As a cheap solution, you can go to data/upcdatage/upccrewdata/specialabilities.upc and change the torpedoman's reduce loading time passive ability to do the opposite, make the reloading last longer.
Change the red values to positive (without the +). I have no idea if this actually works, but it should.
Code:
[SpecialAbility 16]
ID=Ability-Reduce-Torpedo-Loading-Time
NameDisplayable=Ability-Reduce-Torpedo-Loading-Time-Name
Description=Ability-Reduce-Torpedo-Loading-Time-Description, Ability-Reduce-Torpedo-Loading-Time-Description, Ability-Reduce-Torpedo-Loading-Time-Description, Ability-Reduce-Torpedo-Loading-Time-Description, Ability-Reduce-Torpedo-Loading-Time-Description
Levels= 5
AbilityType=TorpedoLoadingTimeSimple ;reduce torpedo loading time (in percents)
AbilityValue= -6, -12, -18, -24, -30