24 ms·

Bring back hydrogen lifting gas

253 points by harporoeder 5y ago

epistasis 5y ago
This is really interesting... I am suspicious of fossil fuel based hydrogen, but as electrolyzed hydrogen gets cheaper, this could be very useful for some applications.
- fire 5y ago
  There are some really interesting chemical methods of creating hydrogen gas using like, aluminum and sodium ( or potassium? ) in water that might be able to allow for on demand gas generation with otherwise solid/condensed fuel sources; it's "simple" enough of a concept that creators[1] are doing it to power their own systems, though I imagine scaling it up carries its own set of difficulties ( e.g., using aluminum nanoparticles for greater surface area to more rapidly generate gas, but keeping it cool enough to avoid problematic side effects, or like, you know, exploding in general ) Edit: it looks like MIT is actually actively working[2] on this type of clean hydrogen production from the viewpoint of creating a scalable system! 1: https://youtu.be/LKfbZvpoQ0g?t=5m23s https://youtu.be/LKfbZvpoQ0g?t=5m23s 2: https://energy.mit.edu/news/using-aluminum-and-water-to-make-clean-hydrogen-fuel-when-and-where-its-needed/ https://energy.mit.edu/news/using-aluminum-and-water-to-make...
- ajuc 5y ago
  Interesting. I did some back of the envelope calculations. A 100% efficient electrolyser requires 39 kWh of electricity to produce 1 kg of hydrogen. Best practical ones need about 50 kWh [1]. Hinderburg had about 18 metric tons of hydrogen [2], filling it would require about 1 GWh of energy. The good thing is - it could be used as a way to balance the electric network because we don't particularly care when we fill it as long as it's done. So we can do it when there's overproduction only. The energy would be quite cheap - in some cases you can get paid for using energy when electrical network needs balancing. Same thing is done with other energy-intensive industrial processes like smelting. In Germany (not particularly sunny but a lot of solar panels so effects of scale are there) the low bounds for price of 1 MWh of solar energy in 2018 was about 37 euro [3], let's round that up to 50 - filling Hindenburg would require about 50 000 euro of renewable energy. Additionally it would require about 9 * 18 ~= 162 tons of water and some additives to make it conductive. Maybe sea water could be used as is? [1] http://www.renewableenergyfocus.com/view/3157/hydrogen-production-from-renewables/ http://www.renewableenergyfocus.com/view/3157/hydrogen-produ... [2] https://www.history.com/news/the-hindenburg-disaster-9-surprising-facts https://www.history.com/news/the-hindenburg-disaster-9-surpr... [3] https://en.wikipedia.org/wiki/Cost_of_electricity_by_source#Germany https://en.wikipedia.org/wiki/Cost_of_electricity_by_source#...
  - epistasis 5y ago
    Current cost of electrolyzed hydrogen is €2.5-€5.5/kg, and the EU hopes to get that to less than half by 2030: https://about.bnef.com/blog/liebreich-separating-hype-from-hydrogen-part-one-the-supply-side/ https://about.bnef.com/blog/liebreich-separating-hype-from-h... $100k for a filling, with many many re-uses, could maybe be feasible today, and $20k should definitely be. One note about hydrogen production, as I understand it, is that electrolyzers are enough of a capital expense that you want to be running them at fairly high capacity factors. Cheaper energy helps, but cheaper electrolyzers would probably help more.
kozak 5y ago
I've been thinking of it the same way since I learned that helium is a non-renewable fossil resource. Once it's gone, it's gone.
- aeternum 5y ago
  Only on earth. Helium is the 2nd most abundant element in the universe.
  - Xylakant 5y ago
    You’ll have a hard time extracting it from the sun, though.
    - bena 5y ago
      But an easier time from the Moon. The Moon's soil is apparently lousy with Helium. There was a movie named Moon about a decade back where that was the main character's job, helium mining on the Moon. That's not to say it would be easy, but it's closer than the Sun. Because it is everywhere. In the various Star Trek shows, ships are made with something called "Bussard collectors" which basically scoop up particles like helium and hydrogen from space for use in the ship. Obviously both of those example are fiction. We don't have the capability to mine on the Moon or catch elements free floating in space. But those fictions are based on the fact that those elements are that abundant.
      - perl4ever 5y ago
        >"Bussard collectors" I think I read somewhere that despite this being a science fiction trope forever, there may not be a region between "too thin to produce net power" and "thick enough to blow up a spaceship at relativistic speeds". And in practice, the interstellar medium turned out to be the former, too thin. In fact, I'm not sure but what someone may have calculated drag would exceed power generated, regardless of density.
        5y ago
FabHK 5y ago
TLDR: > With modern engineering standards, there is no doubt that hydrogen could be made a safe lifting gas. Disadvantages of hydrogen: * burns (but only with sufficient oxygen, eg a mixture of air and 4% up to 75% hydrogen) Advantages of hydrogen: * lifts 8% more than helium (per volume). Not a huge difference, but not trivial for an airship * costs 98.5% less than helium (!) (Airships have crashed because helium was too expensive to vent: safety valves on the USS Shenandoah were capped, 14 crew members lost their lives.) > Airships are too slow for human travel Too slow for transportation, maybe. But leisure travel? Imagine a one week air safari from Kilimandjaro and the Serengeti to Kruger Park. It could be awesome. Edit to add: (Leisure air travel/Safari is my own pipe dream. The article suggests cargo): > If airships were to make a major comeback, it would be in cargo service. > Cargo airships would need to be big—bigger than the Hindenburg. [...] ”’the lift-to-drag ratio, a critical parameter in aircraft performance, gets better as the airship gets bigger) > Ginormous airships require a lot of lifting gas—perhaps a million cubic meters > FAA has discouraged the return of the airship in the use case that makes the most sense
- pitaj 5y ago
  Airships are being investigated as a method of shipping to remote locations without ship, train, or truck access.
- R0b0t1 5y ago
  Airships would be good for freight. Far less carbon footprint than airplanes.
  - newsclues 5y ago
    I’ve been thinking they are a good idea to help with overloaded ports, as they can pick up cargo cans and move them without any of the current bottlenecks.
    - lb1lf 5y ago
      -The airship would likely be the bottleneck; a 40ft shipping container may weigh anything up to approx. 30 metric tons. You wouldn't be able to put many of those under an airship, hence you'd need a lot of rather space-hogging airships.
renewiltord 5y ago
An entertaining read https://twitter.com/RealhumanSchwab/status/1421949421781061633?s=20 https://twitter.com/RealhumanSchwab/status/14219494217810616... Very related. I won’t spoil it for you but it’s entertaining. Edit: Responders, please! You’re spoiling the fun! If https://twitter.com/RealhumanSchwab/status/1421949607542616064?s=20 https://twitter.com/RealhumanSchwab/status/14219496075426160... doesn’t give it away I don’t know what will.
- jandrese 5y ago
  That thread went down the insane conspiracy rabbit hole in a hurry.
  - stickfigure 5y ago
    Disappointing. The first 2/3 of the thread was pretty good, nice narrative with pictures. The twitter format sucks though.
    - itsyaboi 5y ago
      https://threader.app/thread/1421949421781061633 https://threader.app/thread/1421949421781061633
- paxswill 5y ago
