Curious Aardvark wrote on Apr 18
th, 2019 at 6:17am:
well if you ar going nuclear - hot air makes way more sense.
You could have a continuous flow through and use the cooling air as propulsion.
nuclear power plants can be made pretty small these days.
But I suspect it would be something like project Orion. People would object to having nuclear over their heads
Hot air has worse lift than either hydrogen or helium.
A nuclear airship could use heated-helium, though. This would have as much lift, if not more, than standard hydrogen.
The ship would have to be really big though, +300 meters long, 60 meters diameter. Rigid airships only start making sense at those sizes and beyond, to be honest. And nuclear starts making sense when airships become that big.
A big problem with regular airships is the burning of fuel, which lightens the ship. A nuclear airship would not be bothered by this, and could stay in the air for nearly a decade. Previous airships topped out at 130 km/h, a nuclear airship could/should reach 200 km/h and more.
It would be able to carry +500 people, and be quite spacious.
There would be no exhaust and much less noise pollution.
But yeah, two big problems here. Nuclear isn't going to get approved, and even though airships become much more economical at greater size, the opposite is the case for the hangars.