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Cargo airships could be big

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Re: Cargo airships could be big

#311

Post by topkai22 »

So many problems missing in the analysis:

- No analysis of last mile logistics. I am not a logistics expert, but I know enough to know that last mile logistics dominate costs. How does this setup improve the issues with the transfer of containers once they arrive in port? I can see some possible improvements by opening up more direct routes such that you can avoid rail transport and reduce truck line times, but then again most of the global population lives near the coast...

- The whole autonomous angle doesn't deal with the fact that modern cargo vessel area already highly automated. For the most part, the crews are there to maintain and deal with emergencies, not sail it. Would you really want your $100M investment to be wandering alone over the ocean with no one there to fix things if they go wrong?

- They massively underplay the safety issues. Yes, the vessel spends most of its time over open ocean, but its got to come into port somewhere, and last mile logistics are simpler the closer it is to population centers. Regulators will rightly demand lots of controls and compliance on half a kilometer long floating bomb.

Re: Cargo airships could be big

#313

Post by bruce511 »

avereveard wrote: post #213
bruce511 wrote: post #180

Earlier quoted context omitted.

It depends on the plane, but both your point and the parent point are correct. Piston engines run on high octane gasoline (Avgas) . This is the stuff that powered planes up to, and just past, ww2. Today it's still used in planes from that era, and some smaller general aviation planes. Jet fuel (jet a1) is basically paraffin. All turbine engines (think "jets", but also turbofan etc) run on this. It's a lot less flamma…

You can dump plane fuel before an emergency landing, making the whole process safer. it's not just double standards.

Yes and no, but mostly no.

Planes dump fuel to get below maximum landing weights. This typically happens when planes encounter an issue right after takeoff, and need to return to the airport.

There are two kinds of emergency landing - those that happen in a hurry, and those that happen slowly.

If it happens in a hurry there's no time to vent fuel. If it happens slowly fuel can be vented, but typically just enough to get below max landing weight. It's not like they "empty the tanks".

Re: Cargo airships could be big

#314

Post by bruce511 »

throwaway894345 wrote: post #217
bruce511 wrote: post #180

Earlier quoted context omitted.

It depends on the plane, but both your point and the parent point are correct. Piston engines run on high octane gasoline (Avgas) . This is the stuff that powered planes up to, and just past, ww2. Today it's still used in planes from that era, and some smaller general aviation planes. Jet fuel (jet a1) is basically paraffin. All turbine engines (think "jets", but also turbofan etc) run on this. It's a lot less flamma…

> Hydrogen is also dangerous, and there does appear to be a double standard here. I don't have beef with hydrogen, but I suspect it's a lot easier to secure fuel in a liquid state versus a gaseous state. Putting a lot of hydrogen in a relatively small steel container for use in an engine seems quite a lot safer than putting it in a big bubble and then dangling people from it. But I am not an aerospace engineer, could…

I too am not an aerospace engineer, but venting hydrogen after touch down seems easy enough. After all if you open the cells the gas just goes away.

By contrast a broken fuel tank leads to liquids spilling on the ground, which seems like fun.

That all said, liquids don't explode, gasses do. So if you were unlucky and the hydrogen exploded then life would get very exciting very quickly.

Re: Cargo airships could be big

#315

Post by entangledqubit »

smegger001 wrote: post #288
oofta-boofta wrote: post #274

Earlier quoted context omitted.

How much do you want to bet the employees working on this were apart of the anointed 12k that just got laid off

one does not lay of the team of a pet project of the confounder/board member with controlling interest in your company lightly.

Pet projects often get replaced with new pet projects...

Re: Cargo airships could be big

#316

Post by o_1 »

cogman10 wrote: post #272
lordnacho wrote: post #237

Earlier quoted context omitted.

I think the key is in the wikipedia article: You only gain 14% lift with a vacuum vs helium. The tradeoff is either: - Build a pressure vessel to withstand the differential to the atmosphere - Let the helium do the pushing from the inside but make the thing 14% bigger I don't see how the vacuum ever wins.

> I don't see how the vacuum ever wins. 3 ways. - Vacuums aren't combustible. - Vacuums can be created without sourcing a gas. - Vacuums allow you adjust buoyancy without requiring you to carry extra gases. The major downside of a vacuum is finding something ridged enough, light enough, and cheap enough to maintain a vacuum.

"vacuums aren't combustible" oh I love it idk what you did here, but the assumption of hydrogen still being used is awesome. reminds me of a great Archer episode.

Re: Cargo airships could be big

#318

Post by BurningFrog »

throwaway2037 wrote: post #293
hguant wrote: post #97

Earlier quoted context omitted.

I know some of the Canadian provincial governments were looking at using airships to provide a means of supplying some of the more remote northern towns - because of weather/terrain conditions, you can't build a rail head that far north, and the roads aren't reliable, so light cargo planes are the only reliable means of getting goods around. Airships, even of the good year variety, would be far cheaper for the weight…

You wrote: you can't build a rail head that far north The Trans-Siberian Rail can do it... but Canada cannot?

Beside the point, I know, but the Trans-Siberian goes through southern Siberia.

Re: Cargo airships could be big

#319

Post by worik »

jcranmer wrote: post #178
worik wrote: post #165

Earlier quoted context omitted.

An extreme example. One extraordinary event is not very good evidence. The safety record of the Zepplin company in Germany is very impressive They had many failures, no fatalities. Until the Hindenburg

The USS Akron, USS Shenandoah, and USS Macon all failed due to bad weather. That's 3 of the US's 4 operational airships. (Another airship was constructed for the US, but was destroyed by poor handling before it was delivered to the US.) Of the British experience with airships, R101 outright failed due to bad weather, and three more were scrapped after suffering accidents during bad weather, out of a total of 16 compl…

R101 failed because it was a dreadful design.

Re: Cargo airships could be big

#320

Post by worik »

jasamer wrote: post #181
worik wrote: post #151

Earlier quoted context omitted.

> why not fusion powered ships/trains/airplanes[?] What could possibly go wrong?

Afaik what makes fusion hard is maintaining the conditions that allow fusion to occur. Because of this, it’s quite safe - if anything goes wrong, it’ll just stop working.

Safe? Really?

I expect that the containment vessels will get very radioactive.

But all a bit hypothetical, since none exist

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