Moving between levels in a gigantic tower-world?

Question

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.

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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.

Answer 1

If travelling through levels is possible, it's only logical that there are doors that separate them - regardless of what they look like (shafts, gates, holes and whatnot).

For your character that can travel through them frequently I can think of a few solutions:

• A jetpack (or boots, or a drone, or... something) that is portable, inconspicuous and gives him the ability to fly and reach such doors;
• A pair of magnetic boots or an incredibly powerful grappling hook gun that gives him the ability to walk vertically through levels;
• A drone or some small robot that can fly him across levels (this could even be another character altogether);
• A teleporter watch, even though I'm thinking this is too much technology for your universe.

As for the common folk that do not possess such technology, I'm thinking a good answer would be any answer.

You didn't really say that there were a lot of levels, but I'm assuming there are some levels. I'm gonna go with 10 (even though it doesn't really matter). You said each level is different and that the space between levels is also different, so this gap could be just air, water or even thick steel. Hell, you could even have two levels directly connected by a huge 10 km hole in the sky/floor.

In such a level, it would be awesome to see a huge structure built with metallic waste or hundreds of ropes composed of clothes and whatever. Some levels could have the elevator pillars you mentioned. Some could have teleporters, if it's ok in your universe. Flying robots, vehicles... I think if each level had it's own way to travel your story would be even more diverse.

To actually anwer your question, I'm gonna go with vehicles.

You stated yourself they're rare, but in my opinion, they are the only way to safely fly 1 to 15 km without the existence of a HUGE stair-like structure - even if it was build within the walls of the tower.

There's also a narrative element that you could use here. Maybe the people who own the last few flying machines are mercenaries and use this "leverage" to charge anyone who wishes to go to another level. Maybe they're the richest people in each level, since they control one of the most rare resources if not THE most rare) in the world!

If we come back to my statement that there are only 10 levels, you could say that the few dozen owners of such ships are very influent people in their level, like kings or lords.

Answer 2

Counterweight rappelling.

Here and there among your worlds are ropes hanging down through holes. I can clip myself in and ring an attached device and the rope will haul me up through the ceiling, or let me down through the floor. Sometimes as I slowly rise or fall, I can see a counterweight move past me. These counterweights are sometimes just salvaged pieces of machinery but sometimes more interesting things. Often there is no counterweight evident - I conclude it is either far above or below me, or the rope is so long it is on a different floor altogether. Sometimes my travel stops for a little while and I can feel vibrations in the rope. Once I dangled for about a half hour, which got frightening. But no-one I have met has ever had to unclip and climb down, or suddenly gone into free fall while hooked onto a rope - although one guy descending on a rope got killed before he was all the way to the floor which was his own stupid fault.

These ropes are of some unknown substance and extremely tough - ancient tech. They are chewy but don't chew them or you will hurt your teeth. Once I found a rope which had been cut and then reattached through some mysterious joint.

The ropes are very long, extending up and down through many floors. No-one knows who maintains the rope system and counterweights - someone or something at a very high level of the tower. Users of the ropes make a habit of attaching offerings from time to time - food, beer, smokes, jerky, soap, letters of devotion. Offerings are in accordance with who or what they think might be maintaining the ropes to which they trust their lives. On that subject opinions vary. I figure it is someone like me and so I send carbonated water, fresh fruit when I can get it, and pictures I drew. The pictures are of me thanking the rope guardians and us playing basketball together.

Answer 3

If lifts were once used regularily, they ought to have maintenance shafts either in parallel or integrated into the lift. I would expect simple metal ladders or rungs bolted directly to the wall. Bearing in mind that people were supposed to climb thoes shafts for maintenance, there would have to be platforms, intersections or simple resting places in regular intervals.
This involves the risk that ladders are rusted and either snap off the wall or crumble under the weight of the adventurers.

Another possibility is that some big machinery was installed hanging from the ceiling of a level. Either it exploded, corroded or some scavangers made it up there and now there are thick wires or cables hanging down from the ceiling. I'm thinking in the style of a steel ropeway bridge once connecting two buildings hanging from the ceiling. If one corroded, the wires still dangle from the second building. Or scavangers simply build their own rope ladder from the materials they found. (Thanks @Liquid for the idea)

Answer 4

I know you are hesitant about using flight, but I am hoping by that you mean mechanical winged flight as my solution (at least an option) for both upwards and downwards travel is

Hot Air Balloon

Even if past-tech is failing, it might be reasonable that people could maintain and power large hot air balloons. This might be used in several manners from directly transporting people and goods between levels to raising heavy counter weights that drive couterweight lifts or rappelling.

If a main character owned a balloon, it might also be a way explain why they can frequently travel between levels. Maintaining the potentially delicate balloon might also offer some plot points to explore.

