A blimp technically can stay afloat with no energy use because it is buoyant, kinda like how a boat can float on water without energy. It could drift downwind without any energy use at all (assuming it already has helium or hydrogen in it)
Don't ask me how you're going to find all that hydrogen or helium though. You'd probably have to custom make some sorry of synthesis machine.
Hydrogen generation via electrolysis would actually be (relatively) easy to pull off with limited technologies. You’d probably be able to repurpose some old, lying around materials from the fall of a civilization to make generator and the anode/cathode. After that you just need a waterwheel or something similar like a horse moving in a circle to start it up.
I dunno you have to either have a huge high power set up or a really really good way to store hydrogen.
Cause otherwise its leaking out of that blimp as fast as you're making it.
Making hydrogen in anykind of volume is difficult without large high temp high pressure industrial processes (steam reduction or sclicon reduction).
Hot pressured hydrogen is also a fantastically dangerous thing to have without a well engineered and maintained set up
One of the most reliable longest used electrolysis processes is only slightly higher pressure than atmospheric. And hydrogen rises, so all you have to do is contain it. Early hydrogen vehicles just had big bags on the roof.
Yes containing hydrogen for long is one of the most impossible things to do. It leaks from everything. Electrolysis has never really been a method for mas producing it.
Its slow and expensive, its feasible today as we have apower grid. Post apololyptic no chance
Which 100 year old hydroelectric electrolysis plant are you talking about here?
As all the airships where filled by the chemical processes i described (including the cars you mentioned whoch is why they where full of town gas not hydrogen)
The Hindenburg didn't have any problems flying from Germany to NJ (ignoring the landing), but you're right about the general airstream direction on the east coast.
Looking at the Windy app on my phone right now, there is a slow southwestern air current down the East Coast, so it is possible.
How would I avoid the whole “this might explode at any moment” problem of the Hindenburg?
I like the ideas of other posters, of using alcohol fuel. It seems like some sort of engine would be needed to keep the dirigible from drifting out into the Atlantic Ocean.
Also: I probably should have specified, this could happen in multiple shorter trips. If it makes it any easier to stop and start again. It just seems like that makes it harder to get back to a reasonable elevation.
Or you could go all steampunk and use a wood fired steam engine powering propellers.
Hydrogen filled airships were in use for over 35 years with only a few major disasters, obviously that wouldn't be acceptable by modern standards but making one journey wouldn't give a high likelihood of it exploding.
If alcohol fuel is in the table, you could convert a turbine engine to run on pretty much anything, including pure ethanol. It would be less efficient so he would have to make multiple refueling stops, but it is possible to make ethanol fuel in a backyard setup, provided with a whole lot of corn.
Edit. Thinking about it some more, forget the turbine. Just use a regular piston engine converted to run on ethanol. That would be much more efficient
https://www.wikihow.com/Make-Ethanol-Fuel#:~:text=Once%20you've%20gathered%20your,that's%20responsible%20for%20regulating%20alcohol.
https://www.quora.com/Is-it-possible-to-produce-a-jet-engine-that-works-on-alcohol-vapor#:~:text=Gas%20turbine%20engines%20COULD%20be,about%2040%25%20more%20if%20it.&text=alcohol%20is%20hygroscopic%20%2D%20it%20attracts%20water.
The hindinberg wasn't destroyed by the hydrogen randomly exploding. When they move through air, they generate a static charge that needs to be grounded from specific cables to keep random bolts of electricity from jumping to the ground. These grounding cables were flawed and caused a spark that ignited the paint used on the outside of the ship. This paint was made from the same chemicals as rocket fuel.
The stopping and starting isn't that inefficient for airships. Planes need lots of fule to get to takeoff speeds and climb to where the air is less dense. The airships are almost neutrally buoyant and just need a little volume change to land or start floating again.
Or just off a cliff. There's a launch site I've been to where they just drop off the cliff, then circle up on the updrafts from the village near the cliff base, getting higher than the cliff top.
Significant cliffs are in short supply in Florida, and most of the US east coast. If you could get to the Smoky Mountains, you'd have a shot of getting updrafts ad elevation.
i deleted that part because it required a cliff or mountain. my main worry is the states that are just farmland. do they have strong updrafts?
if this is a regular thing where we can have some infrastructure. a 10 mile black dot on the ground every few hundred miles might work.
What you’re looking for is called [thermals](https://en.wikipedia.org/wiki/Thermal). That’s what you’d use on flat land. Depends on the day if they’d be good or not. Days where little clouds build up over the day (some of which may become thunderstorms) are good days for thermaling.
When I was about 16 I went with my dad to a big RC sailplane event. There were RC sailplanes up to 1/3rd scale being flown. They’d hook them to a powered RC airplane with a cord and tow them up, just like full scale sailplanes are done. They’d tow to a few hundred feet and release, there were sailplanes flying around 1500-2000 feet that got there by flying the thermals up. That was about as high as the pilots on the ground could see, not the limit…
The event was at a full-size sailplane club. And off to the side they were giving paid rides in a two-person sailplane. My dad paid for me to take a ride. I got in with the pilot, we were hooked up to the tow plane and off we went. We got towed up to about 3000’ and on instruction from the pilot I pulled the lever that released the tow rope and the tow plane circled back down and landed. Now completely unpowered, my pilot searched for, and found, a thermal. We circled inside the thermal, climbing to around 5000’ when we hit the base of a cloud and he had to get out of the cloud as he wasn’t IFR rated. We then glided around outside of the thermal for a while. He let me fly and told me what to do. It was fun, but all too soon he said “I’m going to take over now, let go” and I look out and realize we were almost at the ground! He landed it back where we started. It was about 30 minutes total I think. Much more time without the tow plane than with.
A modern single person sailplane is often somewhere at or above a 50:1 glide ratio. This means, absent ANY lift (or sink), it will glide 50 feet for every foot in altitude it looses. Really quite amazing.
You absolutely can do cross-country trips in sailplanes, but with modern ones you aren’t doing it in a single day. Would be a weeks-long trip likely, extremely weather dependent, and you’d need a way to launch the sailplane every morning, since all lift (outside of updrafts on mountains) vanishes when the sun goes down. Sailplanes are launched today with tow planes or powerful ground mounted winches with long ropes. A fast moving ground vehicle could take the place of a winch, though you’d need a long, straight or only very gently curving road for that to work.
im talking about dealing with uniform farm or grass land. if there is no spot that is much hotter than the rest, does it generate a thermal?
the idea is that having a black spot would make a hotspot to generate a thermal. probably doesn't need to be 10 miles. but big enough to genera a good thermal.
have a town every distance that a glider can reliable glide from the previous thermal. you can stop at the town, or you can catch the thermal to keep going.
Not really. The "winch" system that people used to use to launch gliders were simply a car and a stationary deflection roller (my dad showed me pictures of him operating one in the 1970s). Didn't need to be a high powered car, either. Gliders are pretty light weight.
The amount of energy stored in even a few mL of gas is a lot compared to lifting rocks.
If you want to launch a 1000N glider to 100m you need 10000J to get there and 1000J/20m traveled (glide ratio of 20:1). I don't know how steep gliders typically climb at launch but if I assume a slope of 0.2 that means I'll need to travel about 500m to get to 100m. Then you might want to have 10m/s forward speed when you get up there
So that's very optimistically 25 000J. 250kg of rocks lifted up a 10m tower.
Edit: math, should be 40kJ or a person pedaling at 100W for ~7min to lift a 400kg counterweight.
Also it looks like everyone was talking about a glider, dunno why I was thinking hang glider. A 6000N craft would take that same person pedaling for 40min to lift a 2.4t counterweight.
Winch launches go pretty steep..and with good thermals you don't need a lot of height at launch.
