Airships as public transport Yay or nay?

[S@tanicoaldo]

In an alternate universe that is exactly like our universe, could we use blimps and airships as public transport to avoid trafic?

[factotum]

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.

[Lvl 2 Expert]

They're kind of slow as well, though faster than I would have expected, with the official world record standing at 115km/h (highway speed), and the larger models from back in the day (when the official standards for measuring the record didn't exist yet) getting closer to 140km/h (speeding on the highway speed, but not enough to lose your license). If they could do that in a straight line with minimal delays for takeoff and landing it would be a pretty good way to cross distances of a few dozen to a few hundred kilometers, but given how big these things are that might not be how it would actually play out. A train is probably faster. It requires more infrastructure, but we already have most of that. (EDIT: Okay, that's not an argument, I had forgotten the alternate universe part.) A train also allows for more stops, which is nice for public transport over less than airplane distances. Airships would also be susceptible to wind influences, making it hard to run on proper timetables. And they're vulnerable to sabotage and attack, like say bladed drones, or properly powerful fireworks. This isn't that big a concern in public transportation, we simply can't drive everyone around in a tank but it is one more penny on the scales.

Then there are two big ones: noise and fuel efficiency. You'd think that since an airship doesn't need to provide powered lift it'd be pretty efficient. But I fear having to move a giant balloon through a whole lot of air will actually negate that advantage. And noise if anything is going to be worse than for airplanes, as it would probably be less practical to fly these things at great heights. (Balloons in general are great for reaching great heights, but heavily laden balloons that also need to come back to earth regularly run into some obstacles.)

The upside might be cost of construction. Yeah, a wooden 30 person cabin and a huge balloon might actually be cheaper than an airplane aluminium 30 person cabin suited for high altitude high speed flight and a modest set of wings. But that's before counting the gas. I don't know how well we could make a permanent helium balloon that doesn't have any leakage but I'd assume there would need to be at least some replenishing. Hydrogen is much, much cheaper than helium, way less rare and actually more suited to the task of providing lift, but, you know, safety standards...

All in all I wouldn't put much money on it.

[halfeye]

Helium is rare and getting rarer, hydrogen burns.

[Manga Shoggoth]

Just for reference, and with El Reg's usual flair for reporting: It is being done with varying levels of failure and success.
.

[Blackhawk748]

Then there are two big ones: noise and fuel efficiency. You'd think that since an airship doesn't need to provide powered lift it'd be pretty efficient. But I fear having to move a giant balloon through a whole lot of air will actually negate that advantage. And noise if anything is going to be worse than for airplanes, as it would probably be less practical to fly these things at great heights. (Balloons in general are great for reaching great heights, but heavily laden balloons that also need to come back to earth regularly run into some obstacles.)

Uh, arent blimps actually incredibly quite?

[Anymage]

When I think public transit, I usually think trains or buses more than airplanes. And keeping an airship afloat to do circuits of the city sounds like more hassle than just building an elevated train. Or a subway. Avoiding traffic is pretty easy when you can build your tracks above/below the road.

Airships as an alternative to airplanes is doable. Possibly also small ones as luxury vehicles, or for special occasions. (Similar to how hot air balloons or horse drawn carriages are used in our world.) So you can get your zeppelins in the sky by just imagining that the Hindenburg didn't happen and something discouraged early airplane technology from taking off.

[S@tanicoaldo]

I'm reading about this on the net and a lot of places say they are very good for surveillance and were used in wars for that.

That goes back to my original inspiration for this idea, Gotham city that sues blimps as surveillance tools.

But how does that work? Anyone knows?

[gomipile]

First, yes hydrogen burns, but people forget that the Hindenburg disaster wasn't all that bad by today's measure. Only about a third of the people on board died. With modern standards, hydrogen could be even safer than that in a major accident.

Anyway, my first thought in remain to the OP is places where ground travel is very difficult, but distance is short enough that you don't want to use runways and fixed-wing aircraft. Imagine if there were two cities on opposite sides of the Grand Canyon, for example.

Also, imagine one of those sprawling London-like cities that show up in science fiction and fantasy. Airships ep could be useful to connect stations on opposite sides of such cities. Hell, I could imagine an airship route being useful to get from one side of Pittsburgh to the other, because of the hills and rivers.

[S@tanicoaldo]

Wasn't The Empire State Building used as Airship Docking Station?