You mentioned that inter-level spacing could be as much as 15km. The world record altitude for balloons is just over 21km. So it might still work for very high levels - pressure/oxygen opportunities aside :-)

Answer 5

A hang-glider

It uses massive bursts of hot air from various heat exchange units to travel upwards, and traveling downwards is still relatively uncomplicated.

Due to the incredibly complex geometry of the world, this relatively simple device would be unsuitable for this kind of travel, if it weren't for the very important secondary piece of equipment your character(s) possess(es) -

A map

Knowledge of the structure and organization of each level is vital, or you'd never find paths in the interstitial spaces between the levels. Additionally, you might never even find where the access ports are, especially when traveling upward.

This makes an excellent pairing narratively as it's relatively easy to damage or repair a hang glider, and so it can be removed from the story when and where it seems appropriate.

Additionally, the map may be difficult to read, have corrupted data, or be unreliable due to an environment that has changed susbstantially, which, again, makes even the knowledge of your protagonist an advantage that can be just as reliable or unreliable as it needs to be to suit the advancement of the plot.

Answer 6

Without going super-pseudo-science on you you could use pneumatic transfer tubes, human sized ones have been proposed and designed in the past. It's got a bit of a retro feel these days but it could be quite effective.

Otherwise I'd suggest large ducts, or pipes, that travel through the structural walls between levels. Possibly cables/ropes/vines that hang or grow across multiple floors. Obviously either of these is going to need areas of respite where one can rest between long vertical climbs. I imagine metres thick mixed material bundles of cabling hug down through natural or artificial breaches in multiple floors with rest stops selling food and drink and renting bedding space to tired travelers hanging off them at odd intervals and toll booths at the floors taxing travelers who want to move through "their space". The cable trees will have to be anchoured at each floor they pass through as well to spread the load.

Answer 7

An answer I don't see covered by other answers is some people ride on the machines that maintain the tower. This would help explain why for some people it is near impossible to go up or down they are afraid of the machines or don't have the knowledge to know how to predict or control where one is going. A person from a nomadic tribe may have some form of old world technology (a tablet, a pair of goggles, etc) that tells them where certain robots go, their current task list, their level of hostility to humans, etc. Or they may have a way to directly command the machines. Perhaps some robots respond predictably when shown a qr code(eg a cargo robot that scans a codes that is for 2 floors up will take the cargo 2 floors up no questions asked)

I would recommend against giant stair cases or kilometer long rope ladders if you want travel to be common(or have once been common) since unless other floors have some resource that the floor you're on doesn't why would anyone want to spend days climbing a 1-15km staircase. I doubt that such large stair cases would be built with people in mind and would be more of gentle ramps often traversed by large machines carrying loads of resources to levels that need them

If the elevators/monorails/other forms of automated travel still work then I would think that anywhere these easy to use forms of travel meet inside a level or between levels a village may pop up. Don't be afraid to have some elevators work and others are broken. Say you want to get to floor 45 from floor 44, you may need to take an elevator down to floor 34 and then up to floor 46 where you can then take a tram line down to floor 45 since unless you want to walk that is the fastest route

Answer 8

I think one main question you should answer at least for yourself (and maybe for us if it's important for all answers) is whether this travel depends on 'old world' technology left behind by the constructors of the tower, or relies on newly or rebuild stuff from the current inhabitants (or a combination of these two).

The lifts and staircases you mentioned can work either way. Ancient lift shafts will probably be huge and could be travelled by all kind of contraptions: anything from a normal lift to some wierd wall-crawler (potentially even a wall crawling animal).

I think flying technology should also be fine if its rebuild: it will likely only be available (or at least usable) within a given floor so your characters can't really take use it more than once.

Another cool option I can think of are teleporters left behind by the tower constructors - potentially seen as "Magic of the gods" by those who still know the legends about them. Obviously accessing or activating them is anything but easy and for some reason you're not allowed to skip any floors ...

Answer 9

I would suggest that each level have a different mode of transportation, because it makes a better story. A couple of things to consider:

• Going down is a lot easier than going up. You could parachute down, rappel down on a rope, roll down a ramp, slide down a fireman's pole or a slide or a water slide, or walk down some stairs.

• 1km to 15km is a pretty long way up. The tallest skyscraper in the world isn't quite 1km. The Grand Canyon is 2km deep and Mount Everest is 9km tall. Many people don't like to live on the highest floors of today's skyscrapers because they sway a little with the wind and heights are terrifying. So, even a 1km staircase or a ramp is going to be perilous and dramatic.

• On the other hand, that space allows for lots of possibilities. You could literally have a mountain range on one of the levels and people could hike up it while munching trail mix and enjoying the view. You could have aircraft or blimps flying between levels and it wouldn't even be crowded.

