In my eyes zeppelin travel would be a welcome alternative to current air accommodations. In the same way I prefer taking a room on a train to air travel, I would prefer a cabin on an airship to either. If cargo can be transported, then I would expect a similar arrangement to the existing container ship passages.
Many aeroplane disasters have involved far more people.
> An unmanned hydrogen filled airship may spare passengers and crew in case of an accident because there is none of either, but if catches fire over a stadium or a highway while carrying 5 grand pianos that wouldn't make it less deadly than the Hindenburg.
The riskiest bits seem to be takeoff and landing, so one should take care that those don't happen near a stadium, at the very least.
Just imagine that thing floating mightily in the sky like the actual starship from Star Wars.
You could even jump with a parachute or a wingsuit from the starfighter hangar bay.
If any zillionaire out there wants to tackle this...
I think your dream is unlikely to come to fruition, but zillionaire is in the right ballpark!
> But for all their high-tech advances, Hunt said, the new airships would still get their buoyancy from hydrogen, a highly flammable gas that is 14 times lighter than air. It’s the same gas the Hindenburg and the other big zeppelins used in the 1930s.
As a reminder, the Hindenburg was originally designed for helium. They were unable to get the US to lift its ban on the export of helium under the Helium Control Act of 1927.
> As an additional bonus, Hunt said, the fuel cell would generate as a byproduct water that could be released as the craft passed over regions hit by drought.
That's isn't much amount of water, and certainly not enough to affect a drought.
Figuring 2km long x 200m x 200m that's about 3E9 mol of gas. You need some lifting gas for the vehicle weight - call it 1E9 mol or 5E8 mol of water, which is 30K tons. That's 27 acre feet, which appears to be enough for about 15 acres of potatoes for a growing season, using numbers from https://www.ardentmills.com/media/1725/colorado-quinoa-susta... .
And I think I'm highly over-estimating.
Venting hydrogen is not nearly as expensive a proposition as venting helium. Nevertheless, the Graf Zeppelin was fueled by blau gas, which has a density almost the same as air, to avoid the issue.
> Docking airships is challenging due to their large size, limited control mechanisms, and high wind drag. Another particular issue is to keep the airship attached to the ground during windy episodes. The diameter of the airship hydrogen carrier (Fig. 2) is similar to the height of the Empire State Building in New York. It would be very challenging to keep such large airship from collapsing under strong superficial winds. On the other hand, balloon hydrogen carriers are not rigid and vary in size. Their volume on the ground is around seven times smaller than in the stratosphere (assuming a maximum operation height of 15 km). This is convenient because the size of the balloon hydrogen carrier on the ground is only 58% larger than the Hindenburg class airship
Just because we find a pocket or two that we haven't found before doesn't mean that the problem is gone. The new pockets are usually more difficult to extract helium from, and storing it and transporting it is a painful process to say the least. The problem won't be truly gone until we find a way to gather it from outer space.
I have wondered about a similar thing in the context of solar panels floating on the oceans: if the weather and the waves get too rough, just go drive to -5 meters or so to avoid damage from the waves and surface after the storm is over. But of course, salt water corrosion and growth of marine life on the panels is going to be a big problem with that
Even if the problem was somehow solved for blimps, (perhaps with an internal "diving bladder" filled by compressing some of the carrying gas), their cross section at lower altitudes would be prohibitively big, making them effectively unmaneuverable. A very high altitude blimp would effectively be a one-way vehicle, it could raise as an uncontrolled balloon (then it might even be acceptable to not solve the slack issue at all), then operate as a dirigible at target altitude.
In WW1, Germany flew some "height climber" zeppelins, which could reach 20,000 feet (still well within the range of stormy weather), but they could carry very little payload. They were also fragile, vulnerable to damage by quite ordinary weather. I think all other airships were limited to a few thousand feet, at least in practice.
"Unlike blimps built in the last 50 years, the the suggestion is to revert to an even older technology and using hydrogen for lift, cheaper, safer and more environmentally friendly than the alternatives."
Why should Zeppelins be held to a far higher standard than airliners?
Envelope volume of the Goodyear blimp is ~8.5e6 liters.
Density of hydrogen at STP is ~0.09g/L. If we filled the Goodyear blimp with that we'd have ~765kg of hydrogen gas. Let's round up to cover the slight operating pressure and say we have 800kg of hydrogen.
