Star Trek Expanded Universe

Starbase 512 was a Federation Starfleet starbase active in the 24th century located near Ferengi space. It was the closest starbase to Deep Space Three, a few days travel at warp. (Star Trek: Outpost)

In 2364 Starbase 512 was the home base of the 214th Starfleet Construction Battalion under the command of Commander Olivia Twist, and its assigned starships, the Oberth-class starship USS Trosper, and the Bristol-class USS Goldberg.The Mediterranean-class USS Gorgon also makes regular supply runs from this facility. (Star Trek: Outpost)