A repair scaffold is a lattice-like installation used to repair starships at the Utopia Planitia Fleet Yards.
In 2369, a repair scaffold was visible from the observation deck of Benjamin Sisko's apartment, as were the EVA crew working on the hull of the starship docked in it. (DS9 novel: Lesser Evil)
In 2254 Starbase 45 had two repair scaffolds orbiting over Algol II. (EV comic: "Futures, Part One")