Airships as public transport Yay or nay?

[snowblizz]

Then, I think your second big change is not WW2. WW2 basically destroyed every major city in Europe, Russia, China, and Japan. That made it possible to effectively and economically deploy railway networks through the core of all these cities in the postwar environment. Networks that remain fundamental transit solutions to this day. In the US, where WW2 did not damage cities, development proceeded differently and we have huge congestion problems.

That's just incredibily incorrect.

Before WW2 the European railnetwork was essentially fully built. How exactly do you imagine that the resources for two world wars got around the continent? By rail.We have had basically a century of building rails to existing cities before ww2 tears stuff down. No major European city I know has rails going through it, all the big cities have various stations in the north, west, east and south as applicable because it simply was not possible pull in rail through the already established city cores. WW2 did not change this, it's not Simcity we are talking about where a clean slate is a clean slate. You are vastly overestimating the nothingness of the ruins of a bombed city. Probably 80% at least of old citycores were restored more or less back to how they were before the war. In fact modernism in the 1960s and 70s probably destroyed more old housing that both worldwars together.

After the war it was essential to get infrastructure back up and running which meant rebuilding stuff back up in a hurry. Not fiddling around with planning new solutions.
That the US has a somewhat different take on it is not due to WW2 bombing or lack there of but other societal and geographical considerations.

[Grey_Wolf_c]

No major European city I know has rails going through it, all the big cities have various stations in the north, west, east and south as applicable because it simply was not possible pull in rail through the already established city cores.

I agree with this (and indeed with the rest of the post), but you also have to take into account that cities have grown massively in the last 70-odd years, and so many cities that "feel" like they have stations in the middle of the city is only due to the city having grown around the stations that used to be in the outskirts. I've been to several European cities were the "North" and "South" stations don't feel like they are north or south, and their name only become logical when you see the old maps (which a lot of those stations have hanging on the walls as decoration, in my experience).

GW

[Eldan]

Zurich Main Station is pretty much the heart of the city. That said, Zurich also has a several hundred metres wide swathe of train tracks running through the entire city that everyone agrees is ugly as heck, but that nothing can be really done about.

[halfeye]

Then, I think your second big change is not WW2. WW2 basically destroyed every major city in Europe, Russia, China, and Japan. That made it possible to effectively and economically deploy railway networks through the core of all these cities in the postwar environment. Networks that remain fundamental transit solutions to this day.

That some cities were partially destroyed is true, that the railways took advantage of that is basically not true in western Europe at least, most train routes were already in place.

Zurich Main Station is pretty much the heart of the city. That said, Zurich also has a several hundred metres wide swathe of train tracks running through the entire city that everyone agrees is ugly as heck, but that nothing can be really done about.

Notice that Zurich is in Switzerland, which was neutral, and was never bombed.

Also, if the intermodal shipping container had never been invented - which synergized cargo between road, rail, and sea in highly advantageous ways - and we were forced to rely on traditional break bulk cargo deployments, then zeppelins as a slow but low-cost air freight option would retain much more favorable cargo economics.

That was a what? '60s? '70s? thing? The odds of that not happening are about zero. The main transport costs of products today are apparently moving those containers onto and off ships and lorries, the journeys themselves are apparently cheap.

<edit>

https://en.wikipedia.org/wiki/Intermodal_container

So they started in the 1830s, grew through the 20th century, and a finalised ISO standard was adopted in 1972. Good luck stopping that idea, it's not a one stop, it's a matter of long slow refinement by many people, even if some were more important than others.

</edit>



To compete with cruise ships is also a non-starter, those things are floating hotels, and they are huge, with ballrooms and swiming pools built in, that's the size of gondola you would need, and the size of the gas bag to lift that would be beyond immense, and the strength required would make it impossibly heavy.

I'm a nay, if anyone hadn't guessed.

