Cargo Airships Are Happening

The (biggest) problem that keeps airships from practical use is that they are huge sails. Big sails mean even small amounts of wind can be powerful forces acting on the airship. In the air a big push from the wind might be safely managed, but if you're near anything solid such as the ground, you can get smashed to bits.

To safely operate a suitably efficient (large) airship, we'd need both huge specialized docks with extremely strong mooring structures to keep wind from smashing the airship into whatever is near it, and a system (such as a 3-axis propulsion system on the airship) that is capable of counteracting wind force acting on the airship when it's near the ground or other solid objects and not docked.

Despite the many attractive advantages of airships, there's yet been anything like a good solution to this problem. There are other challenges too (what do you do when you drop off your cargo and the airship wants to shoot up into the air? Vent gas? Rapidly compress your gas?), this is just the biggest.

> There are other challenges too (what do you do when you drop off your cargo and the airship wants to shoot up into the air? Vent gas? Rapidly compress your gas?)

Not to detract from your overall point, but you do the same thing you do when burning fuel while cruising: Add ballast.

Yes, but how do you add ballast to an airship while it is underway? Simple: condense water out of the exhaust like the zeppelins did.

> Simple: condense water out of the exhaust like the zeppelins did.

Citation? Would not the condenser need to burn fuel, thus lightening the ship?

You are carrying fuel and using oxygen from the atmosphere to combust it. When it's hot, it's a gas. By simply cooling it and recovering most of it, you are potentially left with more mass than you started off with... and Oxygen is relatively heavy.

The article describes electric airships

The GP asked about burning fuel. But in the case of electric airships, you can run an electric condenser, extracting atmospheric water vapor.

I think they're aware of all these problems because they do mention almost everything you said in the linked post thinking through the idea: https://www.elidourado.com/p/cargo-airships

Obviously that was simply a post thinking through everything hypothetically and I didn't read anything that seemed like they actually had the best solution, but at least they seem to be aware of the challenges to landing and off-loading cargo efficiently.

Reading that article I see no proposed solutions to this sail problem. They mention wind as an issue for delivery times but not safety. There's also no acknowledgement that the "scaling law" that makes building huge airships lucrative also makes these problems worse.

I think if that was the biggest problem, they'd be used much more. There are a lot of places with light and regular winds, and we're also pretty good at predicting winds in the 1 day forward timescale. And of course there's the regular and predictable high winds that were traditionally used by sail ships.

The article is talking about atlantic freight trips - middle of the ocean is not one of those places with light winds.

That seems like it would be really bad for energy efficiency: now you need batteries large enough for propulsion during the whole trip, plus extra for extracting water vapor.

Why not just take on some liquid water at the destination when you drop the cargo?

You're both missing the forest for the trees, when the airship is electric obviously you don't have to add ballast while flying because you don't have to compensate for burnt fuel.

This idea of extracting water from air keeps coming back, but every time someone tries it, they learn of the same thermodynamic limits. It is extremely energy-intensive to extract water from the air, and it only really works if the climate is humid enough that there is water in the air to extract. This is exactly what a dehumidifier does, and the off-the-shelf version you can buy at home depot is no more than 5-10x worse than the thermodynamic limits - those generate a pitiful amount of water for a lot of energy intake.

"Hindenburg made 17 round trips across the Atlantic in 1936 — its first and only full year of service — with ten trips to the United States and seven to Brazil."

The ballast is for cargo, which needs to be picked up and dropped off. Fuel is just a potential solution.

Do we even need to extract the water? The point is to capture weight, and the only reason to liquefy the water is to store it more efficiently, by volume.

Storing higher humidity air doesn't sound very efficient, storing liquefied humid air sounds like a disaster waiting to happen, and storing compressed air sounds like an unnecessarily complicated alternative to just compressing the hydrogen.

Because that's less flexible and there may not be water at the destination in the first place. That said, Flying Whales are trying to do exactly that, because ballast tech just isn't capable enough yet.

The article describes diesel electric airships.

You're failing to see the secret that is exposed by the fact that their Chief Engineer comes from hyperloop. They're going to dig tunnels connecting all their destinations and run the airships underground in a vacuum sealed network. No atmospheric drag at all! Bingo!

Right, I am not saying they're right or wrong (not something I would know anything about), but it seems they've been vaguely aware of the issues from the start. Namely, before the SpaceX engineer and starting the company.

Just cover the thing in solar, and run it on electric. Add a couple of wind turbines too. I mean, the whole concept is preposterous, so why not just lean into it?

> what do you do when you drop off your cargo and the airship wants to shoot up into the air? Vent gas? Rapidly compress your gas?

As long as it's just one small bubble with hydrogen, you can flare it off or combine with oxygen from the air outside to reduce lift.