[Grey_Wolf_c]

Wasn't The Empire State Building used as Airship Docking Station?

No. It was attempted, and that's when they discovered that buildings in a city cause unpredictable updrafts that prevented the airships from docking stably, and the idea was abandoned. There might have been a couple of successful docks, but it was never a regular occurrence.

GW

[Mechalich]

Zeppelins are a poor choice for transport of humans. Like airplanes they require large amounts of space and considerable time to load and unload humans onto, while being no faster and in many cases slower than rail-based transport and usually less economical. So this technology is primarily of value for transport where rail is not an option, which mostly means over water. It is possible that in areas with large number of islands in relatively close proximity airships might make more sense than surface-based ferries. So in places like Hawaii or the Philippines this could be a valuable technology.

[Palanan]

Originally Posted by Grey_Wolf_c
…buildings in a city cause unpredictable updrafts….

This touches on a major issue that hasn’t been mentioned yet, which is that airships in flight are tremendously vulnerable to storms and strong winds. A thunderstorm can produce violent updrafts that would push an airship thousands of feet higher in less than a minute. This happened to at least one early airship, and apart from the sheer terror for passengers, it wreaks havoc on schedules and flightplans.

Originally Posted by Lvl 2 Expert
You'd think that since an airship doesn't need to provide powered lift it'd be pretty efficient. But I fear having to move a giant balloon through a whole lot of air will actually negate that advantage.

In fact some airships generate lift when moving forward, as a consequence of the aerodynamics of the airframe. Some modern airships are designed as lifting bodies, but some of the old airships would do this unintentionally as well.

[2D8HP]

.....A typical helicopter is far smaller for a similar lift capacity......

When I was a little kid (1972?) I remember that you could see commuters boarding helicopters at the Berkeley/Emeryville/Oakland mudflats near the Bay Bridge that were going to San Francisco, I'm guessing that the oil embargo of '73 made it too expensive to continue?

When I worked in "Silicon Valley" (cursed be that place!), I'd sometimes see "Hanger One" where U.S. Navy blimps were kept in the '30's, so it looks like they require a lot of infrastructure, but maybe not as much as the runways for jets.

Sure would be neat!

[Lvl 2 Expert]

Uh, arent blimps actually incredibly quite?

They are pushed forwards by engines, so it all depends on what kind of engines you use, how fast you want to go and how high you're flying. My guess was that you often don't want to go too high, because that would cost more energy (for hot air) and put you in wilder weather. Not flying too high would put the engines relatively close to the ground. But I could be wrong. (The noise from making the hot air is much less then in a similarly sized balloon, because most of the lift is provided by helium/hydrogen.) I also don't know my aircraft engines too well, maybe powerful but slow engines are just plain quieter than fast ones. Or it might help that at least in terms of payload and number of passengers zeppelins are tiny, and a lot of small planes don't make the same noise a single large one does.

I'm reading about this on the net and a lot of places say they are very good for surveillance and were used in wars for that.

That goes back to my original inspiration for this idea, Gotham city that sues blimps as surveillance tools.

But how does that work? Anyone knows?

You hang them up in the sky and watch stuff. As long as your goal is to be in the air rather than to go to a specific place fast blimps are amazingly efficient, and they can stay in the air much longer than a typical plane.

This touches on a major issue that hasn’t been mentioned yet, which is that airships in flight are tremendously vulnerable to storms and strong winds. A thunderstorm can produce violent updrafts that would push an airship thousands of feet higher in less than a minute. This happened to at least one early airship, and apart from the sheer terror for passengers, it wreaks havoc on schedules and flightplans.

And there goes the option to use them for archipels in the ocean.

[khadgar567]

looks like we all agree blimps and similar airships are bad idea for long distance travel but good for advertisement.

[Bucky]

I think it could be done at somewhere between bus and subway cost.

The main advantage it has is that you only need the vehicles themselves and the stations; there's no requirement for roads or tracks. You can just stick a docking tower wherever you want to expand your network.

The main disadvantages I see are that the vehicles are more expensive than trains, busses etc., especially on a per-passenger basis. And, yes, that they're vulnerable to weather.

The loading time issue could be solved in principle.

[factotum]

They are pushed forwards by engines, so it all depends on what kind of engines you use, how fast you want to go and how high you're flying. My guess was that you often don't want to go too high, because that would cost more energy (for hot air) and put you in wilder weather.

