# What geographic characteristics for a world would be needed/be most beneficial for airships to be a common mode of transportation?

Airships are a hallmark of countless steampunk and dieselpunk constructed universes. Of course, in our world, they were around for a short while. I want to know what effects geographical circumstances had on this.

I feel like one thing that lead to the death of airships as a viable form of passenger transportation in real life was that it took days to travel from New York to London, especially with the advent of jet airlines. If that's true, what type of proposed global geography would be most beneficial to a strong airship industry? I'd imagine either a world full with archipelagos with numerous small islands, with many medium islands and a few large ones as well (the largest having an area approximately similar to Honshu or Great Britain;) or a world with slightly more land density, with no more than two the size of Australia. I see that an island-based world would grant short travel distances between major regional population centers, many islands would mean that railways would be only of regional importance, and airships would have the advantage of transporting people on a regional basis at a speed faster than an ocean liner.

I also am aware that the Hindenburg disaster helped kill airships; which was influenced by the USA's ban of helium sales to Nazi Germany. As helium is extracted from natural gas fields, I would also presume that, at this point in tech level, more geopolitically balanced natural gas deposits would benefit as well.

What other geographic affects would there be on airships? Do these ones here make sense?

• I suggest keeping to the question in the title, and make your question a little less broad, and a little more clear on what you are actually asking. Basically remove the line asking why airships are no longer in use. That should be a different question. This one is about the geographic effects. Or change it to answer that question, be limit it to one question. – DonyorM Sep 30 '14 at 7:11
• @DonyorM Thanks for letting me know, sorry. – artist_designer Sep 30 '14 at 9:35
• No problem, though you may want to edit the post so it is good and can be answered, and so it doesn't get closed. I think it is a good question at the core. I edited some, make sure that the question is still what you want it to be. – DonyorM Sep 30 '14 at 9:39

The main reason airships stopped being used (apart from the hydrogen safety issue) is speed.

Airplanes just get you there faster, a lot faster.

In a hypothetical world where wings were never invented (or just don't work), or where high density power sources such as aviation fuel are not available, then airplanes would not take over and development on airships would continue.

For example one big factor that if changed might help airships remain dominant is gravity. Increased gravity would make it much harder for wings to function, but would not affect airships anything like as badly.

The presence of strong and reliable trade winds at certain altitudes or locations would also help with this, get the airship to the correct position to ride the trade winds and it will then take you where you want to go.

It may interest you to know that airships are still not completely out of the running in the real world. There is a lot of interest in using them as heavy lifters since they can carry massive loads much more cheaply and easily than other air transportation and several military and civilian outfits are looking into them.

http://aeroscraft.com/aeroscraft/4575666071

• There was a similar project in Germany. They built an impressive hangar and built a small-scale prototype in it, but went bankrupt in 2002. – Philipp Sep 30 '14 at 14:33
• Actually stronger gravity would help airships, since it would make the uplift stronger (remember, the uplift is just the weight of the air displaced by the airship). – celtschk Sep 30 '14 at 21:38
• I'll have to second the "lack of high-density fuel" as a reason. If you're in a world without crude oil, long-distance heavier-than-air flight is impossible until you either develop the ability to synthesize hydrocarbon fuel, push battery technology far beyond what we've managed, or decide to stick a nuclear reactor in an airplane. Ethanol or hydrogen fuel will let you island-hop, but not cross oceans. – Mark Sep 30 '14 at 21:54
• @celtschk But remember, everything that you're trying to lift is also heavier by exactly the same amount. The only net effect on an airship is that you need stronger materials. – 2012rcampion Jan 12 '15 at 3:26
• re: "lack of high-density fuel". Perhaps a very young planet that was seeded with life from elsewhere might make a good location. All planets that have had hundreds of millions of years worth of carbon-based life on them will likely have significant deposits of fossil fuels*. By making the planet young, you can explain why there are no available sources of hydrocarbon fuel. – Pink Sweetener Oct 14 '18 at 14:49

Easy access to a gas with a lower density than the rest of the atmosphere would help. In our world the available alternatives for this are:

• Hydrogen which is easy to manufacture in large quantities but has proven to be too unsafe for use in airships.
• Hot air which is free and has the great advantage that its density can be adjusted by adjusting its temperature which allows to regulate the height, but requires a constant heat source which makes it resource-intense.
• Helium which is both safe (like air) and has a density which is almost (but not quite) as low as hydrogen. The main downside with it is that it is very expensive to manufacture.

