Sky sailors

I'm glad we see so much of the airship in these three - It's such a cool design, and I'm reminded of Philip Reeve's airships in his Mortal Engines series. The music you linked in the first and second pieces is quite perfect for it too - I can hear how it influenced the drawing.

Though, it's implied there's a lighter-than-air gas in the balloon, such as helium - and there's clearly no elaborate hot-air set-up. Where'd they get that from? I'll assume natural helium-or-likewise vents.