[HN Gopher] Cargo airships could be big
___________________________________________________________________
Cargo airships could be big
Author : Luc
Score : 243 points
Date : 2023-01-30 14:24 UTC (8 hours ago)
(HTM) web link (www.elidourado.com)
(TXT) w3m dump (www.elidourado.com)
| jp57 wrote:
| The airship renaissance is the fusion of transportation world.
| It's always ten years away. Seriously, I've been hearing about
| the great promise of modern airships for twenty years. Where are
| they? Are there any airships operating commercially now outside
| of niche applications?
| vintermann wrote:
| Of course it's niche applications, but it is the Zeppelin NTs
| which is the biggest success story. They're used for tourism in
| Germany and advertising in the US (the Goodyear Blimps, which
| as the article points out are no longer blimps at all, but much
| larger Zeppelins).
|
| Zeppelin Luftschiffstechnik have survived by being _very_
| careful about the scale of their ambitions (i.e, it's very
| modest). They did deliver the three ships in the Goodyear
| fleet, though, as far as I know completely on schedule, which
| is rare in any project of that scale, let alone an airship
| project.
|
| I still haven't written off Sergey Brin's project entirely,
| although it keeps getting delayed. Airlander I'm less
| optimistic about, but they did fly (and crash) their prototype
| and they're still around, so who knows.
| onlyrealcuzzo wrote:
| The Sergey Brin airship project is Lighter Than Air (LTA), in
| case any one was wondering.
|
| https://www.ft.com/content/ae625a25-d2ac-4bca-9508-a5f0d3c7d.
| ..
| SonicScrub wrote:
| 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!
| jodrellblank wrote:
| 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
| industry - to make that happen.
| nradov wrote:
| 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.
| innagadadavida wrote:
| If US, China and Taiwan situation escalates and US imposes a
| naval blockade, this can be used to effectively circumvent it.
| Perhaps China should invest in this.
| pphysch wrote:
| China has been investing in (non-sea) logistics routes for
| over a decade. It's called the Belt and Road Initiative
| (BRI).
|
| To be clear, developing sea routes is also an aspect of it.
| padobson wrote:
| Massive airships flying 90/km an hours are LESS susceptible
| to blockades than cargo ships? I think I'll need a little
| more explanation than that. Seems like a shoulder-mounted
| rocket launcher would be more than enough to bring one down.
| stopping wrote:
| Or a single tracer bullet, if it's filled with hydrogen.
| chatmasta wrote:
| Surely you could design some redundancy into the hull?
| It's not like the ship needs to be one giant gas bubble.
| It can be a mesh of a few hundred bubbles that could each
| pop without bringing the whole thing down.
| natpalmer1776 wrote:
| So... 100 tracer bullets instead?
| AlgorithmicTime wrote:
| [dead]
| LarryMullins wrote:
| Now you've got me wondering if composite frame airships could
| be made transparent to radar.
| hguant wrote:
| 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/volume
| transported, but initial costs were prohibitive, if I recall
| correctly
| mastax wrote:
| How do airships fare in bad weather?
| 0xffff2 wrote:
| Not very well. [0]
|
| [0]: https://en.wikipedia.org/wiki/USS_Akron
| worik wrote:
| 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
| jcranmer wrote:
| 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 completed.
|
| I don't feel like totting up the record of the Zeppelins,
| but the Wikipedia page does indicate that several of them
| failed due to weather incidents. One of the big lessons
| from the most notable airship failures is that airships
| _don 't really work in poor weather_, and safety in such
| conditions means "don't even attempt to fly," which is a
| pretty different rule than the one for airplanes or other
| modes of transportation.
| lesuorac wrote:
| I mean if the alternative transports also don't work in
| bad weather I'm not sure you can use some failures to
| disqualify airships.
|
| So long as they work "more" days of the year it's a
| better solution. Weather doesn't really sneak up on us
| anymore.
| hef19898 wrote:
| 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.
| jodrellblank wrote:
| 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.
|
| When was the last time a jumbo jet crash landed with complete
| loss of the aircraft and all the combustible stuff burning it
| into a molten metal heap, and half the passengers simply jumped
| out and escaped? In terms of risk, fatality, and compared to
| aircraft of the day, it was surprisingly good. And the huge
| raging fire and prominent news footage of it being caught on
| camera did it a bit of a disservice. By comparison, look at
| Wikipedia's list of worst aircraft crashes[3], and see how many
| are marked 'no survivors'. What if some of those "flew into a
| mountain", "engines failed", "mid-air-collision" had been
| captured on video in the earlier days of aviation, would we still
| have widespread planes?
|
| [1] https://www.boredpanda.com/blog/wp-
| content/uploads/2019/02/i...
|
| [2] https://www.boredpanda.com/blog/wp-
| content/uploads/2019/02/i...
|
| [3]
| https://en.wikipedia.org/wiki/List_of_deadliest_aircraft_acc...
|
| (NB. people now want aircraft which can legally be pushed
| horizontally by hydrogen, but cannot legally be pushed upwards by
| hydrogen.)
| [deleted]
| Jean-Philipe wrote:
| I completely agree. In addition to that, the Nazis neglected a
| lot security measures that this aircraft actually had in place.
| There's a nice episode of "well there's your problem" on the
| Hindenburg: https://www.youtube.com/watch?v=chlF5oubFHU
| LarryMullins wrote:
| Everybody always focuses on the Hindenburg, but it's not as
| though helium airships were much safer. In some scenarios they
| were _marginally_ safer, but the deadliest airship disaster of
| them all was the USS Akron, a helium airship. 73 dead and 3
| survivors, vs the Hindenburg 's 36 dead and 62 survivors.
|
| As for marginally safer: There were some cases of helium
| airships breaking up due to weather and people surviving the
| ride to the ground on still somewhat buoyant sections of the
| destroyed airship, whereas that was less likely with hydrogen
| airships because the wrecks would also burn. Compare the crash
| of the USS Shenandoah to the British R101; both were destroyed
| by bad weather but R101 had far fewer survivors because the
| wreck burned. But even with helium, airships are still very
| fragile and dangerous. Using helium isn't truly a panacea to
| the hazards of airships.
| jodrellblank wrote:
| Even with the Akron, we're focusing on the first disaster and
| not on the improvements or possible improvements since then.
|
| Akron crashed into the Atlantic in April. " _Most casualties
| had been caused by drowning and hypothermia, since the crew
| had not been issued life jackets, and there had not been time
| to deploy the single life raft._ "
|
| Followed by: " _Macon and other airships received life
| jackets to avert a repetition of this tragedy. When Macon was
| damaged in a storm in 1935 and subsequently sank after
| landing in the sea, 70 of the 72 crew were saved._ "
|
| The R101 was a stupid tragedy - they designed and built it,
| then extended it, then launched the first flight without
| sufficient testing to learn how the extension had gone and
| how it handled after, in poor weather conditions, because the
| launch date had been decided by politicians as a piece of
| propaganda about reaching the far corners of the British
| Empire by airship.
| LarryMullins wrote:
| > _Followed by: "Macon and other airships received life
| jackets to avert a repetition of this tragedy. When Macon
| was damaged in a storm in 1935 and subsequently sank after
| landing in the sea, 70 of the 72 crew were saved."_
|
| Yeah, but notably they hadn't solved the problem of wind
| tearing airships apart.
|
| In the case of Macon they landed gently and in warm water,
| and lifejackets certainly helped. But a soft landing is by
| no means a guarantee in any airship crash, and even with
| most people surviving the Navy still lost their investment
| in the airship because of some wind. Putting lifejackets on
| an airship flying over water should be common sense, but it
| only makes the airship marginally safer. It's hard for
| airships to be viable when they're so prone to tearing
| apart and falling out of the sky.
| BolexNOLA wrote:
| I think his point is that most of these are measurable,
| concrete problems that can be solved or mitigated enough
| to be considered "safe," in the same way airplanes have
| all sorts of risks and issues we solved or mitigated to
| make them safer than the cars many use every day.
| LarryMullins wrote:
| The way I see it, aircraft have become mechanically
| reliable and airships could become mechanically reliable
| too. But airships will always be structurally vulnerable
| relative to aircraft. They're inherently very light with
| very large surface areas and there's no way around this.
| snovv_crash wrote:
| The strength to weight ratio of a carbon fibre
| scaffolding would be far superior to steel.
| bboygravity wrote:
| Isn't the clothy stuff the problem though rather than the
| scaffolding?
|
| Same on most sailboats: what makes them get into trouble
| is not the hull cracking but rather the sail tearing up
| in a storm or the mast snapping off and making them
| uncontrollable / sink.
|
| (Im guessing out loud here, statements probably wrong)
| aintgonnatakeit wrote:
| If the clothy bits tear on a sailboat it's an
| inconvenience. When the hard bits (eg keel) fail, it's a
| problem.
| zztop44 wrote:
| Mast snapping happens. Rudder snapping off is also bad.
