8 ms·

Zeppelins look so surreal. So much work put into a now-totally-dead technology, making these huge, incredible machines, that were only favored for a very brief

Zeppelins look so surreal. So much work put into a now-totally-dead technology, making these huge, incredible machines, that were only favored for a very brief span of time.

WaxProlix 4y ago
But they're so cool. Maybe with advances in materials science this kind of design could be viable again. Probably not likely with the looming helium shortage, lack of replacement gasses (?), etc. But I want my sweet 1920s art deco retrofuturist reality :(
- jakear 4y ago
  Could some combination of a partial vacuum and hot air substitute for helium? Of course you'd need some ultra light superstructure to maintain the giant vacuum, but that's "just" engineering.
  - masklinn 4y ago
    > hot air Air at 175C has about 40% the lifting power as the same volume of helium (or hydrogen). That is very hot, and requires a lot of energy to sustain. Lower temperatures will reduce the lifting power. That's why thermal airships (https://en.wikipedia.org/wiki/Thermal_airship https://en.wikipedia.org/wiki/Thermal_airship) are very uncommon, the lift inefficiency means the structural weight doesn't scale, and the cross-section makes them very hard drive and control.
    - jandrese 4y ago
      I guess because airships were already out of fashion by the time the atomic age came, but a thermal airship where the heater is just a radioactive pile seems like a super simple design. The enormous bulk of the airship is an advantage in this case, you can reduce the amount of shielding you need by keeping the radioactive stuff way off on one side of the vehicle and the people on the other. Of course it would still be a nasty cleanup effort if your airship crashes, and you have to deal with radioactive materials when landed or when doing maintenance. From a practical standpoint there are issues, but in theory the concept works.
      - robonerd 4y ago
        A reactor powered thermal airship is a fascinating idea! I'm skeptical that it could work though. Some quick web searching suggests that 3 MW burners for hot air balloons is fairly typical. I'm not sure how light and powerful a reactor could be made, but wikipedia says the Convair NB-36H had a 1 MW air-cooled reactor weighing 16,000kg. That reactor definitely wouldn't work then, too heavy by far and not enough power output. But that was a prototype reactor in the 50s. Also, shielding seems like a big concern even if the reactor can be built light. To stop neutron radiation you need light nuclei like hydrogen, making water or concrete (containing water) popular choices. These are heavy and bulky though, not conducive to airships.
        jandrese 4y ago
        That's why my consideration for shielding was mostly just distance. Certainly a concept for a time when people were more cavalier about radiation safety.
        deleted 4y ago
        [deleted]
    - jakear 4y ago
      That’s where the vacuum comes in. Extract half of that hot air, seal the container, and you have 70% of the helium lifting force. (Math may be wrong there but you get the idea) Really you don’t need hot air at all. If you have a massive vacuum contained by a rigid shell of some super light super strong material you’d be set. Density of air at sea level is around 1 kg/m^3, so 100 m^2 of material lifts 3 tons. Assuming one ton for material, one for propulsion, one for cargo, you end up needing a shell material that can weigh up to 1 kg/m^2 and can hold a near vacuum. Like I said earlier, “just” and engineering problem. The good news is economies of scale are on your side: 10000 m^2 of shell can lift 3 thousand tons. At that scale your shell can be up to 300 kg/m^2. A bit more reasonable.
- bombcar 4y ago
  The revival will truly come when we accept running them on hydrogen for lifting gas. It can likely be done quite safely, as the gasbag of the Hindenburg was very flammable and could have burned even if full of helium. And hydrogen is basically free.
  - masklinn 4y ago
    The reality is that airships are kinda crap: 1. they get "free lift" but you need a lot of gas to lift a lot of mass, which quickly makes them extremely unwieldy as it leads to gigantic cross sections (and sheer stuff to move, positioning a lift bag the size of a sports stadium is not exactly great, and requires humongous engines) 2. they're so damn slow 3. even ignoring the tendency to get on fire, hydrogen is a pain in the ass, it absolutely refuses staying put and embrittles structural metals leading to accelerated fatigue
    - bombcar 4y ago
