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Cargo airships could be big

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Re: Cargo airships could be big

#351

Post by tim333 »

vintermann wrote: post #83
rsynnott wrote: post #37

Earlier quoted context omitted.

Partially or completely wind-powered cargo ships appear to be on the way, so this might happen anyway.

Personally I'm pretty disappointed that hobby drones use so much power, when the seagulls just glide out there, not even flapping their wings for minutes on end. We should be able to manage the same with microcontrollers now, surely?

Radio controlled gliders are a thing but quite tricky to fly compared with a quadcopter. I built one in my 20s which worked very well until it hit a concrete pillar at about 50mph.

I sometimes wonder if you could put in a sophisticated processor that could do dynamic soaring like albatross and probably seagulls do. (https://en.wikipedia.org/wiki/Dynamic_soaring)

Then you could chuck it in the air and have it fly across the Pacific or some such. It would probably want a pop up propeller for take off also. It could maybe recharge the battery if it hit a good thermal. It's tricky though even for a good human pilot.

Here's a RC one with a fold back prop https://youtu.be/A1H0js2OqJo?t=521

Re: Cargo airships could be big

#352

Post by dspillett »

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…

> Helium would do just fine.

Though that creates another problem: there is a shortage of Helium developing that is starting to cause concerts in a few places (like medical imaging, which it is used as a coolant for devices like MRI scanners). That $8E6 might grow significantly not long after the first airships roll off the production line, and it'll raise for other users significantly too as available supply becomes more contested.

> There's actually no need for hydrogen.

The Hindenburg was originally designed with Helium in mind, but because of a US export ban (at the time Helium was in even shorter supply, and most of it was being produced from resources in the US) forced a redesign.

Unless new practical+affordable sources are found, the same sort of design limitations could strike again.

Re: Cargo airships could be big

#353

Post by sigmoid10 »

marcosdumay wrote: post #27
ansible wrote: post #20

Earlier quoted context omitted.

Venus also does not have a magnetic field: https://astrobiology.nasa.gov/news/in-search-of-an-ancient-g... So baseline humans would still want radiation protection.

It does have plenty of atmosphere, so radiation isn't a problem. (The problem is everything else, as usually is the case on space.)

Magnetic fields will only protect you from charged particle radiation anyway. EM radiation is a whole different story and needs a special atmospheric composition for e.g. hard UV to be filtered. Venus does have a small ozone layer, but it's 100 times less dense than earth's. So you'd get sunburn immediately if you walk outside without a full body protective suit.

Re: Cargo airships could be big

#354

Post by _hypx »

TylerE wrote: post #74
rootusrootus wrote: post #42

Earlier quoted context omitted.

There is a large dichotomy between the value of goods sent by plane vs ship, almost certainly due to the trade-off on speed. The intent with the airship idea seems to be to make something roughly similar in price and speed to trucking on land, but over the ocean. There is arguably a big chunk of cargo that would like to be in that middle area.

Why airships, a known failed technology, rather, than, say, a large hydrofoil/catamaran, tech that has been proving quite successful on long distance ferries for decades. The Hindenberg-class Zeppelins had the theoretical lift capacity of approximately... 8 40ft containers.

Note that airships gain capacity with the cube of the dimensions. So if you can imagine an airship twice as long, that number increases to 64 40 ft containers. Actually more, since less room is taken up by scaffolding and equipment.

Re: Cargo airships could be big

#355

Post by _hypx »

credit_guy wrote: post #159
rimunroe wrote: post #146

Earlier quoted context omitted.

> 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…

> It will have the same outgassing problems. It will not. The outgassing is proportional with the difference in partial pressure. On the outer foil the difference in partial pressure is 1 atmosphere (only helium inside, no helium outside). In time helium will leak out. Air will probably not leak in, by you can add it, to maintain equal pressure. The point is that you won't add a lot. Let's say that in one year 5% of…

Even once in the lifetime of the airship will be millions of dollars though.

Re: Cargo airships could be big

#356

Post by moring »

m0llusk wrote: post #307
hef19898 wrote: post #136

Earlier quoted context omitted.

No, the airship renaissance was over a decade ago. Cargolifter tried, and failed. From what I heard so, the water and holiday park they built in the ex Cargolifter hangars has to be quite good so.

They mostly had trouble with landings and takeoffs. Cargo ships could have specialized cranes load and unload cargo while airborne.

Could they use a circular lift that loads ballast at the same rate as they unload cargo, the way usually proposed for a space elevator? That would at least solve the ballast problem and lift problem (while still needing a solution to keep the airship in place horizontally AND needing tough materials for the lift).

Re: Cargo airships could be big

#357

Post by hef19898 »

moring wrote: post #356
m0llusk wrote: post #307

Earlier quoted context omitted.

They mostly had trouble with landings and takeoffs. Cargo ships could have specialized cranes load and unload cargo while airborne.

Could they use a circular lift that loads ballast at the same rate as they unload cargo, the way usually proposed for a space elevator? That would at least solve the ballast problem and lift problem (while still needing a solution to keep the airship in place horizontally AND needing tough materials for the lift).

Or one could stick with the existing transport solutions: sea, air, rivers, truck and rail. Those work just fine to get basically everything anywhere on the planet.

Re: Cargo airships could be big

#358

Post by perilunar »

mcv wrote: post #346
pr_nik2 wrote: post #338

Earlier quoted context omitted.

One thing they struggled with was ballast. If you plan on carrying 100+ metric tons, what do you do once you're done? Suck up the nearest lake maybe and dump it back at base when you load your next cargo? Now this restricts your use cases. Not that many lakes people wanna part with in Africa...

Can't you compress the helium and let in some normal air?

Yes: https://en.wikipedia.org/wiki/Ballonet

Re: Cargo airships could be big

#360

Post by berniedurfee »

badcppdev wrote: post #44

They have a very small section on wind and don't seem to have the word storm at all. Ships could be massive as well and far more fuel efficient if they didn't have to be engineered to weather storms.

That was my thought as well. Airships are hella slow, so they wouldn’t be able to go around a fast moving storm very easily.

I don’t imagine they’d do well in much of a storm, lightning being an issue I’d imagine.

It also appears they couldn’t gain enough altitude to ride above a storm.

I could be wrong, but it seems like encountering even a small storm would make for a bad day in a giant airship.

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