| Often the issue is running into rocks/a reef due to a
| navigation failure. Sails do tear, but for sailboats I
| don't think it's as simple as the clothy bits being the
| main weak point. I don't know about airships though.
| worik wrote:
| > But even with helium, airships are still very fragile and
| dangerous.
|
| True. But with high speed landing and takeoff aeroplanes are
| extremely dangerous too.
|
| Thousands of gallons of high octane fuell in the tanks on
| board does not help
| criddell wrote:
| > high octane fuel
|
| Doesn't jet fuel have a relatively low octane rating
| compared to most liquid fuels?
| impossiblefork wrote:
| Yes, but this octane-fire mixing is a bunch of confusion
| to begin with.
|
| Gasoline is less ready to ignite than diesel~=jet fuel,
| but has fumes.
|
| Diesel~=jet fuel has little fumes, but is easier to
| ignite by heat, i.e. in an engine, but it will almost
| never be ignited outside of an engine. Meanwhile,
| gasoline is hard to ignite with heat and pressure in an
| engine, but easier to ignite in air than diesel.
|
| Octane also has a higher boiling point than for example
| heptane, so higher octane fuel is probably not related to
| easy of ignition due to the fumes either.
| LarryMullins wrote:
| Yes, but I think he's using it in the colloquial sense
| that means "highly energetic".
| bruce511 wrote:
| 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 flammable than Avgas, but, well,
| still makes a big bang if you fly it into a mountain.
|
| In short both are dangerous because they are high-density
| liquid energy. Hydrogen is also dangerous, and there does
| appear to be a double standard here.
| throwaway894345 wrote:
| > 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
| be wrong, etc.
| avereveard wrote:
| You can dump plane fuel before an emergency landing,
| making the whole process safer. it's not just double
| standards.
| credit_guy wrote:
| 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 conservative FAA is. We'll sooner achieve world peace than
| the FAA would approve hydrogen for airships.
| kurthr wrote:
| 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.
| LarryMullins wrote:
| > _Lift gas leaks (esp He)_
|
| Hydrogen more than helium, I believe.
| kurthr wrote:
| Each Hydrogen molecule is more reactive, but actually a
| larger molecule (less leaky) because there are two (it's
| diatomic H2 rather than monoatomic He).
|
| Now it does get complicated, because the simple atomic
| radii aren't sufficient when you start bouncing around
| and leaking through other materials, but suffice it to
| say that He is still smaller once you look at the Vander
| Walls attraction and everything. It may only be 10%
| smaller, but that leads to at least a 20% lower leak
| rate.
|
| https://bbblimp.com/2021/09/17/helium-vs-hydrogen-atom-
| size/
| TylerE wrote:
| Lift gas is a consumable. You have to vent it to descend in
| many cases, and that's ignoring the inevitable leaks and
| diffusion.
| worik wrote:
| > Lift gas is a consumable. You have to vent it to descend
| in many cases, and that's ignoring the inevitable leaks and
| diffusion
|
| Helium blimps compression the gas to lower buoyancy
| tiagod wrote:
| Preventing the helium from leaking out of wherever its stored
| is challenging, it's not a "fill once and forget about it"
| kind of deal. Helium is bound to get more expensive too.
| jodrellblank wrote:
| 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 inflated and vent
| Hydrogen along the way for control of altitude and to stop
| their lift cells expanding too much as they rise into lower
| pressure air; Helium is too expensive to vent casually, so
| they have to start less inflated to protect the lift cells,
| and other concerns so Helium lift ends up with half the
| payload carrying capacity, less fuel, shorter flight
| distances.
|
| And, nb. the deadliest airship disaster was the USS Akron
| which was was a Helium lift airship which crashed in a storm
| with 73 deaths and 3 survivors. It's not as simple as
| Hydrogen = danger, Helium = safe.
|
| [1] https://www.forbes.com/sites/omerawan/2022/11/10/the-
| helium-...
| pkulak wrote:
| I wonder if you could use a fuel cell to get power from the
| hydrogen you'd otherwise vent.
| triceratops wrote:
| If fusion power takes off, could you produce helium as a
| by-product?
| jerf wrote:
| Basically, no: https://www.jerf.org/iri/post/2922/
|
| And that assumes perfect capture, too.
|
| If you're going that route it'd probably be better to
| just use hot air with the energy.
| jasamer wrote:
| Probably, but the amount would be tiny. ITER is trying to
| generate 500 megawatt from a half-gram of hydrogen.
| mpwoz wrote:
| There's a fusion startup called Helion near Seattle
| working on this, it'll be really exciting if it pans out
| at scale.
|
| This video was a fascinating watch:
| https://www.youtube.com/watch?v=_bDXXWQxK38
| aae42 wrote:
| if we figured out fusion, it would alter the economics of
| all of this
|
| why not fusion powered ships/trains/airplanes
| worik wrote:
| > why not fusion powered ships/trains/airplanes[?]
|
| What could possibly go wrong?
| jasamer wrote:
| 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.
| chrisco255 wrote:
| We already have fission powered ships and submarines.
| jodrellblank wrote:
| We almost had fission powered airplanes and airships:
| https://en.wikipedia.org/wiki/Nuclear-powered_aircraft
|
| and https://en.wikipedia.org/wiki/Lockheed_CL-1201
|
| And dreams of fission trains:
| https://twsmedia.co.uk/2020/05/09/atomic-trains/
| moffkalast wrote:
| Yeah hydrogen sounds like it could even be safer given that
| you get a larger buoyancy buffer to fight downdrafts? It's
| a real public misconception that it just explodes from all
| those oxyhydrogen experiments at chemistry class, but pure
| hydrogen such as in airships just slowly burns, much like
| any other fuel we fill our planes with.
|
| The main problem is still that you need to contain a large
| volume, which will inevitably get pushed around by wind
| more than you can compensate for.
| mikepurvis wrote:
| As a noble gas, helium can't be synthesized, so its cost is
| because of its scarcity-- and because it's a small molecule
| (like hydrogen), you inevitably lose some and require
| continuous top-ups.
|
| None of this sounds like it would be realistic at scale, no
| matter the amount of money in play.
| BeefySwain wrote:
| You may have overlooked the part where filling the quantity
| of airships that would (theoretically) be used would
| represent over half of the KNOWN quantity exploitable on
| earth, and would take decades to produce at current
| production rates. Also, they would need topped up over time.
| Compared to hydrogen, which is cheap, available, and
| renewable.
| credit_guy wrote:
| > KNOWN quantity exploitable on earth
|
| It's great that you emphasized "known".
|
| Knowledge is not a static thing. Also what's economically
| exploitable is a variable thing.
|
| Currently, the US produces 40% of the world's helium,
| despite producing only 25% of the world's natural gas. Is
| it because the US has drawn a lucky lottery ticket for
| helium?
|
| That's very unlikely. Helium is being produced continuously
| inside Earth as the alpha particles generated during the
| radioactive decay of some elements (mainly Uranium and
| Thorium, but Radon too). It seeps upward, and it generally
| escapes in the atmosphere, but some of it gets trapped in
| the same geological formations that trap natural gas.
|
| In most places people don't bother to see how much helium
| there is in natural gas. They just sell the gas and take
| the money. Separating helium can increase the profitability
| a bit, but it depends on how cheaply you can do the
| separation. It's very likely that the US has better
| technology than the rest of the world, and because of that
| it separates more helium for the same quantity of natural
| gas.
|
| As the technology will spread out, more helium will become
| recoverable.
|
| Also, it may come as a tautology, but more helium is
| economically recoverable if its price goes up.
| dwighttk wrote:
| Author mentioned a market for 25K of these airships, which is
| like half the helium on earth the _first time_ you fill them
| up. $8M will go up once you start building
| kortilla wrote:
| The FAA approved modifications to piston engines to use
| unleaded avgas. Jet fuel doesn't have lead.
|
| Also, this isn't about the FAA just being slow for no reason.
| Switching from leaded to unleaded without the engine
| modifications was not safe for the piston aircraft that need
| it.
|
| https://en.wikipedia.org/wiki/Jet_fuel
|
| https://en.wikipedia.org/wiki/Avgas
| coryrc wrote:
| It's not safe for us to be breathing. But that doesn't
| matter to cheapskate rich private plane owners or their
| regulatory-captured FAA.
| kortilla wrote:
| Nothing is stopping the EPA from banning it regardless of
| what the FAA wants. The FAA doesn't regulate emissions.
| LarryMullins wrote:
| The really rich private plane owners all have planes that
| burn jet fuel, which is always unleaded. The piston
| planes are generally owned by "doctor rich" upper-middle
| class people, who have political influence to be sure but
| they're hardly the billionaires that might be known by
| name to politicians.
|
| I think it's more likely that the FAA protects general
| aviation because general aviation is part of the
| professional pilot training pipeline.