Hot air? Airships usually use helium or hydrogen as the lifting gas, they don't need any hot air. Also, being higher up means thinner air which means it takes less energy to push through it, which is probably more important in the long run--that's why commercial jet airliners typically cruise at around 30,000 feet, the extra energy expended getting that high is more than offset by the fuel savings of flying at altitude.

The main reason you don't want to go high in an airship is because the higher you go, the greater the pressure differential between the lifting gas and the outside air--before long, you get to an altitude where the pressure relief valves in the gas bladders go off, so you lose lifting gas. This is a fire hazard if you're using hydrogen as your lifting gas, and there are limited stocks of helium in the world so you ideally don't want to lose any of that either. (For reference, the typical cruising altitude of the Hindenberg was as low as 650 feet, and lower if they had to avoid going into a cloud bank).

[Eldan]

Uh, arent blimps actually incredibly quite?

Only if you don't actually want them to move much. If you want any kind of practicable speed, you'd still be strapping propellers or turbines to them.

[Lvl 2 Expert]

Hot air? Airships usually use helium or hydrogen as the lifting gas, they don't need any hot air.

Oh, my mistake. I thought I had read somewhere that they use hot air to control their altitude, a bit similar to the ballast tanks of a submarine. Except instead of replacing air by water and vice versa they replace cold air by hot air. But maybe they just waste helium/hydrogen on adjusting their lift, you probably know more about it than I do.

[Cespenar]

In an alternate universe that is exactly like our universe, could we use blimps and airships as public transport to avoid trafic?

I don't mean to be dismissive, but why would anything be different in a universe that is exactly like our universe?

What I mean to say is, if some social/political/logistical/geographical differences were possible in your alternate universe, then it could have actually made sense to use blimps and airships. But now, it's just not feasible for a hundred different reasons.

[snowblizz]

But maybe they just waste helium/hydrogen on adjusting their lift, you probably know more about it than I do.

In fact they do exactly that. Now as was mentioned there's some aerodynamics in the airframes and some have wings to aid wit hlift and and such, which means they kinda work like incredibly slow airplanes. So I guess there's the possibility of one that doesn't waste gas quite the same way hotair balloons do. Also anything transporting humans will have ballast of various kinds, fuels, water etc. And you normally don't *want* to lose expensive gas, in fact one problem th eHindenburg had was that it had an open valve letting hydrogen out all throughout the last voyage. In general though helium and hydrogen is basically impossible to store effectively without some (very minor) leakage.

Hot air? Airships usually use helium or hydrogen as the lifting gas, they don't need any hot air. Also, being higher up means thinner air which means it takes less energy to push through it, which is probably more important in the long run--that's why commercial jet airliners typically cruise at around 30,000 feet, the extra energy expended getting that high is more than offset by the fuel savings of flying at altitude.

Actually since most airships used propellers any thinnening of the air has a direct consequence in less air to push back against with propellers. Basically I think we sorta run into a Newton's 3rd law problem. Jetliners can take advantage of flying high because they are less reliant on thick air to propel themselves. However there is a limit there too since thin air has less, well air, to push through the jetengine so there comes a point where you simply can't feed the engine enough oxygene to keep it running and yourself aloft.

I also don't know my aircraft engines too well, maybe powerful but slow engines are just plain quieter than fast ones. Or it might help that at least in terms of payload and number of passengers zeppelins are tiny, and a lot of small planes don't make the same noise a single large one does.

Slow engines are indeed plain quieter than fast ones. It all boils down to volume of moving air. You can do it in 2 ways, big slow propellers or small fast ones. This is why computers are steadily increasing the size of their chassis fans, the 120mm ones are noticeably quieter than the 80mm fans that are more silent than the class below I think 55mm or some such. Basically the bigger the blade the more each stroke counts for. The sounds an aircraft makes is not so much the engine itself but the the air being pushed aside/through/around. Wind-power turbines are pretty darned big and you don't hear them nearly as well as a plane (also the soundwaves they make arne't audible to us). Disregarding most jetengines ofc. An airship could have much larger propellers than most small aircraft because they don't have the same ground clearance issues.

In general for sound-issues, keep in mind historical airships were prized exactly because they were quiet stately craft, and the passengers onboard would be much closer to the engines than anyone on ground.

[Lvl 2 Expert]

I don't mean to be dismissive, but why would anything be different in a universe that is exactly like our universe?

