1YR 262 5YR 3923 Max Repair 300 MSP
Intended Deployment Time: 16 months Spare Berths 0
Magazine 915
600 EP Ion Drive (2) Power 600 Fuel Use 30% Signature 600 Exp 10%
Fuel Capacity 750,000 Litres Range 37.5 billion km (86 days at full power)
Delta R300/360 Shields (5) Total Fuel Cost 75 Litres per hour (1,800 per day)
Size 1 ML (10s) (15) Missile Size 1 Rate of Fire 10
Missile PD Fire Control FC10-R1 (3) Range 10.6m km Resolution 1
Active Search Sensor MR10-R1 (1) GPS 96 Range 10.6m km MCR 1.2m km Resolution 1
Thermal Sensor TH1-8 (1) Sensitivity 8 Detect Sig Strength 1000: 8m km
ECM 10
This design is classed as a Military Vessel for maintenance purposes
And finally the Aeneas Missile Destroyer. Originally 20 launchers, but I had 4HS left over so I squeezed in another launcher and matching magazine space.
Aeneas class Missile Destroyer 12,000 tons 218 Crew 1702.14 BP TCS 240 TH 1200 EM 360
5000 km/s Armour 3-46 Shields 12-300 Sensors 8/1/0/0 Damage Control Rating 7 PPV 27.72
Maint Life 1.75 Years MSP 621 AFR 164% IFR 2.3% 1YR 249 5YR 3735 Max Repair 300 MSP
Intended Deployment Time: 16 months Spare Berths 0
Magazine 840
600 EP Ion Drive (2) Power 600 Fuel Use 30% Signature 600 Exp 10%
Fuel Capacity 750,000 Litres Range 37.5 billion km (86 days at full power)
Delta R300/360 Shields (5) Total Fuel Cost 75 Litres per hour (1,800 per day)
Size 4 Missile Launcher (33% 600s) (21) Missile Size 4 Rate of Fire 600
Missile Fire Control FC118-R100 (1) Range 118.8m km Resolution 100
Active Search Sensor MR123-R100 (1) GPS 11200 Range 123.2m km Resolution 100
Thermal Sensor TH1-8 (1) Sensitivity 8 Detect Sig Strength 1000: 8m km
ECM 10
This design is classed as a Military Vessel for maintenance purposes
I would probably deploy them as a flotilla with 3x Memnon, 2x Penthesilea and 4x Aeneas to cover my survey fleet when exploring a new jump point, so anticipated deployment times are month out, 6 months on station, and a month back to base.