  Echoing a sibling comment, that thread goes down the conspiracy rabbit hole very quickly. A few inaccuracies I noticed before giving up: * "Remember, only 13 deaths out of the 36 passengers on the airship died." This skips the crew deaths (who also died at about the same rate). * There were a bunch of photographers present at Lakehurst as it was the first crossing of 1937. The audio recording was not scripted, the original disc records a pressure wave which is followed by Morrison exclaiming that the Hindenburg is on fire. * "Mary Jane" can be a real person's name. * "Hugo Eckener, former head of the Zeppelin Company, Charles Rosendahl, commander of the Naval Air Station at Lakehurst, Max Pruss, captain of the Hindenburg and most of the surviving crew believed the airship had been sabotaged.". Eckener stated that it could be sabotage when he was first told the Hindenburg had gone down. He later backed the static spark theory.
ckastner 5y ago
Hydrogen is probably not as unsafe as the general population might think it is, but it find it bizarre just how much the article downplays the flammability issue. For example: > Fun fact: pure hydrogen doesn’t burn. It needs an oxidizer—like the oxygen in air. Airships literally float in that oxidizier!
- contravariant 5y ago
  Yeah it kind of defeats the point when your definition of 'doesn't burn' covers every single substance.
  - dragontamer 5y ago
    Except Li-ion batteries, which burn with their own oxidizer.
    - hobs 5y ago
      Well there's plenty of monoprops that supply their own oxidizer, and oh boy are they absolutely dangerous as hell. https://en.wikipedia.org/wiki/Monopropellant https://en.wikipedia.org/wiki/Monopropellant
    - yellow_lead 5y ago
      And rocket fuel? Technically
      - dragontamer 5y ago
        Rocket fuel is more of a "pre-mixed with oxidizier" sorta thing. Although I am enjoying the side discussion about monopropellants.
      - gpm 5y ago
        Most modern rockets are liquid and mix the fuel and oxidizer only at the point of combustion, burning H2/O2, Kerosene/O2 or more recently CH4/O2. Mono-propellant, and solid (not hybrid) rocket fuel fits the description though
iso1210 5y ago
Fossil fuel companies getting PR to spin everything they can into trying to improve hydrogen's image.
- toiletaccount 5y ago
  What's wrong with hydrogen? You can produce it with renewables, it basically works with existing IC technology and the exhaust is just water. The only hangup is the energy/volume ratio, which is an area of ongoing research.
  - throw37388 5y ago
    Hydrogen burns and produces greenhouse gas!
    - detaro 5y ago
      uh, no?
      - throw37388 5y ago
        Yes 》Water vapor is known to be Earth’s most abundant greenhouse gas https://www.nasa.gov/topics/earth/features/vapor_warming.html https://www.nasa.gov/topics/earth/features/vapor_warming.htm...
        toiletaccount 5y ago
        Run it through a condenser, feed it into a holding tank and dispose of the water at each filling station?
        jbotz 5y ago
        No need, the atmosphere is a sufficient condenser. Unless you heat the atmosphere with a lot more energy than the little bit you get from combusting the hydrogen in question... but then you'll have bigger problems as your oceans begin to evaporate.
trenning 5y ago
I've found it interesting that power plant generators are sealed and cooled with hydrogen gas. A hundred tons of steel and copper generating thousands of volts of electricity is cooled with hydrogen. Sounds like a recipe for an explosion movie style, yet there aren't any.
- jeffbee 5y ago
  There aren't any because hydrogen cooled turbomachinery is complex and high-touch. There are systems that circulate the gas out of the generator and into separators that remove the inevitable air contaminants and dryers to remove the water. They aren't really seal-and-forget systems like a helium-filled hard disk drive might be.
binbag 5y ago
Is this a reprint from April 1st?
CuriouslyC 5y ago
One nice feature of hydrogen is that you can use it for lift and also for fuel (and it has good energy density). I've been wondering for a while if hydrogen airships couldn't make flying cars a reality. It seems like a hybrid jet/zeppelin could find a sweet spot in terms of performance and sustainability.
- jandrese 5y ago
  The necessary bulk of the airship for human transportation is a serious crimp in the practicality of such a solution. Technology can't make the bag small enough because it is limited by physics. Even if we could build ultra-rigid and outrageously light bags that could have all of the air pumped out for a vacuum you still need a fairly large balloon to carry people. One person would displace 70 meter^3 of air, not counting anything else. That's not going to fit in your driveway.
fsckboy 5y ago
this article reads like the "a world without zinc!" school documentary spoof subplot on the Simpson's https://www.youtube.com/watch?v=U1iCZpFMYd0 https://www.youtube.com/watch?v=U1iCZpFMYd0 and the spat He... no, that's helium... She has with helium and in favor of hydrogen overshadows the more interesting suggestion at the end, that airships might make a lot of sense for cargo transportation. I wish the article made that case better!
joefigura 5y ago
Interesting piece! I think the article makes some good points, but I don't think that helium is the reason that airships have failed to find use cases. The benefits of hydrogen do not change the fundamentals of the business case. Hydrogen's cheaper, but even using helium the lifting gas is <20% of the operating cost of the airship. The hangar, cost of the vehicle, and maintenance are all more impactful than the cost of the lifting gas. The bigger hurdle that airship startups have faced is the upfront cost of developing a new vehicle with a many ton payload. Projects trying to build very large airships have so far to get a vehicle to market, because of the amount of capital it requires and the lack of a strong, specific commercial case (Hybrid Air Vehicles, Cargolifter, Lockheed's Hybrid Airships). Changing the lifting gas to hydrogen does not address those challenges. But airships are certainly underutilized - I'm optimistic for their future!
csours 5y ago
I thought the bigger safety problem with lighter than air travel was weather? As in, anything less than perfect surface conditions may result in disaster when you go to moor the aircraft.
findthewords 5y ago
A clear example how money in the military-industrial complex (or DARPA) directs innovation paths. The military does not approve of hydrogen blimps, and so neither can the civilian sector use them.
- jeffreyrogers 5y ago
  None of the other countries are doing it either, so it isn't just DARPA. I think it just doesn't have an obvious use case. Everyone says cargo, but what is it better at at than rail, truck, ship, or air (cargo jet)? If you want cheap you go with rail or ship. If you want fast you go with jet and then truck for the last mile. Airship would be cheaper than air, but noticeably slower, so it basically has to compete with truck on price. Can it do that? Maybe, I have no idea.
- toomanybeersies 5y ago
