10 ms·

Caltech professor helps solve Hindenburg disaster

137 points by chmaynard 5y ago

ChuckMcM 5y ago
This is pretty good, it has a both the theory of how it started, an experiment to validate the theory, and math to show that the event timeline matches the theory. I'm generally convinced this is the correct answer (at last). What that means, is that if the Germans had use slightly conductive spacers rather than wooden dowels, they would have been able to keep the voltage difference between the frame and the envelope below the dielectric breakdown point of the gap. At the cost of the sparks happening at the ends of the mooring ropes as they touched the ground. Another useful experiment if you still had a zeppelin would be to see if you could usefully use the voltage differential to do some useful work (like flashing lights on the sides of the ship or something)
- Paddywack 5y ago
  What surprises me is why this "giant capacitor" phenomena did not occur elsewhere? Surely it docked previously in wet/damp conditions? Would the effect have been visible? Or was it that there has never been any leak across the whole structure when docked in wet?
  - WalterBright 5y ago
    The leak was a necessary component of the disaster.
- Stratoscope 5y ago
  There still are zeppelins! If you lived on the SF Peninsula or South Bay 10-15 years ago, you might have seen the Airship Ventures zeppelin flying low and slow over the area. Alas, Airship Ventures went out of business about ten years ago, due in part to the loss of a corporate sponsor and no luck getting a new one. I remember seeing 23 and Me on the zeppelin when it flew overhead. Ten years ago, a good friend treated me to a ride on one of their last local flights (this time the zepp was decorated with the Farmers Insurance logo). They still fly in Germany, though, so if you are ever in the Friedrichshafen area and can afford the somewhat pricey flight, do it! I promise you won't regret it; it was truly an experience of a lifetime. I posted a couple of comments here in the last year or two, so rather than repeat all the details and photo gallery, you can find them here: 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 p.s. These new Zeppelin NT airships do use helium!
chmaynard 5y ago
My compliments to the writer of this story, Emily Velasco. She clearly communicated the science and still managed to keep the reader (me) on the edge of my seat.
WalterBright 5y ago
> Imagine a cigar-shaped balloon as large as a skyscraper filled with explosive gas. Combine that hydrogen with oxygen from the air, and a source of ignition, and you have "literally a bomb," Giapis says. Imagine a tin cigar filled with explosive gas! Combine that with oxygen from the air, and a source of ignition, and kaboom! Today we call those "airliners". If people had continued to develop Zeppelins, the problems with safely handling hydrogen would have been solved, just like the problems with handling aviation gas and jet fuel have been solved. There's a lot of consideration with airliners about dealing with lightning strikes and all sorts of possible sources of sparks so the fuel is not ignited.
- fastball 5y ago
  Don't we have Helium anyway?
  - timbit42 5y ago
    We don't have an unlimited supply.
  - echelon 5y ago
    Helium is extremely limited and cannot be manufactured at any appreciable scale (you're not dealing with typical chemistry, but physics. Helium is an element.) What we have naturally comes from radioactive decay deep in the earth. This will continue for some time, but it's a fixed, slow rate. Helium evaporates into space. Once it's gone, it's gone for good. The other options we have are hydrogen (extremely reactive), heated oxygen (also reactive), methane (reactive), ammonia... It's a hard problem.
    - fastball 5y ago
      One more problem that will be solved by fusion energy!
    - fatsdomino001 5y ago
      We can theoretically do vacuum zeppelins, which is of course lighter than helium and unlimited tho it has its own problems too.
deleted 5y ago
[deleted]
jonny_eh 5y ago
I recall seeing a previous documentary where they found evidence that the paint on the exterior of the balloon was new, never used, and highly flammable. Perhaps that, combined with this latest capacitor theory, full explains what happened. Update: nvm, just found this: https://www.airships.net/hindenburg-paint https://www.airships.net/hindenburg-paint
- emmelaich 5y ago
  That article says it's not "rocket fuel", but everyone knows that Cellon dope is highly flammable. At least, those who used to make model aircraft with balsa wood and dope.
jonsen 5y ago
Relevant for the discussion here. ”Reinforced aerostat technology for safe hydrogen use in airships”: https://safeairship.com/ https://safeairship.com/
emmelaich 5y ago
I wonder whether the Cellon dope caught fire first. It's highly flammable and unstable. From another article, about a 1916 German bomber .. https://eandt.theiet.org/content/articles/2017/11/eccentric-engineer-the-painfully-visible-birth-of-the-world-s-first-invisible-bomber/ https://eandt.theiet.org/content/articles/2017/11/eccentric-... > First, Cellon, a type of cellulose acetate, was highly flammable, which, combined with the wooden fuselage, made the plane a tinderbox. Secondly, it wasn’t very strong or stable; in dry weather the material shrank, warping the wooden fuselage, while in damp weather it expanded and made the whole structure sag. This had a very unnerving effect in flight, as the control surfaces changed characteristics from moment to moment depending on humidity. Cellon also decayed in ultraviolet light, becoming yellowed, brittle and prone to explosive shattering.
- dmix 5y ago
  From another person's post: > The truth is that the dope used on the Hindenburg was specifically chosen for its low flammability, and the composition of the dope had almost nothing in common with the formula used to make rocket fuel. https://www.airships.net/hindenburg-paint/ https://www.airships.net/hindenburg-paint/
  - emmelaich 5y ago
    It's relative compared to cellulose nitrate (ie. guncotton). Cellulose acetate has lower flammability but that isn't saying much. Have a look at the Pathé video of the Hindenburg disaster. The "skin" is clearly on fire.
- schlupa 5y ago
  Mythbuster dispelled that the coating paint could have been the cause of the disaster. https://en.wikipedia.org/wiki/MythBusters_(2007_season)#Hindenburg_Mystery https://en.wikipedia.org/wiki/MythBusters_(2007_season)#Hind...
  - emmelaich 5y ago
    from that wikipedia page ... > they concluded the Hindenburg's demise could be attributed to both the hydrogen and the paint, which is what I'm suggesting.
deleted 5y ago
[deleted]
fernly 5y ago
Umm -- the Mythbusters explored the issue of the flammable skin in their usual style. Season 5, Episode 1, available here: https://www.dailymotion.com/video/x2ncm5i https://www.dailymotion.com/video/x2ncm5i The OP article pretty much takes the flammability of the doped skin for granted. The "distributed capacitor" theory certainly would account for the rapidity of the fire spread, with multiple ignition points.
anitil 5y ago
Along this theme, I highly recommend Bill Hammack's (The Engineer Guy) book "Fatal Flight - The True Story of Britain's Last Great Airship". It's also available as an audio book on youtube [0]. (I couldn't find it as an audio feed) [0] https://www.youtube.com/watch?v=97OnTDaLqqk&list=PL0INsTTU1k2Vh4m4jS9oVE7GFga7OLaBZ https://www.youtube.com/watch?v=97OnTDaLqqk&list=PL0INsTTU1k...
- Johnythree 5y ago
  Also see "Slide Rule: Autobiography of an Engineer" by Nevil Shute, who was the senior stress engineer of the British R100.. (beside being a famous author, eg "On the Beach", "A Town like Alice", etc)
dmix 5y ago
Premieres in 2 days, trailer of NOVA doc: https://www.pbs.org/wgbh/nova/video/hindenburg-the-new-evidence/ https://www.pbs.org/wgbh/nova/video/hindenburg-the-new-evide...
- kristofferR 5y ago
  Great documentary, I just watched it now (it was aired by SBS a month ago)!