For further reading, I recommend the Wikipedia article on lifting gas.

A society which has easy access to a gas which is lighter than air and safe to handle would likely develop balloon/blimp based transportation much earlier than aerodynamic flight.

A possible world could be one with a layered atmosphere where the lower layers are breathable air and the upper layers are pure helium. When the world has mountains which are so high that they reach into the helium layer, those could be used to harvest the helium and use it for airship construction. When there aren't many of such mountains, they would be of huge economical value.

To make air travel even more important in this world, it could have obstacles which can not be crossed by other means than by air. As we already established a layered atmosphere, why not make the lowest layers of the atmosphere consist of a heavy gas which is toxic and/or corrosive (the guys at chemistry stackexchange might have some nasty suggestions), so that life is only possible on isolated islands which are on a height between the toxic layer and the helium layer. Travel by aircraft would then be the only feasible method to travel over the toxic chasms between these islands.

• I'd dispute hydrogen being "proven to be too unsafe" with this. Perhaps s/proven/perceived/. – hyde Oct 1 '14 at 6:09
• @hyde Comparison of the death toll of the Hindenburg disaster with arbitrary other disasters, most of them not even related to air transport or even transportation at all is completely meaningless. That's an apples and oranges comparison. A more useful comparison would be to compare the average safety records of airships running on hydrogen, helium and hot air (normalized by number of passengers, distance traveled or operating time). Do you have numbers for that? – Philipp Oct 1 '14 at 7:56
• I think it is you who is claiming that hydrogen zeppelins are proven to be too unsafe, so perhaps you should come up with the statistics. It could be said that my link "proves" airplanes are too unsafe, too. A single incident (like Hindenburg, which probably was not because of just hydrogen anyway), doesn't prove anything, but it may still determine what people think. – hyde Oct 1 '14 at 8:07
• @hyde I think we all know that Hydrogen is a much more volatile gas that helium or air. I think that is the point that was being made. The likely hood of a catastrophic incident is significantly higher when you are working with volatile components. Statistics are not required for us to know this is true, a basic understanding of the two elements is sufficient. – James Jan 14 '15 at 21:29
• @James Higher, but most likely not so much higher, that it offsets cheaper cost and better performance. Also, for example just a whiff of halon in the mix would probably help a lot. Also, common sense says that having a device where tens or hundreds of gasoline explosions per minute happens, and which cranks out insane amount of power for its weight is suicidal, yet we sit just a meter from such devices operating at full power when we drive a car. Common sense does not always apply. – hyde Jan 15 '15 at 5:49

Perhaps an extremely mountainous landscape, with cities separated by mountain ranges higher than Everest? Airships can manage very high altitudes and don't require long runways for landing.

Moving bulk cargo through such extreme mountains would be difficult. With plentiful helium as suggested by Philipp, airships would have a natural advantage over trucks, trains and ships.

There are of course heavier than air planes that can operate in these ranges too but they have limited capacity and need long runways. Passenger airliners, cargo planes and helicopters wouldn't be able to reach the required altitude to cross the mountains. Higher altitude aircraft might still be used for military uses, airmail and (costly) passenger transport.

• I like this one the best, along with either Philipp's idea of a layered atmosphere (which may however have strong environmental implications, that the OP may or may not be ok with) or, combining a very rocky and mountainous (and/or heavily islanded) geography with lots of gaseous vents, possibly underwater as well. It would establish a plentiful source of gases and perhaps even a strongly gas-vent-based economy to match. – mechalynx Sep 30 '14 at 19:25
• +1, my first thought was about the VTOL capability of airships, which becomes much more necessary if you don't have space for a runway. In the real world, we have other VTOL craft such as helicopters and tiltrotors, but those took longer to develop than airships. Certainly Harrier jump jets (with STOL capability) would have never been invented in a world where CTOL is impractical. – Brian S Sep 30 '14 at 20:19
• Also, extremely dense population centers could potentially substitute for mountains: varying elevation isn't the issue at hand for this answer, but rather limited space for takeoff and landing. If building a runway required the space of 1,000 homes while a landing pad required the space of 10 and your country is facing overpopulation, the choice is obvious. – Brian S Sep 30 '14 at 20:23
• @BrianS That's an interesting idea, but I think it would require more work than a mountainous landscape to justify appropriately (why not expand outward instead of upward?) - and the easiest justifications are mountains or islands, which are sufficient in and of themselves. Tall cities would of course compound the problem, but it would have to be solved before that, that's all. – mechalynx Sep 30 '14 at 20:45
• @ivy_lynx, My assumption in such a setting is that they've already expanded outwards as much as possible. They've run out of room. – Brian S Oct 1 '14 at 18:39