  The military haven't used airships since the 1930's because transatlantic aeroplanes rendered them obsolete. Not because of some military-industrial complex conspiracy. Every couple of decades the DoD decides that blimps are back in fashion and throws millions of dollars into blimp projects. Inevitably they cancel the project and decide they don't want them. Admittedly they've all been helium, but the reasons for cancelation are usually related to capability and the intrinsic qualities of lighter-than-air flight, and not cost. The past 20 years, they tried Integrated Sensor is Structure (USAF) [1]; Long-endurance, Multi-intelligence Vehicle (Army) [2], Blue Devil (USAF) [3], Walrus advanced technology demonstration (DARPA) [4], and a handful of other boondoggles [5]. If anything, the concept of viable airships in the 21st century is just a defence contractor gravy train. [1] https://en.wikipedia.org/wiki/Integrated_Sensor_is_Structure https://en.wikipedia.org/wiki/Integrated_Sensor_is_Structure [2] https://www.ainonline.com/aviation-news/defense/2013-02-22/us-army-cancels-lemv-surveillance-airship https://www.ainonline.com/aviation-news/defense/2013-02-22/u... [3] https://defense-update.com/20120529_blue-devil-2-airship-deflated.html https://defense-update.com/20120529_blue-devil-2-airship-def... [4] https://www.flightglobal.com/darpa-details-plans-for-ultra-large-army-airship/54350.article https://www.flightglobal.com/darpa-details-plans-for-ultra-l... [5] Congressional Budget Office, "Recent Development Efforts for Military Airships" (2011) https://fas.org/irp/program/collect/cbo-airship.pdf https://fas.org/irp/program/collect/cbo-airship.pdf
Baeocystin 5y ago
Hydrogen gas leaks through everything, and embrittles most metals. It is not an easy substance to work with. Combine that with having one of the widest ignition ranges of any flammable material, and I'll just stay on the dubious side of it ever getting used as a large-scale lifting gas again.
- jeffreyrogers 5y ago
  It doesn't embrittle aluminum at normal temperatures and stainless steel is significantly less affected. I agree it is hard to work with, but think the reason it isn't used in this sort of application is more due to economics than inherent properties of hydrogen.
xphos 5y ago
So like I think the claim about the thermite coating could be wrong. That is my only concern you can't have the ship burst into flames in a minute. I don't know the truth of the hindenburg but it does seem like you could mitigate the flammability risk under good conditions but like security also comes to mind what if these things get hijacked. Like they do move slow but are basically a moving ball of death if they light on fire. https://www.airships.net/hindenburg/disaster/myths/ https://www.airships.net/hindenburg/disaster/myths/
- rozab 5y ago
  Aeroplanes are also all of these things. And things go south a lot quicker when they get hijacked.
deleted 5y ago
[deleted]
foota 5y ago
Out of curiosity, would it be feasible to produce enough helium for commercial use through fusion (either power generating or not)?
dragosmocrii 5y ago
Although there's a slight difference in meaning, I prefer the term zeppelin to blimp. fyi: the difference is in the frame construction. A zeppelin has a rigid frame that keeps it's shape if the gas is lost, whereas a blimp has a semi-rigid frame that will deflate if the gas isn't present.
- kQq9oHeAz6wLLS 5y ago
  I think "rigid airship" is an often used term as well
- dredmorbius 5y ago
  "Zeppelin" is a manufacturer designation or brand name, akin to "Kleenex", though it's become somewhat genericised. "Rigid airship" is the generic term.
newbie789 5y ago
This article is interesting. “Hydrogen doesn’t explode without being mixed with air first then ignited” is a kind of funny statement. I read that as “hydrogen doesn’t explode outside of when it does” I’d ask “was this written by a hydrogen sales team?” but it’d be mind boggling if it weren’t. The blaming of special interest groups right off the bat, and the blaming the lower-performing helium as the cause for a crash (that iirc, involved a leak so I’m not sure how that 8% difference could’ve saved everyone) are naked examples of sales speech. “Maybe you’ll blow up! Who cares? You get 8% more lift and stick it to the uh, Bureau Of Mines”
- Tepix 5y ago
  The article does have a point. On airplanes we have highly flammable fuel. It's safe because it is contained. The same could be done with the hydrogen in an airship.
  - dredmorbius 5y ago
    Jet fuel doesn't inherently mix with air, on its own. (It does mix with air in high-speed impacts, which results in flame but not *explosions.) Jet fuel, kerosene (intermediate in weight, viscosity, and volatility between petrol and diesel fuels) is remarkably inert for something that burns. You can extinquish a match in it.
frompdx 5y ago
I'm always hopeful that airships will make a comeback. I would love to be able to travel from the United States to Europe on an airship, just like they did at the in the early 20th century. I can see a lot of advantage from a comfort perspective, even if it does take more time than a plane. If you are interested in the history of airship travel, and its rise and fall, I highly recommend The Deltoid Pumpkin Seed by John McPhee. It's a short book about an unlikely union of ex Navy airshipmen and evangelical Christians chasing the impossible dream of brining airship travel back in an era where the world had moved on from airship travel.
briefcomment 5y ago
Is it possible to make a road ready hovercraft that uses lifting gas like hydrogen? Getting tired of particulate matter from tires, brakes, road wear, etc.
artichikin 5y ago
This article is very USA centric — it centers around it being banned for lift in the states — but that wouldn’t stop just about everywhere else on the planet from building hydrogen air ships, if they are viable.
supernova87a 5y ago
How often are the blimps fully deflated of their helium and then refilled, and is all that helium just basically let up into the atmosphere and wasted? Given some of our recent helium shortages, it seems really wasteful, even if it may be (currently) not costly.
elihu 5y ago
A couple other options beside hydrogen/helium: vacuum chambers, hot air. I don't know if we have the technology to build a compressive structure that can withstand atmospheric pressure and yet be lighter than the air it displaces. That sounds like an interesting problem to work on. I imagine getting it to work out would be easier the larger the structure is, within reason. I assume that hot air isn't competitive with either hydrogen or helium in terms of lift, and it takes additional energy to keep it hot. On the other hand, air is free and it's not inherently flammable by itself. Maybe a well-insulated airship that acts as a solar greenhouse could get quite warm and stay that way?
- ant6n 5y ago
  > I don't know if we have the technology to build a compressive structure that can withstand atmospheric pressure and yet be lighter than the air it displaces. That sounds like an interesting problem to work on. I imagine getting it to work out would be easier the larger the structure is, within reason. It doesn´t exist so far. There are very strong forces involved. I`d say it´s more likely there would be connected small enclosures that could make that work. Perhaps some sort of solid foam blocks with vacuum inside - but it may provide much less lift than a true vacuum.
- elihu 5y ago
  To follow up my own comment: I suppose these aren't mutually exclusive. For instance, you could have an airship filled with hydrogen or helium at 1/2 atmospheric pressure and kept hot by solar heating. For helium especially it might be an effective way to keep costs down (since helium is so expensive) and maybe keep it from leaking out quite so much. Similarly, using hydrogen at partial vacuum would mean having less of it on board, which is sort of good from a flammability point of view. Though on the other hand, it means that if the skin is ever broken you'd have outside air mixing very quickly with the hydrogen inside due to the pressure difference. That's probably a bad thing.
cycomanic 5y ago
I haven't seen anyone mentioning cargolifter [1] which was a company in Germany which tried to commercialise the development of a cargo airship (incidentally using helium). They had a lot of press coverage at the time and many shareholders were private investors. They did got bankrupt in 2002, largely because development of an aircraft is expensive and long. Maybe someone needs to excite Elon about it to get sufficient funding. [1] https://en.m.wikipedia.org/wiki/CargoLifter https://en.m.wikipedia.org/wiki/CargoLifter
