Here is my current Missile Frigate design. Its a little old, needing a refresh on some sensors. Also, I am going to swap out the CIWS for a guass cannon turret in the next upgrade.
Decatur class Missile Frigate 5 000 tons 90 Crew 669.14 BP TCS 100 TH 240 EM 0
2400 km/s Armour 3-26 Shields 0-0 Sensors 24/8/0/0 Damage Control Rating 2 PPV 12.5
Maint Life 3.36 Years MSP 167 AFR 100% IFR 1.4% 1YR 22 5YR 337 Max Repair 65 MSP
Intended Deployment Time: 18 months Spare Berths 1
Magazine 225
C-M-1 60 EP Ion Drive (4) Power 60 Fuel Use 66.5% Signature 60 Exp 10%
Fuel Capacity 650 000 Litres Range 35.2 billion km (169 days at full power)
B-1 CIWS-120 (1x4) Range 1000 km TS: 12000 km/s ROF 5 Base 50% To Hit
MB-5L-B Size 5 Missile Launcher (50% Reduction) (5) Missile Size 5 Rate of Fire 375
C-MFC-AS-H-1 Missile Fire Control FC24-R40 (70%) (1) Range 24.3m km Resolution 40
ASM-3 (45) Speed: 18 000 km/s End: 21.1m Range: 22.8m km WH: 6 Size: 5 TH: 78/46/23
C-ASR-H Active Search Sensor MR26-R40 (70%) (1) GPS 2080 Range 26.3m km Resolution 40
B-PT-1-H Thermal Sensor TH4-24 (1) Sensitivity 24 Detect Sig Strength 1000: 24m km
C-PEM-M-1 EM Detection Sensor EM1-8 (1) Sensitivity 8 Detect Sig Strength 1000: 8m km
Missile to hit chances are vs targets moving at 3000 km/s, 5000 km/s and 10,000 km/s
This design is classed as a Military Vessel for maintenance purposes
Also, I had a question regarding AMM's (what I call Counter Missiles or CM's on my design). At low tech, the only decent design I could make where size 2, although my engines and warheads are probably good enough to switch over to a size 1 in the near future. In either case, is it advantageous to use lightweight/slow launch tubes, or simply carry more fast tubes. I have been using lightweight tubes, but it seems to me, with enough ammo less fast tubes might work. My biggest concern is whether or not that will lead to overkill and wasted ammo.