137 points by chmaynard 5y ago

This is pretty good, it has a both the theory of how it started, an experiment to validate the theory, and math to show that the event timeline matches the theory. I'm generally convinced this is the correct answer (at last). What that means, is that if the Germans had use slightly conductive spacers rather than wooden dowels, they would have been able to keep the voltage difference between the frame and the envelope below the dielectric breakdown point of the gap. At the cost of the sparks happening at the ends of the mooring ropes as they touched the ground. Another useful experiment if you still had a zeppelin would be to see if you could usefully use the voltage differential to do some useful work (like flashing lights on the sides of the ship or something)

Paddywack 5y ago
What surprises me is why this "giant capacitor" phenomena did not occur elsewhere? Surely it docked previously in wet/damp conditions? Would the effect have been visible? Or was it that there has never been any leak across the whole structure when docked in wet?
- WalterBright 5y ago
  The leak was a necessary component of the disaster.
Stratoscope 5y ago
There still are zeppelins! If you lived on the SF Peninsula or South Bay 10-15 years ago, you might have seen the Airship Ventures zeppelin flying low and slow over the area. Alas, Airship Ventures went out of business about ten years ago, due in part to the loss of a corporate sponsor and no luck getting a new one. I remember seeing 23 and Me on the zeppelin when it flew overhead. Ten years ago, a good friend treated me to a ride on one of their last local flights (this time the zepp was decorated with the Farmers Insurance logo). They still fly in Germany, though, so if you are ever in the Friedrichshafen area and can afford the somewhat pricey flight, do it! I promise you won't regret it; it was truly an experience of a lifetime. I posted a couple of comments here in the last year or two, so rather than repeat all the details and photo gallery, you can find them here: 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 p.s. These new Zeppelin NT airships do use helium!

chmaynard 5y ago

My compliments to the writer of this story, Emily Velasco. She clearly communicated the science and still managed to keep the reader (me) on the edge of my seat.

