 It was also intended to supply components to Rover's main shadow factories at Acocks Green and Solihull, to supply spare parts, and to act as a backup facility if either of the main shadow factories was damaged by enemy action.The cost to complete was estimated at a further £184,000; Rover’s requirements included acid-resistant floors and specially painted walls in production areas.Drakelow, originally called "Drakelow Underground Dispersal Factory", was designated Rover No.