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Who are the people always cited as being concerned by using hydrogen, every single time there is an article on airships? Do they exist? If so, are they just con

Who are the people always cited as being concerned by using hydrogen, every single time there is an article on airships? Do they exist? If so, are they just contrarians we can ignore? The technology is doomed if every time someone suggests it they start by explaining why it won't explode like that incident that happened 80 years ago that your parents might remember from a Led Zeppelin album cover. "Unlike blimps built in the last 50 years, the the suggestion is to revert to an even older technology and using hydrogen for lift, cheaper, safer and more environmentally friendly than the alternatives."

WalterBright 7y ago
Airliners take off full of fuel. Many airliners have ended in fiery crashes. Yet we still fly in them, all the time. Myself included. We drive around in cars full of fuel, that burn, too. People even drive around in hydrogen fueled cars. Why should Zeppelins be held to a far higher standard than airliners?
- weinzierl 7y ago
  Makes me thinking: What is the total energy of a full airplane vs a Zeppelin for roughly same cargo or passenger number.
  - jcims 7y ago
    Just stubby pencil work here because I'm up at entirely the wrong hour and this might help me go back to sleep. Envelope volume of the Goodyear blimp is ~8.5e6 liters. Density of hydrogen at STP is ~0.09g/L. If we filled the Goodyear blimp with that we'd have ~765kg of hydrogen gas. Let's round up to cover the slight operating pressure and say we have 800kg of hydrogen. Energy density of hydrogen is very high, 141MJ/kg. Energy density of Jet A is ~45MJ/kg. So our hypothetical blimp has the equivalent of 2600kg of Jet A on board. The Goodyear blimp only holds 8 passengers plus two pilots. A similarly sized jet would be the Learjet 60. It holds 3500kg of fuel. So, most jets probably have more on takeoff and less on landing.
    - pixl97 7y ago
      Also one should include the operating fuel needed to push the airship.
    - lorenzhs 7y ago
      The Hindenburg carried around 200k m³ of hydrogen, or 18,000kg, storing 2.54 PJ of energy, or equivalent to 56,400 kg of jet fuel. A 747 can carry more than four times that (240k-ish); an A320 or 737 carries slightly more than half (25k-ish). The Hindenburg only carried some 70 passengers, though.
      - jcims 7y ago
        Whoa the Hindenburg was huge: http://thesaratogasake.blogspot.com/2010/06/big-things-again.html?m=1 http://thesaratogasake.blogspot.com/2010/06/big-things-again...
  - larkost 7y ago
    There is an important distinction in hydrogen fires from jet fuel ones: the moment it is released hydrogen escapes upwards, taking any fire with it. Jet fuel on the other hand tends to pool downward, while releasing its vapor (the part that actually burns) upwards. So it tends to spread fires in both directions. So a hypothetical of a zeppelin crashing into a building might light that building on fire, but most of the hydrogen from the vehicle would escape upwards into the atmosphere without having contributed to the building's fire.
- whoisthemachine 7y ago
  The likely answer (and perhaps this was a rhetorical question) is marketing.
mannykannot 7y ago
Indeed - relatively few people are put off from air travel by pictures of airliners enveloped in flames, as in the recent crash at Sheremetyevo. I once imagined a "double-bagged" airship, in which the bulk of the lift is from hydrogen held within a shell of helium. I also wondered about a non-flammable hydrogen-helium mix, but it would apparently have to be mostly helium. I would guess, however, that modern developments in strong antistatic films and hydrogen detectors would make pure-hydrogen airships safe from fire.
- labawi 7y ago
  I thought hydrogen was mostly safe, as it inherently floats up and away.
yummypaint 7y ago
There is a clear sustainability advantage in using hydrogen since we can produce it trivially. Helium is a very limited resource, and its the most challenging to contain due to its small size. Plus the hydrogen delivers so much more lifting force per volume that some extr mass could be used for safety measures.

WalterBright 7y ago

Airliners take off full of fuel. Many airliners have ended in fiery crashes. Yet we still fly in them, all the time. Myself included. We drive around in cars full of fuel, that burn, too. People even drive around in hydrogen fueled cars. Why should Zeppelins be held to a far higher standard than airliners?

weinzierl 7y ago
Makes me thinking: What is the total energy of a full airplane vs a Zeppelin for roughly same cargo or passenger number.
- jcims 7y ago
  Just stubby pencil work here because I'm up at entirely the wrong hour and this might help me go back to sleep. Envelope volume of the Goodyear blimp is ~8.5e6 liters. Density of hydrogen at STP is ~0.09g/L. If we filled the Goodyear blimp with that we'd have ~765kg of hydrogen gas. Let's round up to cover the slight operating pressure and say we have 800kg of hydrogen. Energy density of hydrogen is very high, 141MJ/kg. Energy density of Jet A is ~45MJ/kg. So our hypothetical blimp has the equivalent of 2600kg of Jet A on board. The Goodyear blimp only holds 8 passengers plus two pilots. A similarly sized jet would be the Learjet 60. It holds 3500kg of fuel. So, most jets probably have more on takeoff and less on landing.
  - pixl97 7y ago
    Also one should include the operating fuel needed to push the airship.
  - lorenzhs 7y ago
    The Hindenburg carried around 200k m³ of hydrogen, or 18,000kg, storing 2.54 PJ of energy, or equivalent to 56,400 kg of jet fuel. A 747 can carry more than four times that (240k-ish); an A320 or 737 carries slightly more than half (25k-ish). The Hindenburg only carried some 70 passengers, though.
    - jcims 7y ago
      Whoa the Hindenburg was huge: http://thesaratogasake.blogspot.com/2010/06/big-things-again.html?m=1 http://thesaratogasake.blogspot.com/2010/06/big-things-again...
- larkost 7y ago
  There is an important distinction in hydrogen fires from jet fuel ones: the moment it is released hydrogen escapes upwards, taking any fire with it. Jet fuel on the other hand tends to pool downward, while releasing its vapor (the part that actually burns) upwards. So it tends to spread fires in both directions. So a hypothetical of a zeppelin crashing into a building might light that building on fire, but most of the hydrogen from the vehicle would escape upwards into the atmosphere without having contributed to the building's fire.
whoisthemachine 7y ago
The likely answer (and perhaps this was a rhetorical question) is marketing.

mannykannot 7y ago

Indeed - relatively few people are put off from air travel by pictures of airliners enveloped in flames, as in the recent crash at Sheremetyevo. I once imagined a "double-bagged" airship, in which the bulk of the lift is from hydrogen held within a shell of helium. I also wondered about a non-flammable hydrogen-helium mix, but it would apparently have to be mostly helium. I would guess, however, that modern developments in strong antistatic films and hydrogen detectors would make pure-hydrogen airships safe from fire.

labawi 7y ago
I thought hydrogen was mostly safe, as it inherently floats up and away.

yummypaint 7y ago

There is a clear sustainability advantage in using hydrogen since we can produce it trivially. Helium is a very limited resource, and its the most challenging to contain due to its small size. Plus the hydrogen delivers so much more lifting force per volume that some extr mass could be used for safety measures.