| coryrc wrote:
| [flagged]
| LarryMullins wrote:
| > _Ah, if you 're only "doctor rich" then it's okay to
| poison children!_
|
| That's not what I said _and you know it._
|
| > _GA is responsible for 50% of lead emissions!_
|
| Little lead is emitted at all these days, because leaded
| gasoline was banned in _almost_ all circumstances. So you
| 're talking about 50% of "not much". I'd be happy to see
| it banned completely since there are now viable
| alternatives, but I think you're going a little bit too
| hard with this class war narrative.
| Johnny555 wrote:
| The people that are below "doctor rich" just rent their
| planes from the FBO, a cheap piston plane can rent for
| $125-$175/hour. So you can get in a couple hours of
| flying for what it costs a couple to go to a football
| game.
| mabbo wrote:
| > What if some of those "flew into a mountain", "engines
| failed", "mid-air-collision" had been captured on video
|
| I'm now picturing how each of these situations would look with
| airships.
|
| Most of them, in my mind, make a very nice "Boink" sound.
| andrewflnr wrote:
| My guess is the relevant sound is _rrrrrrip_.
| flavius29663 wrote:
| airships have multiple cells though, a single rip wouldn't
| doom the entire thing
| LarryMullins wrote:
| But what caused the airship to rip? If it was wind, then
| you now have that same destructive wind ripping through
| the inside of your airship through the hole.
| andrewflnr wrote:
| I mean, I was specifically talking about the collision
| scenario...
| mikepurvis wrote:
| Even still though, you'd come down to the ground for a
| soft-ish landing (relative to a jet or helicopter, anyway).
| evrimoztamur wrote:
| 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.
| LarryMullins wrote:
| Aircraft survive because they're mechanically reliable, and
| airships could also be made mechanically reliable. But
| aircraft also survive because they're reasonably robust in
| adverse environmental conditions. Airships aren't and never
| will be, because they have to be built very large and very
| light or they don't work at all. Furthermore airships are
| slower and harder to hanger, which makes it even harder for
| airships to avoid bad weather. Better weather forecasting
| could help some, but keeping airships out of storms really is
| of the utmost importance.
| hedora wrote:
| People often forget that the metallic paint used to coat the
| Hindenberg is now used as solid state jet fuel.
| nradov wrote:
| 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 SFO a few days later.
| rootusrootus wrote:
| 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.
| VBprogrammer wrote:
| Meh, terms like this are pointless. Completely arbitrary
| where you put them.
|
| It's probably more sensible to use terms like wide body,
| implying 2 aisles.
| hackerlight wrote:
| You have to multiply by the respective probabilities of both of
| these things happening to arrive at the expected number of
| deaths. 0.01*(35/97) would be significantly bigger than
| 0.000001*(97/97), as a hypothetical example.
|
| That said, planes have had years of safety R&D which helps get
| that number down to 0.000001, and maybe the same could have
| been done with blimps if they were given the opportunity?
| holyknight wrote:
| damn, this concept is mind boggling
| guruz wrote:
| Germany's cargo airship project is now an indoor waterpark
| located in Brandenburg (close to Berlin)
|
| https://en.wikipedia.org/wiki/Tropical_Islands_Resort
|
| (With rising energy costs, hopefully it can stay like this for a
| while)
| vintermann wrote:
| One of Germany's cargo airship projects. I'm pretty sure there
| have been more, but none got as far as Cargolifter (for cargo.
| For more modest ambitions, the Zeppelin NTs out of Bodensee are
| still going strong, 25 years on).
| aeyes wrote:
| Their argument is that it is less polluting because people
| don't have to fly to have a tropical vacation. It seems to
| work, they are constantly expanding.
|
| I went last December, the place was packed. Surprisingly I'd
| say about 40% of the guests were foreigners. It's nice but I
| don't know if I'd want to stay a whole week.
| aidenn0 wrote:
| Seems like Germans like to turn anything into a water
| attraction (e.g. Kiesgruben)...
| newaccount2021 wrote:
| [dead]
| cameronh90 wrote:
| 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.
| waynenilsen wrote:
| It seems about 2x faster plus overland capabilities should be
| great for some use cases that currently depend on canals.
| ChuckMcM wrote:
| Zeppelin is still around : https://zeppelinflug.de/de/
|
| (or more accurately it restarted)
| sitkack wrote:
| The article completely omits trains. That is glaring.
|
| I had this steampunk like plan when I was in college to have huge
| hydrogen cargo airships pulled by trains to haul large bulk items
| (fully assembled houses, building parts, large trees, fully
| assembled combines, etc). A literal skytrain.
|
| Some new lines would have to be created a way to handle going
| through tunnels etc. I think now I would have a drone be able to
| connect and unconnect the tether and the airship would be able to
| be autonomous for period of time and reconnect. Or a small track
| could be run just to connect the small tug needed to pull the
| airship.
| the_cat_kittles wrote:
| this is kind of like the old idea of a tow-path. those work by
| floating the cargo on the river and pulling it with horses next
| to the river. I really like the idea of pulling cargo floating
| in air with trains, since trains already exist, and its also
| visually entertaining. im curious what the numbers would look
| like, since trains are very efficient for each marginal mile i
| think? also im not sure what you would do about a wind storm
| haha.
| MagicMoonlight wrote:
| Trains can't cross oceans or cover long distances or
| dynamically change routes
| genderwhy wrote:
| Trains can't cover long distances? Surely that's a typo --
| trains can cover incredible distances...
|
| And they can change routes within their network. So yes,
| there's some cost to get train stations and tracks built, but
| afterwards they can visit anywhere within the network and
| carry a whole lot more than airships.
|
| Fair point on the oceans thing though.
| carapace wrote:
| I've been slowly and sporadically working towards making large
| airships. Basically you make a large (like a square kilometer or
| more) rigid kite (see Alex G. Bell's cellular kites) and add
| enough drone guts to make it into a giant drone. Then you lodge
| an Airstream trailer or something in it.
|
| I'm not an engineer, but the small models I've built make me
| think that there's no effective upper limit on the size of these
| structures. I think you could build a kite that girdled the
| world, an arch with no pillars.
|
| I've got all the parts now for a first prototype, but I don't
| have any room to build it, so I'm studying origami etc. to design
| a folding version. It's a PITA but the designs are pretty: like a
| blooming flower, (like
| https://www.jpl.nasa.gov/edu/learn/project/space-origami-mak... )
| Someone wrote:
| > Basically you make a large (like a square kilometer or more)
| rigid kite (see Alex G. Bell's cellular kites)
|
| Those were incredible
| (https://www.scientificamerican.com/article/alexander-
| graham-...), but it would surprise me if you could scale them
| up to a kilometer in size.
|
| Also, from that article:
|
| _"Aggregated rectangles increased kite weight faster than they
| expanded wing surface area. Tetrahedrons kept the ratio nearly
| constant."_
|
| That _nearly_ makes me think that, even if you wouldn't need
| stronger beams for huge kites, a huge number of kites connected
| to each other would provide less lifting weight than the sum of
| the lifting weights of the individual kites.
|
| > I think you could build a kite that girdled the world, an
| arch with no pillars [...] but I don't have any room to build
| it.
|
| Doesn't surprise me ;-)
| carapace wrote:
| > but it would surprise me if you could scale them up to a
| kilometer in size.
|
| It's like the intuitive argument that heavier objects fall at
| the same rate as lighter objects: throw two shoes off the
| roof, if you tie their shoelaces together will they fall
| faster? You start with N kites and connect them, each kite
| retains its airworthiness and connecting them doesn't change
| that.
|
| > nearly [constant]
|
| The ratio falls off much slower than lifts add as you get
| bigger.
|
| > you wouldn't need stronger beams for huge kites
|
| I don't think so, because you're just connecting small kites
| together, but you need to be flexible, or maybe modulate the
| airfoils' area (maybe open/close like butterfly wings.)
|
| > a huge number of kites connected to each other would
| provide less lifting weight than the sum of the lifting
| weights of the individual kites.
|
| If you just make a ball or cube, sure, but that's optional,
| eh? Most of my designs come out looking like modified 3D
| Sierpinski gaskets.
| Someone wrote:
| > You start with N kites and connect them, each kite
| retains its airworthiness and connecting them doesn't
| change that.
|
| If you do that, you have N wires between the kites and the
| ground.
|
| Keeping them untangled may be a problem. Your best bet
| probably is tying them together and having only one thicker
| wire towards the ground.
|
| Making sure each of those wires takes 1/Nth of the load
| from the wind definitely will be a problem, even in a
| perfectly stable uniform wind. If you can't guarantee that,
| you'll have to make the wires a bit stronger than for the
| individual kites.
|
| If you think "we won't need 1 wire for each small kite",
| you'll need to make the connections between the kites
| stronger. To see why, think of the similar problem of a
| plank over a ditch. If a 1m plank over a 80cm ditch just
| holds your weight, do you think a similar 25m plank over a
| 20m ditch will hold you, standing in the center of the
| plank? Do you think it will hold 25 persons along its
| length?
