This may sound like I’m being flippant, but I really would like to know…
If the Hindenburg had been allowed to use helium instead of hydrogen as its source of lift, would every passenger have sounded like Donald Duck?
I separate passengers and crew because the passengers were lodged within the hull, and the crew hung in the gondola beneath. While I realize that there were decks and partitions within the ship for passenger compartments, wouldn’t helium with its lighter than air poperties permeate those partitions?
I agree that the explosion wasn’t caused by the hydrogen (there have been numerous other articles and, I think, even TV programs about that), but I wonder whether helium would still have helped in the sense of reducing the speed of the fire and collapse so that more people could have survived?
No, this isn’t correct. Yes, helium is twice as dense as hydrogen, however lifting capacity depends on the difference in density between the lifting gas and the ambient air. As such, helium has roughly 92% of the lifting capacity of hydrogen.
You’re using molar density. But the molar volume of hydrogen is 11.42 ×10[sup]-6[/sup] m[sup]3[/sup]/mol, while that of helium is 21.0 ×10[sup]-6[/sup] m[sup]3[/sup]/mol, at STP. Run your calculations again using the density per unit volume.
You’ll also get the right answer if you use the right molecular weight for helium, which is 4. It’s twice as dense as hydrogen, not 4 times. Hydrogen comes in molecules of two atoms each, while helium is an inert gas, and a molecule is a single atom.
Agreed that the paint was the start of the fire, but the hydrogen was a huge source of combustible material. With helium instead of hydrogen, there would have been a lot less to burn.
Picture a fire in your house. now, picture a fire at a petrol station. See the difference?
</educated guess>
BTW, it didn’t actually explode, it burned rapidly.
Nope. The report I saw analyzed the spectrum from color film reels and noted the burn speed, and it burned faster than hydrogen, and was the long color. Why? Because the paint wasn’t just flammable, it was basically rocket fuel. It contained its own oxidizer, etc. Hydrogen gas can’t burn that fast because it doesn’t have its own oxidizer.
Really? That’s interesting, since all the “color” footage of the disaster is actually colorized black-and-white film. The colors were added later to match the descriptions of witnesses.
The flames were reported as red and yellow - hydrogen burns a nearly invisible blue even under ideal conditions, in daylight and at a distance it would have been invisible. So that’s significant data right there
To wander into the general vicinity of the OP again:
Obviously the passengers weren’t breathing large amounts of the lift gas, but in the event of, say, a leak–would hydrogen not have a similar effect on the voice? Disregarding any other side effects of breathing high concentrations of the stuff, of course.
I must have gotten that wrong then. The color must have been from still photos. The climax to the documentary was that they took some of the remaining fabric found at the accident scene and it still ignited very easily only a few years ago.