The Salvo Swap Body lock is a key operated mechanical locking device designed to fit into the twist lock aperture on a swap body trailer. When fitted the Salvo Swap Body Lock can only be removed with the permit key. The Salvo Swap Body lock brings added safety to the loading dock procedures by locking into a swap body trailer’s twist lock aperture. The Salvo Swap Body Lock remains in place when the Castell key is removed. When the loading/ unloading procedures are complete, the Castell key may be inserted, and the Salvo Swap Body Lock removed, allowing the trailer to connect and the vehicle to depart from the loading bay.