Some civilian components seem to react very poorly to being placed in military ships. As an example of this:
Pyro class Ammunition Ship 30,000 tons 530 Crew 5388.8 BP TCS 600 TH 3960 EM 0
6600 km/s JR 3-50 Armour 2-86 Shields 0-0 Sensors 40/40/0/0 Damage Control Rating 27 PPV 15.74
Maint Life 4.56 Years MSP 7031 AFR 266% IFR 3.7% 1YR 550 5YR 8252 Max Repair 990 MSP
Intended Deployment Time: 8 months Flight Crew Berths 15
Hangar Deck Capacity 1000 tons Magazine 6272 Cryogenic Berths 200
Radiant Dynamics K609-50 Max Ship Size 30450 tons Distance 50k km Squadron Size 3
Rocketdyne AMS-1980 (2) Power 1980 Fuel Use 13.96% Signature 1980 Exp 11%
Fuel Capacity 1,280,000 Litres Range 55.0 billion km (96 days at full power)
Turret, Single, Gauss Cannon, Mk1 Mod0 (2x5) Range 50,000km TS: 50000 km/s Power 0-0 RM 5 ROF 5 1 1 1 1 1 0 0 0 0 0
GE CIWS Mk1 Mod0 (2x10) Range 1000 km TS: 50000 km/s ROF 5 Base 50% To Hit
Sperry OWG-3 (1) Max Range: 50,000 km TS: 50000 km/s 80 60 40 20 0 0 0 0 0 0
Lockheed Martin OPS-4 (1) GPS 80 Range 32.0m km Resolution 1
TI OAR-3 (1) Sensitivity 40 Detect Sig Strength 1000: 40m km
TI OPR-3 (1) Sensitivity 40 Detect Sig Strength 1000: 40m km
ECM 40
Strike Group
1x U-2 Shuttle Speed: 15200 km/s Size: 10
2x U-1 Shuttle Speed: 15200 km/s Size: 5
This design is classed as a Military Vessel for maintenance purposes
Haven class Hospital Ship 30,000 tons 438 Crew 4447.8 BP TCS 600 TH 3960 EM 0
6600 km/s JR 3-50 Armour 2-86 Shields 0-0 Sensors 40/40/0/0 Damage Control Rating 27 PPV 15.74
Maint Life 2.22 Years MSP 6502 AFR 266% IFR 3.7% 1YR 1782 5YR 26728 Max Repair 990 MSP
Intended Deployment Time: 8 months Flight Crew Berths 12
Hangar Deck Capacity 1000 tons Cryogenic Berths 65000
Radiant Dynamics K609-50 Max Ship Size 30450 tons Distance 50k km Squadron Size 3
Rocketdyne AMS-1980 (2) Power 1980 Fuel Use 13.96% Signature 1980 Exp 11%
Fuel Capacity 1,270,000 Litres Range 54.6 billion km (95 days at full power)
Turret, Single, Gauss Cannon, Mk1 Mod0 (2x5) Range 50,000km TS: 50000 km/s Power 0-0 RM 5 ROF 5 1 1 1 1 1 0 0 0 0 0
GE CIWS Mk1 Mod0 (2x10) Range 1000 km TS: 50000 km/s ROF 5 Base 50% To Hit
Sperry OWG-3 (1) Max Range: 50,000 km TS: 50000 km/s 80 60 40 20 0 0 0 0 0 0
Lockheed Martin OPS-4 (1) GPS 80 Range 32.0m km Resolution 1
TI OAR-3 (1) Sensitivity 40 Detect Sig Strength 1000: 40m km
TI OPR-3 (1) Sensitivity 40 Detect Sig Strength 1000: 40m km
ECM 40
This design is classed as a Military Vessel for maintenance purposes
Merrimack class Oiler 30,000 tons 370 Crew 4435.8 BP TCS 600 TH 3960 EM 0
6600 km/s JR 3-50 Armour 2-86 Shields 0-0 Sensors 40/40/0/0 Damage Control Rating 27 PPV 15.74
Maint Life 2.19 Years MSP 6495 AFR 266% IFR 3.7% 1YR 1814 5YR 27216 Max Repair 990 MSP
Intended Deployment Time: 8 months Flight Crew Berths 15
Hangar Deck Capacity 1000 tons Cryogenic Berths 200
Radiant Dynamics K609-50 Max Ship Size 30450 tons Distance 50k km Squadron Size 3
Rocketdyne AMS-1980 (2) Power 1980 Fuel Use 13.96% Signature 1980 Exp 11%
Fuel Capacity 17,600,000 Litres Range 756.4 billion km (1326 days at full power)
Turret, Single, Gauss Cannon, Mk1 Mod0 (2x5) Range 50,000km TS: 50000 km/s Power 0-0 RM 5 ROF 5 1 1 1 1 1 0 0 0 0 0
GE CIWS Mk1 Mod0 (2x10) Range 1000 km TS: 50000 km/s ROF 5 Base 50% To Hit
Sperry OWG-3 (1) Max Range: 50,000 km TS: 50000 km/s 80 60 40 20 0 0 0 0 0 0
Lockheed Martin OPS-4 (1) GPS 80 Range 32.0m km Resolution 1
TI OAR-3 (1) Sensitivity 40 Detect Sig Strength 1000: 40m km
TI OPR-3 (1) Sensitivity 40 Detect Sig Strength 1000: 40m km
ECM 40
This design is classed as a Military Vessel for maintenance purposes
The three designs are as alike as I could make them, but for some reason, the Haven class and Merrimack classes have half the maintainence life of the Pyro class, despite the fact that the failure rates are the same, and the main components on the Merrimack and Haven classes are civilian components.