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Cargo airships could be big

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Re: Cargo airships could be big

#111

Post by rootusrootus »

nradov wrote: post #99
jodrellblank wrote: post #66

I'd like to draw your attention to " killing 35 of the 97 people on board in the inferno. " The Hindenburg had 7 million cubic feet of Hydrogen gas. It was the biggest aircraft disaster of its time. It had such rudimentary technology that the cockpit looked more like a sailing ship than an aircraft[1]. Despite that, well over half the passengers jumped out the windows[2], ran away and survived with few or no injuries…

I guess the last time was in 2013. Asiana Airlines Flight 214, a Boeing 777 jumbo jet, crashed at SFO with only 3 fatalities. Those are tough airplanes and low-speed crashes are often survivable if passengers can evacuate before the inevitable fire spreads. https://en.wikipedia.org/wiki/Asiana_Airlines_Flight_214?wpr... It was kind of freaky seeing the burned-out wreck sitting next to the runway when I flew out of SF…

I was going to say that the 777 isn't a jumbo, but it looks like they're now calling it a 'mini jumbo'. Feelings of inadequacy, I guess, compared to the 747.

Re: Cargo airships could be big

#112

Post by bobthepanda »

danbolt wrote: post #109
the_af wrote: post #76

Earlier quoted context omitted.

Sounds very interesting, could you share the title anyway? I once had an idea to write a collection of scifi stories with this premise, where every "seed" pod reaches a different planet and each society of clones evolves differently, providing a bunch of different stories related by a "framing" story.

I think it’s Mighty Kaiju Deimos .

That is a name of a piece of media in the game.

It's 13 Sentinels Aegis Rim. It is like 90% visual novel and 10% RTS.

Re: Cargo airships could be big

#113

Post by nradov »

jodrellblank wrote: post #94
SonicScrub wrote: post #56

Earlier quoted context omitted.

Direct weather control is the prerequisite technology for at scale operation of commercially viable airships. So once we crack that I'm sure we will see them!

We have very good weather prediction these days. After the Titanic sank and people argued about mandating lifeboats on ships, one of the arguments against was that global shipping had already settled into the least stormy most safe sea routes and accidents where lifeboats might help had reduced year on year because it was already in everyone's interests - cargo sellers, shipping industry, passengers, insurance indust…

We have very good weather prediction for tomorrow. For longer airship trips like spending a few days crossing the Pacific Ocean the exact tracks of storms are harder to predict, and dangerous squalls can brew up with little notice during certain seasons.

Re: Cargo airships could be big

#114

Post by evrimoztamur »

jodrellblank wrote: post #66

I'd like to draw your attention to " killing 35 of the 97 people on board in the inferno. " The Hindenburg had 7 million cubic feet of Hydrogen gas. It was the biggest aircraft disaster of its time. It had such rudimentary technology that the cockpit looked more like a sailing ship than an aircraft[1]. Despite that, well over half the passengers jumped out the windows[2], ran away and survived with few or no injuries…

Aircraft today are so safe because we had decades of improvements in both engineering and safety regulations. I am adamant that we could improve reliability and reduce potential damage in accidents so as long as we apply the same principles to airships.

Re: Cargo airships could be big

#115

Post by credit_guy »

Great analysis.

A few random thoughts

1. The dreaded helium leakage. It might not be a problem at all. Think of a party balloon of the foil type. It stays afloat for weeks. And it has positive pressure. A neutral pressure one would leak much less. But maybe not to zero. Ok, now use a double layer. Just like there are double hull submarines, this would be a double foil balloon. The distance between the outer foil and the inner foil would be only 1cm or so, so 99.9999% of the helium would be inside the inner foil. The gas between the two foils would in time become mixed with air, but the amount of double leakage would be negligible. The weight of the double foil would also be negligible compared to the overall weight of the structure.

2. Going up and down. Hindenburg had a cruising altitude of 200m. Up to 2000 meters or so, the air density goes down by about 1% every 100 meters. So, lowering a balloon from 200m to 0m does not mean you need to fully deflate it, only that you need to reduce its buoyancy by 2%, or add 2% ballast. For a 1100 ton airship, you need to add 22 tons of ballast. Pumping 22 tons of water 200 meters high is not easy feat. But there's a cute shortcut: you could send only 2.5 tons of hydrogen with a hose (hydrogen is more than happy to flow up), and you burn it there. The resulting water vapor needs to be condensed, but you can probably arrange that with a small refrigeration unit that you power with the electricity from a generator powered by the said hydrogen. The current cost of hydrogen is about $5 per kilogram, so this whole affair would cost you less than $15k. It's a rounding error when you ship 500 tons of cargo.