[Eldan]

There was for a while a Zeppelin over Lake Constance where people could take short tourist flights. Part of the Graf Zeppelin museum, I seem to remember. No idea what happened to it. I've only been the Museum, not the Zeppelin itself. It might work as a tourist attraction, maybe. Half hour tour of some country side or over some city, take in the sights, land again.

Seems the web page is still there, at least. The prices are pretty damn steep, though. 240 Euroes for a 30 minute flight.

[snowblizz]

That was a what? '60s? '70s? thing? The odds of that not happening are about zero. The main transport costs of products today are apparently moving those containers onto and off ships and lorries, the journeys themselves are apparently cheap.

Pre-WW2 actually it seems. The idea in fact is about as old as trains. And it seems really started as way to revitilize the railways. In the US!

To compete with cruise ships is also a non-starter, those things are floating hotels, and they are huge, with ballrooms and swiming pools built in, that's the size of gondola you would need, and the size of the gas bag to lift that would be beyond immense, and the strength required would make it impossibly heavy.

Yea... see, here's the thing. This is *exactly* what the Zeppelins did fairly successfully until the Hindenburg disaster. Also, the Hindenburg type had internal passanger spaces not a gondola. Basically the 30's Zeppelisn were luxurious *enough* but much much faster than regular shipliners.
That said IIRC the Zeppelin business was subsidized (they certainly enver ran in an actual competitive market) as a prestige project by the 3rd reich so wheter it's economical or not I may have to leave unsaid.

I agree with this (and indeed with the rest of the post), but you also have to take into account that cities have grown massively in the last 70-odd years, and so many cities that "feel" like they have stations in the middle of the city is only due to the city having grown around the stations that used to be in the outskirts. I've been to several European cities were the "North" and "South" stations don't feel like they are north or south, and their name only become logical when you see the old maps (which a lot of those stations have hanging on the walls as decoration, in my experience).

GW

Oh just something I remembered. Take the UK where the existing railnetwork simply could not be electrified and there are bottlenecks due to using centuires old tunnels and such limiting dimensions of locomotives which is why the UK has diesel-electric trains. And almost no (or maybe it was no) high-speed raillines. The bends can't cope with a 400 km/h train and you cna't build away those either.


Still don't necessarily see airships as replacements for trains and boats or buses, but there may be a role to play in an alternate wolrd for sure.

[halfeye]

Pre-WW2 actually it seems. The idea in fact is about as old as trains. And it seems really started as way to revitilize the railways. In the US!

Yee har, we read the same Wikipedia page.

Yea... see, here's the thing. This is *exactly* what the Zeppelins did fairly successfully until the Hindenburg disaster. Also, the Hindenburg type had internal passanger spaces not a gondola. Basically the 30's Zeppelisn were luxurious *enough* but much much faster than regular shipliners.

Faster than ships, but slower than planes.

The most luxurious planes were the Clippers and the Empires, I'm not getting a Wikipedia quote on the standard of accomodation in the Empires, but this for the Clippers:

The 314s had a lounge and dining area, and the galleys were crewed by chefs from four-star hotels. Men and women were provided with separate dressing rooms, and white-coated stewards served five and six-course meals with gleaming silver service. The standard of luxury on Pan American's Boeing 314s has rarely been matched on heavier-than-air transport since then; they were a form of travel for the super-rich,

https://en.wikipedia.org/wiki/Boeing_314_Clipper

[factotum]

Basically the 30's Zeppelisn were luxurious *enough* but much much faster than regular shipliners.

The difference is surprisingly small if you look at the figures. The big Zeppelins would take around two and a half days to cross the Atlantic; the fastest passenger liners did the same trip in less than four days, and the liner was obviously far more luxurious. So, would shaving a day or so off your journey be worth the extra expense and probable reduction in comfort of an airship journey? (Note that Zeppelins were heavily subsidised by the German government to reduce ticket prices into the sort-of-affordable range, it would have been a hugely expensive crossing otherwise).

[pendell]

So, if I may ask:

Why is helium rare?

And a science fiction question: Could we mine helium from orbital sources or other planets?

