Salvaging beam : recycle the hulk of dead ship (5% of hp is converted in supply) to reload the supply of repair, carrier bay or 2 others specials module.
More hulk is large more take time ( 5 sec for figther, 15 sec for frigate, 30 sec for cruiser) the hulk disappear in the process.
Exemple : a cruiser with 1000 hp give 50 supply.
Shield recharger : after this supply (500) is full relaunch one shield module except if shield module is destroyed.
Reconstructor: after this supply (500) is full reconstruct one destroyed module to 1 hp (if a repair module is present can repair the module at maximum hp).
For balance of this modules, they are expensive, heavy, weak, very bad stack effectiveness and demand big number of crew and power.
Is made for survivial mission. (clean the hulk for save ressource of PC and augment the duration of battle).
And sorry for my english.