ivanb 5y ago
Hydrogen airships are terrible against any kind of attack. They are so slow and flammable that one can bring them down with just a flying toy. I'm not even talking about incendiary ammunition. You would not put people or expensive cargo on a low and slow flying bomb in 21 century.
dredmorbius 5y ago
Airships are a concept which is inherently attractive given their theoretical simplicity, but highly impracticle on closer examination. They're not impossible, but they're far less viable than would first appear. Heavier-than-air powered aircraft were largely a result of powerful engines and energy-dense fuels. Emergence of mass-produced automobiles and the first aircraft occurred within a few years of each other. Materials science (duraluminium) was another major factor. Aeronautical engineering was largely secondary and likely would have emerged with experience regardless. For airships, the key enabling factors are lifting gases and materials, in this case the gas-bag envelopes. For early-20th-century airships, the material of preference was ox intestines, glued together. One airship required the entrails of ~800,000 oxen. See EngineerGuy’s video (accompanies his book) on the doomed British Airship R-101: https://youtube.com/watch?v=ixxXhZVFXxQ https://youtube.com/watch?v=ixxXhZVFXxQ There are some factors which might help, and others which still work against, airships. Rather than hydrogen, a "hot helium" design might offer greater flexibility. There's actually some research of such concepts: https://ui.adsabs.harvard.edu/abs/1987STIA...8748646R/abstract https://ui.adsabs.harvard.edu/abs/1987STIA...8748646R/abstra... Materials science might allow for improvements in gas-bag design. Plastics made mid-century blimps possible, and modern Zeppelin semi-rigid airships rely on PVF (polyvinyl fluouride), principally. Graphene or other monatomic sheet materials might allow for thinner and/or stronger designs. Similarly structural components (frames, guy-wires) might benefit by both materials and computer-aided design and improve mass:volume ratios, safety margins, maintenance requirements, or other factors. Improved lifting gas properties or mixes might also be an option, though here chemistry is fundamentally limiting. Integrating PV capabilities into an outer skin might reduce fuel requirements, though even covering all the top surface of a USS Los Angeles sized airship (200m x 30m) would provide less than 300 kW of power. The Zeppelin NT (70m x 14m) has 3x 150 kW engines (450 kW total). Routing electricity next to hydrogen gas bags might prove problematic. https://en.wikipedia.org/wiki/Zeppelin_NT https://en.wikipedia.org/wiki/Zeppelin_NT In all, I expect materials innovation might contribute to fractional improvements in airship capabilities or aspects, but not improvements of multiples. Note that airships also have the submariner’s problem concerning buoyancy: lift is proportional to volume, but volume varies with pressure. As a submarine descends, there’s additional pressure on its buoyancy tanks, compressing the gas within them, reducing buoyancy further. As a submarine sinks, it wants to sink further, which may prove interesting if crush depth is exceeded. (Destin Sandlin’s recent “Smarter Every Day” series aboard the USS Toledo is pretty fascinating in this regard.) By contrast, in an airplane, lifting forces increase as one descends, and decrease as one ascends. For airships and balloons, you’ve got the reverse problem: as they rise, the lifting gas expands. After a point one of three things must occur: the gas is vented (and lost forever), the envelope expands, or the gas is pressurised (meaning carrying the additional mass of compressors and pressure vessels). One of the biggest disadvantages of airships compared to jet aircraft is that jets fly above the weather, at 30k--40k feet, whilst airships fly in it, often at only a few hundred feet altitude. The Hindenberg’s cruise altitude was 200m (650 ft), see: https://www.airships.net/hindenburg/flight-operations-procedures/ https://www.airships.net/hindenburg/flight-operations-proced... Operating and flight ceilings of 16k and 21k feet were apparently possible. Passenger Zeppelins were unpressurised. Note that this makes crossing even relatively low mountain ranges a challenge. Given the large number of airship failures in which wind and weather were primary or contributing causes, this is a major handicap. The altitude record for an airship is 95,000 ft, though that’s for an unmanned system consisting of little more than the lifting balloons, frame, and propulsion. https://newatlas.com/highest-airship-flight-record/20379/ https://newatlas.com/highest-airship-flight-record/20379/ High-altitude flight requires a pressurised passenger compartment (increasing costs and risks), supplemental oxygen (the jet airliner's air-bleed pressurisation system is not available), and other factors. The other massive disadvantage is that airships serve a limited number of roles and compete poorly against alternatives. They're highly intermediate between heavier-than-air airplanes and ships. They lack the former's speed (115 kph vs. 1,000 kph), and the latter's cargo capacity (160 tonne vs. 210,000 tonne for a Triple E-class Maersk container ship). Overland, airships would have to compete with river and canal traffic, rail, and trucking. The remaining remote-location work is likely of relatively limited economic value. https://en.wikipedia.org/wiki/Triple_E-class_container_ship https://en.wikipedia.org/wiki/Triple_E-class_container_ship That leaves the prospect of intercontinental trans-oceanic voyages, probably largely passenger and high-value cargo. Airships are likely to be limited to ~100 -- 200 kph. A transatlantic trip (NYC-LON) would take 1dy 4h to 2dy 8h. A Los Angeles -- Shanghai trip would be 2--4 days. Los Angeles to Sydney, 2.5--5 days. Given no other options, I could see that happening, but even a drastically curtailed fuel-based airliner industry would likely be preferable. Given either a carbon offset, synthetic hydrocarbon analogues, or carbon-neutral fuels, this seems more likely.
cantagi 5y ago
Why could an airship not be made using a vacuum instead of a lifting gas? A quick google reveals that someone has thought of this before: https://en.wikipedia.org/wiki/Vacuum_airship https://en.wikipedia.org/wiki/Vacuum_airship and it seems like it might not be possible with currently available materials. Would it be possible to reduce the density of helium for the same pressure by electrostatically charging it to make the molecules repel, effectively turning the airship into a giant capacitor with alternating +ve and -ve sections?
DonHopkins 5y ago
SF author Fritz Leiber wrote an alternative history short story called "Catch That Zeppelin!", which won the 1975 Nebula Award for Best Short Story and the 1976 Hugo Award for Best Short Story. https://en.wikipedia.org/wiki/Catch_That_Zeppelin https://en.wikipedia.org/wiki/Catch_That_Zeppelin! >When Fritz Leiber sees a Zeppelin moored at the Empire State Building one afternoon in 1973, he realizes that he has shifted into another timeline — one where a more decisive defeat of Germany at the end of the First World War led to greater international prosperity and a deeper, more acceptable peace, with the result that America was willing to sell Germany helium for use in airships, thereby preventing the Hindenburg disaster. Also, the year has changed from 1973 to 1937, and Leiber has become a patriotic-but-peaceful German airship engineer named Adolf Hitler. https://www.goodreads.com/book/show/40626645-catch-that-zeppelin https://www.goodreads.com/book/show/40626645-catch-that-zepp...