Respectfully,

Brian P.

[Anymage]

Helium is rare for two reasons. First, it's light enough that if left alone in the atmosphere, it'll escape into space. And second, being nonreactive, that also means that you won't find it in compounds with other substances. (Compare hydrogen, where it's simple to break water into component hydrogen and oxygen.) The only way we have to make helium is through pricey nuclear reactions, and the existing stocks formed from radioactive materials decaying underground in places where the resulting product could remain trapped.

Mining for helium on other planets would be tricky, since the same factors would keep it from being abundant on other planets as well. It's common in stars and it may be easily found on gas giants, I don't know enough about them to say confidently. I will say that if we're going sci fi, though, you might as well go with the nuclear decay byproduct bit. Say that whatever nuclear fuels they use emit helium nuclei as part of their decay, turning spent fuel into a resource. Once you get past conventional fuels into more speculative sci fi, having the energy to initiate hydrogen fusion shouldn't be too much trouble.

[S@tanicoaldo]

So could airships be used as transporation from city to city in the same country? Would that be viable?

[halfeye]

So could airships be used as transporation from city to city in the same country? Would that be viable?

If by viable you mean would it be cheap enough that a lot of people would want to use it, in my view probably not. That depends on the state of the roads and rails, if they're unusable then maybe, but then how do you get to the blimp?

This is a popular event:

https://en.wikipedia.org/wiki/Bristo...Balloon_Fiesta

That's for hot air balloons:

https://en.wikipedia.org/wiki/Hot_air_balloon

You can pay to ride in balloons sometimes, or buy one for your own sporting flying if you're rich, but they aren't regular transport.

[sktarq]

So could airships be used as transporation from city to city in the same country? Would that be viable?

Not in any nation in our world. . . if however you are dealing with a physics/chemically similar world world that had a FAR more difficult geography then it would be possible
Think is much of the world was built up of land like fiordland in New Zealand, Ahaggar of Algeria, and the Shilin Stone forest as a NORM in the world and lots of infrastructure weakening earthquakes then I could see air transport become more viable. Airships and hot air balloons for heavy lift would become for normal and thus large airship would be available for converting to transporting people.

But it would take something like that.

[factotum]

Fundamentally it takes more energy to move things through the air than it does to move them on land, even in an airship. It's therefore something you don't do unless there's a significant advantage to it. The advantage we have with helicopters is the ability to get to places land-based travel cannot, and with planes the advantage is much greater speed. Airships of sufficient size to carry significant numbers of people don't really have either advantage, so you have to ask why they would be used in preference to, say, a train?

[Kato]

I feel you're being too critical of airships. Of course I'm not an expert but I feel if we had invested as much time in improving them as in planes, at least things like speed compared to trains and efficiency compared to planes (or maybe even cars) could be way better than they are. Building and maintaining long distance roads and railways isn't cheap and if you go international you get into more issues. The sky is less problematic and I'm not sure why airports would be worse than ours.
I guess the part I was most worried about was the discussed bit about weather conditions. Not sure how well you could work against them.

It might be more likely if there is a cause for land or sea travel to be more dangerous or less convenient but I don't want to dismiss airships as a viable mid to long distance vehicle. At least for larger transports.

Though in a world with fewer roads and railways the world in general might be less connected over long distances, so this could have further consequences.

[pendell]

So. Helium is only available on Earth naturally in underground deposits as a result of natural radioactivity.

...

It occurs to me that Helium is a byproduct of nuclear fusion. So if we ever achieve controlled nuclear fusion and use it as a power supply, then we will also be able to manufacture a great deal more helium than is currently available. This might make airships more attractive; I daresay no one wants a hydrogen-filled envelope any longer, not after what happened to the Hindenburg.

Respectfully,

Brian P.

[Lvl 2 Expert]

So. Helium is only available on Earth naturally in underground deposits as a result of natural radioactivity.

...

