"To those of you that said humans would never fly, I now offer you a hand up so you can enjoy the view." -Collective inventor on the maiden voyage of the aerostat Ideals
An aerostat refers to the extremely rare, mechanically built, long-distance, floating aircraft, manufactured exclusively in Ironspire. They were first developed in the Citadel during the late Classical Era, and later, in Ironspire, sometime during the Golden Age. Aerostats are most commonly used for cargo and passenger transport within the Circle and its allies, and are found almost exclusively in the Eastern Block. Most notably, the basic infrastructure needed to effectively utilize the technology seems to be owned exclusively in Ironspire and the Citadel.
The hot air balloon is considered to be a primitive precursor to the modern aerostat. Unlike the aeorostat, the balloon design and make have a poor fuel-to-lift and -thrust ratio, severely limiting distance and carrying capacity. The balloon is also not as fast or maneuverable as the aerostat, and runs a much greater risk of being blown off-course.
The hot air balloon is still the most commonly used model of airship in the Circle due to its cheap construction costs and lack of specialized materials needed to make and maintain.
While the technology is not well understood outside of the airship yard in Ironspire, the basic premise involves hydrogen gas in insulated bags, which is heated to generate more lift, a system of propellers and sails to generate directional thrust, and a system of pulleys and counters to adjust tilt and stability. A cabin is hung from the pulleys below the bags for crew, cargo, and passengers, with control of the sails on the sides relying on more pulley systems.
Capacities range from small, four person scouting ships to massive passenger and cargo carriers. The infrastructure required to build them is not available outside of Ironspire, while the specialized materials needed to build them require a somewhat large area for mining or a large trade network, and the sheer expense of a single vessel makes smaller models impractical in most cases. The largest and most advanced aerostat prototypes have been built with the capability of staying high in the atmosphere for especially long periods. The most famous of these is the "Cumulus Rex", capable of transporting sixty people at a time, or 4500 kg, often seen flying routes between inner-circle cities as a symbol of technological prowess.
Proper utilization of aerostats requires advanced meteorology and physics, and can be increasingly dangerous without a proper system in place; even the smallest error could result in catastrophic failure and combustion of the entire thing.
The most common usage of the aerostat is fast transport of large quantities of goods, as a single large aerostat can move the same cargo as several flat-road wagons at more than twice the speed. This is unnecessary for most consumer goods, but is commonly used for perishables, such as fruit and processed products. As an added bonus, the cold air at the high altitudes eliminates the need for active cooling, especially at night.
The second most common usage is passenger transport between major cities. Aerostats are not as safe or comfortable as ground travel methods, but are the fastest way to travel between cities with airports. They are a form of public transit in the Inner Circle, but most seats are often reserved for important and time-sensitive matters. Smaller, more independent variants are also useful for long-range transports for far-off expeditions.
As aerostats provide access to high altitudes, they are exceedingly useful for scientific endeavors, and have been heavily utilized for these purposes.
Aerostats are generally built to land in specialized facilities, called airports, which contain tall structures for them to perch on for loading, unloading, refueling, inspection, and routine maintenance, as well as stadium-like areas built for ground landings and more extensive repairs. Aerostat docking involves ropes, light-based coordination, and bumpers, and is generally a short affair in good conditions. In bad enough weather, an aerostat pilot may choose to stay above the cloud layer while waiting for better conditions. Airports also have meteorological facilities for plotting weather patterns, and trade reports over existing aerostat routes.
The Great Engineer designed the airport in Ironspire, which was originally used for docking balloons, with long strips of undeveloped land around it for as-of-yet unknown reasons. Other major airport locations include (from south to north) Mother's Gate, Whitewood, Camelot, Stoneport, and Irongate.
Aerostat classifications and popularity
- Small- Single passenger, small carrying capacity, owned by a few inventors and influential rulers in the Circle.
- Large- Capable of carrying a dozen people or a transport wagon's worth of cargo, the most common kind of aerostat, dozens in use by the Collective transportation network.
- Gargantuan- Capable of carrying nearly a hundred passengers or several wagons worth of Cargo. Only two are in existence, the "Cumulus Rex" and "The Way Forward".