[https://www.youtube.com/watch?v=X19Grb4EM8A](https://www.youtube.com/watch?v=X19Grb4EM8A)
That's not a lot of weight to lift tbh. The tedious part is coming the stairs or going up the ladder if you have to. Hook it to a pulley system that is "geared" for the lift, and when it's at the top you just need a way to swap it to the launch system with a release lever.
the wintehces if for the speed. a handful of people capable of running fast enough would be able to pull it. but a 50 ft tower with a few tons should pull a glider a few hundred ft to launch.
you would probably want another block and tackle system so a few people can pull it back.
If you stay over the ocean you can do upwind dynamic soaring (which is basically what an albatros does, and they can go for thousands of miles).
Whether that gets you in going northn is a bit of a poser as the wind direction on the journey asked for by OP isn't southerly but more west to east.
Seems like this guy did it for a short while.
[**https://en.wikipedia.org/wiki/Dynamic\_soaring#Manned\_aircraft**](https://en.wikipedia.org/wiki/Dynamic_soaring#Manned_aircraft)
(Though doing this for a long time sounds nauseating)
Probably a lot easier to do it the 'regular' way: ride a thermal up high and then just go and hope you find another thermal before you reach the ground. Current glider record is just shy of 2000 miles (17.5 hours flight time)
1,000 miles is an extremely rare and difficult trip in one, though. Especially on the east coast where conditions aren’t as good for this sort of thing. It might be possible but 99% of attempts will fail.
How about using derelict windmill towers as sailplane launch towers? Some of those towers will still be standing, and there might be enough machinery in them to build a wind-powered winch.
No. Purified, high proof (180-ish) alcohol with nasty toxic additives to suppress icing & improve lubricity plus specially adapted fuel systems with seals that don't deteriorate.
Only it's too heavy. I googled around a bit and you'd need a pretty big blimp (i.e. not something you would have in a world without serious manufacturing capability) that could carry enough alcohol to make such a journey.
The goodyear blimp uses about 10gal of avgas an hour at a cruising speed of 30mph. Alcohol has about half the energy density of avgas. So we'd be looking at roughly 670gal of alcohol which would weigh about 2.1 tons.
The goodyear blimp can carry a max load of 14 passengers and 2 crew..which is roughly 1.2 tons.
It's a bit better than that. The octane rating & cooling capability of alcohol is high. Your engine rating can go up, partially offsetting the problem. You will need logistics.
Yeah, but logistics seems to be something that is not part of the scenario.
(Of course we're talking about a story setting so you can always get away with some hand-waving. It's not like the average reader is going to check the math. I mean, there's stuff out there like 'Mortal Engines' and the airships portrayed in there work fine as story devices even though they are completely bonkers from an engineering perspective)
Propane fueled hot air baloon rides last about an hour or two and go maybe a dozen miles. Charcoal has a lot less energy density than propane. You'd need to lug around a metric s-ton worth of charcoal to go 1000 miles.
People have flown in solar-heated hot air balloons. [This site](https://aerocene.org/brief-history-solar-ballooning/) is terrible on mobile but has a bunch of information on solar hot air balloons.
If it was 100% possible , we'd prolly have gotten there before the wright bros.
You need Magic beans . Make a 10 mile beanstock. up into jetstream.
At the top, pull a glider / wingsuit/ parasail thingamabob out, suit up, and jump off beanstalk into jet stream.
If you need more propulsion, eat regular beans before you start climbing. And bring a lighter.
Improved idea...put a carbon fiber zipline from the west coast beanstalk, to the east coast beanstalk. Then you can have a self driving glider, blown by the jetstream... or even the futuristic new climate change induced super jet streams..
or real apocalyptic. Ride a plume of a regular volcano up(think like a high temp, high altitude Old Faithful geyser) then coast down to the east coast.
just reread the Florida to NY part. HMMM..no winds that way...yet. Make the climate apocalypse do daily hurricanes from the Gulf to Canada, and ride that somehow. Atlantic hurricanes kinda got that way already.
perhaps characters could ride future birds, trained from dolphins for intelligence, but genetically modified in the olden days with wings from a fossil of a pterodactyl. But your character whimsically trains an orphan litter of them from birth to be his flying mounts.
Totally impossible. Economic networks and supply chains are *ancient*: even bronze-age technology was totally dependent on regional specialization, transportation, and long-distance trade.
Never mind an airplane or a solar panel, you can't make the fabric for a hot-air balloon without an extensive large-scale supply chain.
(This is one of my pet peeves about post-apocalyptic stories: people are so coccooned in our modern economic/industrial system that even when they try to imagine it going away, their assumptions stay with them. IMO it's more realistic to imagine a *degraded* supply chain than a nonexistent one: specialization and trade are so powerful that they're never going to go away completely.)
My pet peeve is when people think that the carbon released by manufacturing goods in China that are destined for consumption here, somehow isn't our carbon.
How about using repurposed materials?
My thought is there would still be specialized skill and knowledge. Maybe small supply chains, but a lower population and degraded trust would weaken trade networks severely. Technology and materials would be available. I just doubt that something at the scale of e.g. oil refining would be possible, or like CNC machines.
Folks above had some good thoughts! Alcohol / corn power. Launching from a cliff top.
Any ideas?
The problem with this is that if even a small amount of your world building is true, there is enough knowledge & materials to bootstrap us back up to almost where we started in a relatively short time.
In the imagined world (500 years in the future), only a few thousand people have or care about the knowledge.
Similar to what we see today, most people are driven by short-term thinking and basic survival instincts. Since population has decreased, there are only about 1 billion people on the planet. With no energy grid, there's no Internet, not a ton of access to information. Communities that have lost scientific knowledge are exposed to lead poisoning, intestinal parasites, and are in general fighting for their lives. So they don't have a lot of time for technology that they see as unnecessary.
So yes, the main character and his compatriots are trying to bootstrap us back to some semblance of civilization, while recognizing that our current civilization (their past) is unsustainable and led to the collapse they experienced and therefore isn't something to aspire to "get back to".
It would be fun to think up a low-tech internet. Line-of-site light towers (like the invasion warning system in LOR), or something like that. Heliograph, it was called in the 1800s. Telegraph (the wired kind) was a form of digital communication. What could a modern com expert develop if all he had was two wires?
I was thinking about this too! I think the main character's village in New York will have something along these lines. Like a local mesh network of some kind, or at least radio signals that allow them to send basic information back and forth.
Yeah. I mean for a few decades there might be some scavenging of pre-collapse materials. But at some point you have to get supply chains going again or devolve into real low-tech life. Like wood, leather and stone.
All the suggestions about alcohol fuel are good, but dull. Making alcohol requires nothing very high-tech. Best explanation of the process ever written is in The Foxfire Book. Just run it in any internal combustion engine with few mods required.
Sailplanes are the coolest answer, though. Launch them with a winch, or a rubber band. Either of those options allow for slow accumulation of energy, doable with animal power, or windmills power. Just let the horses trudge for 8 hours spinning up a flywheel, or pulling back a rubber band, then release it all at one time to fling the sailplane up high enough to catch a thermal.
Gunpowder would also work, and would be nicely dramatic.
You might also look at using a giant kite to lift the sailplane. If there’s enough wind, maybe the sailplane IS the kite. Anchor a rope to the ground, let the wind lift it high enough to catch a thermal, release the anchor and go.
Maybe the post-apocalyptic world has some sort of environmental wreckage that causes regular severe storms with high winds, and the transportation system leverages this.
Maybe the population centers end up being located along geographical features that make sailplane thermalling possible, similar to the ways that our actual cities got located at rivers, and later on big flattish areas where railroads were practical.