253 points by harporoeder 5y ago

This is really interesting... I am suspicious of fossil fuel based hydrogen, but as electrolyzed hydrogen gets cheaper, this could be very useful for some applications.

fire 5y ago
There are some really interesting chemical methods of creating hydrogen gas using like, aluminum and sodium ( or potassium? ) in water that might be able to allow for on demand gas generation with otherwise solid/condensed fuel sources; it's "simple" enough of a concept that creators[1] are doing it to power their own systems, though I imagine scaling it up carries its own set of difficulties ( e.g., using aluminum nanoparticles for greater surface area to more rapidly generate gas, but keeping it cool enough to avoid problematic side effects, or like, you know, exploding in general ) Edit: it looks like MIT is actually actively working[2] on this type of clean hydrogen production from the viewpoint of creating a scalable system! 1: https://youtu.be/LKfbZvpoQ0g?t=5m23s https://youtu.be/LKfbZvpoQ0g?t=5m23s 2: https://energy.mit.edu/news/using-aluminum-and-water-to-make-clean-hydrogen-fuel-when-and-where-its-needed/ https://energy.mit.edu/news/using-aluminum-and-water-to-make...
ajuc 5y ago
Interesting. I did some back of the envelope calculations. A 100% efficient electrolyser requires 39 kWh of electricity to produce 1 kg of hydrogen. Best practical ones need about 50 kWh [1]. Hinderburg had about 18 metric tons of hydrogen [2], filling it would require about 1 GWh of energy. The good thing is - it could be used as a way to balance the electric network because we don't particularly care when we fill it as long as it's done. So we can do it when there's overproduction only. The energy would be quite cheap - in some cases you can get paid for using energy when electrical network needs balancing. Same thing is done with other energy-intensive industrial processes like smelting. In Germany (not particularly sunny but a lot of solar panels so effects of scale are there) the low bounds for price of 1 MWh of solar energy in 2018 was about 37 euro [3], let's round that up to 50 - filling Hindenburg would require about 50 000 euro of renewable energy. Additionally it would require about 9 * 18 ~= 162 tons of water and some additives to make it conductive. Maybe sea water could be used as is? [1] http://www.renewableenergyfocus.com/view/3157/hydrogen-production-from-renewables/ http://www.renewableenergyfocus.com/view/3157/hydrogen-produ... [2] https://www.history.com/news/the-hindenburg-disaster-9-surprising-facts https://www.history.com/news/the-hindenburg-disaster-9-surpr... [3] https://en.wikipedia.org/wiki/Cost_of_electricity_by_source#Germany https://en.wikipedia.org/wiki/Cost_of_electricity_by_source#...
- epistasis 5y ago
  Current cost of electrolyzed hydrogen is €2.5-€5.5/kg, and the EU hopes to get that to less than half by 2030: https://about.bnef.com/blog/liebreich-separating-hype-from-hydrogen-part-one-the-supply-side/ https://about.bnef.com/blog/liebreich-separating-hype-from-h... $100k for a filling, with many many re-uses, could maybe be feasible today, and $20k should definitely be. One note about hydrogen production, as I understand it, is that electrolyzers are enough of a capital expense that you want to be running them at fairly high capacity factors. Cheaper energy helps, but cheaper electrolyzers would probably help more.

kozak 5y ago

I've been thinking of it the same way since I learned that helium is a non-renewable fossil resource. Once it's gone, it's gone.

aeternum 5y ago
Only on earth. Helium is the 2nd most abundant element in the universe.
- Xylakant 5y ago
  You’ll have a hard time extracting it from the sun, though.
  - bena 5y ago
    But an easier time from the Moon. The Moon's soil is apparently lousy with Helium. There was a movie named Moon about a decade back where that was the main character's job, helium mining on the Moon. That's not to say it would be easy, but it's closer than the Sun. Because it is everywhere. In the various Star Trek shows, ships are made with something called "Bussard collectors" which basically scoop up particles like helium and hydrogen from space for use in the ship. Obviously both of those example are fiction. We don't have the capability to mine on the Moon or catch elements free floating in space. But those fictions are based on the fact that those elements are that abundant.
    - perl4ever 5y ago
      >"Bussard collectors" I think I read somewhere that despite this being a science fiction trope forever, there may not be a region between "too thin to produce net power" and "thick enough to blow up a spaceship at relativistic speeds". And in practice, the interstellar medium turned out to be the former, too thin. In fact, I'm not sure but what someone may have calculated drag would exceed power generated, regardless of density.
      - 5y ago

FabHK 5y ago

TLDR: > With modern engineering standards, there is no doubt that hydrogen could be made a safe lifting gas. Disadvantages of hydrogen: * burns (but only with sufficient oxygen, eg a mixture of air and 4% up to 75% hydrogen) Advantages of hydrogen: * lifts 8% more than helium (per volume). Not a huge difference, but not trivial for an airship * costs 98.5% less than helium (!) (Airships have crashed because helium was too expensive to vent: safety valves on the USS Shenandoah were capped, 14 crew members lost their lives.) > Airships are too slow for human travel Too slow for transportation, maybe. But leisure travel? Imagine a one week air safari from Kilimandjaro and the Serengeti to Kruger Park. It could be awesome. Edit to add: (Leisure air travel/Safari is my own pipe dream. The article suggests cargo): > If airships were to make a major comeback, it would be in cargo service. > Cargo airships would need to be big—bigger than the Hindenburg. [...] ”’the lift-to-drag ratio, a critical parameter in aircraft performance, gets better as the airship gets bigger) > Ginormous airships require a lot of lifting gas—perhaps a million cubic meters > FAA has discouraged the return of the airship in the use case that makes the most sense

pitaj 5y ago
Airships are being investigated as a method of shipping to remote locations without ship, train, or truck access.
R0b0t1 5y ago
Airships would be good for freight. Far less carbon footprint than airplanes.
- newsclues 5y ago
  I’ve been thinking they are a good idea to help with overloaded ports, as they can pick up cargo cans and move them without any of the current bottlenecks.
  - lb1lf 5y ago
    -The airship would likely be the bottleneck; a 40ft shipping container may weigh anything up to approx. 30 metric tons. You wouldn't be able to put many of those under an airship, hence you'd need a lot of rather space-hogging airships.

renewiltord 5y ago

An entertaining read https://twitter.com/RealhumanSchwab/status/1421949421781061633?s=20 https://twitter.com/RealhumanSchwab/status/14219494217810616... Very related. I won’t spoil it for you but it’s entertaining. Edit: Responders, please! You’re spoiling the fun! If https://twitter.com/RealhumanSchwab/status/1421949607542616064?s=20 https://twitter.com/RealhumanSchwab/status/14219496075426160... doesn’t give it away I don’t know what will.

