Warp core engine

Warp core engines were the propulsion systems of Rutan Motherships, and were apparently grown rather than built, as the Doctor described the engines of a ship that had been buried under the town of Stockbridge for several centuries as suffering a heart attack when they started malfunctioning. This would suggest that the engines were organic, or at least semi-organic, structures. They contained a cardio-electric capacitor and a metabolic failsafe. If damaged, an engine could cause a hyperspatial warp that would result in a time bubble. (AUDIO: The Eternal Summer)