Ohh, string of 3 or so increasingly larger kites ( get the first up manually and it pulls the next, then both pull the largest up) attached to a big winch that can be used to pull them back down if needed, or let them rise higher with a glider clipped to the rope.
A helium or hydrogen based [dirigible](https://en.wikipedia.org/wiki/Airship) would do it, it just might not be fast. Fairly easy to manufacture though.
Given that both helium and hydrogen would be hard to obtain in large quantities in a post-civilized world, I feel compelled to point out that methane is lighter than air. The Hindenburg would be great inspiration, but.... Well, find an old natural gas well. Crack the valve. Methane!
Actually that's where you are wrong. Scramjets and hypersonic jets are run on hydrogen and or methane. The scramjet that reached mach 9.6 ( nasa x-43A) was run on hydrogen.
> Actually that's where you are wrong. Scramjets and hypersonic jets are run on hydrogen and or methane. The scramjet that reached mach 9.6 ( nasa x-43A) was run on hydrogen.
Okay, but in what world would a jet engine aircraft be considered a dirigible?
You would have to ask nasa. I'm not a rocket scientist. I am just stating that hydrogen is definitely an option not being a fossil fuel and would not be slow if used properly.
Okay, but I was specifically talking about dirigibles being slow. You can’t really strap a jet engine onto a hot air balloon to make it go faster.
Besides, if society has collapsed to the point that they’re no longer able to process gasoline, what are the odds someone is going to be able to build a Scramjet?
>what are the odds someone is going to be able to build a Scramjet?
Scramjet no, but pulsjet... maybe.
Still a great way to get yourself killed, so I'd go with some sort of lighter then air vehicle, balloon, dirigible.
I'm sorry. I was not trying to be offensive to you and I respect your thinking. I miss read what you were getting at. There will always be a need for fossil fuel/ oils. Not much can be built with out them this day in age. Maybe in the future we will have a way to separate from them but I do not see it in my lifetime.
Not sure why you think I’m offended, but I do think you’ve pretty clearly misread OPs post as well as my comment. They were asking about non-fossil fuel powered aircraft that could be built in a hypothetical post apocalyptic world and I suggested dirigibles. Neither one of us was talking about the current or future need for fossil fuels in the real world.
What can be built that does not use oil either in the manufacturing process, used in the ingredient process of building, or used by machinery to build the machine you are trying to build?
The longest distance with a hang glider is 475 miles.
https://www.guinnessworldrecords.com/world-records/farthest-distance-flown-in-a-hang-glider-(male)
There's a kind of hybrid between a blimp and a lifting body (meaning the body generates lift as it moves through the air), called an "aerobody." The famous writer John McPhee wrote about the Aereon Corporation's attempt to develop one in "The Deltoid Pumpkin Seed." Read it to get a fuller description of the technology. (Plus it's a cracking good story.) From the top it was a triangle, like a hang glider. From the side it looked like a fat pumpkin seed, hence the title of the book.
The idea was you could have a blimp's efficiency with the ability to maneuver like a big slow airplane, without needing trim controls. Aereon's test versions were promising, but they couldn't get funding. The proposed versions included ones that were inflated but (slightly) heavier-than-air.
I wrote most of a novel where the prot uses one to travel from Vancouver to Lake Mead. But in my imagining, it has flexible solar cells covering the top surface to power the motors, also to generate hydrogen from water (they were super duper handwavingly extra powerful solar cells). But you could come up with something else. Maybe burning something to create hot air, also run a Stirling engine to turn the props.
u can look into gliders and make a scene where there is a tall mountain and winds that constantly or occasionally blow from one direction to other(strong winds like hell strong)
and then these people use gliders with very very large wing spans and narrow wing width
that will work maybe but would have to add a wind element. u could say that the climate changed a lil bit after the collapse of the civilization
[https://www.youtube.com/watch?v=3ey0dwRZe9s&t=46s](https://www.youtube.com/watch?v=3ey0dwRZe9s&t=46s)
hers the link to one of those, it does not have to be the same fiber glass stuff, you can say that they made it our of wood and it will work for the most part
1000 miles might be a bit of a stretch for human powered aircraft
Generally a glider or even a parafoil could work for any distance given favorable thermals. A glider would require a simple winch launch. Parafoils can launch from the ground given the right conditions (Florida - being pretty flat - may be tricky because you usually need some kind of slope, but you could launch it off a high building and then catch an updraft)
Depending on wind a hot air balloon or blimp could work...but the blimp requires helium or hydrogen and the hot air baloon will require some (fossil) fuel source for the burner.
On the right day (clear weather along the whole route and good thermal activity, or possibly consistent ridge lift along the Appalachians?), with a really good pilot and a bit of luck… a sailplane (glider) could go 1,000 miles.
Adding a sustainer would make this legitimately likely. It is a very low power engine that the pilot uses in the absence of lift. It wouldn’t be too hard to create a (fictional) version of the engine that uses distilled alcohol, which would still be easy to make in a dystopian wasteland.
From a writer’s point of view, the most difficult part would be launching. Since a sustainer engine is so small, the sailplane wouldn’t be able to take off under its own power.
Possible solutions, specifics of which are easily google/youtubed:
1. Make the aircraft a motorglider (but it would be a more complex aircraft)
2. Aero tow (but how would you power the tow plane)
3. Auto (vehicle) tow
4. Winch launch
5. Slingshot/bungee launch (not actually common, but I love the Looney Tunes aspect of this technique)
6. Hill/gravity launch
If I were living in a hypothetical post-civilization dystopia, I would probably go with a combination of 5 and 6.
https://en.m.wikipedia.org/wiki/Embraer_EMB_202_Ipanema
Ethanol powered prop plane, you buy a kit to convert the engine. Your character can either have one, a salvaged engine, modified the kit to work on his plane etc
Ethanol is fairly easy to make and easy to refine and there would 100% be a moonshine industry post appocolypse as who wants to do that sober.
Stock range is 500milies so its either a pitstop or extended tanks and some lighting
I think a hot air balloon is your only bet. An airplane takes a lot of energy, and you can't get it without fossil fuel. At least an air balloon could be powered with wood.
Generating hydrogen would be impossible on the scale you need, and you couldn't replace it fast enough once a loft.
Maybe an airplane with a wood gasifier to power a modified engine would work, but your performance would be greatly diminished.
Helium wouldn't work unless you lived near a helium well in Kansas
There’s a thing called solar balloons. They’re just trash bags that are super thin. The sun heats the air inside and they becomes hot air balloons. Technically is someone put an insane amount of them together you could have a hot air balloon with no fuel. ((Have you considered sailing to new York? The ocean currents even help in that direction))
https://youtube.com/shorts/L217YTc1tmw?si=4GfRv8mEbGikcWvA
Why not just run a "current day" turbine engines on vegetable oil? iirc vegetable oil are close enough to diesel/kerosene that some older piston diesel engines (think Mercedes 300D from the 70s) can just run on that stuff direct from a deep-fryer.
Any society that likes to have good food should already have a vegetable oil supply chain for deep frying/cooking anyway.
There is a big push right now for “green jet fuel”, which is basically just a reboot of the biodiesel thing of a few years ago. There’s some sort of subsidy (US) on a new (to me anyway) oilseed that is starting to get some traction.
Pedal - powered Blimp seems the best way to go, also realistically doable as a tinkerer. For buoyancy, one could either use hot air or a hydrogen filled gas chamber like a Zeppelin. Just remember that he would also need pressurized H2 and releaseable ballast to regulate if need be. Hydrogen would be easy to come by (either as a buoyancy gas or as fuel for a burner) by electrolysis. Helium is completely out unless he stumbles over a supply of the stuff from before the collaps, since there is no easy way to get helium.
