[Spaceships 7] Homebrew: Expanding on Gasbags

[ericbsmith]

Originally Posted by ericthered

I'm fairly sure that if hydrogen had twice the lifting power of helium (as suggested by your numbers) we'd use it for gasbags more, flammable or not.

According to this website Helium weighs about twice as much as Hydrogen, however the important factor isn't their relative weights to each other but rather their relative weight to the Air, which primarily consists of Nitrogen and Oxygen. Due to impurities in both gases this the lifting power of Helium is between 88%-93% of the same volume of Hydrogen. This is why airships pretty much switched to Helium - you only get about 10% less lift, but the risk of flammability is drastically reduced and necessity to prevent all leaks means you can even save a little weight on materials.