Initially developed on the Akatsu planet of Hiroshi due to the low surface to land ratio, the Akatsu Liner is a zeppelin/airship like design used across the Akatsu home system. Some have been sold or leased to others and some of those nations, most notably the Kochevnik, have bent them to military purpose. Liners are huge, extremely light, and capable of carrying a large amount of cargo within an atmosphere. Current generation liners use a vacuum foam technology where the foam is expanded inside a lightweight hull where it hardens to form an exceptionally low-density matrix, almost as light as vacuum in an atmosphere. Built in orbit the hull is then heavily weighted and towed to the surface for outfitting. Liners are long, streamlined vessels with a flattened oval cross-section, typically varying in length from five hundred to fifteen hundred metres, two hundred to five hundred metres across the beam and, once the superstructure is added, up to half a kilometre in height. Using a combination of thrust-vectoring lift fans and control vanes the vessels normally cruise at around fifty kilometres per hour but can go faster and, locked down, anywhere between one hundred and fifty and two hundred kph. Landlocked cities need sophisticated landing areas built but coastal communities and cities with nearby lakes do not since the vessels are entirely capable of landing on and moving across water. The hulls come with pre-built with cargo areas, locations for internal quartering, engines, control rooms and so on complete with access tunnels running through the vacufoam. Safety has been paramount in design considerations with the vessels able to float unaided and unpowered on any water surface, able to stay airborne with sixty percent engine and control its descent with as little as half. Even in the event of a catastrophic power failure, the fans can be jettisoned and the ship can "feather" down to land or sea. On Hiroshi, liners are generally considered the safest form of transport and there are cargo, passenger and military variants.