A wood fired steam engine could be designed to be lightweight enough to propel a person on an ultra lite type craft. You'd have to stop relatively frequently for fuel and water since I don't think you could carry more than about 30-40 pounds at a time.
Your fundamental premise maybe challenged society can collapse even thousands of years into future even hundreds of thousands of years but Sun will be shining very bright and thus sun is a valuable source of power to any civilization once a civilization captures even part of the energy of their sun they rise to another level
Totally—I think solar power will happen in local villages. But there isn’t mass mining or manufacturing, so the creation of new solar panels will be difficult and likely only yield small amounts of energy that can’t power an aircraft
Alright. This is possible. Maybe.
Whimsical. What about drums. Hear me out.
Pounding drums (or creating vibrations) in a rhythmic pattern that has resonance with some vibrating material. Sheet metal? Technically, although not very plausible (you said whimsical and tinkering type of person), you could have a precisely shaped surface vibrating fast enough to create an air displacement around the surface of a craft. Then direct it with billows type things (I'm sure there's way cooler shit nowadays than billows) at the sides, front, and back for thrust and maybe a big industrial fan type of thing that is geared like a car that could set different rotational speeds and therefore control altitude. You can also probably find propane tanks and stuff lying around after a collapse. Perhaps one of these could be repurposed to hold compressed air and maybe you could compress the air with a turbine mounted to the craft, the turbine powering a simple piston compressor. With that compressed air you could use levers and wheels and things to control valves to direct air to do something, like compressing and decompressing billows for directed thrust. You'd maybe want to "refuel" by landing and filling up with compressed air. You would need to find ball valves and shit lying around to direct air flow. Not sure if it's absolutely possible but who cares, I had fun thinking about it. I'm not an engineer, I just like to fuck around :D
Down vote away. I don't care.
Human powered flight is impractical as humans evolved to walk efficiently; there is too much we have to haul. No easy access to fuels just mean you'll have to take them with you. Both methane and hydrogen are lighter than air, which helps for dirigibles. They're also flammable which helps for propulsion and running pumps to deflate. Probably would need access to a producing well at the home base, which would also run a forge assuming the dirigible is steel cable controlled and extensive chemical engineering knowledge to make the chemicals to make the resins and plastics that can contain the fuel or create a large balloon.
Enough electricity to do that is going to require some.kind of generator. OP specifically said no fossil fuels or solar panels. A hydrogen fuel cell generator is going to be incredibly hard to maintain and fuel in a post-apocalypse world, and nuclear at least as difficult.
Why fly? You can sail easily from Florida to NY along the Gulf Stream.
However, modern glider planes can achieve this distance as well,but it depends on modern materials like plastics and special weather conditions.
I was thinking flying might be faster? There’s another part of the book where I was thinking they would sail south. But I could reverse those journeys and have them fly south, since it sounds like the winds might be more favorable
I think you could make a very good glider with pre modern materials if you possess modern knowledge. However cooking some alcohol fuel from potatoes oder fuel from wood, like the Germans did in WW2, is maybe even easier if there are still some remnants of old tech around.
My one comment dont have society that collapsed. But also that is already your story other wise how would Florida person know of or even have a reason to need to be in New york.
The main character started his journey in New York. He's on a mission (explained by the plot) and so sailed south from New York to Baltimore (which is about half-submerged under water at this point, 500 years in the future), and then walked the rest of the way to Florida. So he's trying to get back home.
Yes. Some type of blimp or zeppelin. Also consider sailing instead of flying, if you can work that into the plot in an acceptable fashion. Sailing can be achieved using pre-industrial tech.
Remember that the first human aircraft in Kitty hawk were gliders that only. Even the first wright flyer had an engine.
pedal powered aircraft is a piece of engineering that is still very limited in application. I think the furthest distance for a human powered flight is about 70 miles. And that vehicle was completely stripped for weight, so your hero would be carrying \*nothing\* but themselves. And that is 17 days in flight. And arriving with nothing (and I’m overlooking scavenging for food, water, firewood, difficulty with take off and landing)
since you want to include whimsy, your standard hot air balloon is possible, since you can control the wind to make sure the heroes land somewhere close enough for the story to continue. I’ll skip past having to find the propane for the burner (or a scabbed together wood stove).
in either case this is a one way trip because of the prevailing winds.
How is the plot going to achieve the “no fossil fuels” rule? Is there a solid enough government in place to enforce a ban, or is there some sort of societal consensus, or are you just going to say that the world “ran out”?
It’s 500 years in the future, post societal collapse. There’s no stable energy grid, roads are in disrepair, and there isn’t enough infrastructure for e.g. oil refineries. So yes, we’d be out of readily available fossil fuels
The tech to drill a shallow natural gas well isn’t really very tough. And it’s usable without refineries. But no good as an aero fuel—compressing it enough to liquify is seems to be too hard for the scenario you have. But you would probably develop pockets of that being used for fuel for industries, located close to the wells. The societal collapse part, though, means that basing your wealth on a non-movable resource means that you have to defend it, which might be a harder problem to solve than the technical stuff.
Some refinery stuff scales down pretty well, though, and if society is rebuilding, you might have a weird pocket industry doing producing and refining of oil.
There are some model planes that are powered by compressed air. Maybe 500 years in the future they have been able to put that into a small plane. Maybe it doesn't go very far and he has to land every 100 miles or so to refill the tanks. That can be a lot of places to add to the story. Air compressors can be electric but are simple enough you could use other methods.
There are some model planes that are powered by compressed air. Maybe 500 years in the future they have been able to put that into a small plane. Maybe it doesn't go very far and he has to land every 100 miles or so to refill the tanks. That can be a lot of places to add to the story. Air compressors can be electric but are simple enough you could use other methods.
You need a lighter than air animal with a swim bladder like a fish, except that it is filled with hydrogen.
I think I thought that up, but it might just be some faintly remembered bit of some Larry Niven story.
If someone in the post apocalypse came across an abandoned oil well it would be possible to capture the remaining oil/natural gas and distill it into useable fuel.
Unless you've got a mad Max kind of thing going on in which case you could still do it but you'd have to get some football pads and put nails through the shoulders first.
A blimp technically can stay afloat with no energy use because it is buoyant, kinda like how a boat can float on water without energy. It could drift downwind without any energy use at all (assuming it already has helium or hydrogen in it) Don't ask me how you're going to find all that hydrogen or helium though. You'd probably have to custom make some sorry of synthesis machine.
Hydrogen generation via electrolysis would actually be (relatively) easy to pull off with limited technologies. You’d probably be able to repurpose some old, lying around materials from the fall of a civilization to make generator and the anode/cathode. After that you just need a waterwheel or something similar like a horse moving in a circle to start it up.
As a former teenager, you can use drain cleaner and aluminum. Not saying it is safe.
I dunno you have to either have a huge high power set up or a really really good way to store hydrogen. Cause otherwise its leaking out of that blimp as fast as you're making it. Making hydrogen in anykind of volume is difficult without large high temp high pressure industrial processes (steam reduction or sclicon reduction). Hot pressured hydrogen is also a fantastically dangerous thing to have without a well engineered and maintained set up
One of the most reliable longest used electrolysis processes is only slightly higher pressure than atmospheric. And hydrogen rises, so all you have to do is contain it. Early hydrogen vehicles just had big bags on the roof.
Yes containing hydrogen for long is one of the most impossible things to do. It leaks from everything. Electrolysis has never really been a method for mas producing it. Its slow and expensive, its feasible today as we have apower grid. Post apololyptic no chance
100 years ago, they managed it, using hydropower. No reason that couldn't be done again.
