A garbage barge was an automated waste transport vehicle in operation in San Francisco in 2259.
Khan Noonien Singh attempted to flee on a garbage barge as it began its route while being pursued by Spock that year. Spock jumped on as well and the two fought, before Khan leaped onto another barge. Spock jumped on that barge as well, and Uhurabeamed down to fire several stun shots at Khan, enabling Spock to knock him unconscious. (Star Trek Into Darkness)
The garbage barges were identified as such in an article on the website FXGuide and another article in the magazine Cinefex. (; Cinefex, No. 134, p. 90)
The production crew that worked on Star Trek Into Darkness constructed the garbage barge as a full-scale set piece. The film's effects team mounted this to a hydraulic turntable which they built on the Playa Vista lot. The turntable was designed to spin and the resultant centrifugal force slid and swung the performers around, making the barge set seem to really be traveling. This illusion was heightened by the movements of shadows that the performers cast and by air movers that were used to input liquid nitrogen and live smoke effects, causing atmospherics to travel across the set. (Cinefex, No. 134, p. 90)