      Yeah, they'd likely be best used as "cruise ships in the sky" where they can take advantage of large swaths of empty space (you could have ballrooms in a zeppelin pretty easily as they wouldn't weigh much) and the speed wouldn't be a huge issue. And you'd likely have to make them out of something other than metal, and it would vent hydrogen most of time.
      - WalterBright 4y ago
        I'd love to take a low and slow tour.
    - outworlder 4y ago
      For passengers sure, they are slow. They could instead transport cargo. I think the biggest problem with them is mooring. It's a complex process, much more so than landing a plane, and requires lots of ground crew. It would have to be automated first.
      - masklinn 4y ago
- samizdis 4y ago
  Not sure how the company is doing atm, but the Airlander project by Hybrid Air Vehicles seemed quite promising: https://www.hybridairvehicles.com/ https://www.hybridairvehicles.com/
RangerScience 4y ago
A fun observation that strongly relates to this: In fiction, alternative universes always have more zeppelins. (It's actually one of the most common ways to visually signal "alternate timeline").
- bee_rider 4y ago
  Now I'm imagining some sort of steampunk multiverse tour guide character popping into our universe with a bunch of customers, like "And here we see the local-minimum zeppelin universe. Notice how, due to the fact that their flying vehicles are heavier than air, they've isolated them to areas outside their cities for safety! They call these 'air-ports.' Yes, like a regular port, but for the air!"
  - Aperocky 4y ago
    > isolated them to areas outside their cities for safety I'd imagine massive balloons are no more safe over the city than current aircrafts.
    - bee_rider 4y ago
      I dunno, in a hypothetical world where massive balloons had had as much R&D put into them as a modern aircraft, they maybe they can use the loitering advantage to make skyscraper landings possible. Anyway, these travelers come from a steampunk universe, so theirs are probably unrealistically capable.
      - RangerScience 4y ago
        Fun fact: The builders of the Empire State Building aimed for this: https://www.smithsonianmag.com/air-space-magazine/docking-on-the-empire-state-building-12525534/ https://www.smithsonianmag.com/air-space-magazine/docking-on...
- jacobolus 4y ago
  Cars/trucks, diesel-electric or electrified freight trains, diesel ships, jet planes, electrical wires, and pipelines, (and tracked vehicles, helicopters, nuclear subs, rockets, cable railways, etc. in niche roles), are practical means of transportation given our particular available resources, history of infrastructure investment, etc., but they are familiar and boring to make a speculative fiction story about. Coming up with an alternative set of constraints where other kinds of transportation (zeppelins, space elevators, pneumatic tubes, conveyor belts, ornithopters, futuristic sailboats, teleporters, ...) are economically/physically viable is fun for authors and readers.
Stratoscope 4y ago
Zeppelins still fly out of Friedrichshafen, their original home! Those of you who lived on the SF Peninsula 10-15 years ago may remember seeing the Airship Ventures Zeppelin NT. That company eventually went out of business and the Zeppelin was dismantled and taken back to Friedrichshafen, but I got to ride on one of their last Bay Area flights. It was the coolest thing ever. I posted a couple of comments here in recent years with more information and links to my photos from the Airship Ventures flight and information about their current operations in Friedrichshafen: https://news.ycombinator.com/item?id=21662645 https://news.ycombinator.com/item?id=21662645 https://news.ycombinator.com/item?id=18897492 https://news.ycombinator.com/item?id=18897492 Airships.net also has an article about the Zeppelin NT used in the Airship Ventures and Friedrichshafen flights: https://www.airships.net/zeppelin-nt/ https://www.airships.net/zeppelin-nt/
- bombcar 4y ago
  Today I learned that the Goodyear Blimps are now Goodyear Zeppelins, at least in some cases.
  - mcv 4y ago
    A couple of years ago at a work event we were in the Goodyear Blimp (grounded, unfortunately), and back then it was definitely a blimp. Though I vaguely recall a rumour that it might have been a different blimp that they'd repainted with the Goodyear logo. No idea if that's true.
mNovak 4y ago
If we're pining for lost technologies, I still vote for the large ekranoplan (ground effect plane). It just seems so unreasonably effective.
iancmceachern 4y ago
Totally. The tech that went into making them work at the time was incredible. Before polymers they were made from among many other things, cow gut. They had a ban on sausage making in Germany during the war to ration all the cow casing for use in the zeppelin program.