Solar powered airships floating around the world, following the prevailing winds, accepting durable goods by… catapult or something, delivery by chucking it out the window over populated areas. Paint them some nice pastel colors and we’re in Solarpunk world.

Jet packs and tax free shopping as next step. Wait for your friendly airship to come around and go get your duty free stuff somehow... Surely there is some places they can visit on the way so it counts...

Why condense water from fuel or the air then when you can just connect to the local municipal water system? You're already at port!

How can you call yourself an engineer and work on the hyperloop. Literally only takes about 30s of thought to realize it is an impossible idea.

A modern ship can make the same number of trips and not be dependent on weather at all.

Please reveal the impossibility of the idea?

Wouldn't delivery be done by quadcopter drones? There have already been pilots projects where Amazon does delivery by drone in a couple of places. I don't think they were a success, but an airship adds some constraints that might make the more viable. Downside is the copters needs to return to whatever altitude the ship is currently cruising at, which might be close to their ceiling.

But on a side note my first reaction to the headline of this article was "no they are not". Airships have a number of fundamental drawbacks that I don't think we are any closer to solving. Ultimately they're as slow as a cargo ship, can only carry a relatively small and light payload like an airplane, require specialized ports like ships and airplanes, and are expensive to build and operate. They just don't have a viable niche.

> Wouldn't delivery be done by quadcopter drones?

But if you drop them via cheap parachute, you wouldn't need anything to return. I bet they'd only be slightly less accurate delivery than what their "don't give a damn" delivery system in place now.

I avidly wait for that factorio mod!

The fine article shows them lowering a container from a crane. I'd love to see them connect the crane to an electric generator and actually regen the potential energy of the container into electricity.

or the final panel of an xkcd comic!

What makes you think "docks with extremely strong mooring structures" is a particularly difficult problem to solve? A giant metal hook anchored in concrete attached to the ship with some steel cables doesn't seem like it would be that difficult for a team of smart engineers with a multi-million dollar budget to figure out a good design for. Certainly not so difficult or expensive as to threaten to make the entire concept nonviable.

Even a light wind with a giant sail area is dangerous. An empty 20ft shipping container weighs about two tons. If it's hanging from an airship and the wind causes it to shift even a foot it'll kill you dead if it hits you. If it hit a light frame building it would bust right through a wall. It would also easily knock down a non-reinforced cinder block wall.

A cargo airship would lowering cargo would essentially be an incredibly dangerous crane. The sail area of the airship makes it far more dangerous than lowering external cargo with a helicopter.

I don't particularly defend feasibility of Hyperloop, but did want to point out that your comment sounded awfully like when people were ridiculing the idea of human flight, landing on the moon etc... Finding engineering solutions to what looked as "impossible" challenges were some of the best feats of humanity so far.

Maybe, but as you point out you lose your pinpoint accuracy and also it consumes a parachute for every delivery. Your customers end up with a whole bunch of cloth to dispose of and you have to store enough for every delivery. The beauty of the quadcopter is that it is reusable. It can also use air brakes to help slow the descent and really only burn power on the very last bit of the delivery and then on the ascent back up, where it is no longer burdened by the package.

It has to be more energy efficient to re-compress your lifting gas back into storage bottles. What do modern airships do? This has to be a solved problem.

Historically the difficulty isn't in building the mast, it is in preventing the airship from being smashed into the mast by the wind. Or in dramatic cases flipping end over end because it was only moored on one location.

You seem to be losing the spirit of the conversation, and that spirit is the idea is preposterous. In that spirit, being reusable is irrelevant. I'm sure if they wanted, they could figure out how to make a disposable parachute that can be composted or recycled. At that's a far as practical as I'm willing to go

Interesting. Why a mast and not just the ground? Pull up the mooring lines (probably more than the amount needed to actually hold the ship, for redundancy), connect them to the ship, then pull on the lines with winches until the ship is on the ground. That's basically how seafaring ships work... are there any unique challenges with airships?

The unique challenge is that everything is way up in the air and constantly moving around.

how about people? why only freight?

enter the Jump-o-cabin, press The Button, be catapulted into airship 3, fly to somewhere else, get parachuted down..

Bonus: the just-landed Jump-o-cabin can be used as free-standing toilet. uh, Was already used as...

I calculated, than the airship with 100tonns capacity, and wind speed 25m/s require 25tons trust to compensatecthenwind. It is Boeing jet engine, not Electric fan require.

Sure.

If you put it above ground, you are a few short bullets from killing everyone in the loop. Hitting a wall of air in a vacuum at hundreds of miles per hour is going to be like hitting a brick wall. Ask any reentering spacecraft.

The same problem exists underground, the weakest points being the stations themselves which can be bombed.