What I mean to say is, if some social/political/logistical/geographical differences were possible in your alternate universe, then it could have actually made sense to use blimps and airships. But now, it's just not feasible for a hundred different reasons.

Assume physically and chemically identical, including a similar distribution of elements and their various basic atomic and molecular forms. Go crazy with anything else and give us your best scenario.

[factotum]

Actually since most airships used propellers any thinnening of the air has a direct consequence in less air to push back against with propellers.

In general for sound-issues, keep in mind historical airships were prized exactly because they were quiet stately craft, and the passengers onboard would be much closer to the engines than anyone on ground.

In 1952, a Spitfire--a propeller driven aircraft--achieved an altitude of over 50,000 feet. It's probably not particularly efficient to run a prop at that altitude, certainly, but I suspect the actual sweet point between drag reduction and propeller efficiency is a bit higher than the 650 feet the Hindenberg usually flew at!

As for sound, the passengers might be closer to the engines than people on the ground, but they have the skin of the airship in between to baffle the sound. People on the ground don't get that advantage.

[Cespenar]

Assume physically and chemically identical, including a similar distribution of elements and their various basic atomic and molecular forms. Go crazy with anything else and give us your best scenario.

Assuming everything else, it's really easy. Perhaps the blimp inventor was closer to the government and had driven the competitors to the ground? We're not even in the crazy territory here.

Sure, eventually they would find the most feasible method, but for a given period, blimps would rule.

[pendell]

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.

I watch the airship interiors of Final Fantasy 12, I'd be willing to try it if I had tons of money to burn on a speculative venture which might very well fail.

Respectfully,

Brian P.

[Hunter Noventa]

I just think of the scene with the airship in Indiana Jones and the last Crusade, that was pretty luxurious-looking on the inside. Until someone finds out you have no ticket anyway.

But yeah, for airships to make sense at all there would have to be some kind of dearth of the materials used to make aircraft today that doesn't affect materials for airships, and I couldn't for the life of me figure out what kind of material shortage that would be.

[pendell]

Here's a science question which I hope someone will answer: What's the carbon footprint of a blimp vis-a-vis an aircraft? Might we move to airships from heavier-than-air craft in order to be more sustainable?

Respectfully,

Brian P.

[sktarq]

Here's a science question which I hope someone will answer: What's the carbon footprint of a blimp vis-a-vis an aircraft? Might we move to airships from heavier-than-air craft in order to be more sustainable?

Respectfully,

Brian P.

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)
and Helium has issues with the fact there are limited stocks and so are using a very finite resource that we also need for things like MRI's, the LHC collider at CERN etc.....so may be better per mile but have other environmental costs. Plus you'd need more of them to move the same number of people between two points relative to an aircraft (who could make the trip more often) and so the carbon costs of making the fleet would be stacked against it.

There have been improvements with inflating and recompressing lighter than air cells inside of fixed cells for ballast control instead of venting the lighter than air gas....though I don't know if the huge vessels currently under testing in the UK and San Diego incorporate such things. But gases that small (they are just S1 shells) can slide between the atoms of almost anything made to hold them, so some are going to leak

There does seem to be some future in them for specialized heavy lift transports (for things too big to get there by road and too far for helicopters for example) but people pay for time saved more than just about anything else and airships are slow. Possible as a luxury unit were the trip is not about getting somewhere but about the experience itself.

as for public transport like buses trains etc. Well they are slower, harder to fly, need more space/equipment at each landing point than say a helicopter so I wouldn't think so.....if you wanted to go a different way

[Mechalich]

Assuming everything else, it's really easy. Perhaps the blimp inventor was closer to the government and had driven the competitors to the ground? We're not even in the crazy territory here.

Sure, eventually they would find the most feasible method, but for a given period, blimps would rule.

Well, the first assumption is that the Hindenburg disaster doesn't happen. That basically killed zeppelin (and we're talking about zeppelins here, with an internal frame inside the balloon for structural support, not blimps - a much more limited approach) development at the technological moment when they had the great viability. If there's no Hindenburg disaster zeppelins continue to be supported and innovations are found to make them more efficient in terms of lift, safer, and more stable in flight.

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. The possibility of taking a zeppelin from, for example Toulouse to Paris - a four and half hour train ride but almost seven by car - would be much more viable in a scenario where the train option was removed.

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.