In my sci-fi setting, people live in a gigantic metallic tower. For the sake of simplicity, let's say that each floor, or level, is a circle of around 200 km radius.
Levels can be either empty, full of houses and dismissed machinery, or something in between. Rings any bells? It's
a blatant copy inspired by Tsutomu Nihei's "Blame!" manga.
Science used to be to be extremely advanced in this world, but now most levels have regressed to a post-apocalyptic, scarcity kind of society. Technology is there, but it's mostly ruined and people either lack the skill, the knowledge, or the resources needed to repair it.
Between each level there is a thick ceiling standing, let's say, from 1km to 15km in height (again, it depends). On some levels, there's nothing but air between the floor and the ceiling. On others, the whole level is stacked full of buildings.
Of course, each level has also a set of outer walls; said "walls" are considered impenetrable. If there's something outside, no one knows or cares (for the sake of this question).
Now I need a way for my main characters to travel from one level to another. Between-level travel was somewhat common once, but now is very rare (and very difficult). I imagined most levels can be accessed through lifts, or, if necessary, sets of stairs in tower or pillar-like structures.
Are there other solutions for inter-level travel?
P.S.: I'm also considering flying vehicles, but they won't always be a viable option both due to lack of resources and the disparity in the various levels architecture.
Edit - Additional and miscellaneous Infos
- Inter-level travelling is common for at least one of my main characters. It's a once-in-a-lifetime thing for the others, and somewhat a remarkable feat for most of the normal population of the world.
- There's nothing wrong with lifts and scales, per se. But lifts, since they rely on old technology, could well be broken ...
- Stairs are somewhat more reliable, but it's safe to assume that the builders of the tower didn't fill it with many stairs (after all, it would make sense for them to prefer the more advanced, faster solution). With each level being as big as a country, having only, let's say, 4 sets of stairs etched in the outer walls at each cardinal point means you'll have to walk. A lot.
- Both very advanced, "old technology" solutions and makeshift, minimal and survival-like solutions are welcomed as answers.
- Despite the odd architecture, gravity, temperature, air pressure and such enviromentals conditions are all earth-like across the levels. Outside the scope of this questions, arrays of machines of all sorts are set up to mantain a stable enviroment. Of course, the occasional level may be "broken" or suffer serious differences.
- Keep in mind that this world features humans, cyborgs, robots, sentient AIs and such.