A Repair Bay is a structure, either static or mobile, that can make quick repairs and replenish the ammunition of BattleMechs and sometimes vehicles. The static version is often found within military installations, and mobile versions can be found in field camps. A repair bay is similar to a Mobile Field Base in its applications, but generally can make more extensive repairs and can be captured by units.
Repair Bays generally replenish both ammunition and armor, but cannot repair a 'Mech's lost limbs. For brevity's sake, the repairs take a fraction of the time they really would take, when they are done in-game.
Computer games are explicitly excluded from the list of products that contribute straight Canon to the BattleTech universe while at the same time it was stated that the IP owners are "not in total denial about these sources either"; it has also been stated that fluff from certain official, licensed products (namely certain computer games including those produced by FASA) can be assumed to be part of the shared universe as long as it is not directly contradicted, and makes sense. On this premise, Repair Bays are considered to be an apocryphal structure.