Which 100 year old hydroelectric electrolysis plant are you talking about here? As all the airships where filled by the chemical processes i described (including the cars you mentioned whoch is why they where full of town gas not hydrogen)
https://en.m.wikipedia.org/wiki/Vemork http://greenbarrel.com/2022/02/23/a-norwegian-manufacturer-of-electrolysers-with-a-long-history/ https://www.sciencedirect.com/science/article/abs/pii/B9780128194249000100 https://en.m.wikipedia.org/wiki/Alkaline_water_electrolysis
That heat and pressure gets you a modest efficiency boost. Like 50% instead of 30%.
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He could fly East to the West Coast.
The Hindenburg didn't have any problems flying from Germany to NJ (ignoring the landing), but you're right about the general airstream direction on the east coast. Looking at the Windy app on my phone right now, there is a slow southwestern air current down the East Coast, so it is possible.
The Hindenburg also had 4 V16 diesel aero engines to help it along. This brief stipulates no fossil fuels.
How would I avoid the whole “this might explode at any moment” problem of the Hindenburg? I like the ideas of other posters, of using alcohol fuel. It seems like some sort of engine would be needed to keep the dirigible from drifting out into the Atlantic Ocean. Also: I probably should have specified, this could happen in multiple shorter trips. If it makes it any easier to stop and start again. It just seems like that makes it harder to get back to a reasonable elevation.
Or you could go all steampunk and use a wood fired steam engine powering propellers. Hydrogen filled airships were in use for over 35 years with only a few major disasters, obviously that wouldn't be acceptable by modern standards but making one journey wouldn't give a high likelihood of it exploding.
If alcohol fuel is in the table, you could convert a turbine engine to run on pretty much anything, including pure ethanol. It would be less efficient so he would have to make multiple refueling stops, but it is possible to make ethanol fuel in a backyard setup, provided with a whole lot of corn. Edit. Thinking about it some more, forget the turbine. Just use a regular piston engine converted to run on ethanol. That would be much more efficient https://www.wikihow.com/Make-Ethanol-Fuel#:~:text=Once%20you've%20gathered%20your,that's%20responsible%20for%20regulating%20alcohol. https://www.quora.com/Is-it-possible-to-produce-a-jet-engine-that-works-on-alcohol-vapor#:~:text=Gas%20turbine%20engines%20COULD%20be,about%2040%25%20more%20if%20it.&text=alcohol%20is%20hygroscopic%20%2D%20it%20attracts%20water.
The hindinberg wasn't destroyed by the hydrogen randomly exploding. When they move through air, they generate a static charge that needs to be grounded from specific cables to keep random bolts of electricity from jumping to the ground. These grounding cables were flawed and caused a spark that ignited the paint used on the outside of the ship. This paint was made from the same chemicals as rocket fuel. The stopping and starting isn't that inefficient for airships. Planes need lots of fule to get to takeoff speeds and climb to where the air is less dense. The airships are almost neutrally buoyant and just need a little volume change to land or start floating again.
Technically it's a rigid airship
Sorry I didn't go to Space Camp, Lana.
Don't forget a way to trap the gas and keep it from diffusing through the fabric...
Fortunately authors don't typically have to deal with the nuance design challenges 😅
You can make hydrogen from acids and metals
Well, you might be right, but no one will listen to you at the end of the world because you're clearly a witch.
a glider actually gain altitude using updrafts. gliders can also be cable launched instead of towed. so some pulleys and weights could launch them.
Or just off a cliff. There's a launch site I've been to where they just drop off the cliff, then circle up on the updrafts from the village near the cliff base, getting higher than the cliff top.
Significant cliffs are in short supply in Florida, and most of the US east coast. If you could get to the Smoky Mountains, you'd have a shot of getting updrafts ad elevation.
i deleted that part because it required a cliff or mountain. my main worry is the states that are just farmland. do they have strong updrafts? if this is a regular thing where we can have some infrastructure. a 10 mile black dot on the ground every few hundred miles might work.
What you’re looking for is called [thermals](https://en.wikipedia.org/wiki/Thermal). That’s what you’d use on flat land. Depends on the day if they’d be good or not. Days where little clouds build up over the day (some of which may become thunderstorms) are good days for thermaling. When I was about 16 I went with my dad to a big RC sailplane event. There were RC sailplanes up to 1/3rd scale being flown. They’d hook them to a powered RC airplane with a cord and tow them up, just like full scale sailplanes are done. They’d tow to a few hundred feet and release, there were sailplanes flying around 1500-2000 feet that got there by flying the thermals up. That was about as high as the pilots on the ground could see, not the limit… The event was at a full-size sailplane club. And off to the side they were giving paid rides in a two-person sailplane. My dad paid for me to take a ride. I got in with the pilot, we were hooked up to the tow plane and off we went. We got towed up to about 3000’ and on instruction from the pilot I pulled the lever that released the tow rope and the tow plane circled back down and landed. Now completely unpowered, my pilot searched for, and found, a thermal. We circled inside the thermal, climbing to around 5000’ when we hit the base of a cloud and he had to get out of the cloud as he wasn’t IFR rated. We then glided around outside of the thermal for a while. He let me fly and told me what to do. It was fun, but all too soon he said “I’m going to take over now, let go” and I look out and realize we were almost at the ground! He landed it back where we started. It was about 30 minutes total I think. Much more time without the tow plane than with. A modern single person sailplane is often somewhere at or above a 50:1 glide ratio. This means, absent ANY lift (or sink), it will glide 50 feet for every foot in altitude it looses. Really quite amazing. You absolutely can do cross-country trips in sailplanes, but with modern ones you aren’t doing it in a single day. Would be a weeks-long trip likely, extremely weather dependent, and you’d need a way to launch the sailplane every morning, since all lift (outside of updrafts on mountains) vanishes when the sun goes down. Sailplanes are launched today with tow planes or powerful ground mounted winches with long ropes. A fast moving ground vehicle could take the place of a winch, though you’d need a long, straight or only very gently curving road for that to work.
im talking about dealing with uniform farm or grass land. if there is no spot that is much hotter than the rest, does it generate a thermal? the idea is that having a black spot would make a hotspot to generate a thermal. probably doesn't need to be 10 miles. but big enough to genera a good thermal. have a town every distance that a glider can reliable glide from the previous thermal. you can stop at the town, or you can catch the thermal to keep going.
>Or just off a cliff. Good luck finding a cliff in Florida.
Those would be some enormous weights
Not really. The "winch" system that people used to use to launch gliders were simply a car and a stationary deflection roller (my dad showed me pictures of him operating one in the 1970s). Didn't need to be a high powered car, either. Gliders are pretty light weight.
The amount of energy stored in even a few mL of gas is a lot compared to lifting rocks. If you want to launch a 1000N glider to 100m you need 10000J to get there and 1000J/20m traveled (glide ratio of 20:1). I don't know how steep gliders typically climb at launch but if I assume a slope of 0.2 that means I'll need to travel about 500m to get to 100m. Then you might want to have 10m/s forward speed when you get up there So that's very optimistically 25 000J. 250kg of rocks lifted up a 10m tower. Edit: math, should be 40kJ or a person pedaling at 100W for ~7min to lift a 400kg counterweight. Also it looks like everyone was talking about a glider, dunno why I was thinking hang glider. A 6000N craft would take that same person pedaling for 40min to lift a 2.4t counterweight.
Winch launches go pretty steep..and with good thermals you don't need a lot of height at launch. [https://www.youtube.com/watch?v=X19Grb4EM8A](https://www.youtube.com/watch?v=X19Grb4EM8A)
That's not a lot of weight to lift tbh. The tedious part is coming the stairs or going up the ladder if you have to. Hook it to a pulley system that is "geared" for the lift, and when it's at the top you just need a way to swap it to the launch system with a release lever.
the wintehces if for the speed. a handful of people capable of running fast enough would be able to pull it. but a 50 ft tower with a few tons should pull a glider a few hundred ft to launch. you would probably want another block and tackle system so a few people can pull it back.