A failure in the system itself (even just a power outage or malfunctioning equipment) would mean people suffocate inside after a matter of minutes.

So, sure, it is possible to create it, but it is impossible to make any sort of safety guarantees. In other words, literally any other mode of transport would be safer, including a hydrogen-filled dirigible.

So, sure, the concept itself might be possible, but an engineer doesn't concern themselves with possible. That is for scientists. An engineer considers what is realistic AND possible, because that is an engineer’s job: to make the possible real. This cannot be real; literally no regulator would ever sign off on it.

I like the people delivery idea. Maybe wrap them in bubble wrap, and then drop them with a smallish parachute like NASA did with the Mars lander.

I've seen some YouTube videos converting Boeing jet engines to electric, but you have to smash that like and ring that subscribe bell to be able to see the build

Even more efficient might be raising another container at the same time in a (mostly) balanced manner. Then you don't have as much loss from conversion/storage.

Fun fact: many inclined elevators work this way :)

Not necessarily - the great thing about airships is that they can go anywhere, and pick up cargo at places that aren't ports. You can go pick up logs from logging camps directly, for example.

The copters can fly into a net suspended from the airship, rather than needing to gain all the altitude themselves.

Huh? In what world is a hyperloop going maybe 700mph comparable to a spacecraft reentering from orbit at 17,000mph? Also, maybe there's something I'm missing but spacecraft can and do renter from orbit intact, thus proving that this problem is solvable even when the forces at play are orders of magnitude greater. Apply your safety argument to passenger airliners or even ordinary trains and you'll see that they are also "impossible to make safety guarantees" for.

> Your customers end up with a whole bunch of cloth to dispose of

We're coming up on Great Depression 2: Electric Boogaloo pretty soon [citation needed], so we could just do the same thing our ancestors did with flour sacks back in the day and turn them into children's clothes. Or maybe even tents for the ever-growing homeless camp-cities. The dystopian possibilities are endless!

Why bother with a parachute? Just redesign houses with bungee-net drop zones for packages. It'd probably result in less damages than the average FedEx delivery anyway.

> So, sure, it is possible to create it, but it is impossible to make any sort of safety guarantees.

Right, because cars and planes and trains and boats and bicycles and footpaths and airships all famously have 100% perfect safety track records, right?

... with unsustainable CO2 emissions. We need to be ramping down fossils use rapidly.

> The same problem exists underground, the weakest points being the stations themselves which can be bombed.

Few if any modes of transportation are safe when bombs come into play.

Build two masts and anchor from bow and aft?

Couldn't the sail factor be reduced by ionizing wind coming at the vehicle who then keeps away from the vehicle while going around it, depositing little energy?

Ships are pretty good emissions wise because if the sheer amount of cargo they carry, even with burning the absolutely worst crap they can

Do you think Hydrogen is free or something? Worse, is that Hydrogen comes from water (at least that is the current cheapest way), meaning you get Oxygen and Hydrogen from it, but if you let the Hydrogen go, it will escape the atmosphere and be whisked away by solar wind (same with Helium). Then, you have just Oxygen, which is a green-house gas.

At least the ships release other chemicals in their emissions that decrease solar warming.

Blowing up an empty train station doesn't kill everyone on a train.

They have mitigations. If a plane breaks down, it can glide. If a regular vehicle breaks down, it can be moved off. If a train breaks down, people can just get off the train. On a hyperloop, where are they going to go when surrounded by a vacuum? What about whatever is behind them also waiting?

There are no mitigations and the only option is death. Maybe you can repressurize the tubes ... assuming there is power to do so ... to evacuate people. This is the main issue, there is no air outside your vehicle. If a window breaks (see: airplanes where this happens every so often) everyone inside is dead. No discussions, no second chances.

That's the problem. The main problem and you can't engineer around it. There are no emergency procedures because if you have an emergency, you are dead; and there will be emergencies.

> In what world is a hyperloop going maybe 700mph comparable to a spacecraft reentering from orbit at 17,000mph?

In that case, the air can just "go around" the space craft. Try pushing down a syringe with the end capped. Bet you can't do it. Now imagine that at 700 mph; you will get a lot of heat and destruction. No heat shielding will save you.

> Apply your safety argument to passenger airliners or even ordinary trains and you'll see that they are also "impossible to make safety guarantees" for.

See sibling comment.

There are mitigations though. Assuming you have sensors in every segment, you could detect the vacuum ahead deteriorating and brake.