jandrese 5y ago
That thread went down the insane conspiracy rabbit hole in a hurry.
- stickfigure 5y ago
  Disappointing. The first 2/3 of the thread was pretty good, nice narrative with pictures. The twitter format sucks though.
  - itsyaboi 5y ago
    https://threader.app/thread/1421949421781061633 https://threader.app/thread/1421949421781061633
paxswill 5y ago
Echoing a sibling comment, that thread goes down the conspiracy rabbit hole very quickly. A few inaccuracies I noticed before giving up: * "Remember, only 13 deaths out of the 36 passengers on the airship died." This skips the crew deaths (who also died at about the same rate). * There were a bunch of photographers present at Lakehurst as it was the first crossing of 1937. The audio recording was not scripted, the original disc records a pressure wave which is followed by Morrison exclaiming that the Hindenburg is on fire. * "Mary Jane" can be a real person's name. * "Hugo Eckener, former head of the Zeppelin Company, Charles Rosendahl, commander of the Naval Air Station at Lakehurst, Max Pruss, captain of the Hindenburg and most of the surviving crew believed the airship had been sabotaged.". Eckener stated that it could be sabotage when he was first told the Hindenburg had gone down. He later backed the static spark theory.

ckastner 5y ago

Hydrogen is probably not as unsafe as the general population might think it is, but it find it bizarre just how much the article downplays the flammability issue. For example: > Fun fact: pure hydrogen doesn’t burn. It needs an oxidizer—like the oxygen in air. Airships literally float in that oxidizier!

contravariant 5y ago
Yeah it kind of defeats the point when your definition of 'doesn't burn' covers every single substance.
- dragontamer 5y ago
  Except Li-ion batteries, which burn with their own oxidizer.
  - hobs 5y ago
    Well there's plenty of monoprops that supply their own oxidizer, and oh boy are they absolutely dangerous as hell. https://en.wikipedia.org/wiki/Monopropellant https://en.wikipedia.org/wiki/Monopropellant
  - yellow_lead 5y ago
    And rocket fuel? Technically
    - dragontamer 5y ago
      Rocket fuel is more of a "pre-mixed with oxidizier" sorta thing. Although I am enjoying the side discussion about monopropellants.
    - gpm 5y ago
      Most modern rockets are liquid and mix the fuel and oxidizer only at the point of combustion, burning H2/O2, Kerosene/O2 or more recently CH4/O2. Mono-propellant, and solid (not hybrid) rocket fuel fits the description though

iso1210 5y ago

Fossil fuel companies getting PR to spin everything they can into trying to improve hydrogen's image.

toiletaccount 5y ago
What's wrong with hydrogen? You can produce it with renewables, it basically works with existing IC technology and the exhaust is just water. The only hangup is the energy/volume ratio, which is an area of ongoing research.
- throw37388 5y ago
  Hydrogen burns and produces greenhouse gas!
  - detaro 5y ago
    uh, no?
    - throw37388 5y ago
      Yes 》Water vapor is known to be Earth’s most abundant greenhouse gas https://www.nasa.gov/topics/earth/features/vapor_warming.html https://www.nasa.gov/topics/earth/features/vapor_warming.htm...
      - toiletaccount 5y ago
        Run it through a condenser, feed it into a holding tank and dispose of the water at each filling station?
        jbotz 5y ago
        No need, the atmosphere is a sufficient condenser. Unless you heat the atmosphere with a lot more energy than the little bit you get from combusting the hydrogen in question... but then you'll have bigger problems as your oceans begin to evaporate.

trenning 5y ago

I've found it interesting that power plant generators are sealed and cooled with hydrogen gas. A hundred tons of steel and copper generating thousands of volts of electricity is cooled with hydrogen. Sounds like a recipe for an explosion movie style, yet there aren't any.

jeffbee 5y ago
There aren't any because hydrogen cooled turbomachinery is complex and high-touch. There are systems that circulate the gas out of the generator and into separators that remove the inevitable air contaminants and dryers to remove the water. They aren't really seal-and-forget systems like a helium-filled hard disk drive might be.

binbag 5y ago

Is this a reprint from April 1st?

CuriouslyC 5y ago

One nice feature of hydrogen is that you can use it for lift and also for fuel (and it has good energy density). I've been wondering for a while if hydrogen airships couldn't make flying cars a reality. It seems like a hybrid jet/zeppelin could find a sweet spot in terms of performance and sustainability.

jandrese 5y ago
The necessary bulk of the airship for human transportation is a serious crimp in the practicality of such a solution. Technology can't make the bag small enough because it is limited by physics. Even if we could build ultra-rigid and outrageously light bags that could have all of the air pumped out for a vacuum you still need a fairly large balloon to carry people. One person would displace 70 meter^3 of air, not counting anything else. That's not going to fit in your driveway.

fsckboy 5y ago

this article reads like the "a world without zinc!" school documentary spoof subplot on the Simpson's https://www.youtube.com/watch?v=U1iCZpFMYd0 https://www.youtube.com/watch?v=U1iCZpFMYd0 and the spat He... no, that's helium... She has with helium and in favor of hydrogen overshadows the more interesting suggestion at the end, that airships might make a lot of sense for cargo transportation. I wish the article made that case better!

joefigura 5y ago

Interesting piece! I think the article makes some good points, but I don't think that helium is the reason that airships have failed to find use cases. The benefits of hydrogen do not change the fundamentals of the business case. Hydrogen's cheaper, but even using helium the lifting gas is <20% of the operating cost of the airship. The hangar, cost of the vehicle, and maintenance are all more impactful than the cost of the lifting gas. The bigger hurdle that airship startups have faced is the upfront cost of developing a new vehicle with a many ton payload. Projects trying to build very large airships have so far to get a vehicle to market, because of the amount of capital it requires and the lack of a strong, specific commercial case (Hybrid Air Vehicles, Cargolifter, Lockheed's Hybrid Airships). Changing the lifting gas to hydrogen does not address those challenges. But airships are certainly underutilized - I'm optimistic for their future!

csours 5y ago

I thought the bigger safety problem with lighter than air travel was weather? As in, anything less than perfect surface conditions may result in disaster when you go to moor the aircraft.

findthewords 5y ago

A clear example how money in the military-industrial complex (or DARPA) directs innovation paths. The military does not approve of hydrogen blimps, and so neither can the civilian sector use them.