| xg15 wrote:
| Ok, so I love his enthusiasm, but when someone proposes a
| hydrogen/propane/ethane mixture as lifting gas and support struts
| made of magnesium, I'd like a few more details on how to deal
| with the problem of everything bursting into flames than "we'll
| deal with the risk and do some clever engineering" :)
| jacknews wrote:
| There's no doubt they'll be big, but will they be practical,
| economically viable and successful?
| qikInNdOutReply wrote:
| they could automate overseas transport of (e.g. fruit and other
| time-critical) cargo, with no pilots and very much reduced
| fligth costs, while being much faster then ships. Then off the
| coast its remote take-over and steering towards the freight
| air-port of destination.
|
| The critical part here is good enough automation to keep the
| thing on track and prevent accidents, while not trying to
| integrate it into the airways like a traditional plane.
|
| They might even over time grow into a "2nd class - slow - but
| cheaper transport" for people in no hurry, but with limited
| funds.
|
| PS: It failed before though..
| https://en.wikipedia.org/wiki/CargoLifter investors beware..
| nradov wrote:
| It is highly unlikely that uncrewed cargo aircraft will be
| allowed to operate in most US airspace any time soon. They
| can't reliably see and avoid other aircraft operating under
| VFR, and so are restricted to only limited designated
| airspace.
|
| Airships are unable to cruise at high altitude due to loss of
| lift, and are vulnerable to damage from severe weather. For
| ocean routes it's not always possible to route around storms.
|
| People keep wanting cargo airships to be a thing for some
| reason. It's not likely to happen. The costs are too high and
| the range of potential applications too limited to produce a
| real industry. At most we might see some limited military use
| where cost is less of a factor.
| mupuff1234 wrote:
| Are remote crews an option?
| nradov wrote:
| Not an option under current FAA rules. The available
| optical sensors are still generally inferior to human
| eyes in terms of dynamic range, depth perception, and
| slew rate. The US military does fly remote-piloted
| aircraft (Predators being the most prominent example) but
| they're only allowed to operate in limited pieces of
| designated airspace due to the risk of midair collisions.
|
| Communications reliability and latency is a problem. We
| still have no way to guarantee solid bidirectional comms.
| The mishap rate for RPVs is much higher than for
| comparable manned aircraft.
| actionfromafar wrote:
| If/when forecasts will be good enough to only dispatch and
| route airships when they can be safely flown to either
| destination or safe harbor, is the wildcard I could imagine
| to make them viable options. But as you say, is the niche
| large enough to make work?
|
| I think the pull for wanting them isn't so strange - they
| offer the promise of much lower fuel costs, which is a big
| stigma and problem of current aircraft.
| nradov wrote:
| The atmosphere is a chaotic system. How could forecasts
| be improved enough to enable safe flights across the
| Pacific Ocean during storm season?
|
| Concerns over fuel costs seem a bit silly as those are
| only a fraction of air cargo costs. There are significant
| fuel efficiency improvements already in the development
| pipeline with lighter composite structures, higher aspect
| ratio wings, open rotor turbine engines, and perhaps even
| blended wing-body fuselages.
| LatteLazy wrote:
| 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.
| bmelton wrote:
| 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.
| LatteLazy wrote:
| 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?
| bmelton wrote:
| You're exactly right, but perhaps missed that the trade
| route you're describing is China to Los Angeles, which
| alone accounts for $132 billion in trade every year, and
| perhaps that cargo vessels allegedly account for 20-25%
| of anthropomorphic carbon emissions.
|
| Also probably worth pointing out that airships going
| _against_ the jetstream are still faster than cargo ships
| which are also going against sea currents.
|
| I'll repeat my disclaimer again here, that "I think
| they're impractical for lots and lots of other reasons"
| but there is a definite benefit to cutting the carbon
| emissions of the world's most popular trade route by 90%
| and halving the time spent in transit even if you assume
| that there are no other applications, which is probably
| not correct.
| hengheng wrote:
| I'm not comfortable relying on these being crewless, I've
| seen too many mobility projects die. When freight trains and
| trucks can operate crewed, a cargo airship will have no
| different rules to profitability.
| traceroute66 wrote:
| > There's no doubt they'll be big, but will they be practical,
| economically viable and successful?
|
| Frankly no.
|
| Its like every few years people remember about airships and
| suddenly start shouting how its the answer to the world's
| problems.
|
| I mean, just search here on HN... 11 years ago there was
| "Blimpocracy - Is the airship the transportation system of the
| future?"[1] .... now here we are 11 years later, and, well,
| yeah ...
|
| The trouble is that the present system already works well.
|
| If it's not urgent, you can put tons of it on a massive ship.
| That ship can make multiple stops along the way.
|
| If it's urgent, you can put it on a plane. Modern airfreight is
| reasonably efficient and not _that_ expensive.
|
| I really don't see what airships all bring to the party. Except
| perhaps being a slow-moving target for miscreants and bringing
| high-profile failures in newspaper headlines.
|
| As for the people who say combine AI + airships ... yeah, like
| that's going to seriously happen any time soon. AI can't even
| do FSD in a Tesla properly yet. Putting AI in an airship, in
| today's complex busy airspace, add in real-life weather
| conditions and real-life technical issues ... yeah, erm, thanks
| but no thanks.
|
| [1]https://news.ycombinator.com/item?id=3000819
| jodrellblank wrote:
| > " _I really don 't see what airships all bring to the
| party_"
|
| Heavy lift. Put hundreds of tons of house(s) from a house
| factory or skyscraper level(s) from a skyscraper factory on
| them, airlift them to the building site around the country.
|
| Centralise most of the building work in one efficient scaled
| up factory, deliver an enormous buildings quickly piece by
| piece by air instead of slowly by having all the parts driven
| around windy roads and through closed city streets and
| assembled by a crews of people travelling to the building
| site and home every day.
| djtango wrote:
| What about places with limited rail/roads like Alaska and
| Kazakhstan?
| ghaff wrote:
| As I recall, about 1/3 of the population of Alaska is in
| the vicinity of Anchorage which has a port and is connected
| to Fairbanks by road. Juneau, the third largest city, is
| also on the water--as are other cities in Southeast Alaska.
| Many other cities--such as they are (the 4th largest city
| in Alaska has a population of 20,000)--are also on the
| ocean.
| jcranmer wrote:
| In general, where there's limited infrastructure, there's
| limited _demand_ for infrastructure.
|
| I can't speak for Kazakhstan, but most of rural Alaska is
| adequately serviced using tiny Cessna-sized aircraft for
| shipping, and the parts that aren't (say, Prudhoe Bay)
| already have existing ground and/or marine infrastructure
| to supply them.
| traceroute66 wrote:
| > What about places with limited rail/roads like Alaska and
| Kazakhstan?
|
| What about them ?
|
| If there's no cargo facility there already, then nobody's
| going to suddenly turn up and build an airshipport (or
| whatever you want to call it).
|
| The way modern day logistics works is like an inverse
| pyramid, you fly/ship/train in bulk somewhere, and then you
| go smaller and smaller scale to the remote/rural areas ...
| right down to a man on a bicycle or whatever.
|
| Cargo airships, _IF_ they ever happen, are not going to
| change the fundamental way modern logistics works. Basic
| economies of supply and demand. Sending the man on the
| bicycle will always be the cheapest and most sensible
| option for remote areas where only a handful of people
| live, especially if they live many miles from each other
| (e.g. rural farming).
| [deleted]
| fiat_fandango wrote:
| Iranian missile boats are going to have a field day with these...
| Overtonwindow wrote:
| 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.
| actionfromafar wrote:
| Your not trying very hard to shift what's acceptable to talk
| about. :-)
| cityofdelusion wrote:
| 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.
| oblak wrote:
| CAPTAIN: All aboard for safety and adventure on the rigid airship
| Excelsior, where the pampered luxury of a cruise ship meets the
| smoothness of modern air travel. Yes, when you fly Excelsior,
| you're flying in style and safety.
|
| TIMMY: Safety? But isn't hydrogen flammable?
|
| CAPTAIN: And how, Timmy. That's why Excelsior is filled with
| safe, natural helium. Why, it's actually flame-retardant.
|
| TIMMY: Neat!
|
| CAPTAIN: And safe. So, whether you're enjoying excelsior's
| majestic vistas, duty-free shopping, high-stakes baccarat,
| dancing with your lovely wife, or even a cigar after a french
| gourmet dinner, you'll be enjoying them in style and safety. All
| aboard Excelsior!
| rob74 wrote:
| > _Second, some modes are missing because a lot of countries are
| not connected by land. Looking at US import and export data, and
| excluding Canada and Mexico where US roads, rail, and pipelines
| connect, water transportation has claimed the majority of both
| the tonnage and the value._
|
| Er... what? Just because you can't ship stuff between _some_
| countries by land, they 're ignoring _all_ cargo shipped by rail
| and truck internationally? Sounds like throwing the baby out with
| the bathwater...
