Starships and warp drives

Main article: Ship types (The Culture)

As an almost fully space-borne culture, starships (next to orbitals) are the main living spaces, vehicles and ambassadors of the Culture. A proper Culture starship (as defined by hyperspace capability and the presence of a Mind to inhabit it) may range from several hundreds of metres to several dozens of kilometres. The latter may be inhabited by billions of beings and are artificial worlds in their own right, including wholeecosystems.

The Culture (and most other space-faring species in its universe) use a form of Hyperspace-drive to achieve faster-than-light speeds. Banks has evolved a (self-confessedly) technobabble system of theoretical physics to describe the ships' acceleration and travel, using such concepts as "infraspace" and "ultraspace" and an 'energy grid' between universes (from which the warp engines 'push off' to achieve momentum). An 'induced singularity' is used to access infra or ultra space from real space; once there, 'engine fields' reach down to the Grid and gain power and traction from it as they travel at high speeds.

These hyperspace engines do not use reaction mass and hence do not need to be mounted on the surface of the ship. They are described as being very dense exotic matter, which only reveals its complexity under a powerful microscope. Acceleration and maximum speed depend on the ratio of the mass of the ship to its engine mass. As with any other matter aboard, ships can gradually manufacture extra engine volume or break it down as needed. In Excession one of the largest ships of the Culture redesigns itself to be mostly engine and reaches a speed of 233,000 times lightspeed. Within the range of the Culture's influence in the galaxy, most ships would still take years of travelling to reach the more remote spots.

Other than the engines used by larger Culture ships, there are a number of other propulsion methods such as gravitic drive at sublight speeds, with antimatter, fusion and other reaction engines occasionally seen with less advanced civilizations, or on Culture hobby craft.

Warp engines can be very small, with Culture drones barely larger than fist-size described as being thus equipped. There is also at least one (apparently non-sentient) species (the "Chuy-Hirtsi" animal), that possesses the innate capability of warp travel. In Consider Phlebas, it is being used as a military transport by the Idirans, but no further details are given.