Well, I stumbled into Design and decided to make a big-ass ship. I think that I've hit all the marks, but I don't know if it would be a powerful missile platform or a expensive piece of target practice. I think it could use more missiles and magazines, though.
Chatham class Dreadnought 34700 tons 3557 Crew 5074.8 BP TCS 694 TH 1320 EM 540
1902 km/s Armour 1-94 Shields 18-300 Sensors 36/1/0/0 Damage Control Rating 81 PPV 120
Annual Failure Rate: 118% IFR: 1.7% Maint Capacity 17404 MSP Max Repair 150 MSP Est Time: 13.47 Years
Flag Bridge Magazine 2760
Ion Engine E8 (22) Power 60 Fuel Use 80% Signature 60 Armour 0 Exp 5%
Fuel Capacity 1,050,000 Litres Range 68.1 billion km (414 days at full power)
Beta R300/12 Shields (12) Total Fuel Cost 144 Litres per day
Size 5 Missile Launcher (24) Missile Size 5 Rate of Fire 75
Missile Fire Control FC32-R56 (4) Range 53.8m km Resolution 56
Active Search Sensor S96-R56 (5) GPS 5376 Range 53.8m km Resolution 56
Active Search Sensor S48-R56 (10) GPS 2688 Range 26.9m km Resolution 56
Thermal Sensor TH6-36 (5) Sensitivity 36 Detect Sig Strength 1000: 36m km
This design is classed as a military vessel for maintenance purposes
It's the latter of the two, IMO.
First off, your armor is really low. 1-94 isn't much more than an eggshell. As I understand it, the first number is the thickness of the armor, and the second is the width. I'd want the thickness up around 5 or 10 if I didn't want the ship to explode at the first sign of combat, the higher the better.
I have no idea about the shields. I haven't gotten around to using them yet...
Your failure rate is excellent, if you want a long range ship spending most of it's time away from the home system. Unfortunately, the ship is slow and won't be able to get too far from fueling bases due to only being able to run for 414 days, so why not cut back on engineering and maintenance supplies? Just keep it in system with a large maintenance facility, and you can lose a fair bit of weight.
Why the hell do you have 15 active sensors and 5 thermal sensors? Cut off all the sensors reading out to 27 mkms, they see the same size stuff as their bigger brothers, just worse. I'd cut back to just one each of the other sensors, maybe two of the actives. Hell, if you send these out in fleets, I'd design an anti-missile ship with sensors for the whole fleet. You don't need actives on a ship if another ship does, and you can save weight and minerals by cutting back like that.
Fair enough on the guns. As I count it, you have 20 something salvos per ship, which damn well better be enough since getting into a slugging match isn't good for anyone. I'd up your reload rate as much as possible, though. I love 5 second salvos, and the quicker you blow the other guy up, the less missiles you have to worry about shooting down.