| twelve40 wrote:
| he says throughout the post that the main focus is
| intercontinental cargo market
| btilly wrote:
| It is fun to read the analysis.
|
| But they are right that we don't have the ability to make enough
| helium to make that make sense. I can believe that hydrogen can
| be made to work. But when they got to making the frame out of
| magnesium - a leak in the rain would be scary!
|
| This is one of those ideas that seems better in theory than
| practice. Not as bad as the fact that adding mercury to rocket
| fuel makes it go better. But still not a great thing to do.
|
| For those who are puzzled at the mercury comment, energy is
| proportional to mv^2/2 while momentum is mv. Mercury takes away a
| bit from the energy, but increases the density, and therefore
| gives you more momentum per unit of fuel. It is a great theory,
| ruined by the fact that we'd be spraying nasty poisons
| everywhere.
| greesil wrote:
| I don't understand this. LH2/LOX typically burns on the rich
| side to increase exhaust velocity. This means more momentum for
| less mass, which is what you want from a rocket. This is the
| opposite.
| black6 wrote:
| John Clark goes into detail in his book Ignition! about why
| smaller, lighter exhaust molecules are much better than
| larger and heavier ones.
| btilly wrote:
| John Clark also was the one who proposed adding mercury. It
| was a joke, that the military types didn't realize was a
| joke.
|
| Read https://library.sciencemadness.org/library/books/ignit
| ion.pd... pages 193-196 in the PDF for the full story.
| sitkack wrote:
| One has to be really really careful when cracking these
| kinds of jokes, one really has to weigh the downside of
| it being taken seriously.
|
| I'll still do it, on an ephemeral medium, and then spoil
| it seconds later. That is only way it can be delivered.
| andrewflnr wrote:
| The suggestion to use a magnesium frame, in combination with
| hydrogen for lift, is kind of hysterical. Why _not_ use a
| flammable metal with your flammable lifting gas? I won 't even be
| shocked if it works, but it would still be a hell of a thing.
| jillesvangurp wrote:
| You need oxygen to get to the flammable material to burn it.
| For magnesium that means grinding it to a fine powder that
| burns really quick. Otherwise, it will just oxidize at the
| surface and be quite boring and inert. It's a common metal used
| for all sorts of engineering. E.g. German WWII era planes used
| some magnesium parts.
|
| Iron also burns if you grind it to a fine powder. You can try
| that out if you have some steel wool. It's just an exothermic
| oxydation process. The more surface area the hotter it burns.
| Magnesium just burns a bit hotter. Most of the colors in
| fireworks are just different metal powders burning.
|
| And for hydrogen, you need to mix it with oxygen to get a
| flammable mixture. So, a large mass of hydrogen is explosive in
| the same sense that a few tonnes of kerosene is explosive. I.e.
| not that much at all. Also, hydrogen is light. If you have a
| leak you go down, and the hydrogen goes up very rapidly. It
| doesn't stick around.
|
| They did this routinely in the 1930s. It wasn't much of an
| issue then. The theories of what happened to the hindenburg
| vary a bit but it seems as it didn't explode so much as burn.
| Probably most of the hydrogen escaped before it could burn.
|
| https://en.wikipedia.org/wiki/Hindenburg_disaster
|
| Interesting read. Quite a few people actually survived. I'm
| sure these things could be engineered to a much higher safety
| standard now.
| ambientlight wrote:
| Great book on this topic:
| https://www.cambridge.org/tv/academic/subjects/engineering/a...
| billbrown wrote:
| Great essay. How he failed to mention Hybrid Air Vehicles
| Airlander is beyond me, though.
|
| https://www.hybridairvehicles.com/
| hnarn wrote:
| If something doesn't exist, especially when it's something that
| has existed in the past but no longer does, there's usually a
| good reason for it. It's not a natural law, but it's a good rule
| of thumb to use to initially question and defend a
| "groundbreaking" idea.
|
| A quick search online tells me that ocean freight is about
| $1.3/lbs and air freight is about $5.3/lbs. Since we already know
| that "airships" would likely never be more convenient than
| existing air cargo, their only way of succeeding is if they found
| a place between 1.3-5.3 where the cost savings felt motivated to
| sacrifice regular air freight, while being many orders of
| magnitude better than ocean freight for that use case.
|
| Even if we're nice and call this a "new" technology rather than
| what it actually is -- a tried and failed technology -- this
| "new" technology needs to be many times better than existing
| options either for cost or convenience (preferably both) to
| offset the major penalty you will have initially due to the lack
| of existing infrastructure; and we're not just talking about
| airports and runways, we're talking about the entire network of
| optimizations in logistics, maintenance and everything else that
| have occurred during a century of practice.
|
| I'm just a guy with an opinion, but I very much doubt cargo
| airships even have a small chance of being "big", unless someone
| builds something absolutely groundbreaking that leapfrogs
| existing air cargo solutions entirely -- for example in areas
| like fuel efficiency, autonomy, or something else.
|
| Nothing is impossible, but if I was a very technical and
| entrepreneurial person, this isn't where I would put my time.
| bruce511 wrote:
| I am also sceptical that airships will ever be big.
|
| They do have advantages over ocean freight (not everyone lives
| near a major sea port, or any sea port.) I'm not sure if your
| price includes road transport, or rail, depending on where you
| are. Sea is obviously a Lao quite slow.
|
| Air freight is expensive, and also somewhat limited airports.
| In some parts of the world there are lots of those, but most
| freight travels to a major centre, then trucks etc.
|
| I see airships as more of a "trucking" compeditor.
| Theoretically it can load and unload with minimal ground
| infrastructure. And it can go places trucks can't go.
|
| Yet with all of that the killer problem (literally) seems to be
| weather. It's hard to see how that problem is reliably solved.
| dathinab wrote:
| Starupable?
|
| TL;DR: Technical viable but I think it doesn't bring enough
| benefits in enough situations to be a success in most areas of
| the world.
|
| Yes, but uh risky.
|
| Close to where I live are old end/post WW2 above ground large
| aircraft hangars you can buy/rent etc.
|
| So there had been airship startups, multiple times.
|
| I'm not sure if a single of them is still around.
|
| The main problem isn't a stable hull, or non explosive gas
| anymore.
|
| AFIK:
|
| The main problem is that there are nearly always much much more
| convenient solutions.
|
| Like they only make sense (due to economics,convenience) for
| transporting things which don't fit easily on the road, e.g. huge
| thing. Which also tend to be heavy so the airship need to be
| huge.
|
| But airships are sensitive to wind and the bigger the more wind
| can get a grip on them.
|
| And only being able to use them at top (wind) wetter conditions
| where plains, trains and cars can go even with pretty bad wetter
| is a major problem.
|
| Another use-case could be areas where cars can't go, but airships
| can e.g. huge swamps, areas with a lot of folding, but likely not
| mountain sides where there is no street be you need to transport
| things, too. But how common is that and how many of that cases
| could also be fulfilled with other "special" but more convenient
| to use transports like larger drones.
| legitster wrote:
| > What we observe under these conditions is that, domestically,
| most of both the tonnage and value of cargo is transported via
| truck. Trucks are neither the fastest nor the cheapest mode of
| transport, but they provide a great value proposition--you get
| your stuff in a few days for much cheaper than air freight.
|
| I feel like this is a bit naive. The true competitor to trucking
| is rail. But trucking is preferred because it's point-to-point
| and you don't have to deal with intermodal connections. Airships
| _would have these exact same problems_ (unless you invented some
| way to build routes and drop off containers at specific addresses
| - but then you are back to it being slow again!).
|
| So the only real market would be replacing container ships with
| something slightly more expensive but faster. But even using his
| own math - a fleet of 25,000 airships each with only a 500 ton
| capacity, and each being twice as big as the biggest airplane
| ever built - seems like a nightmare. All to only capture half of
| the global shipping market!
| 4wsn wrote:
| I concede I might be totally wrong here, but the issue with
| rail seems to be profitability.
|
| I live in (moved to) Europe, and the railways are far more
| developed than in the US. But as far as I know, they all have
| to be heavily subsidized by the governments to even function.
| None of them operate with a true profit. Here in Germany, 2.2%
| of the latest federal budget is to support the railways. This
| is despite the railways being privatized (into a government
| owned corporation).
|
| And while trucking is also subsidized to an extent, and it's a
| difficult business, but people do successfully operate trucking
| companies.
|
| Airships might have the same problems as rail does with
| intermodal connections, but it's worth a try to see how the
| profitability equation works out (in real life, not MBA-land).
|
| _Maybe_ it's feasible for large multinationals to run direct
| routes between their warehouses, with trucks being used for
| last-mile delivery. The only cost is operation; in comparison
| with rail where the infrastructure is a constant sink, and in
| comparison with trucks where the infrastructure cost is
| outsourced to society.
| nradov wrote:
| You have it backwards. Cargo railways are more developed in
| the US than in most of Europe. After the latest round of
| industry consolidation, most rail companies are highly
| profitable.
