From Warhammer 40k - Lexicanum
A Segmentum Fortress is an orbital base for fleet operations throughout its associated Segmentum. Each of the five Segmentae, the Imperium's primary administrative/fleet zones, has a Segmentum Fortress or fleet base.
These bases are huge ports with docks, shipyards and repair facilities. In reality however, relatively few of the fleet ships ever travel to their theoretical base. The main function of a fleet base is fleet administration.
A Segmentum Fortress is controlled directly by an Administratum Master.[Needs Citation] The fleets based in each Segmentum are led by a Lord High Admiral; these commanders may hold a place amongst the High Lords of Terra.
Locations of the five Segmentum fleet bases:
- Bakka - Segmentum Tempestus
- Cypra Mundi - Segmentum Obscurus
- Hydraphur - Segmentum Pacificus
- Mars - Segmentum Solar
- Kar Duniash - Ultima Segmentum
- 1: Battlefleet Gothic Rulebook, p. 86