[phreeza]

I don't get why none of these companies try to get ultrarich people to finance their development by selling "air yachts". Basically strap a luxury RV with big windows to the bottom of one of these airships.

Imagine the splash you could make at your friends yacht meeting when you float in from above. Watch emperor penguins migrate or elephants in the Okavango delta from the comfort of a couch.

What am I missing, why isn't this a thing?

[maxwell86]

Because it doesn’t work. You’d need a foot ball field of area, and a 3 story building, to life a small yacht like space.

The wind forces on the surface would be extreme, and you’d need a lot of power to even stay somewhere stationary instead of flying away. All of this would add weight, increasing the volume of helium needed, increasing the wind exposed surface area, making the problem worse.

You’d need a huge industrial hall to store it safely on the ground, and you can’t tie it with a rope anywhere.

The helium required to fill the balloon would make the operating costs of this thing absurd, cause it’s a lot of helium, that leaks all the time and have to be replenished, and helium is super expensive (and necessary for pricy things like cooling superconducting magnets applications, which have infinite budget).

Any 3rd year University student with basic knowledge of fluid mechanics, thermodynamics, and mechanic, can draft in a napkin why we already know that this can’t work.

I’ve sat in meetings where the VCs contracted me and others to do DD on these types of companies, where every contractor told them that this can’t physically work, and the VCs with too much money take that knowledge and translate it to “very high risk investment”. These companies got 100 million dollars and burnt through them, without nothing to show, but for the VC was more important to not have that money parked somewhere and be able to tell investors that they have “mobility companies” in their portfolio, which I think is borderline misleading / scamming because everyone knew that these companies “concepts” couldn’t physically move a thing, cause that was a physical impossibility with the tech that they wanted to use.

[Toutouxc]

I'm not sure I understand your point, are you saying that airships don't work? Because the Hindenburg was able to take 100+ people across the Atlantic (86 years ago!), that's much more than the maybe 10-person "luxury RV" that the OP was suggesting. Today's Zeppelin NT semi-rigid airships are reasonably small and can carry 10+ passengers on shorter flights.

Yes, airships are expensive, inconvenient and slow, they leak helium and they require huge hangars and mooring masts, but that's far cry from "can't work".

[masklinn]

> Yes, airships are expensive, inconvenient and slow, they leak helium and they require huge hangars and mooring masts, but that's far cry from "can't work".

"Can't work" is a pretty good effective compression of "work on the barest of technicality while being more expensive, slower, less flexible, and less reliable than pretty much all alternatives".

Also the Hindenburg was absolutely not able to take 100+ people across the atlantic, half of that was crew which you don't usually consider "taken over" as they have to fly back. So Hindenburg took 3 days to carry 72 passengers across the atlantic, needing 40 crew to do so, at a ticket price of $7460 (one way, in modern USD).

By comparison, bloody Concorde transported up to 128, with a crew of 3, in 3.5 hours, at lower prices.

[doikor]

> By comparison, bloody Concorde transported up to 128, with a crew of 3, in 3.5 hours, at lower prices.

Pretty sure the crew of Hindenburg included a whole bunch of waiters, cooks, etc. just like the Concorde had flight attendants on top of its flight crew of 3. Hindenburg was basically a small cruise ship in the air.

https://www.airships.net/hindenburg/interiors/ has some nice drawings/photos about the interior.

Basically traveling on it was more like a nice sleeper train with cabins and a good restaurant than a modern airplane.

[cycomanic]

What sort of comparison is that the concorde was flying from 1976, the Hindenburg disaster was in 1937. You say can't work is a good compression of not economically feasible and you come to the economically feasible by comparing 1937 tech/economics with 1976 one?

For comparison a commercial plane service didn't even exist for airfoil planes in 1937. So by your argument it was impossible to fly across the Atlantic (it wasn't actually, people had done it but your argument is uneconomical=impossible) , but nowhere close to bringing 100 passengers across.

[maxwell86]

> Because the Hindenburg was able to take 100+ people across the Atlantic (86 years ago!), that's much more than the maybe 10-person "luxury RV" that the OP was suggesting. Today's Zeppelin NT semi-rigid airships are reasonably small and can carry 10+ passengers on shorter flights.

You can also build a car with square wheels and cross north america in one.

> I'm not sure I understand your point, are you saying that airships don't work?

No, I'm saying that companies that try to sell airships don't work.

These companies are good at raising money, because the idea they sell is simple to explain, and many people don't do due diligence.

But in the same way that a car with square wheels is a worse solution to the problem, along pretty much any axis of comparison, than any of the alternatives available in the market, so are airships. With the difference that airships are also way more expensive than the solutions that are already in use.

This is why companies that build and try to sell them, default in 3-5 years after having raised the money.

---

The only types of airship that "works" are balloons able to cary 2-5 people. The weight is small, so the balloon surface is also small against the wind, the components required to drive them are simple and easy because the balloon is "small", and their use is purely occasional and recreational (or a tourist attraction where you can charge a bonus), so cost isn't a "huge" issue. People pay for the "fun", not to go from A to B.

[phreeza]

Why is it that small craft work but large craft don't, when two of the main problems you mention (leakage and wind shear attack surface) scale favourably with increased volume? Both should scale as 1/r per transported mass if my math is correct?

[maxwell86]

> Why is it that small craft work but large craft don't,

Because the goal of small craft is to go with the flow wherever the wind brings you, because that's fun.

The goal of commercial crafts is to go or transport stuff from A to B, independently of wind, and they are really bad at that.

[phreeza]

So you're saying a luxury air yacht could work after all?

[phreeza]

I don't know, I'm sure you are right that it's not practical as a mass market product. But just coupling together two Zeppelin NTs, they should be able to lift an average RV, so it doesn't seem impossible to me. And something like that should definitely be within the budget of an average billionaire?