WalterBright 5y ago

> Imagine a cigar-shaped balloon as large as a skyscraper filled with explosive gas. Combine that hydrogen with oxygen from the air, and a source of ignition, and you have "literally a bomb," Giapis says. Imagine a tin cigar filled with explosive gas! Combine that with oxygen from the air, and a source of ignition, and kaboom! Today we call those "airliners". If people had continued to develop Zeppelins, the problems with safely handling hydrogen would have been solved, just like the problems with handling aviation gas and jet fuel have been solved. There's a lot of consideration with airliners about dealing with lightning strikes and all sorts of possible sources of sparks so the fuel is not ignited.

fastball 5y ago
Don't we have Helium anyway?
- timbit42 5y ago
  We don't have an unlimited supply.
- echelon 5y ago
  Helium is extremely limited and cannot be manufactured at any appreciable scale (you're not dealing with typical chemistry, but physics. Helium is an element.) What we have naturally comes from radioactive decay deep in the earth. This will continue for some time, but it's a fixed, slow rate. Helium evaporates into space. Once it's gone, it's gone for good. The other options we have are hydrogen (extremely reactive), heated oxygen (also reactive), methane (reactive), ammonia... It's a hard problem.
  - fastball 5y ago
    One more problem that will be solved by fusion energy!
  - fatsdomino001 5y ago
    We can theoretically do vacuum zeppelins, which is of course lighter than helium and unlimited tho it has its own problems too.

deleted 5y ago

[deleted]

jonny_eh 5y ago

I recall seeing a previous documentary where they found evidence that the paint on the exterior of the balloon was new, never used, and highly flammable. Perhaps that, combined with this latest capacitor theory, full explains what happened. Update: nvm, just found this: https://www.airships.net/hindenburg-paint https://www.airships.net/hindenburg-paint

emmelaich 5y ago
That article says it's not "rocket fuel", but everyone knows that Cellon dope is highly flammable. At least, those who used to make model aircraft with balsa wood and dope.

jonsen 5y ago

Relevant for the discussion here. ”Reinforced aerostat technology for safe hydrogen use in airships”: https://safeairship.com/ https://safeairship.com/

emmelaich 5y ago

I wonder whether the Cellon dope caught fire first. It's highly flammable and unstable. From another article, about a 1916 German bomber .. https://eandt.theiet.org/content/articles/2017/11/eccentric-engineer-the-painfully-visible-birth-of-the-world-s-first-invisible-bomber/ https://eandt.theiet.org/content/articles/2017/11/eccentric-... > First, Cellon, a type of cellulose acetate, was highly flammable, which, combined with the wooden fuselage, made the plane a tinderbox. Secondly, it wasn’t very strong or stable; in dry weather the material shrank, warping the wooden fuselage, while in damp weather it expanded and made the whole structure sag. This had a very unnerving effect in flight, as the control surfaces changed characteristics from moment to moment depending on humidity. Cellon also decayed in ultraviolet light, becoming yellowed, brittle and prone to explosive shattering.

dmix 5y ago
From another person's post: > The truth is that the dope used on the Hindenburg was specifically chosen for its low flammability, and the composition of the dope had almost nothing in common with the formula used to make rocket fuel. https://www.airships.net/hindenburg-paint/ https://www.airships.net/hindenburg-paint/
- emmelaich 5y ago
  It's relative compared to cellulose nitrate (ie. guncotton). Cellulose acetate has lower flammability but that isn't saying much. Have a look at the Pathé video of the Hindenburg disaster. The "skin" is clearly on fire.
schlupa 5y ago
Mythbuster dispelled that the coating paint could have been the cause of the disaster. https://en.wikipedia.org/wiki/MythBusters_(2007_season)#Hindenburg_Mystery https://en.wikipedia.org/wiki/MythBusters_(2007_season)#Hind...
- emmelaich 5y ago
  from that wikipedia page ... > they concluded the Hindenburg's demise could be attributed to both the hydrogen and the paint, which is what I'm suggesting.

deleted 5y ago

[deleted]

fernly 5y ago

Umm -- the Mythbusters explored the issue of the flammable skin in their usual style. Season 5, Episode 1, available here: https://www.dailymotion.com/video/x2ncm5i https://www.dailymotion.com/video/x2ncm5i The OP article pretty much takes the flammability of the doped skin for granted. The "distributed capacitor" theory certainly would account for the rapidity of the fire spread, with multiple ignition points.

anitil 5y ago

Along this theme, I highly recommend Bill Hammack's (The Engineer Guy) book "Fatal Flight - The True Story of Britain's Last Great Airship". It's also available as an audio book on youtube [0]. (I couldn't find it as an audio feed) [0] https://www.youtube.com/watch?v=97OnTDaLqqk&list=PL0INsTTU1k2Vh4m4jS9oVE7GFga7OLaBZ https://www.youtube.com/watch?v=97OnTDaLqqk&list=PL0INsTTU1k...

Johnythree 5y ago
Also see "Slide Rule: Autobiography of an Engineer" by Nevil Shute, who was the senior stress engineer of the British R100.. (beside being a famous author, eg "On the Beach", "A Town like Alice", etc)

dmix 5y ago

Premieres in 2 days, trailer of NOVA doc: https://www.pbs.org/wgbh/nova/video/hindenburg-the-new-evidence/ https://www.pbs.org/wgbh/nova/video/hindenburg-the-new-evide...

kristofferR 5y ago
Great documentary, I just watched it now (it was aired by SBS a month ago)!