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I would like us to eventually get back to hydrogen though. It has more lift and isn't in limited supply. If we can drive around with 20 gallons of gasoline unde

by pkulak 3y ago

I would like us to eventually get back to hydrogen though. It has more lift and isn't in limited supply. If we can drive around with 20 gallons of gasoline under our butts, we can probably figure out how to fly around with hydrogen above our heads.

dheera 3y ago
- Liquid gasoline ignites, but doesn't explode like a pressurized hydrogen balloon does - In the event of a fuel leak you can stop a car within seconds and evacuate, that isn't possible with a flying device Once we figure out how to do fusion power, helium won't be in limited supply anymore.
- saalweachter 3y ago
  I feel like hydrogen should still be an option for long-range, unmanned cargo zeppelins. Don't fly over cities, and the worst (likely) case scenario is you lose a load.
  - jodrellblank 3y ago
    Why don't fly over cities? Aeroplanes fly over cities and they're full of jet fuel. Hydrogen fuelled aeroplanes can fly over cities. Airships.net has a list of Hydrogen airship fires[1] and I question how many of them could be avoided, and how many accidents that is in comparison to early aeroplane accidents of 1908-1937; Wikipedia has a very long list of aircraft accidents[2]. Some of the fires are very avoidable - cleaning the gondola with gasoline, for example. I wonder what happened with 'static from the rubber bags igniting the gas' - was there a gas leak from a tear in the bags? Through the bag material? Gas buildup inside the canopy? Oxygen leaking into the bags making an air/gas mix inside? "Torn from its temporary mooring by wind" - is that avoidable today? "suffered in-flight structural failure over the city of Hull, England and crashed into the River Humber where it ignited", "ignited when it hit high-tension electrical wires", the R101 was a bad design modified in a rush to meet a political deadline. It might be that this really is unavoidably dangerous, but the advantages of Hydrogen for its extra lifting power and affordability and renewability make me want to see some good engineers and safety officers, with today's tech and air travel safety experience, work the problem for a few years and see how safe it could become. [1] https://www.airships.net/hydrogen-airship-accidents/ https://www.airships.net/hydrogen-airship-accidents/ [2] https://en.wikipedia.org/wiki/List_of_accidents_and_incidents_involving_commercial_aircraft https://en.wikipedia.org/wiki/List_of_accidents_and_incident...
- jodrellblank 3y ago
  Hydrogen balloons shouldn't be pressurized, the last thing you want is more mass in the same volume, that would make it less buoyant. Hydrogen doesn't explode, it's only Hydrogen + Oxygen mixtures that can explode, so an airship with intact gasbags regularly checked to contain pure Hydrogen can be at very low risk of sudden explosion. Hydrogen is allowed in airoplanes to propel them forwards[1], why not in airships to propel them upwards as well? > "In the event of a fuel leak you can stop a car within seconds and evacuate, that isn't possible with a flying device" Have you read the details of the Hindenburg disaster? If not, would you be surprised to learn that most of the people on board survived?[2] Compare with Wikipedia's list of commercial aircraft disasters[3] and the survival rate of those. And the sheer quantity of accidents, for that matter. (And Hydrogen in airships isn't a fuel, and it can be vented out of the top of the bags far away from the people in the gondola below, and anyway leaking Hydrogen goes upwards and away). [1] https://www.bbc.com/future/article/20210401-the-worlds-first-commercial-hydrogen-plane https://www.bbc.com/future/article/20210401-the-worlds-first... [2] https://en.wikipedia.org/wiki/Hindenburg_disaster https://en.wikipedia.org/wiki/Hindenburg_disaster [3] https://en.wikipedia.org/wiki/List_of_accidents_and_incidents_involving_commercial_aircraft https://en.wikipedia.org/wiki/List_of_accidents_and_incident...
- mahkeiro 3y ago
  Hydrogen doesn’t explode but burn if the hydrogen is pure and not mixed with air in stoichiometric proportion. The Hindenburg never exploded.
- angiosperm 3y ago
  In other words, helium will always be in limited supply.
lesuorac 3y ago
I mean for the most part we did figure out how to fly with hydrogen above our heads. The 1/3 of the occupants of the Hindenburg than did die (the remaining 2/3 survived) died because they couldn't escape the wreckage _on the ground_. I do think the more accurate thing to compare to are diesel submarines. A fire there is going to be even worse than one in a zeppelin (unless that zeppelin is over the ocean).