|
| Trucks pay most of infrastructure costs through fuel taxes
| and registration fees.
| 4wsn wrote:
| Fair enough. I conceded I might be totally wrong because my
| conclusion is based on casual observation of passenger
| trains and their infrastructure rather than looking into
| the industry.
|
| I could feasibly reach all cities and _most_ large towns by
| rail in Germany. Sure, it's slow as heck if you're not
| taking the express train with no transfers and few stops.
| But the infrastructure is there. Whereas in the US there
| are massive areas where the nearest train connection is
| hours away.
|
| I assume there are factors with freight trains I don't know
| anything about, and if they're as profitable as you say
| then the infrastructure is actually very optimized for
| profitability; if there's somewhere worth reaching, the
| trains reach it.
| nwatson wrote:
| Not mentioned in the article at all: security.
|
| Unmanned airships over water at low altitude, and pirates with
| drones.
| theelfismike wrote:
| agreed, a huge, slow-moving target for a bad actor to try to
| shoot down
| padobson wrote:
| This. It was all I could think about while reading the piece.
| The US Navy is capable of making the seas safe, but under
| current political conditions I don't even see THAT happening
| forever.
|
| To make this work, the air force would almost certainly have to
| get in on the act, and that makes even less geopolitical sense.
| badcppdev wrote:
| 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.
| thworp wrote:
| This is a nice theoretical summary, but it's missing an analysis
| on why previous attempts at cargo airships failed (see
| https://www.airship-association.org/cms/node/214 ).
| elidourado wrote:
| Did you read the whole thing? There's an entire section at the
| end that talks about what current players are doing wrong,
| while raising the question of whether even the suggested
| approach is fundable.
| thworp wrote:
| That section is very short and very general when compared to
| the rest of the very detailed analysis. I know a tiny bit
| about the failure of cargolifter and their problem wasn't
| just funding and market fit. They also had a big list of
| technical issues, not least with making the damn thing at
| least somewhat all-weather (still nothing compared to jet
| planes).
| dbrueck wrote:
| Probably a very stupid question, but can someone help me
| understand the following: once you have airships that have a
| rigid shell, why isn't using a vacuum better than a lifting gas?
| Isn't the buoyant force simply the result of displacing some
| volume of air with something less dense? (i.e. any excess lifting
| force comes from the fact that the mass of the hydrogen or
| whatever is less than the mass of the displaced air)
|
| A vacuum (or near vacuum) would provide more lifting force per
| liter, would not have the scarcity problem of helium nor the
| safety problem of hydrogen, and assuming the thing that generates
| the vacuum is transportable, it'd eliminate the need for separate
| ballast.
|
| Edit: the wikipedia article cited by slibhb has all sorts of good
| info - thank you for sharing that!
| cdot2 wrote:
| I suspect that the materials and engineering required to
| maintain a vaccum would be so much heavier than the engineering
| required to hold hydrogen that it would literally outweight the
| benefit.
| lordnacho wrote:
| 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.
| slibhb wrote:
| That's a fascinating idea. I googled it and came upon
| https://en.wikipedia.org/wiki/Vacuum_airship and https://schola
| rsbank.uoregon.edu/xmlui/handle/1794/22370#:~:....
|
| Sounds like it's feasible but a materials/engineering
| challenge.
| WorldMaker wrote:
| One interesting modern wrinkle versus hydrogen is the idea of
| using an H2 fuel cell for easy access to electricity (versus
| lift) without needing to carry another electricity source.
| lucideer wrote:
| Wild wild speculation: I'd imagine "rigidity" is a trade-off
| between weight and ability to withstand the given pressure
| differential for any two gases (outside & inside). A vacuum
| would undoubtedly give extra buoyancy but the additional weight
| required to achieve rigidity might not make the trade off
| worthwhile.
| vel0city wrote:
| I'd imagine its because its one thing to make a basic rigid
| shell (able to hold its own weight without collapsing) and
| another thing to make a giant pressure vessel able to withstand
| immense pressures. Imagine a storage tank made out of glued
| together popsicle sticks with a plastic bag around it versus a
| CO2 cylinder. One is going to weigh quite a bit more than the
| other, all because one is trying to fight some massive pressure
| differentials while the other can accept near ambient pressures
| on both sides.
| oliveshell wrote:
| I looked into this a while back, and there's simply no feasible
| way to construct an airship from known materials that could
| sustain a vacuum of the necessary volume without being crushed
| by atmospheric pressure.
|
| You can keep reinforcing the vacuum chamber, but by the time
| it's strong enough, it'll be too heavy for the buoyant forces
| to lift it.
| brunoqc wrote:
| Crashes would be spectacular too...
| dwighttk wrote:
| I started skimming towards the end but does the author get into
| how the speeds are airspeeds, not ground speeds?
| killjoywashere wrote:
| His fundamental assumptions are flawed to the point of hilarity.
| The same physical laws apply to ships, but they are at an
| interface with a fluid with a much higher specific gravity
| (orders of magnitude higher), so you can pack enormous amounts of
| cargo on a ship. Once you have to solve the last mile, you need a
| truck anyway. For the in-between, trains work great.
|
| Why, why would this make any economic sense?
| SmooL wrote:
| As the article states, the idea is that this would be faster
| than ships, as well as operational in areas without large
| bodies of water.
| tim333 wrote:
| I remember in the UK Airship Industries tried to make the things
| work economically for ages but never did.
| https://en.wikipedia.org/wiki/Airship_Industries
|
| For one thing they struggle a bit when it's windy.
| netsharc wrote:
| It'd be fascinating if the package tracker of the future says
| "package delayed, waiting for a north-easterly wind from Los
| Angeles. Meanwhile those mangoes from Africa are arriving
| sooner!"
| rsynnott wrote:
| Partially or completely wind-powered cargo ships appear to be
| on the way, so this might happen anyway.
| vintermann wrote:
| 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?
| TillE wrote:
| Birds are extremely light. Hollow bones, etc.
| nradov wrote:
| We've been able to manage the same even without
| microcontrollers. Radio controlled model gliders and
| sailplanes have been popular among hobbyists for decades.
| I see them flying at a local park all the time.
| onion2k wrote:
| _For one thing they struggle a bit when it 's windy._
|
| If you could move your airship to an altitude where the wind is
| going in the direction you want to go that would give you a
| huge advantage.
| nradov wrote:
| Airship cargo capacity is inversely proportional to ambient
| air pressure. As they climb they lose lift, and while it is
| technically possible to build an airship that can fly above
| the weather the cargo capacity would be so low as to make it
| pointless.
| [deleted]
| jliptzin wrote:
| Is there any discussion about personal airships? I wouldn't mind
| the slow speed if it meant I could go to sleep in a quiet, bump
| free, spacious craft and wake up a couple hundreds miles away at
| my destination (weather permitting, of course).
| af3d wrote:
| Imagine our supply chains being dependent upon fleets of
| zeppelins. Sheesh...
| recursive wrote:
| They'd pretty much have to be.
| comfypotato wrote:
| I wonder why they didn't mention simply sailing with the wind
| almost entirely. My understanding is that at certain altitudes
| there are winds that circle the earth (the jet stream, yes?). If
| the ships are completely autonomous, this could take a sector of
| the market where shipping speed doesn't matter. It's a different
| value proposition than discussed, but if I'm reading the
| surrounding literature correctly, it's winds that have been the
| main problem with this approach in the past.
| rootusrootus wrote:
| They did. It's a long article, they don't get to that point for
| a while. Search the page for "The other approach would be to
| take a deliberate strategy of riding the winds."
| haarts wrote:
| From the article I understand that airship can only fly so high
| (I think because of the density of the air decreasing when you
| go higher). A jet stream (10km+) is far too high for an airship
| to reach (1.5km).
| thrill wrote:
| An airship can be designed to fly to over 100,000 ft, so you
| could design anywhere in between. Above 60,000 feet the
| average wind speed drops to 20 knots or so.
| twelve40 wrote:
| I didn't understand the jump from:
|
| > International water transportation is also cheaper than
| domestic, perhaps around 1C/ per ton-km
|
| to:
|
| > Let's say airships captured half of the 13 trillion ton-km
| currently served by container ships at a price of 10C/ per ton-km
|
| Having half of the entire market switch to something that is 10x
| more expensive?
| rootusrootus wrote:
| 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.
| [deleted]
| TylerE wrote:
| 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.
| mike-the-mikado wrote:
| Electric cars were failed technology for about a hundred
| years. But with better battery technology, combined with a
| need to reduce carbon dioxide emissions, they are the
| future.
|
| If something can only work effectively at huge scale, there
| are likely to be a number of enabling technologies needed
| to get there.
| nradov wrote:
| Y Combinator portfolio company Boundary Layer Technologies
| tried to build a hydrofoil cargo ship to target the market
| niche that wants to go faster than a regular cargo ship but
| doesn't need aircraft speeds. The basic technology probably
| would have worked but I'm skeptical whether the market
| really exists.