jeffreyrogers 5y ago
None of the other countries are doing it either, so it isn't just DARPA. I think it just doesn't have an obvious use case. Everyone says cargo, but what is it better at at than rail, truck, ship, or air (cargo jet)? If you want cheap you go with rail or ship. If you want fast you go with jet and then truck for the last mile. Airship would be cheaper than air, but noticeably slower, so it basically has to compete with truck on price. Can it do that? Maybe, I have no idea.
toomanybeersies 5y ago
The military haven't used airships since the 1930's because transatlantic aeroplanes rendered them obsolete. Not because of some military-industrial complex conspiracy. Every couple of decades the DoD decides that blimps are back in fashion and throws millions of dollars into blimp projects. Inevitably they cancel the project and decide they don't want them. Admittedly they've all been helium, but the reasons for cancelation are usually related to capability and the intrinsic qualities of lighter-than-air flight, and not cost. The past 20 years, they tried Integrated Sensor is Structure (USAF) [1]; Long-endurance, Multi-intelligence Vehicle (Army) [2], Blue Devil (USAF) [3], Walrus advanced technology demonstration (DARPA) [4], and a handful of other boondoggles [5]. If anything, the concept of viable airships in the 21st century is just a defence contractor gravy train. [1] https://en.wikipedia.org/wiki/Integrated_Sensor_is_Structure https://en.wikipedia.org/wiki/Integrated_Sensor_is_Structure [2] https://www.ainonline.com/aviation-news/defense/2013-02-22/us-army-cancels-lemv-surveillance-airship https://www.ainonline.com/aviation-news/defense/2013-02-22/u... [3] https://defense-update.com/20120529_blue-devil-2-airship-deflated.html https://defense-update.com/20120529_blue-devil-2-airship-def... [4] https://www.flightglobal.com/darpa-details-plans-for-ultra-large-army-airship/54350.article https://www.flightglobal.com/darpa-details-plans-for-ultra-l... [5] Congressional Budget Office, "Recent Development Efforts for Military Airships" (2011) https://fas.org/irp/program/collect/cbo-airship.pdf https://fas.org/irp/program/collect/cbo-airship.pdf

Baeocystin 5y ago

Hydrogen gas leaks through everything, and embrittles most metals. It is not an easy substance to work with. Combine that with having one of the widest ignition ranges of any flammable material, and I'll just stay on the dubious side of it ever getting used as a large-scale lifting gas again.

jeffreyrogers 5y ago
It doesn't embrittle aluminum at normal temperatures and stainless steel is significantly less affected. I agree it is hard to work with, but think the reason it isn't used in this sort of application is more due to economics than inherent properties of hydrogen.

xphos 5y ago

So like I think the claim about the thermite coating could be wrong. That is my only concern you can't have the ship burst into flames in a minute. I don't know the truth of the hindenburg but it does seem like you could mitigate the flammability risk under good conditions but like security also comes to mind what if these things get hijacked. Like they do move slow but are basically a moving ball of death if they light on fire. https://www.airships.net/hindenburg/disaster/myths/ https://www.airships.net/hindenburg/disaster/myths/

rozab 5y ago
Aeroplanes are also all of these things. And things go south a lot quicker when they get hijacked.

deleted 5y ago

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foota 5y ago

Out of curiosity, would it be feasible to produce enough helium for commercial use through fusion (either power generating or not)?

dragosmocrii 5y ago

Although there's a slight difference in meaning, I prefer the term zeppelin to blimp. fyi: the difference is in the frame construction. A zeppelin has a rigid frame that keeps it's shape if the gas is lost, whereas a blimp has a semi-rigid frame that will deflate if the gas isn't present.

kQq9oHeAz6wLLS 5y ago
I think "rigid airship" is an often used term as well
dredmorbius 5y ago
"Zeppelin" is a manufacturer designation or brand name, akin to "Kleenex", though it's become somewhat genericised. "Rigid airship" is the generic term.

newbie789 5y ago

This article is interesting. “Hydrogen doesn’t explode without being mixed with air first then ignited” is a kind of funny statement. I read that as “hydrogen doesn’t explode outside of when it does” I’d ask “was this written by a hydrogen sales team?” but it’d be mind boggling if it weren’t. The blaming of special interest groups right off the bat, and the blaming the lower-performing helium as the cause for a crash (that iirc, involved a leak so I’m not sure how that 8% difference could’ve saved everyone) are naked examples of sales speech. “Maybe you’ll blow up! Who cares? You get 8% more lift and stick it to the uh, Bureau Of Mines”

Tepix 5y ago
The article does have a point. On airplanes we have highly flammable fuel. It's safe because it is contained. The same could be done with the hydrogen in an airship.
- dredmorbius 5y ago
  Jet fuel doesn't inherently mix with air, on its own. (It does mix with air in high-speed impacts, which results in flame but not *explosions.) Jet fuel, kerosene (intermediate in weight, viscosity, and volatility between petrol and diesel fuels) is remarkably inert for something that burns. You can extinquish a match in it.

frompdx 5y ago

I'm always hopeful that airships will make a comeback. I would love to be able to travel from the United States to Europe on an airship, just like they did at the in the early 20th century. I can see a lot of advantage from a comfort perspective, even if it does take more time than a plane. If you are interested in the history of airship travel, and its rise and fall, I highly recommend The Deltoid Pumpkin Seed by John McPhee. It's a short book about an unlikely union of ex Navy airshipmen and evangelical Christians chasing the impossible dream of brining airship travel back in an era where the world had moved on from airship travel.

briefcomment 5y ago

Is it possible to make a road ready hovercraft that uses lifting gas like hydrogen? Getting tired of particulate matter from tires, brakes, road wear, etc.

artichikin 5y ago

This article is very USA centric — it centers around it being banned for lift in the states — but that wouldn’t stop just about everywhere else on the planet from building hydrogen air ships, if they are viable.

supernova87a 5y ago

How often are the blimps fully deflated of their helium and then refilled, and is all that helium just basically let up into the atmosphere and wasted? Given some of our recent helium shortages, it seems really wasteful, even if it may be (currently) not costly.

elihu 5y ago

A couple other options beside hydrogen/helium: vacuum chambers, hot air. I don't know if we have the technology to build a compressive structure that can withstand atmospheric pressure and yet be lighter than the air it displaces. That sounds like an interesting problem to work on. I imagine getting it to work out would be easier the larger the structure is, within reason. I assume that hot air isn't competitive with either hydrogen or helium in terms of lift, and it takes additional energy to keep it hot. On the other hand, air is free and it's not inherently flammable by itself. Maybe a well-insulated airship that acts as a solar greenhouse could get quite warm and stay that way?

ant6n 5y ago
> I don't know if we have the technology to build a compressive structure that can withstand atmospheric pressure and yet be lighter than the air it displaces. That sounds like an interesting problem to work on. I imagine getting it to work out would be easier the larger the structure is, within reason. It doesn´t exist so far. There are very strong forces involved. I`d say it´s more likely there would be connected small enclosures that could make that work. Perhaps some sort of solid foam blocks with vacuum inside - but it may provide much less lift than a true vacuum.
elihu 5y ago
To follow up my own comment: I suppose these aren't mutually exclusive. For instance, you could have an airship filled with hydrogen or helium at 1/2 atmospheric pressure and kept hot by solar heating. For helium especially it might be an effective way to keep costs down (since helium is so expensive) and maybe keep it from leaking out quite so much. Similarly, using hydrogen at partial vacuum would mean having less of it on board, which is sort of good from a flammability point of view. Though on the other hand, it means that if the skin is ever broken you'd have outside air mixing very quickly with the hydrogen inside due to the pressure difference. That's probably a bad thing.