It occurs to me that Helium is a byproduct of nuclear fusion. So if we ever achieve controlled nuclear fusion and use it as a power supply, then we will also be able to manufacture a great deal more helium than is currently available. This might make airships more attractive; I daresay no one wants a hydrogen-filled envelope any longer, not after what happened to the Hindenburg.

Respectfully,

Brian P.

The funny thing about the Hindenburg is that it actually wasn't all that bad. The canvas the balloon was made out of was very flammable, and that was a problem, but the hydrogen itself mostly burned nicely away from the passengers. It also managed to lose hydrogen/drop out of the air slow enough that between the fire and the fall itself only a bit over 1/3 of the people on board were killed. That could have gone way worse, and I'm not even sure if the hydrogen would be the first thing a modern engineer would fix to make it safer. (Although it would definitely be the second or third thing or so.)



Instead of restating the reasons I think zeppelins were always a bit of a long shot (I prefer ekranoplans if we have to travel weird anyway) I decided to calculate if nuclear fusion could contribute significant amounts of helium. The energy density of deuterium used for fusion (presumably turned into helium, the page doesn't quite specify) is around 4 million MJ/L. A cubic meter of helium can be used to lift roughly a kilogram of mass off the ground. So that's 1000 liters. Assuming we can make an airship where the ship weights half of the load it can take in passengers and freight, and assuming 70kg standard humans each with 30kg of clothing, luggage and inflight meals, an airship made for 100 passengers would weight around 15,000kg when full, thus requiring around 15,000m^3 or 15 million liters of helium. 15 million times 4 million is 60 trillion MJ or 60EJ (exajoule, 10^18 joule) of energy produced in the process of making that much helium (more if you can start from regular hydrogen, but we're disregarding that for now).

How much is that, 60 exajoules? Well, roughly the yearly energy consumption of South Korea, or one tenth of the yearly energy consumption of the US. That means this is actually sort of feasible, assuming most of our energy would come from fusion, the number of airships stays small (think more private jet, less vacation liner) and we don't develop a shortage of helium due to other applications, like needing a lot of it for medical scans and electron microscopes or something. Under ideal circumstances and assuming no losses during operation the US could float 10 large airships a year using waste products of nuclear fusion.

[Rockphed]

Instead of restating the reasons I think zeppelins were always a bit of a long shot (I prefer ekranoplans if we have to travel weird anyway) I decided to calculate if nuclear fusion could contribute significant amounts of helium. The energy density of deuterium used for fusion (presumably turned into helium, the page doesn't quite specify) is around 4 million MJ/L. A cubic meter of helium can be used to lift roughly a kilogram of mass off the ground. So that's 1000 liters. Assuming we can make an airship where the ship weights half of the load it can take in passengers and freight, and assuming 70kg standard humans each with 30kg of clothing, luggage and inflight meals, an airship made for 100 passengers would weight around 15,000kg when full, thus requiring around 15,000m^3 or 15 million liters of helium. 15 million times 4 million is 60 trillion MJ or 60EJ (exajoule, 10^18 joule) of energy produced in the process of making that much helium (more if you can start from regular hydrogen, but we're disregarding that for now).

How much is that, 60 exajoules? Well, roughly the yearly energy consumption of South Korea, or one tenth of the yearly energy consumption of the US. That means this is actually sort of feasible, assuming most of our energy would come from fusion, the number of airships stays small (think more private jet, less vacation liner) and we don't develop a shortage of helium due to other applications, like needing a lot of it for medical scans and electron microscopes or something. Under ideal circumstances and assuming no losses during operation the US could float 10 large airships a year using waste products of nuclear fusion.

Okay, that is a kinda awesome statistic. I hereby dub "airships floated per year" as a new random statistical measure of energy consumption.

[Xyril]

Helium is rare and getting rarer, hydrogen burns.