Energy density of hydrogen is very high, 141MJ/kg. Energy density of Jet A is ~45MJ/kg.
So our hypothetical blimp has the equivalent of 2600kg of Jet A on board.
The Goodyear blimp only holds 8 passengers plus two pilots. A similarly sized jet would be the Learjet 60. It holds 3500kg of fuel.
So, most jets probably have more on takeoff and less on landing.
So a hypothetical of a zeppelin crashing into a building might light that building on fire, but most of the hydrogen from the vehicle would escape upwards into the atmosphere without having contributed to the building's fire.
I once imagined a "double-bagged" airship, in which the bulk of the lift is from hydrogen held within a shell of helium. I also wondered about a non-flammable hydrogen-helium mix, but it would apparently have to be mostly helium. I would guess, however, that modern developments in strong antistatic films and hydrogen detectors would make pure-hydrogen airships safe from fire.
That'd solve the implosion problem since presumably all the little hulls wouldn't fail at once.
Vacuum airships are an interesting concept but have not advantage compared to gas airships in practice.
Hook up a vacuum pump to a flask. It isn't going to rise as the air is pumped out. Edison's light bulbs did not float.
That was my original question: is it technically feasible to make such a chamber from light enough materials (my first guess would be some carbon tubes supporting a carbon fiber tarp or something like that.
> Edison's light bulbs did not float.
One could argue that it was too small (of course I imagine making a massive lightbulb would not make for a good solid structure, also glass is heavy). A hot air balloon does not float either if you lest it too much.
We'll see, but maybe it is like nuclear fusion energy - always just around the corner.
"Our goal is the presentation of the first vacuum airship in history in Brescia on December 13th of this year , for the anniversary of Francesco Lana, the Brescian inventor of vacuum airship, who was baptized in Brescia on December 13th 1631."
Okay, I wouldn't give up immediately. I'd also try a vacuum onion, with multiple layers of aerogel and aluminum, with each successive layer evacuated to a different pressure.
6) Have you done structural calculations on the vacuum ballon yet? What material can be strong enough to withstand air pressure and light enough to rise in flight?
There are two models: a basic model and an evolution model. The first one, on which a degree research was done at the Polytechnic of Turin, is a sandwich with ceramic skins and foam in between. This model is lighter than air (obviously if emptied of inner air) and holds an external pressure (with zero internal pressure) up to 1.7 atm.
The second model should withstand a similar external pressure but be lighter and easier to build. If you want, you leave us your email, and we send you the research thesis that was made on the first model, with all the structural calculations. Unfortunately, all information regarding the second model is confidential.
Fingers crossed for December 13th!
A very distant possibility.
But yes, a vacuum lifts approximately 10% better than hydrogen.
So whatever the structure is, if filled with hydrogen or helium it'd work similar.
If you have some sort of mesh holding in a vacuum it's hard to see it's average density being less than hydrogen or helium or even air at the end of the day.
Point is, everything is possible now. A void wouldn't value add.
If there are any Hollywood producers reading this, I suddenly have a great idea for an action film involving maleovelent hackers and a slow moving fleet of explosive destruction.
"And in other news, tragedy struck earlier today, as hundreds were killed when a cargo blimp exploded, dropping its 250 tonnes of cargo 40,000 feet into an apartment block in Chicago..."
And years ago ago I remember seeing Airship industry flying around.
Tame, but also quick, cheap, and safe. I'm glad I'm not an investor in such a firm, but also quietly glad that others are.
The cheap footballs that are thin skinned - we used to call them 'flyaway' balls when I was younger. Because even those, substantially heavier than a balloon, would go off in random directions due to their susceptibility to wind from the low weight.
But actually, I've never thought of a zeppelin this way before. It gives a good intuition - but for the opposite reason you've stated, that they _do_ act kind of like balloons, and that's not what you want from a directed vehicle!
Just be sure to keep in mind that while zepperlins, dirigibles and aerostats are subjected to non-negligible amounts of buoyant force due to low density, that does not make them light, nor easy to push around.
If you carry 20kt of cargo, plus the weight of the vehicle (including the weight of the lifting gas), I don't think a wind gust would blow you away, regardless of how strong it is.
Try to push around a big buoy, that gives an idea of the challenge.
Moreover, spheres are one of the aerodynamically poorest shapes (if not the most), actually worse than a flat sail. That's probably the biggest reason for Zeppelin's shape (or the rugby ball, for that matter).