One disadvantage of airplanes is that they need a runway to start/land. So one thing that would discourage airplanes is a geography where you simply have no space for runways (hills/mountains everywhere). Also, airplanes depend on the availability of cheap fuel, so if you don't have that, they cannot compete against airships. So you'd need a geography with no fossil fuel deposits (or at least none which are economically viable to exploit).

Another possibility would be the lack of hard but light substances to build airplanes from.

Another thing that could discourage airplanes is if there are many birds that could interfere with the airplanes (get into the propeller/jet engine and kill the aircraft). Airships are immune to them as long as they are not directly attacked. To have many birds, you'd of course need a bird-friendly geography.

A bird-friendly geography would mean:

• many food sources — for birds that eat insects, that may mean many lakes, and an insect-friendly climate (no cold winters, much humidity, but little direct rain), for birds eating seed it would mean many plants with those seeds.
• many places where they can build their nests — which depending on the type of bird may mean many rocks, or many trees, or simply many open areas if the birds build their nests on the ground.
• maybe also a relative lack of land animals that could compete on the food, or eat the eggs of the birds; that could be caused e.g. by there being little continental land, but only many small islands which are too small to support animals that can neither swim nor fly. As a side effect, those would also be detrimental to building long runways.
• You can design an aircraft for VTOL if it was a requirement, and a small airplane can take off in the space required for a large airship. – Oldcat Jan 16 '15 at 0:39

How about a world where I don't think any other form of long distance transport would be used:

1) The atmosphere is extremely thick but contains a very low percentage of oxygen. A look at how scuba divers fare shows that our lungs care only about the partial pressure of oxygen, not what percent of the atmosphere is oxygen. Thus it is reasonable to assume ETs with the same pattern. Combustion, however, depends on the ratio. An atmosphere with a sufficiently low oxygen pressure won't support combustion. Again, we can see this in the really deep dives--you can have a mix of hydrogen and oxygen that will not burn but is breatheable at depth.

2) The world is part of a close binary which itself orbits a bigger planet. (Robert L. Forward, Rocheworld, although with less water) The result is extreme tides, no large land mass is possible because the water has to flow somewhere. It also means a lot of vulcanism. Thus you have a world of islands in a sea that will smash your ship against the rocks if you don't time things perfectly.

Such a world means no fire-based propulsion other than rockets--and with an atmosphere like that no chemical rocket is going to make it to space. Even the military uses of rockets will be limited because they simply won't go very fast given the density. Sputnik will ride an Orion.

The tides mean no meaningful shipborne transport, it's too dangerous to be on the ocean anywhere remotely near land. You might see some hydrofoils that can make a short crossing timed with the tides but that's about it.

The islands mean no long distance roads or trains.

Note, also, that the dense atmosphere increases the lifting power of a hydrogen or helium based airship. (Given the atmosphere a hydrogen based airship is safe enough.) This means they can be much smaller than terrestrial airships.

One of the things that recently reduced the amount of air travel here in Europe was the volcanic eruption of Eyjafjallajokull which placed a lot of ash into the atmosphere, presenting a risk to planes. Volcanic ash is highly abrasive and quickly causes harm to propellers and jet turbines.

If we were to imagine a world where something like the Deccan Traps was still in operation, or there is very frequent and intense volcanic activity, it is possible that there would be sufficient ash in the atmosphere to make early aeroplane engines or propellers non-viable so that technological avenue may not be significantly explored. Dirigibles would be able to operate with fewer moving parts, effectively sailing for the majority of their journeys, and consequently stay viable in this type of scenario.