As I remember it, a major contributing factor to the big disaster was something in the balloon material that acted like a catalyst to combustion. In fact, a pure hydrogen balloon is rather hard to burn, because combustion involves both fuel and oxygen, and as with most chemical reactions, the rate of reaction is proportional to the concentration of (or some power of the concentration of) each reagent. In fact, it's so hard to ignite a hydrogen-filled zeppelin that it was nearly impossible to do so even intentionally. During WWI, the Germans used hydrogen-filled zeppelins to bomb England. Thinking the same way you do, the British developed incendiary rounds hoping to light them up. This also failed miserably. In fact, they were only able to make this tactic work by first firing so many rounds into the balloons that there was a substantial amount of hydrogen leaking out and mixing with air--it was this mixture that they ultimately ignited, burning away more balloon and allowing the rest of the fuel to ignite as well. Not to take away from the importance of this accomplishment--igniting a zeppelin ASAP prevented it from either dropping the rest of its payload or drifting away to safety--but by the time these bombers became particularly flammable, they had to have sustained so much structural damage to their balloons that they were already on their way down.

Presumably, with modern technology and no WWI aces in bi-planes trying to shoot you out of the sky, we'd be able to get the safety margin to acceptable levels.

I don't have time now to find the source, but I recall one company trying to bring blimps back were trying to make essentially a hybrid blimp--lighter than air, but instead of a simple round or oblong shape, they would use rigid components to create essentially a pudgy airfoil, which would in theory reduce drag.

[factotum]

As I remember it, a major contributing factor to the big disaster was something in the balloon material that acted like a catalyst to combustion.

That's not quite how it works. The envelope of the Hindenberg was flammable, this much is true, but it wasn't quite Thermite as some people have claimed. For that matter, even if it *had* been painted in pure Thermite, the hydrogen was still a significant contributor to the flames--Mythbusters did a test where they painted model airships in Thermite and set them alight, with one filled with air and the other hydrogen; the hydrogen-filled one burned far faster than the air-filled one.

As for the WW1 incendiary rounds thing, I wouldn't expect a burning round fired into a hydrogen gasbag to cause it to burn, because there's no oxygen in there. There are ways that hydrogen can escape the bag and form a volatile mixture with the air outside that don't require a disaster scenario or even a puncture, though--it could happen even if the airship flew a bit too high, because the reduced external pressure would cause the pressure relief valves in the bags to open and release hydrogen into the atmosphere.

I seriously doubt any modern-day government would grant a hydrogen-filled airship an airworthiness certificate unless the builder could prove that the hydrogen would not escape under any circumstances, and I don't think that's possible.

[veti]

Well Hydrogen has safety issues plus is normally made from methane (others are possible but not as used) and very often the excess carbon comes out as CO2 during fuel manufacturing (instead of fuel burning)(a current issue with Hydrogen cars but considered a solvable one)

Methane is an incredibly potent greenhouse gas in itself, so converting it to H2 plus CO2 is a big plus for the environment. (Assuming you use naturally occurring or waste methane, of course. Not so much if you manufacture it specially.)

I'm a big fan of hydrogen for balloons. Not only is it cheaper and more renewable than helium, it's also lighter (only half the density) and, importantly, easier to contain. Helium molecules are so tiny, they quickly leak out practically anything. Hydrogen molecules are very much larger.

[Xyril]

As for the WW1 incendiary rounds thing, I wouldn't expect a burning round fired into a hydrogen gasbag to cause it to burn, because there's no oxygen in there.

I thought I mentioned this already. My mistake.

There are ways that hydrogen can escape the bag and form a volatile mixture with the air outside that don't require a disaster scenario or even a puncture, though--it could happen even if the airship flew a bit too high, because the reduced external pressure would cause the pressure relief valves in the bags to open and release hydrogen into the atmosphere.

True, but I don't really imagine that this would happen at such a high rate that you've got this volatile mixture lingering near the airship and igniting before diffusion and buoyancy do their thing. Just as an example, if you had the valves vent out at the top of the balloon, where you also implement anti-arcing measures, you would reduce the risk of ignition during the brief period of high hydrogen concentration. Another mechanism might be to--taking into account both the structural limitations of the envelop material and the typical rates of dissipation outside of the airship--set the valves to limit the rate of release to minimize the chances that you'll have enough hydrogen concentration to support a chain reaction.