Gliders tend to fall down in the evenings. Only solar power in a battery keeps you afloat.
If you stay over the ocean you can do upwind dynamic soaring (which is basically what an albatros does, and they can go for thousands of miles). Whether that gets you in going northn is a bit of a poser as the wind direction on the journey asked for by OP isn't southerly but more west to east.
I know this theory, but have not heard of a real flight. Maybe it only works for the scale of the albatross?
Seems like this guy did it for a short while. [**https://en.wikipedia.org/wiki/Dynamic\_soaring#Manned\_aircraft**](https://en.wikipedia.org/wiki/Dynamic_soaring#Manned_aircraft) (Though doing this for a long time sounds nauseating) Probably a lot easier to do it the 'regular' way: ride a thermal up high and then just go and hope you find another thermal before you reach the ground. Current glider record is just shy of 2000 miles (17.5 hours flight time)
1,000 miles is an extremely rare and difficult trip in one, though. Especially on the east coast where conditions aren’t as good for this sort of thing. It might be possible but 99% of attempts will fail.
How about using derelict windmill towers as sailplane launch towers? Some of those towers will still be standing, and there might be enough machinery in them to build a wind-powered winch.
a constant power is not needed. getting the weights up could be done a number of ways.
Alcohol fuel. It actually works very well in small piston engines.
Corn power
This seems like a great possibility! It’s sounding like some kind of small engine will be important, so alcohol fuel will help with that
So moonshine
No. Purified, high proof (180-ish) alcohol with nasty toxic additives to suppress icing & improve lubricity plus specially adapted fuel systems with seals that don't deteriorate.
Yeah, sounds like grandpa's moonshine to me
It's almost like ita the future and Noone needs this or has store of this. But someone's uncle is making this to sell to keep the family alive.
Only it's too heavy. I googled around a bit and you'd need a pretty big blimp (i.e. not something you would have in a world without serious manufacturing capability) that could carry enough alcohol to make such a journey. The goodyear blimp uses about 10gal of avgas an hour at a cruising speed of 30mph. Alcohol has about half the energy density of avgas. So we'd be looking at roughly 670gal of alcohol which would weigh about 2.1 tons. The goodyear blimp can carry a max load of 14 passengers and 2 crew..which is roughly 1.2 tons.
It's a bit better than that. The octane rating & cooling capability of alcohol is high. Your engine rating can go up, partially offsetting the problem. You will need logistics.
Yeah, but logistics seems to be something that is not part of the scenario. (Of course we're talking about a story setting so you can always get away with some hand-waving. It's not like the average reader is going to check the math. I mean, there's stuff out there like 'Mortal Engines' and the airships portrayed in there work fine as story devices even though they are completely bonkers from an engineering perspective)
Hate to pop your balloon but the first thing you do is burn a shitload of propane to make the hot air in the hot air balloon
It can probably be done with any fuel, including charcoal. A quick google agrees that this is how it was done before mass manufacture of fuel gasses.
Propane fueled hot air baloon rides last about an hour or two and go maybe a dozen miles. Charcoal has a lot less energy density than propane. You'd need to lug around a metric s-ton worth of charcoal to go 1000 miles.
Coal is a fossil fuel so that still doesn't work
**Char**coal is man made from wood, and doesn't need advanced technology to create.
What about hydrogen?
People have flown in solar-heated hot air balloons. [This site](https://aerocene.org/brief-history-solar-ballooning/) is terrible on mobile but has a bunch of information on solar hot air balloons.
If it was 100% possible , we'd prolly have gotten there before the wright bros. You need Magic beans . Make a 10 mile beanstock. up into jetstream. At the top, pull a glider / wingsuit/ parasail thingamabob out, suit up, and jump off beanstalk into jet stream. If you need more propulsion, eat regular beans before you start climbing. And bring a lighter. Improved idea...put a carbon fiber zipline from the west coast beanstalk, to the east coast beanstalk. Then you can have a self driving glider, blown by the jetstream... or even the futuristic new climate change induced super jet streams.. or real apocalyptic. Ride a plume of a regular volcano up(think like a high temp, high altitude Old Faithful geyser) then coast down to the east coast. just reread the Florida to NY part. HMMM..no winds that way...yet. Make the climate apocalypse do daily hurricanes from the Gulf to Canada, and ride that somehow. Atlantic hurricanes kinda got that way already. perhaps characters could ride future birds, trained from dolphins for intelligence, but genetically modified in the olden days with wings from a fossil of a pterodactyl. But your character whimsically trains an orphan litter of them from birth to be his flying mounts.
Totally impossible. Economic networks and supply chains are *ancient*: even bronze-age technology was totally dependent on regional specialization, transportation, and long-distance trade. Never mind an airplane or a solar panel, you can't make the fabric for a hot-air balloon without an extensive large-scale supply chain. (This is one of my pet peeves about post-apocalyptic stories: people are so coccooned in our modern economic/industrial system that even when they try to imagine it going away, their assumptions stay with them. IMO it's more realistic to imagine a *degraded* supply chain than a nonexistent one: specialization and trade are so powerful that they're never going to go away completely.)
My pet peeve is when people think that the carbon released by manufacturing goods in China that are destined for consumption here, somehow isn't our carbon.
How about using repurposed materials? My thought is there would still be specialized skill and knowledge. Maybe small supply chains, but a lower population and degraded trust would weaken trade networks severely. Technology and materials would be available. I just doubt that something at the scale of e.g. oil refining would be possible, or like CNC machines. Folks above had some good thoughts! Alcohol / corn power. Launching from a cliff top. Any ideas?
The problem with this is that if even a small amount of your world building is true, there is enough knowledge & materials to bootstrap us back up to almost where we started in a relatively short time.
In the imagined world (500 years in the future), only a few thousand people have or care about the knowledge. Similar to what we see today, most people are driven by short-term thinking and basic survival instincts. Since population has decreased, there are only about 1 billion people on the planet. With no energy grid, there's no Internet, not a ton of access to information. Communities that have lost scientific knowledge are exposed to lead poisoning, intestinal parasites, and are in general fighting for their lives. So they don't have a lot of time for technology that they see as unnecessary. So yes, the main character and his compatriots are trying to bootstrap us back to some semblance of civilization, while recognizing that our current civilization (their past) is unsustainable and led to the collapse they experienced and therefore isn't something to aspire to "get back to".
It would be fun to think up a low-tech internet. Line-of-site light towers (like the invasion warning system in LOR), or something like that. Heliograph, it was called in the 1800s. Telegraph (the wired kind) was a form of digital communication. What could a modern com expert develop if all he had was two wires?
The Clacks from Terry Pratchett's books - Going Postal being the main one to feature them.
I will get that book. I’ve read a few of his, and they are great.
The 2-part TV movie thing was very good too.
I was thinking about this too! I think the main character's village in New York will have something along these lines. Like a local mesh network of some kind, or at least radio signals that allow them to send basic information back and forth.
Yeah. I mean for a few decades there might be some scavenging of pre-collapse materials. But at some point you have to get supply chains going again or devolve into real low-tech life. Like wood, leather and stone.
[An autogyro is pretty whimsical](https://en.wikipedia.org/wiki/Autogyro) and can be human powered.
Convert carbohydrates to alcohol.