• That's a really good suggestion, simple and elegant...and also does a lot to shape the rest of the world if you have a constant rain of ash. – Tim B Oct 1 '14 at 9:31

There is one kind of planet on which airships remain feasible and heavier-than-air craft are not: one with an extremely thin atmosphere. This is, at first, counterintuitive: airships rely on buoyancy, so they perform best in very thick atmosphere.

However, "best" is relative. Heavier-than-air craft are even more limited by thin air. Consider the Wikipedia article on Flight altitude records: the balloons beat the heavier-than-air craft every time (not counting rocket planes, thanks). It's easy enough to explain that.

Consider what happens to a heavier-than-air craft as it goes as high as possible. It starts to mush along, unable to ascend anymore, because its engines simply can't provide the necessary thrust to generate increased aerodynamic lift in the thinner air.

By contrast, a lighter-than-air craft that flies too high experiences uncontrolled ascent, because the gas bags expand. If it doesn't have emergency venting capability (which they all do, realistically) it's doomed. The gas envelope, expanding with diminished pressure, will split open - if it's a dirigible, it may damage the airframe first - and the ship's gonna fall out of the sky.

I don't know how much better illustration there could be of the superior flight characteristics of lighter-than-air craft on a planet with thin atmosphere.

It's a fairly sound assumption that, the thinner the atmosphere, the less likely that a technologically advancing culture would develop heavier-than-air flight in the first place. And that if your premise is that an already technologically knowledgeable group of people had entered the world from elsewhere, they would make the same kind of engineering choices.

Now... IF you would accept this as a worldbuilding premise, there'd be a lot of work to do, a lot of questions to answer:

• How much lower ambient air pressure would the world need to have, in order to establish the primacy of lighter-than-air flight?

• What does the answer to the previous question say about the habitability of this world? Are the inhabitants human? If human, what measures do they need to take in order to live there? Loren Pechtel, above, is entirely correct about partial pressure of oxygen; that would be your first line of inquiry.

• If the world has very low atmospheric pressure, does that preclude flying animals? What about flying insects? Any likelihood of lighter-than-air animal forms? What about windborne seed and pollen distribution? The ecological implications could be interesting.

One more thing: it may not be necessary to postulate an entire world with a scant atmosphere.

It might be reasonable to topographically separate the habitable zones with intervening areas of extremely high altitude. A flat land at very high altitude, perhaps, cut with miles-deep canyons, with people living along the bottoms? No feasible way of traversing the high areas except by airship?

If you do that, though, you will have to be very careful about wind. Turbulence and wind shear are, in our atmosphere, exceptionally dangerous for airships. How that would play out in a much thinner atmosphere is hard to say, but it's probably something you'd need to work though.

One way to have an easy source of light gas without the earthly dangers of hydrogen is to have a reducing atmosphere-hydrogen, methane, ammonia. Water is allowed as well. The chemistry of the living things needs to be adjusted. The fuel manufactured by photosynthesis has to be an oxidizer instead of a fuel, which would be "burned" with the reducing chemicals in the atmosphere. Plants would keep the oxygen from splitting water and exhaust the hydrogen to the atmosphere. There is a lot of work to flesh this out.

As far as geography, not having oceans that are useful for moving cargo might help. The slow speed of airships is not so bad for moving non-perishable commodities, like things that move by ship on earth. You care more about the total flow rate than how long a particular item takes to be shipped.

In order to construct a scenario where airships are the preferred form of transport, one needs to assess the relative merits of different forms of transportation.

If you have lots of islands, ships would almost certainly be preferred. They can have considerably higher cargo capacity, be faster, easier to construct/maintain, operate in more extreme weather, etc. Large watercraft will need to be unavailable.

Land transport is far superior over flat stable ground (or ground which can be made so), so essentially you want ground over which heavy duty roads are not plausible (maybe too unstable, needing constant maintenance and still prone to washout/blockage, or too environmentally damaging, etc).

Broken hilly terrain (mountainous in the sense of Appalachians not Rockies else weather will be too deleterious to aircraft) prone to mudslides/avalanches, or possibly heavily forested wet areas like the Amazon rainforest, or sparsely populated Siberian tundra would favor air transport.