I seriously doubt any modern-day government would grant a hydrogen-filled airship an airworthiness certificate unless the builder could prove that the hydrogen would not escape under any circumstances, and I don't think that's possible.

I don't disagree with you, but that's mostly due to my low opinion about modern governments and their relationship to empirical evidence vs. emotion/"common sense." I mean, every government in the world approves of vehicles powered by highly combustible liquids that--also as seen on Mythbusters--are remarkably safe while inside their proper container, but by no means have been proven to "not escape [said container] under any circumstances."

I think other people have raised plenty of valid drawbacks for hydrogen airships, but my gut feeling is that if we were somehow able to do the numbers, the danger would be on par with--if not someone less than--the dangers we already accept. Numerous vehicles run on fossil fuels that become very dangerous when they escape from their proper containers, and these circumstances aren't theoretical--this has happened as the result of the type of events that have happened in the past and are foreseeable in the future. Same with battery power--while I have seen more incidents of spontaneous combustion with phones and small vehicles that are basically toys, the only reason we haven't seen the same happen with a Prius or a Tesla is probably a combination of better quality control, lower numbers, and luck. You could make the argument that your vehicle bursting into flames around you is a much more palatable risk on the ground than in the air, but again, planes have in fact had to make emergency landings due to fires.

[Aeson]

As for the WW1 incendiary rounds thing, I wouldn't expect a burning round fired into a hydrogen gasbag to cause it to burn, because there's no oxygen in there.

This is correct; historically, incendiary rounds were generally ineffective in setting hydrogen-filled zeppelins alight until it was decided to mix them with explosive rounds to create larger holes in the zeppelins' skins, allowing more oxygen to mix with the hydrogen and thereby increasing the likelihood that an incendiary round would ignite the gases as it passed through.

[Grey_Wolf_c]

Helium molecules are so tiny, they quickly leak out practically anything. Hydrogen molecules are very much larger.

No, they are not. H2 is about the half the size and molecular weight of He (2.01588 g/mol vs 4.002602 g/mol), and indeed has the same problems with containment, this being one of the major problems for Hydrogen cars.

---

As to actual modern use of lighter-than-air craft, it won't be used for public transportation anytime soon, but there is a niche in the market for non-urgent air transport:
https://www.cnbc.com/2016/03/29/lock...480m-deal.html

GW

[Rockphed]

No, they are not. H2 is about the half the size and molecular weight of He (2.01588 g/mol vs 4.002602 g/mol), and indeed has the same problems with containment, this being one of the major problems for Hydrogen cars.

---

As to actual modern use of lighter-than-air craft, it won't be used for public transportation anytime soon, but there is a niche in the market for non-urgent air transport:
https://www.cnbc.com/2016/03/29/lock...480m-deal.html

GW

I just looked it up on google, but a single atom of helium is 31 pm in diameter while a single atom of hydrogen is 53 pm. Since a hydrogen molecule is 2 covalently bonded hydrogen atoms, I would put the minimum size of H2 at 53 pm. Now, the molecular mass of H2 is about half that of helium, so it gets to go 4 times as fast at the same temperature, which possibly matters.

[veti]

I just looked it up on google, but a single atom of helium is 31 pm in diameter while a single atom of hydrogen is 53 pm. Since a hydrogen molecule is 2 covalently bonded hydrogen atoms, I would put the minimum size of H2 at 53 pm.

According to Google, H2 is 120 pm, or 4 times the size of He. And half the density.

[Lvl 2 Expert]

This may be straying offtopic a bit, but I wonder if there is a way to make hydrogen more fire resistant. Maybe by adding some gas that readily reacts to oxygen in an endothermic manner? That would probably make the gas heavier than helium before having any noticeable effect though...