• Some assorted ideas for upward travel that haven't been raised yet:

  • A giant tree could connect two levels, with ladders and rope-bridges all the way up.
  • Giant birds (genetically modified or cyborg eagles perhaps) could carry your characters. Bonus points if they live in eyries high up on the side walls and the characters have to climb halfway up the wall by some other method to tame a cyborg eagle.
  • Riding updrafts: heat rises, and since there is breathable air pressure in the upper levels, there must be a heck of a lot of warm air moving up the structure. Perhaps people ride the rising air with parachutes or something.
  • Donkeys: A level with Grand Canyon-like walls could be scaled by riding indefatigable pack animals.
  • Buoyancy: Perhaps somewhere there's a tower of water (maybe a massive, blocked drain pipe that once circulated water between levels) and characters can enter the bottom via airlocks and float to the top. (Pressure would be enormous, so they'd need amazing diving suits or a submarine of some kind.)

Answer 10

An artificial gravity highway

Simply put, in ancient times you would just take your favorite mode of transportation and scoot along a gravity highway that literally goes up and down the outer walls. It was easy, it connected everything, and now... Well, it depends.

In some areas, it's super easy to go between levels, since the highways still work. Walking takes longer than whatever type of bus they had in ancient times, but it works.

In others, there are spots on the highway where the artificial gravity has failed, or perhaps machinery is in the way. Maybe the highway is really wide, but to keep to functioning areas that aren't blocked, you have to zigzag the whole way, greatly increasing travel time and difficulty. Some levels might have areas of functioning gravity completely severed by non-functioning areas. Bridging a few hundred meters with an elevator of some sort isn't terrible, but depending on how many there are, it can be difficult. It can also make transporting supplies extremely difficult.

And finally, you can have levels with their highways completely inoperable. This would require scaling the entire height of the wall, which can be a monumental task.

One of the things I like about this solution is the size of the level matters, but not always. Two 15km tall levels can be easy to travel between if both highways are working perfectly fine. Two 1km levels can be nearly impossible to get between if their highways are non-functional and not easy to climb.

Answer 11

Ramps are better than stairs when workers have to move equipment up and down levels. A ramp can spiral around a column, be five meters wide, and have landings every so often. (For that matter, the column could be an elevator shaft. You could have use for both.)

Also, there could be ramps connected to the inside of the edge-wall. (They needn't circle the entire perimeter, just be steep enough to get to the next level in a reasonable distance)

Since they're on the perimeter, only people who live near the edge use them frequently. Others (if they're even aware of them) would have to travel as much as 200km to get to one.

Answer 12

Maybe there are sections of the outer walls which are lined with little shuttles, looking like Plexiglas bubbles peppered onto a wide set of parallel vertical tracks. The tracks could be slanted slightly, so that even though they might all be broken on one level, people can still clamber up the tracks, and this way the set of tracks for each level is distinct so that you can break them completely on one level but have them be totally pristine on the next. With enough of these, it makes sense for there to have been, at some time in the past, frequent passage between levels.

Answer 13

For me the most common type of travel would just be a series of ropes and ladders that people have put into place to allow them to travel up and down levels. Theses would be tied to easy to access areas and would allow travel up and down the entire structures. Even if a certain floor is damaged, a person who frequently travels up and down levels could slowly build up a series of rope networks to allow them to climb up the levels.

The best thing about the a rope network would that it can tie in with existing infrastructure. Lets take a ruined lift shaft. The ropes could be at several meter intervals with a small rest platform at each section. They could be tied to the metal framework that supports the elevators or even extend the whole length. Even better you could utilize pulleys or counterweight to make moving between levels easier. You can even use it with infrastructure that currently works, like ropes that lead to a working elevator or a series of steps. They can basically fill in the destroyed or decayed areas.

The only problem is however that someone needs to place the rope down. Its much harder to go up when you have just the rope. Of course you have things like grappling hooks, lassos and maybe even strong magnetic tips that would allow the rope to attach itself to something so you could climb up it and setup a much more sturdy and stable rope for proper transportation.

The next solution would be grippers. I'm sure you can all picture that person who used vacuum based grippers to climb up the side of a skyscraper. You could also use magnetic ones or the even newer friction based ones. Of course if its a long climb you want some safety, so most likely a rope which would be attached to certain points to save yourself a very long fall.

This could tie into the rope idea with a series of platforms setup on a very long wall to allow people to climb up and down the wall and take a break when necessary.

I'd like to add that old technology is often more reliable than new technology. Back when things were purely mechanical they wouldn't break as easily as all our new fancy electronically controlled technology. More advance things tend to have more components which can all fail while old technologies usually didn't. A staircase can crumble over time but a lift is unusable without electricity and constant maintenance. Any advance societies technology would crumble pretty dam fast if not maintained regularly.

Answer 14

I reckon the top tier is somewhat of the premium tier which reigns over the other tiers (this information is missing)

This top tier could be outfitted with massive cranes which can reach down on the side of the tower to every level, and carry a little pod which fits as many people as you desire for your story plot.