Dirigibles and blimps can be highly efficient for large cargoes. Despite their slow speed, their considerable weight capacity (compared to heavier than air vehicles and even trucks if large enough) can easily offset that by reducing the number of trips needed (and allowing for the transport of larger items). Instead of needing to ship components one at a time on the back of a truck and constructing a facility onsite, considerably larger units can be put together and lifted over mountains to the final destination, without the need to construct roads capable of supporting a parade of heavy trucks (leave any roads for small lightweight cars rather than cargo).

Environmental concerns favor airships - low impact to the environment as they can travel point to point without destroying a swath between locations for roads (especially if windy switchbacks need to be cut in hillsides), only need a cleared area to get close to the ground or even just a nice aeroport tower to dock to for loading/unloading, and comparatively low fuel usage (if going for modern tech rather than your mentioned steampunk - solar powered engines).

It may be too slow if primarily carrying people rather than cargo - heavier than air craft may still dominate for passenger service (at least for most cases - dirigibles will still be cruise ships), or for fast postal service.

In short, wherever you do not have access to ocean or readily navigable rivers for shipping, and it is impractical to build or effectively maintain roads/rails between destinations, airships are plausible as the dominant form of transport.

Your world could grow airships, all you need is: AIR PLANKTON! But in all seriousness, all your world would need is a whale species that inflates itself with helium or hydrogen when it reaches adulthood to reach a creature that could feed its massive self. If you have a whale big enough, it could even have other air creatures that live on/in it and help feed it. Then, get some really clever maniac who captures and domesticates a few and you have "instant" airships, just add harnesses!

Maybe the answer is more psychological: imagine a culture in which people value comfort & sightseeing opportunities over simply getting there quickly. The people might be wealthy, long-lived, have advanced internet telepresence for business purposes, so travel is only for pleasure.

Or perhaps the potential of large, high-speed aircraft as weapons is seen as even more of a threat than it is in this world.

You could have an alternate history about Earth where certain major events did not happen such as the Wright Brother's successful flight at Kitty Hawk, and the Hindenberg disaster.

Perhaps Orville and Wilbur Wright gave up before they figured out how to design a working aircraft. Maybe Adolph Hitler died of syphilis before he could get into power, and Germany never entered WWII.

In a world such as that, it would be logical that the airship would still be widely used today.

As far as geography goes, a world without many navigable waterways would make it impractical for ships to transport cargo and people. A lack of solid, flat ground would be a big problem. Airplanes are heavy, and require very solid ground to land on. If most of the land was swampy/marshy then there wouldn't be a good place to build runways. Large mountains would also pose issues. Travel by train would also be impractical in those situations.

• If the Wright brothers didn't invent an airplane, someone else would have. – cpast Jan 15 '15 at 17:22

Other answers pointed different advantages of airships and the geography that would make them useful, but I think one advantage is missing: autonomy. Airships could fly without resupplying for much longer than contemporary aeroplanes and it took decades for airliners to reach the same range.

Therefore, in a world with larger islandless oceans, airships could be common for a long time.

For example, if our world had just two continents (Europe and Australia) with no islands at midway between them and we assumed the actual technological progress timeline we have had in real world, airships would have been the only alternative to ships for more than half of a century.

Tom Kratman's Terra Nova has four significant differences in geography from Earth:

• The sun rises in the west.
• The Mediterranean is broken up into large lakes.
• There is a large island somewhere between New Zealand and Chile.
• The planet is less tilted than the Earth. This reduces the risk from windshear and other severe weather.

On Terra Nova, large lighter-than-air vessels that are shaped to achieve dynamic lift are the preferred vessels for reasonably quick freight transport. Such vessels do not go into active warzones. They also compete with heavier-than-air vessels and cruise ships for passenger travel.

Many good valid points on airships.

On geography, high mountains, deep valleys, extreme open spaces with low populations/commerce.

Airship viability depends on human a/o economic needs.

Airship: cruise vacations, high altitude (over 16Km) telecommunications platforms (satellite substitute), heavy lift logistics point2point for storm/catastrophe relief or science or military ops, regional hospital coverage....

Airship: Skin/shell provides solar power for internal functions, propellers... and medical, public education/schools, telecommunications... functionality.

UAV, geostationary for extremely long periods (maybe three years) only lands for maintenance and upgrades on ground....

Extreme/remote mountains/terrain would justify airships for modern conveniences and services.

• In that case, the airship would be a floating building. The question asks how they would be used for transportation. – John Locke Oct 14 '18 at 17:32