[Eldan]

The funny thing about the Hindenburg is that it actually wasn't all that bad. The canvas the balloon was made out of was very flammable, and that was a problem, but the hydrogen itself mostly burned nicely away from the passengers. It also managed to lose hydrogen/drop out of the air slow enough that between the fire and the fall itself only a bit over 1/3 of the people on board were killed. That could have gone way worse, and I'm not even sure if the hydrogen would be the first thing a modern engineer would fix to make it safer. (Although it would definitely be the second or third thing or so.)



Instead of restating the reasons I think zeppelins were always a bit of a long shot (I prefer ekranoplans if we have to travel weird anyway) I decided to calculate if nuclear fusion could contribute significant amounts of helium. The energy density of deuterium used for fusion (presumably turned into helium, the page doesn't quite specify) is around 4 million MJ/L. A cubic meter of helium can be used to lift roughly a kilogram of mass off the ground. So that's 1000 liters. Assuming we can make an airship where the ship weights half of the load it can take in passengers and freight, and assuming 70kg standard humans each with 30kg of clothing, luggage and inflight meals, an airship made for 100 passengers would weight around 15,000kg when full, thus requiring around 15,000m^3 or 15 million liters of helium. 15 million times 4 million is 60 trillion MJ or 60EJ (exajoule, 10^18 joule) of energy produced in the process of making that much helium (more if you can start from regular hydrogen, but we're disregarding that for now).

How much is that, 60 exajoules? Well, roughly the yearly energy consumption of South Korea, or one tenth of the yearly energy consumption of the US. That means this is actually sort of feasible, assuming most of our energy would come from fusion, the number of airships stays small (think more private jet, less vacation liner) and we don't develop a shortage of helium due to other applications, like needing a lot of it for medical scans and electron microscopes or something. Under ideal circumstances and assuming no losses during operation the US could float 10 large airships a year using waste products of nuclear fusion.

Very nice calculation that. As a bonus question, how much Helium would a modern airship lose to the surrounding air when operating? Does anyone have any idea where to start on data for that?

[Eldan]

There are oxygen traps, but I don't think there's a feasible way to make them also light and small enough that they wouldn't negate the benefits. They also tend to be exothermic, AFAIK.

[Deepbluediver]

This thread is neat- I've been thinking about a setting lately that uses airships (maybe some kind of plane-zepplin hybrid? could that be a thing?) as a way to get around and what sort of environment might lead to that.

Airships and blimps both have a fairly major issue in that they're very large in relation to their actual lifting capacity. A typical helicopter is far smaller for a similar lift capacity, is far more manoeuvrable, and can land almost anywhere, while blimps generally need some sort of mast or what-have-you to tie up at. So, overall, no, I don't think you could use them as reasonable public transport. As a replacement for long-haul aircraft flights (assuming we're in a world where planes weren't invented), then maybe.

I'm pretty sure that an airship's maximum lifting capacity exceeds a helicopter's, though, so there are a very few specialized situations where they might be the better choice. Kind of like those commercials on the Home Shopping Network you see at 3 a.m. They are trying to sell you things that are the perfect solution for one particular problem that only a very few people have (or that people have very rarely) and are good for nothing else.

I wonder if airships might be useful for luxury cruises a la the Carnival line. Cruise ships still exist not because they are the most efficient way to transport people from point A to point B, but because the trip itself is a luxurious experience quite beyond what you can experience even in first class on an airline.

What I've read about blimps and zeppelins is that they are slower than a plane and less comfortable than a cruise ship, so they kind of lose out on every metric. Now, doesn't this mean that ABZs (airships, blimps, & zeppelins) are faster than a ship and more comfortable than a plane? Yes, it does, but just like in games, people in real life tend to optimize. If they want to go fast they take a plane, if they want to be fancy they take a ship, and very very rarely does anyone choose the option where everything is medium. Even without accidents like the Hindenburg, ABZs where never going to be able to compete with modern airliners.
(you can make many of the same arguments about luxury long-haul train trips, too)