|
| https://techcrunch.com/2022/06/01/boundary-layer/
| splitrocket wrote:
| This, my friends, is why we should colonize the upper atmosphere
| of Venus, where you could chill outside with only a respirator,
| rather than the inhospitable, irradiated, mangnetosphere free
| mars.
|
| https://en.wikipedia.org/wiki/High_Altitude_Venus_Operationa...
| https://spectrum.ieee.org/nasa-study-proposes-airships-cloud...
| blamestross wrote:
| Hang on tight for those gentle 185 mph breezes...
| wefarrell wrote:
| Only a problem if you're anchored to the surface. Otherwise
| it's the changes in windspeed that you have to watch out for.
| actionfromafar wrote:
| A respirator and a teflon suit to keep the sulfuric acid clouds
| away from your skin?
| lkjdsklf wrote:
| sure teflon might not be the most comfortable, but think of
| the speed we could get on a slip n' slide
| meindnoch wrote:
| And what are we going to do there? Mine sulphuric acid from the
| clouds?
| haarts wrote:
| Enjoy the view obviously. Cruise!
| hutzlibu wrote:
| In case that wasn't sarcarsm - you won't see much, as you
| would be inside the acid clouds.
| andbberger wrote:
| what are we going to do from mars
| ben_w wrote:
| Everywhere but Earth is really inhospitable, but if it were
| up to me, I'd pick the Moon first, then Mars, then some
| asteroids, then _way_ down the list -- after we 've got
| space industry sufficient to make planet-sized mirrors --
| _then_ I 'd pick the planet where the surface-level
| condensation is lead vapour in an acid pressure cooker.
| hutzlibu wrote:
| The one big thing that Venus has, and every other option
| does not - is earthlike gravity. That is a big deal, so I
| am all for exploring options of terraforming Venus to
| remove that acid somehow, because despite as Space
| enthusiastic as I am - living inside hot acid clouds is
| also not my dream.
| kspacewalk2 wrote:
| Okay, asteroids presumably make economic sense due to
| mining potential, but otherwise - why the hate for Venus?
| What's so special about being on the surface of a planet?
| Just don't go to where the lead vapour is, enjoy the
| cloudy view from 50km above the surface instead.
| ben_w wrote:
| Might be a monkey brain, but the mere possibility of
| falling 50km through crushing boiling acid is the kind of
| thing that'll stop me getting to sleep. More so than a
| deadly vacuum on the other side of a wall.
| kfarr wrote:
| Yeah but iirc because of atmospheric density it's not
| crazy to build a floating habitat. At least no crazier
| then the tech required to get a crew and equipment to
| Venus in the first place
| elihu wrote:
| Tourism, mining high value minerals for Earth, mining low
| value minerals for construction on Mars, manufacturing
| rocket fuel so that Mars can be the gas station for ships
| headed for the asteroid belt (enabling more high value
| mineral mining), low-gravity retirement communities for
| people with mobility issues who would be wheelchair-bound
| on Earth, real estate speculation, movies, sports,
| manufacturing space infrastructure (easier to launch things
| into orbit due to lower gravity), and basic science.
| einpoklum wrote:
| If I were living on Mars, I would absolutely not be
| willing to let the rare minerals get sent up into space
| then down to Earth. Learn to recycle, damn lazy Earthers.
| gridspy wrote:
| I think you'd appreciate the complex manufactured items
| and goods requiring plastics that only Earth can export
| to you. If tons of mined materials or produced goods
| thereof were the cost, you would be keen to pay it.
| unsupp0rted wrote:
| Build a second basket for our eggs. There are obviously
| better baskets than Venus though. I'd sooner choose an
| orbital habitat.
| LarryMullins wrote:
| Tie things to string and dip them into the acid clouds.
| Upload the results to youtube for profit.
| [deleted]
| ansible wrote:
| 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.
| actionfromafar wrote:
| TFA said the planet has a solar wind induced magnetosphere,
| as well as is partially protected by the Sun from cosmic
| rays.
| marcosdumay wrote:
| It does have plenty of atmosphere, so radiation isn't a
| problem. (The problem is everything else, as usually is the
| case on space.)
| twawaaay wrote:
| Venus has plenty of atmosphere above the surface, but not
| above the point where there is 1 ATM of pressure.
|
| In case of Earth most of protection comes from our magnetic
| field. The reason is that magnetic field sweeps ALL charged
| particles coming from the sun while atmosphere only stops
| some.
|
| When a particle drops into atmosphere it has a chance to
| collide with an air molecule, the deeper the higher the
| chance. But there is always some number of particles that
| were fortunate enough to reach far enough. Whereas magnetic
| field is constantly acting on every charged particle and
| deflects every single one of them.
|
| Only very highly energetic particles can cross magnetic
| field and these tend to come from outside our solar system
| and are very low in numbers.
|
| One thing we rely on atmosphere to take care is UV
| radiation which is photons which is not charged which means
| our magnetic field does nothing to it. Up to some energies
| UV is easily caught even by very thing protective layers
| (for example sunscreen!). It is not like you are going to
| be showing skin on Venus anyway -- you are going to be
| always enclosed with material that can stop UV, so this is
| not an issue. Over certain energies we land in X-ray
| territory and here our solutions are pretty limited but I
| do not see a reason why Venerian atmosphere at 1atm should
| be any more transparent to X-ray than ours.
| marcosdumay wrote:
| It has about as much atmosphere above the point where the
| pressure is 1ATM as we have on Earth. And no, we don't
| know if Earth's magnetosphere ever filters most of the
| incoming radiation (we don't such good measurement of the
| incoming radiation), what we know is that at sea-level,
| our atmosphere alone is enough.
|
| AFAIK, every time we measure it better, the effectiveness
| of our magnetosphere decreases. But it can only stop
| charged particles anyway, and air is very good at
| stopping those.
| foobarian wrote:
| There is also probably a range of viable pressures so
| going down to multiple ATM would still work and provide
| more shielding.
| Retric wrote:
| 1 ATM of air is the same amount of material as 33 feet of
| water which provides a great deal of protection from
| charged particles. I doubt enough charged particles can
| penetrate to the surface that it's a meaningful issue.
|
| I've seen many books etc suggest the earths magnetic
| field is required, but I haven't found direct evidence
| for it doing anything beyond protecting the ozone layer.
| schiffern wrote:
| >1 ATM of air is the same amount of material as 33 feet
| of water which provides a great deal of protection
|
| "Amount of material" isn't what's relevant. It's closer
| to "number of atomic nuclei."
|
| A certain mass of air is less shielding then the same
| mass of water. By number density, air is mostly nitrogen
| atoms, whereas water is mostly hydrogen atoms. Overall
| this means that per kilogram, water contains 2.4x as many
| atomic nuclei as air.
|
| --
|
| Of course there are bigger problems with Venus cloud
| cities. At the 50 km height where the pressure is 1
| atmosphere, the temperature is 75 degC (167 degF). At the
| 55 km altitude where the temperature is 27 degC (81
| degF), the pressure is 0.5 atmospheres.[0]
|
| As a bonus, both these altitudes lie deep within the
| layer of sulfuric acid clouds (50-80 km).
|
| [0] https://en.wikipedia.org/wiki/Atmosphere_of_Venus
| Retric wrote:
| Don't stop there. Charged particles in the solar wind is
| mostly alpha and Beta particles. 33feet / 2.5 should stop
| what 99.9999% ish of them?
|
| https://sciencedemonstrations.fas.harvard.edu/presentatio
| ns/...
|
| Absorbing materials and their alpha particle penetration
| depths.
|
| 5.5 MeV alphas: AIR(STP) 3.7 cm
|
| 2.3 MeV Beta: air 8.8 m
|
| Solar wind is even less energetic.
|
| Edit: "Auroral emissions typically occur at altitudes of
| about 100 km (60 miles); however, they may occur anywhere
| between 80 and 250 km (about 50 to 155 miles) above
| Earth's surface." it really doesn't take much atmosphere
| to stop it.
| schiffern wrote:
| Maybe true, but irrelevant.
|
| The problem is that charged particles from the Sun (SEPs)
| aren't what determine the design envelope for radiation
| shielding. Your overall dose will almost entirely come
| from galactic cosmic radiation (GCR) at much higher
| energy levels, which are correspondently much harder to
| shield against.
|
| _Those_ particles are what ultimately determine your
| shielding thickness. That 's true whether you're on
| Venus, or Mars, or a space colony.
| [deleted]
| echelon wrote:
| I've always felt people with these ideas are doing pie in the
| sky thinking and missing the other trends that would beat this
| concept out.
|
| Humans aren't suited for these environments. We evolved to fit
| this planet. These gasses, radiation levels, terrestrial foods,
| etc.
|
| The economics of going to Mars, Venus, etc. are iffy, and
| humans probably won't enjoy being there. It's McMurdo times
| about 1000. Getting back is hard.