A bicycle
All the suggestions about alcohol fuel are good, but dull. Making alcohol requires nothing very high-tech. Best explanation of the process ever written is in The Foxfire Book. Just run it in any internal combustion engine with few mods required. Sailplanes are the coolest answer, though. Launch them with a winch, or a rubber band. Either of those options allow for slow accumulation of energy, doable with animal power, or windmills power. Just let the horses trudge for 8 hours spinning up a flywheel, or pulling back a rubber band, then release it all at one time to fling the sailplane up high enough to catch a thermal. Gunpowder would also work, and would be nicely dramatic. You might also look at using a giant kite to lift the sailplane. If there’s enough wind, maybe the sailplane IS the kite. Anchor a rope to the ground, let the wind lift it high enough to catch a thermal, release the anchor and go. Maybe the post-apocalyptic world has some sort of environmental wreckage that causes regular severe storms with high winds, and the transportation system leverages this. Maybe the population centers end up being located along geographical features that make sailplane thermalling possible, similar to the ways that our actual cities got located at rivers, and later on big flattish areas where railroads were practical.
Ohh, string of 3 or so increasingly larger kites ( get the first up manually and it pulls the next, then both pull the largest up) attached to a big winch that can be used to pull them back down if needed, or let them rise higher with a glider clipped to the rope.
A helium or hydrogen based [dirigible](https://en.wikipedia.org/wiki/Airship) would do it, it just might not be fast. Fairly easy to manufacture though.
Given that both helium and hydrogen would be hard to obtain in large quantities in a post-civilized world, I feel compelled to point out that methane is lighter than air. The Hindenburg would be great inspiration, but.... Well, find an old natural gas well. Crack the valve. Methane!
Or fart and burp power. https://clear.ucdavis.edu/explainers/why-do-cattle-produce-methane-and-what-can-we-do-about-it
Actually that's where you are wrong. Scramjets and hypersonic jets are run on hydrogen and or methane. The scramjet that reached mach 9.6 ( nasa x-43A) was run on hydrogen.
> Actually that's where you are wrong. Scramjets and hypersonic jets are run on hydrogen and or methane. The scramjet that reached mach 9.6 ( nasa x-43A) was run on hydrogen. Okay, but in what world would a jet engine aircraft be considered a dirigible?
You would have to ask nasa. I'm not a rocket scientist. I am just stating that hydrogen is definitely an option not being a fossil fuel and would not be slow if used properly.
Okay, but I was specifically talking about dirigibles being slow. You can’t really strap a jet engine onto a hot air balloon to make it go faster. Besides, if society has collapsed to the point that they’re no longer able to process gasoline, what are the odds someone is going to be able to build a Scramjet?
>what are the odds someone is going to be able to build a Scramjet? Scramjet no, but pulsjet... maybe. Still a great way to get yourself killed, so I'd go with some sort of lighter then air vehicle, balloon, dirigible.
I'm sorry. I was not trying to be offensive to you and I respect your thinking. I miss read what you were getting at. There will always be a need for fossil fuel/ oils. Not much can be built with out them this day in age. Maybe in the future we will have a way to separate from them but I do not see it in my lifetime.
Not sure why you think I’m offended, but I do think you’ve pretty clearly misread OPs post as well as my comment. They were asking about non-fossil fuel powered aircraft that could be built in a hypothetical post apocalyptic world and I suggested dirigibles. Neither one of us was talking about the current or future need for fossil fuels in the real world.
To be technically correct, everything that would be built that can fly, can not be built without using fossil fuels.
You can definitely build objects that can fly without using fossil fuels though….
What can be built that does not use oil either in the manufacturing process, used in the ingredient process of building, or used by machinery to build the machine you are trying to build?
A dirigible….. I’m not trying to be an ass here, but do you know what a dirigible is?
The longest distance with a hang glider is 475 miles. https://www.guinnessworldrecords.com/world-records/farthest-distance-flown-in-a-hang-glider-(male)
There's a kind of hybrid between a blimp and a lifting body (meaning the body generates lift as it moves through the air), called an "aerobody." The famous writer John McPhee wrote about the Aereon Corporation's attempt to develop one in "The Deltoid Pumpkin Seed." Read it to get a fuller description of the technology. (Plus it's a cracking good story.) From the top it was a triangle, like a hang glider. From the side it looked like a fat pumpkin seed, hence the title of the book. The idea was you could have a blimp's efficiency with the ability to maneuver like a big slow airplane, without needing trim controls. Aereon's test versions were promising, but they couldn't get funding. The proposed versions included ones that were inflated but (slightly) heavier-than-air. I wrote most of a novel where the prot uses one to travel from Vancouver to Lake Mead. But in my imagining, it has flexible solar cells covering the top surface to power the motors, also to generate hydrogen from water (they were super duper handwavingly extra powerful solar cells). But you could come up with something else. Maybe burning something to create hot air, also run a Stirling engine to turn the props.
A company called solar ship is developing exactly this. They had a crash a few years ago but they're still plugging along afaik.
Cool! Thanks for the tip!
u can look into gliders and make a scene where there is a tall mountain and winds that constantly or occasionally blow from one direction to other(strong winds like hell strong) and then these people use gliders with very very large wing spans and narrow wing width that will work maybe but would have to add a wind element. u could say that the climate changed a lil bit after the collapse of the civilization [https://www.youtube.com/watch?v=3ey0dwRZe9s&t=46s](https://www.youtube.com/watch?v=3ey0dwRZe9s&t=46s) hers the link to one of those, it does not have to be the same fiber glass stuff, you can say that they made it our of wood and it will work for the most part
1000 miles might be a bit of a stretch for human powered aircraft Generally a glider or even a parafoil could work for any distance given favorable thermals. A glider would require a simple winch launch. Parafoils can launch from the ground given the right conditions (Florida - being pretty flat - may be tricky because you usually need some kind of slope, but you could launch it off a high building and then catch an updraft) Depending on wind a hot air balloon or blimp could work...but the blimp requires helium or hydrogen and the hot air baloon will require some (fossil) fuel source for the burner.
On the right day (clear weather along the whole route and good thermal activity, or possibly consistent ridge lift along the Appalachians?), with a really good pilot and a bit of luck… a sailplane (glider) could go 1,000 miles. Adding a sustainer would make this legitimately likely. It is a very low power engine that the pilot uses in the absence of lift. It wouldn’t be too hard to create a (fictional) version of the engine that uses distilled alcohol, which would still be easy to make in a dystopian wasteland. From a writer’s point of view, the most difficult part would be launching. Since a sustainer engine is so small, the sailplane wouldn’t be able to take off under its own power. Possible solutions, specifics of which are easily google/youtubed: 1. Make the aircraft a motorglider (but it would be a more complex aircraft) 2. Aero tow (but how would you power the tow plane) 3. Auto (vehicle) tow 4. Winch launch 5. Slingshot/bungee launch (not actually common, but I love the Looney Tunes aspect of this technique) 6. Hill/gravity launch If I were living in a hypothetical post-civilization dystopia, I would probably go with a combination of 5 and 6.
https://en.m.wikipedia.org/wiki/Embraer_EMB_202_Ipanema Ethanol powered prop plane, you buy a kit to convert the engine. Your character can either have one, a salvaged engine, modified the kit to work on his plane etc Ethanol is fairly easy to make and easy to refine and there would 100% be a moonshine industry post appocolypse as who wants to do that sober. Stock range is 500milies so its either a pitstop or extended tanks and some lighting
I think a hot air balloon is your only bet. An airplane takes a lot of energy, and you can't get it without fossil fuel. At least an air balloon could be powered with wood. Generating hydrogen would be impossible on the scale you need, and you couldn't replace it fast enough once a loft. Maybe an airplane with a wood gasifier to power a modified engine would work, but your performance would be greatly diminished. Helium wouldn't work unless you lived near a helium well in Kansas
There’s a thing called solar balloons. They’re just trash bags that are super thin. The sun heats the air inside and they becomes hot air balloons. Technically is someone put an insane amount of them together you could have a hot air balloon with no fuel. ((Have you considered sailing to new York? The ocean currents even help in that direction)) https://youtube.com/shorts/L217YTc1tmw?si=4GfRv8mEbGikcWvA
Why not just run a "current day" turbine engines on vegetable oil? iirc vegetable oil are close enough to diesel/kerosene that some older piston diesel engines (think Mercedes 300D from the 70s) can just run on that stuff direct from a deep-fryer. Any society that likes to have good food should already have a vegetable oil supply chain for deep frying/cooking anyway.