cycomanic 5y ago

I haven't seen anyone mentioning cargolifter [1] which was a company in Germany which tried to commercialise the development of a cargo airship (incidentally using helium). They had a lot of press coverage at the time and many shareholders were private investors. They did got bankrupt in 2002, largely because development of an aircraft is expensive and long. Maybe someone needs to excite Elon about it to get sufficient funding. [1] https://en.m.wikipedia.org/wiki/CargoLifter https://en.m.wikipedia.org/wiki/CargoLifter

ivanb 5y ago

Hydrogen airships are terrible against any kind of attack. They are so slow and flammable that one can bring them down with just a flying toy. I'm not even talking about incendiary ammunition. You would not put people or expensive cargo on a low and slow flying bomb in 21 century.

dredmorbius 5y ago

Airships are a concept which is inherently attractive given their theoretical simplicity, but highly impracticle on closer examination. They're not impossible, but they're far less viable than would first appear. Heavier-than-air powered aircraft were largely a result of powerful engines and energy-dense fuels. Emergence of mass-produced automobiles and the first aircraft occurred within a few years of each other. Materials science (duraluminium) was another major factor. Aeronautical engineering was largely secondary and likely would have emerged with experience regardless. For airships, the key enabling factors are lifting gases and materials, in this case the gas-bag envelopes. For early-20th-century airships, the material of preference was ox intestines, glued together. One airship required the entrails of ~800,000 oxen. See EngineerGuy’s video (accompanies his book) on the doomed British Airship R-101: https://youtube.com/watch?v=ixxXhZVFXxQ https://youtube.com/watch?v=ixxXhZVFXxQ There are some factors which might help, and others which still work against, airships. Rather than hydrogen, a "hot helium" design might offer greater flexibility. There's actually some research of such concepts: https://ui.adsabs.harvard.edu/abs/1987STIA...8748646R/abstract https://ui.adsabs.harvard.edu/abs/1987STIA...8748646R/abstra... Materials science might allow for improvements in gas-bag design. Plastics made mid-century blimps possible, and modern Zeppelin semi-rigid airships rely on PVF (polyvinyl fluouride), principally. Graphene or other monatomic sheet materials might allow for thinner and/or stronger designs. Similarly structural components (frames, guy-wires) might benefit by both materials and computer-aided design and improve mass:volume ratios, safety margins, maintenance requirements, or other factors. Improved lifting gas properties or mixes might also be an option, though here chemistry is fundamentally limiting. Integrating PV capabilities into an outer skin might reduce fuel requirements, though even covering all the top surface of a USS Los Angeles sized airship (200m x 30m) would provide less than 300 kW of power. The Zeppelin NT (70m x 14m) has 3x 150 kW engines (450 kW total). Routing electricity next to hydrogen gas bags might prove problematic. https://en.wikipedia.org/wiki/Zeppelin_NT https://en.wikipedia.org/wiki/Zeppelin_NT In all, I expect materials innovation might contribute to fractional improvements in airship capabilities or aspects, but not improvements of multiples. Note that airships also have the submariner’s problem concerning buoyancy: lift is proportional to volume, but volume varies with pressure. As a submarine descends, there’s additional pressure on its buoyancy tanks, compressing the gas within them, reducing buoyancy further. As a submarine sinks, it wants to sink further, which may prove interesting if crush depth is exceeded. (Destin Sandlin’s recent “Smarter Every Day” series aboard the USS Toledo is pretty fascinating in this regard.) By contrast, in an airplane, lifting forces increase as one descends, and decrease as one ascends. For airships and balloons, you’ve got the reverse problem: as they rise, the lifting gas expands. After a point one of three things must occur: the gas is vented (and lost forever), the envelope expands, or the gas is pressurised (meaning carrying the additional mass of compressors and pressure vessels). One of the biggest disadvantages of airships compared to jet aircraft is that jets fly above the weather, at 30k--40k feet, whilst airships fly in it, often at only a few hundred feet altitude. The Hindenberg’s cruise altitude was 200m (650 ft), see: https://www.airships.net/hindenburg/flight-operations-procedures/ https://www.airships.net/hindenburg/flight-operations-proced... Operating and flight ceilings of 16k and 21k feet were apparently possible. Passenger Zeppelins were unpressurised. Note that this makes crossing even relatively low mountain ranges a challenge. Given the large number of airship failures in which wind and weather were primary or contributing causes, this is a major handicap. The altitude record for an airship is 95,000 ft, though that’s for an unmanned system consisting of little more than the lifting balloons, frame, and propulsion. https://newatlas.com/highest-airship-flight-record/20379/ https://newatlas.com/highest-airship-flight-record/20379/ High-altitude flight requires a pressurised passenger compartment (increasing costs and risks), supplemental oxygen (the jet airliner's air-bleed pressurisation system is not available), and other factors. The other massive disadvantage is that airships serve a limited number of roles and compete poorly against alternatives. They're highly intermediate between heavier-than-air airplanes and ships. They lack the former's speed (115 kph vs. 1,000 kph), and the latter's cargo capacity (160 tonne vs. 210,000 tonne for a Triple E-class Maersk container ship). Overland, airships would have to compete with river and canal traffic, rail, and trucking. The remaining remote-location work is likely of relatively limited economic value. https://en.wikipedia.org/wiki/Triple_E-class_container_ship https://en.wikipedia.org/wiki/Triple_E-class_container_ship That leaves the prospect of intercontinental trans-oceanic voyages, probably largely passenger and high-value cargo. Airships are likely to be limited to ~100 -- 200 kph. A transatlantic trip (NYC-LON) would take 1dy 4h to 2dy 8h. A Los Angeles -- Shanghai trip would be 2--4 days. Los Angeles to Sydney, 2.5--5 days. Given no other options, I could see that happening, but even a drastically curtailed fuel-based airliner industry would likely be preferable. Given either a carbon offset, synthetic hydrocarbon analogues, or carbon-neutral fuels, this seems more likely.

cantagi 5y ago

Why could an airship not be made using a vacuum instead of a lifting gas? A quick google reveals that someone has thought of this before: https://en.wikipedia.org/wiki/Vacuum_airship https://en.wikipedia.org/wiki/Vacuum_airship and it seems like it might not be possible with currently available materials. Would it be possible to reduce the density of helium for the same pressure by electrostatically charging it to make the molecules repel, effectively turning the airship into a giant capacitor with alternating +ve and -ve sections?

DonHopkins 5y ago

SF author Fritz Leiber wrote an alternative history short story called "Catch That Zeppelin!", which won the 1975 Nebula Award for Best Short Story and the 1976 Hugo Award for Best Short Story. https://en.wikipedia.org/wiki/Catch_That_Zeppelin https://en.wikipedia.org/wiki/Catch_That_Zeppelin! >When Fritz Leiber sees a Zeppelin moored at the Empire State Building one afternoon in 1973, he realizes that he has shifted into another timeline — one where a more decisive defeat of Germany at the end of the First World War led to greater international prosperity and a deeper, more acceptable peace, with the result that America was willing to sell Germany helium for use in airships, thereby preventing the Hindenburg disaster. Also, the year has changed from 1973 to 1937, and Leiber has become a patriotic-but-peaceful German airship engineer named Adolf Hitler. https://www.goodreads.com/book/show/40626645-catch-that-zeppelin https://www.goodreads.com/book/show/40626645-catch-that-zepp...