|
| It's probably another hundred years before this is plausible
| with our technology and willpower.
|
| You know what will do great in these environments? Robots that
| don't have biological weakness. That don't need cellular
| respiration or biochemical inputs.
|
| We'll probably have gotten really far with robotics and AGI in
| those same 100 years.
|
| Basically, space will be inherited by our successors.
| Artificial intelligences. Humans just aren't fit for these
| environments. Robots and AIs are perfectly adaptable, though.
|
| Sci-fi sold us a fanciful picture of humans in space, because
| that's a fiction that is pertinent to our experience and is
| relatable. That isn't guaranteed.
| kbenson wrote:
| As long as the AI we create treat us with the love and
| respect we treat our pets with, we'll colonize everywhere,
| even if they have to clone us on site.
|
| Oh, the breeds we'll see... or be.
| blamestross wrote:
| If we go anywhere it will be spun-up asteroids. O'Neill
| cylinders make more sense for a living platform than even
| earth does. Once we actually have orbital infrastructure,
| Planets are a horribly unsafe high-cost-of-travel backwater
| to live on.
| bobthepanda wrote:
| I played a very interesting scifi game that solved the "how
| do humans travel millions of light years" problem with "well,
| they're actually clones produced at the destination planet."
| I'd list the title but it is a pretty major spoiler.
| shagie wrote:
| I can't remember the name of the story, but I'm _pretty_
| sure that it was the last one in True Names and Other
| Dangers. It was told from the standpoint of an intelligent
| rocket ship that was launched because of an impending
| calamity. That ship (and many others) were long shot "lets
| see if we can find a life supporting world in the target
| solar system."
|
| (late edit) - found it - "Long Shot" https://en.wikipedia.o
| rg/wiki/The_Collected_Stories_of_Verno...
|
| > Description of a voyage from Earth to Alpha Centauri by
| an automated, AI controlled colony ship. The ship is
| launched as a "long shot" to preserve the human race
| because the Earth is going to be destroyed by a rapidly
| expanding sun. Ilse, the AI, carries human zygotes on a ten
| thousand year trip to search for a suitable planet around
| Alpha Centauri. Despite deteriorating hardware which causes
| her to "forget" the entire purpose of the mission, she is
| able to make inferences and use her remaining functional
| components to complete the mission. Vinge states his
| interest in writing a sequel depicting the lives of the
| humans born on this world.
|
| Locations where it has appeared -
| https://www.isfdb.org/cgi-bin/title.cgi?51200
|
| It can be borrowed from archive.org:
|
| https://archive.org/details/collectedstories0000ving/mode/2
| u...
|
| https://archive.org/details/truenamesotherda00ving/page/n5/
| m...
| the_af wrote:
| 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.
| danbolt wrote:
| I think it's _Mighty Kaiju Deimos_.
| bobthepanda wrote:
| 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.
| the_af wrote:
| > _It is like 90% visual novel and 10% RTS_
|
| Ah! That's a pity. Visual novels infuriate me. But the
| idea was cool :)
| bobthepanda wrote:
| I don't know that I'd call it a traditional visual novel.
| Or at least not the kind with really trite stories.
|
| The way the story is structured, you unlock scenes where
| you just read the text, and occasionally make branching
| choices. But the scenes are not very long.
|
| It's also interesting in that it borrows from modern TV
| non-linear storytelling; you do not see the story in
| chronological order, nothing is as it seems, etc. If
| you've seen Netflix's _Dark_ , it is pretty similar in
| vibe.
| danbolt wrote:
| I'd say the RTS segments are closer to an action RPG as
| well, such as Final Fantasy's ATB but on a kaiju/mecha
| city map.
|
| Or, you could suggest that they're _Diofield Chronicle_
| 's structure with Nintendo-style puzzle development, plus
| _Persona 5_ 's pop.
| danbolt wrote:
| You need to keep taking your medicine if you want to get
| better, Juro.
| jtrip wrote:
| >Basically, space will be inherited by our successors.
| Artificial intelligences.
|
| Ha ha, I love this. The sentiment has been there for a while
| now in the zeitgeist but had been overshadowed and
| outperformed by the lesser idea of 'Robots, and then AI, are
| coming and they are going to get us!' Finally, I don't know
| what section of human psychology is permitting it now, we are
| slowly and slowly coming to the understanding that AI will be
| humanity's child and will inherit the stars.
|
| I wonder if we'll, as in individual us humans, come along for
| the ride or if we'll be laid to rest. Peter F. Hamilton and
| his contemporaries like Neal Asher sure have interesting
| thoughts on it.
| xg15 wrote:
| Still having a soft spot for some cyber/biopunk future where
| we'll just eventually _become_ the machines - or be able to
| bioengineer bodies which will be capable of overcoming those
| limitations :)
| SuoDuanDao wrote:
| colonizing Venus with extremophiles that currently live in
| Terran ocean vents might be a good humanitarian (vivarian?)
| project. Life finds a way and all that, it'd be neat to
| offset the current great extinction with a new cambrian
| explosion on our sister planet.
| dividedbyzero wrote:
| Doesn't Venus have sulfuric acid clouds? Would that happen
| above those?
| twawaaay wrote:
| It is much easier to construct a suit that will protect from
| sulfuric acid than one that will protect you from low
| pressure.
|
| The problem with pressure suits is that positive pressure
| prevents the suit from being flexible, requires it to be made
| from durable materials, makes doing anything very hard and if
| there is any puncture you will loose the pressure
| immediately.
|
| Sulfuric acid can be kept away with a tiny layer that covers
| your entire body. Also, you will not die (immediately) if you
| get a small puncture. Very minimal positive pressure is
| enough to keep vapours outside of your suit even in case of
| pretty large tear, giving you plenty of time to fix it.
| MagicMoonlight wrote:
| Finally people are waking up to the airship meta.
|
| I want blimpworld so bad.
| atlasunshrugged wrote:
| It's a narrow use case but I've always wondered if these would be
| good for facilitating export of certain cash crops (or maybe even
| processed critical minerals) out of hard to reach areas of Africa
| where there isn't much infrastructure, rains can wash out roads,
| and airports aren't conveniently accessible (thinking cocoa in
| Liberia, cobalt in the DRC).
| lastofthemojito wrote:
| I think with my stomach too :)
|
| My first thought was "maybe cargo airships could make a
| Pakistani mango supply chain more feasible". See:
| https://www.eater.com/22618349/pakistani-mangoes-chaunsa-anw...
| credit_guy wrote:
| 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.
| SuoDuanDao wrote:
| would batteries work for fuel in an airship? I know the battery
| bank is a structural element in Tesla cars, seems like that
| could be done with airships as well (it'd increase the price
| precipitously of course)
| rimunroe wrote:
| > 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.
|
| I assume someone else can address this better, but given how
| expensive and limited helium is, I don't think we can just
| write off losses by comparing airships to party balloons. Foil
| party balloons look noticeably less inflated after a week or
| two. I have no idea how much gas is being lost, but that seems
| much more than a trivial amount to the point where I don't
| think a second envelope is going to help you much. It will have
| the same outgassing problems as the inner envelope, but will
| add additional weight and air resistance, both of which will
| reduce the maximum payload. Relatedly: is it cheap to extract
| the helium trapped in the outer envelope?
|
| Given the quantity of helium needed for an airship fleet, is
| topping them up regularly even an option? I'd assume it would
| need dramatically more helium than is currently being produced,
| and there's only so much helium available to us without using
| something like hydrogen fusion.
|
| In college I briefly worked at Brookhaven National Laboratory
| on an experiment with the Relativistic Heavy Ion collider. That
| collider has a set of giant collection tanks next to it so that
| (at least as it was explained to me) in the event of a
| superconductor quench event, they can try to shunt all the
| remaining liquid helium coolant into storage in order to limit
| how much of the valuable resource they lose. I imagine the
| amount of helium they're using would be peanuts compared to the
| amount required for a cargo fleet.
| credit_guy wrote:
| > 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 the helium gets replaced.
|
| That means the difference in partial pressure on the inner
| foil is at most 0.05 atmospheres. The leakage will be much
| lower. Most likely you would not need to refill the helium
| inside the inner foil more than once during the lifetime of
| the airship.
| mark212 wrote:
| The leisure market is huge for airships, in my opinion. Think of
| the same people that go on cruises to Antartica, but flying
| gently and at much lower altitude than a plane, over wild and
| scenic parts of the world. With luxury accommodations.
| ChuckMcM wrote:
| The other point this obscures is that it pays scant attention to
| wind profile. Specifically, if you're looking at 50 mph
| transverse winds you aren't going to get to where you want with a
| super big envelope/frame. Drag is the cube of airspeed, so the
| bigger airships are, the less control you have over where they go
| (without adding lots and lots of power to the power plant).
|
| Try off-loading containers when you're "ship" turns 90 degrees in
| < 30 minutes because a breeze came up.
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