Zeppelins look so surreal. So much work put into a now-totally-dead technology, making these huge, incredible machines, that were only favored for a very brief span of time.

WaxProlix 4y ago

But they're so cool. Maybe with advances in materials science this kind of design could be viable again. Probably not likely with the looming helium shortage, lack of replacement gasses (?), etc. But I want my sweet 1920s art deco retrofuturist reality :(

jakear 4y ago
Could some combination of a partial vacuum and hot air substitute for helium? Of course you'd need some ultra light superstructure to maintain the giant vacuum, but that's "just" engineering.
- masklinn 4y ago
  > hot air Air at 175C has about 40% the lifting power as the same volume of helium (or hydrogen). That is very hot, and requires a lot of energy to sustain. Lower temperatures will reduce the lifting power. That's why thermal airships (https://en.wikipedia.org/wiki/Thermal_airship https://en.wikipedia.org/wiki/Thermal_airship) are very uncommon, the lift inefficiency means the structural weight doesn't scale, and the cross-section makes them very hard drive and control.
  - jandrese 4y ago
    I guess because airships were already out of fashion by the time the atomic age came, but a thermal airship where the heater is just a radioactive pile seems like a super simple design. The enormous bulk of the airship is an advantage in this case, you can reduce the amount of shielding you need by keeping the radioactive stuff way off on one side of the vehicle and the people on the other. Of course it would still be a nasty cleanup effort if your airship crashes, and you have to deal with radioactive materials when landed or when doing maintenance. From a practical standpoint there are issues, but in theory the concept works.
    - robonerd 4y ago
      A reactor powered thermal airship is a fascinating idea! I'm skeptical that it could work though. Some quick web searching suggests that 3 MW burners for hot air balloons is fairly typical. I'm not sure how light and powerful a reactor could be made, but wikipedia says the Convair NB-36H had a 1 MW air-cooled reactor weighing 16,000kg. That reactor definitely wouldn't work then, too heavy by far and not enough power output. But that was a prototype reactor in the 50s. Also, shielding seems like a big concern even if the reactor can be built light. To stop neutron radiation you need light nuclei like hydrogen, making water or concrete (containing water) popular choices. These are heavy and bulky though, not conducive to airships.
      - jandrese 4y ago
        That's why my consideration for shielding was mostly just distance. Certainly a concept for a time when people were more cavalier about radiation safety.
      - deleted 4y ago
        [deleted]
  - jakear 4y ago
    That’s where the vacuum comes in. Extract half of that hot air, seal the container, and you have 70% of the helium lifting force. (Math may be wrong there but you get the idea) Really you don’t need hot air at all. If you have a massive vacuum contained by a rigid shell of some super light super strong material you’d be set. Density of air at sea level is around 1 kg/m^3, so 100 m^2 of material lifts 3 tons. Assuming one ton for material, one for propulsion, one for cargo, you end up needing a shell material that can weigh up to 1 kg/m^2 and can hold a near vacuum. Like I said earlier, “just” and engineering problem. The good news is economies of scale are on your side: 10000 m^2 of shell can lift 3 thousand tons. At that scale your shell can be up to 300 kg/m^2. A bit more reasonable.
bombcar 4y ago
The revival will truly come when we accept running them on hydrogen for lifting gas. It can likely be done quite safely, as the gasbag of the Hindenburg was very flammable and could have burned even if full of helium. And hydrogen is basically free.
- masklinn 4y ago
  The reality is that airships are kinda crap: 1. they get "free lift" but you need a lot of gas to lift a lot of mass, which quickly makes them extremely unwieldy as it leads to gigantic cross sections (and sheer stuff to move, positioning a lift bag the size of a sports stadium is not exactly great, and requires humongous engines) 2. they're so damn slow 3. even ignoring the tendency to get on fire, hydrogen is a pain in the ass, it absolutely refuses staying put and embrittles structural metals leading to accelerated fatigue
  - bombcar 4y ago
    Yeah, they'd likely be best used as "cruise ships in the sky" where they can take advantage of large swaths of empty space (you could have ballrooms in a zeppelin pretty easily as they wouldn't weigh much) and the speed wouldn't be a huge issue. And you'd likely have to make them out of something other than metal, and it would vent hydrogen most of time.
    - WalterBright 4y ago
      I'd love to take a low and slow tour.
  - outworlder 4y ago
    For passengers sure, they are slow. They could instead transport cargo. I think the biggest problem with them is mooring. It's a complex process, much more so than landing a plane, and requires lots of ground crew. It would have to be automated first.
    - masklinn 4y ago
samizdis 4y ago
Not sure how the company is doing atm, but the Airlander project by Hybrid Air Vehicles seemed quite promising: https://www.hybridairvehicles.com/ https://www.hybridairvehicles.com/