To be able to travel between tiers you therefore would need to have a permission. There certainly are AAA permissions for certain persons (top tier agents) but every other inhabitant can applies for a one time or a return permission. Your main character could own a AAA permission. Also you can make it a big spectacle every time a crane moves:

"Look the cranes are moving again!" "Who will it be this time?" "What a lucky person. I would love to get off this deck"

This would be the official way of moving between levels.

Having a controlled permission system opens up the possibilities for an interesting story plot.

As not all of the inhabitants will get a permission, there need to be some rouge ways too. Of course they need to be risky. What about ropes? It's highly dangerous but someone can be lowered to a lower deck quite fast. There even could be an underground trafficking guild, which takes a lot of money. Or makeshift ballons... or anything rigid and utterly risky.

Answer 15

In Blame! some sections contain large tubes. For example, at one point there are huge building machines (the builders) which build additional layers and structures using materials transported through giant tubes (mostly liquid I think). A savvy person could probably create a pod and insert it into one of these tubes to go wherever they lead.

Answer 16

Carrier Robots

Keep in mind that this world features humans, cyborgs, robots, sentient AIs and such.

Your protagonist's has contact with (for whatever reason - job, stumble upon, whatever) with a truck/ocean-liner sized robot (named LF-Ent) that currently carry materials within the level. These robots live extremely mundane lives, going between the same two points ad nauseam. Some occasion causes him to talk with this robot for an extended period where he learns that this robot once traveled to (give it some name the protagonist never heard of).

The robot describes how different it is there, which peaks the curiosity of your character. Nobody has gone there for a super long time and everybody has forgotten about it. Everybody else has, but an LF-Ent never forgets.

Conversation turns to a plan to go there for him to see it. Then, you can decide whatever means you want for the robot to go there (fly with engines not seen or used for ages, magnetically climb a wall, call for a lift cable, whatever).

Answer 17

I think you need to develop the detail of your world and its history to come up with a really satisfactory solution to this. Effectively there are two questions to ask:

1) You say that inter-level travel was 'somewhat common' in the past - I think you need to go into this in more detail. WHO used to travel inter-level, HOW OFTEN, and WHY? Think about our own world - could you compare IL travel with, say, driving to the supermarket? Inter-continental air travel? Space travel? Each one requires different types of infrastructure and places limits on who can do it. Would IL travellers have needed to be experts in IL travel (e.g. today's astronauts)? Or could anyone with sufficient resources do it, in which case what level of resources would be necessary (difference between driving/flying).

2) Then you need to think about what has happened since that time to make such options that much more difficult for your protagonists. In other words, what will it take for them to be able to use the options? Why don't other people use them any more?

I think lifts of some sort is probably your best option, but thinking about question 1 will help to decide how many lifts there are, where they are, and how they are used. Perhaps the lifts could have been installed solely for the use of a shadowy group of 'maintainers' who oversaw the workings of the tower-world from behind the scenes. That would mean knowledge of the lifts would be so restricted that our hero has to discover their location and workings for himself (perhaps with the aid of an ancient map of some sort...)

Answer 18

Paragliding

Only for the more adventurous adventurer

If there's a full height shaft open to the atmosphere at the top there will be airflow in it, in at the bottom and out at the top, giving a steady upward flow of air. With sufficient scale or a geothermal energy source at the bottom it would be sufficient to allow paragliding or even just parachuting (?parascending) up the levels.

Answer 19

Pressure Chutes

Probably not a very practical method, but just something to throw into the mix. If you have some kind of volcanic activity, you can dig chutes connecting the levels and move to a higher level by riding magma streams in a pod designed for this. There are a lot of very difficult technical issues that need to be solved to make this feasible:

• Building a pod that can not just resist the heat, but also have enough cooling to keep the passengers alive
• Accurately predicting eruptions
• Stopping the pod when you reached the top and preventing to fall down again (maybe tilt the chute slightly and let the pod drop down onto a platform)

But once set up, the technology should work without much maintenance. You can get up very fast, though not very comfortably.

You would reach lower levels by sliding down a chute, using brakes to control your speed, or by parachute.

Answer 20

Your main character could just be an equivalent of a mountain climber nowdays: it's extremely rare for most people to climb the Everest. He could bring a tent and sleep in the middle way up/down, and would take a day or a few days to change level.

Answer 21

I think stairs should be fine for the vast majority of the population because of this statement:

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.

OK the effort of climbing 15km of stairs is ridiculous, but as you say it's a once in a lifetime event. Perhaps the stairs have rest areas every 1km or so.

As for the lift, OK they are nearly all broken or dangerously unreliable, but the main character has access to a secret emergency lift that was once the method of transport for the king / president / supreme dictator from when the technology was new, and so was built to be extra tough, and is the one lift that he can rely on to work safely.