Equally, if the train stopped in an emergency, the valves around it could fail safe to open and let the atmosphere back in. The train has to be pressurised anyway so a small delay there isn’t unreasonable

Sure. I'll play. I assume those sensors are always powered and never malfunction and so, now the train is stopped in a vacuum. What now? How do we get the people out, and all the trains behind them now also stopping. If the tracks are below ground, where is the nearest valve that can open? Given some parameters to chatgpt, because I can't be bothered to do the math myself, it takes ~5 minutes to fill a 500m section with air. So, that assumes a 500m sealable section with an independent valve. So, there would need to be some kind of system that can seal a section on power loss or breach, without a train running into in-progess.... so, 500m sections are too small. The sections need to be ~5km which would take nearly an hour to fill with air that won't kill you instantly. So, if there were structural integrity issues with the train, everyone is guaranteed to die. If there is a critical power loss, hope that it can scrub the CO2 out of the air for at least an hour without power. If there is a breach, hope that it isn't in your section or is at least 3 sections away.

Killing everyone in the train because someone gets in a fight and fires a gun is pretty much a non-starter. That's the real problem you got to solve. It's not like a plane where someone can fire a gun in nearly any direction without consequence to the plane, firing a gun in literally any direction on a hyperloop would mean certain death for everyone on board.

It's in a vacuum, it's not like you can drop oxygen masks. In a vacuum, your blood boils and your eyeballs are sucked out. It's a pretty shitty way to go, but you'll lose consciousness before the worst of it.

You stretched 500m to 5km but kept only one valve. Why?

And presuming that whole wagon doesn't burst because a couple of bullet holes, is it unrealistic for onboard pressurized tanks to keep up with escaping air while outside is getting pressurized?

Do you mind sharing the parameters you fed GPT?

> You stretched 500m to 5km but kept only one valve. Why?

This is the worst case scenario by assuming only one valve is functioning. Theoretically, even that could break, but I'll assume there are enough redundant valves that at least one will always work.

> is it unrealistic for onboard pressurized tanks to keep up with escaping air while outside is getting pressurized?

It depends on the size of the hole. A bullet hole for an average train car size would take hours to become deadly and could easily be corrected by onboard air (depending on how much air is onboard), but a gun isn't going to cause a bullet sized hole. It is quite violent. Something like a catastrophic door failure, or derailment, would deplete the oxygen in less than a second. Basically, the inverse of oceangate; instead of everyone imploding, everyone would explode. Since I also suspect there will be valves on the vessel to handle releasing small amounts of gas enroute (to allow adjusting internal pressures to match destination atmospheric pressures), this could also get stuck open.

I suspect, if anyone were to actually do this, they would go for low pressure (like high altitude) instead of a vacuum. The speed of sound is so high, they could easily reach it in the tunnel. Further, people just need oxygen masks instead of dying a horrible death.

Nobody has mentioned this while following along with all the US hyperloop failures, so it is clear nobody has really tried engineering this thing, IMHO, and why I said my original comment about it. If someone were actually engineering the system, these are all pretty obvious things. As described in the original 1800's systems and by Elon, it is an impossible system. I used to think about this thing all the time in the '90s, so maybe I've thought too much about it.

I'm also curious about other issues, like maintaining low atmosphere or a vacuum (these were the key failures in older attempts in the late 1800's) in the tunnel in an energy efficient way. If it can't be kept, things will deteriorate at an accelerated rate, introducing catastrophic failures early in the system lifetime. There is also maintenance and inspections to consider. Not to mention that underground is already dealing with increased pressure from the earth, it also has to support it while maintaining a vacuum. I suspect above-ground tubes are probably far cheaper to build and maintain, but at that point, you might as well build a train.

Since moving to Europe, I can go pretty much anywhere in Europe in a day. Heck, I can get on a train this evening, sleep in a bed on the train, and wake up on the other side of Europe tomorrow morning for breakfast, for a little more than the cost of an average hotel room. Trains are great, well understood, and pretty fast. The problem the US has (as seen with the California high speed rail), is that they 'want it to be all US based' instead of hiring experts from across the ocean who work on these things every day. The US has no experience building high speed networks, which is part of the reason the hyperloop even has a chance at getting money. It's a collaborative Dunning-Kruger effect.

I think if the US can get to the point where they can develop high speed networks, in general, then stepping up to something like the hyperloop is a good idea. Other nations are still working on the hyperloop and they are making good progress, but I'm not as familiar with their details.

Is there any evidence that this is really a problem? Zeppelins were in use for decades completely safely, as are modern airships.

Oxygen is not a greenhouse gas lmao

> Maybe you can repressurize the tubes ... assuming there is power to do so

Fail-open air valves are a thing.

> to evacuate people

Emergency exits are a thing.

> If a window breaks

Why would a shuttle in an underground vacuum tube have windows?

> The main problem and you can't engineer around it

Pretty sure people said the same thing about most of the modes of transportation I mentioned above.

...which is why they don't bomb empty train stations. I'm not saying it's just like a train.

Or you try to capture water that's already condensed... cloud droplets.