by pkulak 3y ago

dheera 3y ago

- Liquid gasoline ignites, but doesn't explode like a pressurized hydrogen balloon does - In the event of a fuel leak you can stop a car within seconds and evacuate, that isn't possible with a flying device Once we figure out how to do fusion power, helium won't be in limited supply anymore.

saalweachter 3y ago
I feel like hydrogen should still be an option for long-range, unmanned cargo zeppelins. Don't fly over cities, and the worst (likely) case scenario is you lose a load.
- jodrellblank 3y ago
  Why don't fly over cities? Aeroplanes fly over cities and they're full of jet fuel. Hydrogen fuelled aeroplanes can fly over cities. Airships.net has a list of Hydrogen airship fires[1] and I question how many of them could be avoided, and how many accidents that is in comparison to early aeroplane accidents of 1908-1937; Wikipedia has a very long list of aircraft accidents[2]. Some of the fires are very avoidable - cleaning the gondola with gasoline, for example. I wonder what happened with 'static from the rubber bags igniting the gas' - was there a gas leak from a tear in the bags? Through the bag material? Gas buildup inside the canopy? Oxygen leaking into the bags making an air/gas mix inside? "Torn from its temporary mooring by wind" - is that avoidable today? "suffered in-flight structural failure over the city of Hull, England and crashed into the River Humber where it ignited", "ignited when it hit high-tension electrical wires", the R101 was a bad design modified in a rush to meet a political deadline. It might be that this really is unavoidably dangerous, but the advantages of Hydrogen for its extra lifting power and affordability and renewability make me want to see some good engineers and safety officers, with today's tech and air travel safety experience, work the problem for a few years and see how safe it could become. [1] https://www.airships.net/hydrogen-airship-accidents/ https://www.airships.net/hydrogen-airship-accidents/ [2] https://en.wikipedia.org/wiki/List_of_accidents_and_incidents_involving_commercial_aircraft https://en.wikipedia.org/wiki/List_of_accidents_and_incident...
jodrellblank 3y ago
Hydrogen balloons shouldn't be pressurized, the last thing you want is more mass in the same volume, that would make it less buoyant. Hydrogen doesn't explode, it's only Hydrogen + Oxygen mixtures that can explode, so an airship with intact gasbags regularly checked to contain pure Hydrogen can be at very low risk of sudden explosion. Hydrogen is allowed in airoplanes to propel them forwards[1], why not in airships to propel them upwards as well? > "In the event of a fuel leak you can stop a car within seconds and evacuate, that isn't possible with a flying device" Have you read the details of the Hindenburg disaster? If not, would you be surprised to learn that most of the people on board survived?[2] Compare with Wikipedia's list of commercial aircraft disasters[3] and the survival rate of those. And the sheer quantity of accidents, for that matter. (And Hydrogen in airships isn't a fuel, and it can be vented out of the top of the bags far away from the people in the gondola below, and anyway leaking Hydrogen goes upwards and away). [1] https://www.bbc.com/future/article/20210401-the-worlds-first-commercial-hydrogen-plane https://www.bbc.com/future/article/20210401-the-worlds-first... [2] https://en.wikipedia.org/wiki/Hindenburg_disaster https://en.wikipedia.org/wiki/Hindenburg_disaster [3] https://en.wikipedia.org/wiki/List_of_accidents_and_incidents_involving_commercial_aircraft https://en.wikipedia.org/wiki/List_of_accidents_and_incident...
mahkeiro 3y ago
Hydrogen doesn’t explode but burn if the hydrogen is pure and not mixed with air in stoichiometric proportion. The Hindenburg never exploded.
angiosperm 3y ago
In other words, helium will always be in limited supply.

lesuorac 3y ago

I mean for the most part we did figure out how to fly with hydrogen above our heads. The 1/3 of the occupants of the Hindenburg than did die (the remaining 2/3 survived) died because they couldn't escape the wreckage _on the ground_. I do think the more accurate thing to compare to are diesel submarines. A fire there is going to be even worse than one in a zeppelin (unless that zeppelin is over the ocean).