RangerScience 4y ago

A fun observation that strongly relates to this: In fiction, alternative universes always have more zeppelins. (It's actually one of the most common ways to visually signal "alternate timeline").

bee_rider 4y ago
Now I'm imagining some sort of steampunk multiverse tour guide character popping into our universe with a bunch of customers, like "And here we see the local-minimum zeppelin universe. Notice how, due to the fact that their flying vehicles are heavier than air, they've isolated them to areas outside their cities for safety! They call these 'air-ports.' Yes, like a regular port, but for the air!"
- Aperocky 4y ago
  > isolated them to areas outside their cities for safety I'd imagine massive balloons are no more safe over the city than current aircrafts.
  - bee_rider 4y ago
    I dunno, in a hypothetical world where massive balloons had had as much R&D put into them as a modern aircraft, they maybe they can use the loitering advantage to make skyscraper landings possible. Anyway, these travelers come from a steampunk universe, so theirs are probably unrealistically capable.
    - RangerScience 4y ago
      Fun fact: The builders of the Empire State Building aimed for this: https://www.smithsonianmag.com/air-space-magazine/docking-on-the-empire-state-building-12525534/ https://www.smithsonianmag.com/air-space-magazine/docking-on...
jacobolus 4y ago
Cars/trucks, diesel-electric or electrified freight trains, diesel ships, jet planes, electrical wires, and pipelines, (and tracked vehicles, helicopters, nuclear subs, rockets, cable railways, etc. in niche roles), are practical means of transportation given our particular available resources, history of infrastructure investment, etc., but they are familiar and boring to make a speculative fiction story about. Coming up with an alternative set of constraints where other kinds of transportation (zeppelins, space elevators, pneumatic tubes, conveyor belts, ornithopters, futuristic sailboats, teleporters, ...) are economically/physically viable is fun for authors and readers.

Stratoscope 4y ago

Zeppelins still fly out of Friedrichshafen, their original home! Those of you who lived on the SF Peninsula 10-15 years ago may remember seeing the Airship Ventures Zeppelin NT. That company eventually went out of business and the Zeppelin was dismantled and taken back to Friedrichshafen, but I got to ride on one of their last Bay Area flights. It was the coolest thing ever. I posted a couple of comments here in recent years with more information and links to my photos from the Airship Ventures flight and information about their current operations in Friedrichshafen: https://news.ycombinator.com/item?id=21662645 https://news.ycombinator.com/item?id=21662645 https://news.ycombinator.com/item?id=18897492 https://news.ycombinator.com/item?id=18897492 Airships.net also has an article about the Zeppelin NT used in the Airship Ventures and Friedrichshafen flights: https://www.airships.net/zeppelin-nt/ https://www.airships.net/zeppelin-nt/

bombcar 4y ago
Today I learned that the Goodyear Blimps are now Goodyear Zeppelins, at least in some cases.
- mcv 4y ago
  A couple of years ago at a work event we were in the Goodyear Blimp (grounded, unfortunately), and back then it was definitely a blimp. Though I vaguely recall a rumour that it might have been a different blimp that they'd repainted with the Goodyear logo. No idea if that's true.

mNovak 4y ago

If we're pining for lost technologies, I still vote for the large ekranoplan (ground effect plane). It just seems so unreasonably effective.

iancmceachern 4y ago

Totally. The tech that went into making them work at the time was incredible. Before polymers they were made from among many other things, cow gut. They had a ban on sausage making in Germany during the war to ration all the cow casing for use in the zeppelin program.