Why was HMS Royal Sovereign in such poor condition when the Soviet Navy returned her as Arkhangelsk?
Short answerThe Soviet Navy lacked the infrastructure to maintain a battleship of her size, so machinery and weapons deteriorated badly.
NotesRoyal Sovereign was serviceable when transferred to the Soviet Navy as Arkhangelsk, but the receiving force lacked the facilities to maintain a battleship properly. Machinery seized, guns were not exercised, and the ship deteriorated beyond economical British reuse. Soviet facilities could support smaller ships more effectively. Acquiring a capital ship did not provide the industrial system needed to keep it operational.