3. Fuel. Yes, it would be cool to have neutrally buoyant fuel, like a mix of methane and propane. But do you think the FAA would like that? How is that different from just having some hydrogen gas onboard, like, you know, Hindenburg? I think the most conservative design choice would be to just use plain old jet fuel.

Re: Cargo airships could be big

#116

Post by cityofdelusion »

Overtonwindow wrote: post #22

Airships have one, tremendous problem: Hydrogen. Helium is too expensive and is running out, and hydrogen, well see the Hindenburg. There's a lot of research into "safe hydrogen" but despite decades of research (and money) there has not been any success. Until you can overcome the fizzy lifting gas issue airships will remain a dream.

The article proposes autonomous unmanned cargo airships. Does the world care about "safe hydrogen" in this application? Most zeppelin disasters involved weather or mooring issues, not fire, and usually injured crew/passengers, not ground crew.

Re: Cargo airships could be big

#117

Post by kurthr »

credit_guy wrote: post #77
jodrellblank wrote: post #66

I'd like to draw your attention to " killing 35 of the 97 people on board in the inferno. " The Hindenburg had 7 million cubic feet of Hydrogen gas. It was the biggest aircraft disaster of its time. It had such rudimentary technology that the cockpit looked more like a sailing ship than an aircraft[1]. Despite that, well over half the passengers jumped out the windows[2], ran away and survived with few or no injuries…

There's actually no need for hydrogen. Helium would do just fine. From the blog post, filling the hypothetical airship with helium would cost $8 MM, while filling it with hydrogen would cost only $100k. Sounds like a no brainer. But, the overall cost of the airship would be at $100 MM. Hydrogen would result in a less than 10% cost reduction. Now, the FAA approved unleaded jet fuel in 2022. Yes, that's how conservativ…

So, if filling your gas tank cost 8% of the price of your car... you'ld think nothing of it? Lift gas leaks (esp He) and gets vented. So this seems odd to me. It's kinda like buying your car again every few months to a year or paying $250/gal to fill up. Now 80x lower at 0.1% of the car price you're in the regime where it's negligible like an EV.

Re: Cargo airships could be big

#118

Post by cameronh90 »

As the article says at the end, a key technology here is automation.

Lots of cargo isn't time sensitive, but paying a load of crew to take shifts sailing it slowly over the Pacific will kill the economic viability. Additionally, making it unmanned gets rid of a lot of the safety concerns, especially if you're going to use hydrogen and run them primarily over water.

Still, hard to see the advantages compared to container ships.

Re: Cargo airships could be big

#119

Post by LatteLazy »

bmelton wrote: post #24
LatteLazy wrote: post #9

Earlier quoted context omitted.

I don't think you can send perishable goods via a very slow and delay prone transport medium. More likely this can be used for the opposite sort of goods: durable, low urgency supplies.

They are only 'very slow' when compared to aircraft, which are kind of poor vehicles for transporting cargo in the first place. A dirigible flying with the jetstream is almost twice as fast as a cargo ship doing the same. I think they're impractical for lots and lots of other reasons, and your "delay-prone" critique is probably salient, but "slow" needs to be contextualized somewhat.

Twice as fast as a cargo ship is still only 50kph right?

And the Jet stream only goes one way and only West to East (in the northern hemisphere) and only at certain latitudes right?

So if you're only competing against cargo ships. And you happen to want to head East (only, no returns). And you need to go faster than a ship, but not over 100kph. And you are already at the right latitude and so it your destination. And you're cargo is not going to perish any time soon, and is not too dense, then this can work?

Re: Cargo airships could be big

#120

Post by triceratops »

jodrellblank wrote: post #90
credit_guy wrote: post #77

Earlier quoted context omitted.

There's actually no need for hydrogen. Helium would do just fine. From the blog post, filling the hypothetical airship with helium would cost $8 MM, while filling it with hydrogen would cost only $100k. Sounds like a no brainer. But, the overall cost of the airship would be at $100 MM. Hydrogen would result in a less than 10% cost reduction. Now, the FAA approved unleaded jet fuel in 2022. Yes, that's how conservativ…

Helium is a non-renewable resource drilled out of the ground, of which there is a global 'crisis' shortage[1]. Hydrogen is easy to make in vast quantities and cheaper. But more importantly, while they have similar lift capacities on paper (Helium ~90% of Hydrogen), in practice they don't - https://www.airships.net/helium-hydrogen-airships/ has an explanation and calculations. Hydrogen lift airships set off fully infl…

If fusion power takes off, could you produce helium as a by-product?
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