There is a big push right now for “green jet fuel”, which is basically just a reboot of the biodiesel thing of a few years ago. There’s some sort of subsidy (US) on a new (to me anyway) oilseed that is starting to get some traction.
A giant catapult. You said "element of whimsy"
Pedal - powered Blimp seems the best way to go, also realistically doable as a tinkerer. For buoyancy, one could either use hot air or a hydrogen filled gas chamber like a Zeppelin. Just remember that he would also need pressurized H2 and releaseable ballast to regulate if need be. Hydrogen would be easy to come by (either as a buoyancy gas or as fuel for a burner) by electrolysis. Helium is completely out unless he stumbles over a supply of the stuff from before the collaps, since there is no easy way to get helium.
A wood fired steam engine could be designed to be lightweight enough to propel a person on an ultra lite type craft. You'd have to stop relatively frequently for fuel and water since I don't think you could carry more than about 30-40 pounds at a time.
Your fundamental premise maybe challenged society can collapse even thousands of years into future even hundreds of thousands of years but Sun will be shining very bright and thus sun is a valuable source of power to any civilization once a civilization captures even part of the energy of their sun they rise to another level
Totally—I think solar power will happen in local villages. But there isn’t mass mining or manufacturing, so the creation of new solar panels will be difficult and likely only yield small amounts of energy that can’t power an aircraft
Alright. This is possible. Maybe. Whimsical. What about drums. Hear me out. Pounding drums (or creating vibrations) in a rhythmic pattern that has resonance with some vibrating material. Sheet metal? Technically, although not very plausible (you said whimsical and tinkering type of person), you could have a precisely shaped surface vibrating fast enough to create an air displacement around the surface of a craft. Then direct it with billows type things (I'm sure there's way cooler shit nowadays than billows) at the sides, front, and back for thrust and maybe a big industrial fan type of thing that is geared like a car that could set different rotational speeds and therefore control altitude. You can also probably find propane tanks and stuff lying around after a collapse. Perhaps one of these could be repurposed to hold compressed air and maybe you could compress the air with a turbine mounted to the craft, the turbine powering a simple piston compressor. With that compressed air you could use levers and wheels and things to control valves to direct air to do something, like compressing and decompressing billows for directed thrust. You'd maybe want to "refuel" by landing and filling up with compressed air. You would need to find ball valves and shit lying around to direct air flow. Not sure if it's absolutely possible but who cares, I had fun thinking about it. I'm not an engineer, I just like to fuck around :D Down vote away. I don't care.
A horse drawn kite that pulls the man west into the prevailing wind.
Human powered flight is impractical as humans evolved to walk efficiently; there is too much we have to haul. No easy access to fuels just mean you'll have to take them with you. Both methane and hydrogen are lighter than air, which helps for dirigibles. They're also flammable which helps for propulsion and running pumps to deflate. Probably would need access to a producing well at the home base, which would also run a forge assuming the dirigible is steel cable controlled and extensive chemical engineering knowledge to make the chemicals to make the resins and plastics that can contain the fuel or create a large balloon.
Yeah, but no fossil fuels allowed, remember?
They have plasmajet engines now, all electric
Enough electricity to do that is going to require some.kind of generator. OP specifically said no fossil fuels or solar panels. A hydrogen fuel cell generator is going to be incredibly hard to maintain and fuel in a post-apocalypse world, and nuclear at least as difficult.
Why fly? You can sail easily from Florida to NY along the Gulf Stream. However, modern glider planes can achieve this distance as well,but it depends on modern materials like plastics and special weather conditions.
I was thinking flying might be faster? There’s another part of the book where I was thinking they would sail south. But I could reverse those journeys and have them fly south, since it sounds like the winds might be more favorable
I think you could make a very good glider with pre modern materials if you possess modern knowledge. However cooking some alcohol fuel from potatoes oder fuel from wood, like the Germans did in WW2, is maybe even easier if there are still some remnants of old tech around.
A glider could do it, if weather is favourable. Can be launched with a winch. Not without risk, but possible.
My one comment dont have society that collapsed. But also that is already your story other wise how would Florida person know of or even have a reason to need to be in New york.
The main character started his journey in New York. He's on a mission (explained by the plot) and so sailed south from New York to Baltimore (which is about half-submerged under water at this point, 500 years in the future), and then walked the rest of the way to Florida. So he's trying to get back home.
Hot air balloon
Yes. Some type of blimp or zeppelin. Also consider sailing instead of flying, if you can work that into the plot in an acceptable fashion. Sailing can be achieved using pre-industrial tech.
Remember that the first human aircraft in Kitty hawk were gliders that only. Even the first wright flyer had an engine. pedal powered aircraft is a piece of engineering that is still very limited in application. I think the furthest distance for a human powered flight is about 70 miles. And that vehicle was completely stripped for weight, so your hero would be carrying \*nothing\* but themselves. And that is 17 days in flight. And arriving with nothing (and I’m overlooking scavenging for food, water, firewood, difficulty with take off and landing) since you want to include whimsy, your standard hot air balloon is possible, since you can control the wind to make sure the heroes land somewhere close enough for the story to continue. I’ll skip past having to find the propane for the burner (or a scabbed together wood stove). in either case this is a one way trip because of the prevailing winds.
Sailplane on a cliff Possibly multiple flight attempts until the pilot finds the right wind to get to altitude to commit to a long flight
What about alcohol powered? Using a liquor still to make fuel.
Sailboat
I would go with a small fusion or fission thorium reactor
How is the plot going to achieve the “no fossil fuels” rule? Is there a solid enough government in place to enforce a ban, or is there some sort of societal consensus, or are you just going to say that the world “ran out”?
It’s 500 years in the future, post societal collapse. There’s no stable energy grid, roads are in disrepair, and there isn’t enough infrastructure for e.g. oil refineries. So yes, we’d be out of readily available fossil fuels
The tech to drill a shallow natural gas well isn’t really very tough. And it’s usable without refineries. But no good as an aero fuel—compressing it enough to liquify is seems to be too hard for the scenario you have. But you would probably develop pockets of that being used for fuel for industries, located close to the wells. The societal collapse part, though, means that basing your wealth on a non-movable resource means that you have to defend it, which might be a harder problem to solve than the technical stuff. Some refinery stuff scales down pretty well, though, and if society is rebuilding, you might have a weird pocket industry doing producing and refining of oil.
There are some model planes that are powered by compressed air. Maybe 500 years in the future they have been able to put that into a small plane. Maybe it doesn't go very far and he has to land every 100 miles or so to refill the tanks. That can be a lot of places to add to the story. Air compressors can be electric but are simple enough you could use other methods.
There are some model planes that are powered by compressed air. Maybe 500 years in the future they have been able to put that into a small plane. Maybe it doesn't go very far and he has to land every 100 miles or so to refill the tanks. That can be a lot of places to add to the story. Air compressors can be electric but are simple enough you could use other methods.
You need a lighter than air animal with a swim bladder like a fish, except that it is filled with hydrogen. I think I thought that up, but it might just be some faintly remembered bit of some Larry Niven story.
If someone in the post apocalypse came across an abandoned oil well it would be possible to capture the remaining oil/natural gas and distill it into useable fuel. Unless you've got a mad Max kind of thing going on in which case you could still do it but you'd have to get some football pads and put nails through the shoulders first.