Passenger-carrying airlines do seem to be having their share of troubles. The cargo-only carriers like FedEx and UPS seem to be doing rather well.
Why didn’t you do it the way Lawn Chair Larry did?
If it costs $3000 to fill a man-carrying helium balloon, the cost to fill an airship capable of carrying even a modest amount of cargo would be quite a bit more than $10K.
The essential problem with using lighter-than-air craft for transport is that they must be huge to carry a reasonable payload, and such huge airships would be expensive (both to build and to operate) and fragile. The Hindenberg was 776’ long, had a volume of over 7 million cubic feet, and carried a payload of 112 tons. For a point of comparison, a typical freight train can carry more than 20 times that much, at comparable speeds.
I was going to mention the only marginal difference in lifting capacity between hydrogen and helium, but scr4 beat me to it. I will note, however, that helium is not diatomic molecules, but like all the noble gasses, monatomic (that is, a molecule of helium is a single atom). Hydrogen, however (in common with fluorine, chlorine, nitrogen, and oxygen) is diatomic.
And I’ll also note again that hydrogen doesn’t have nearly the explosion hazard that most folks think it does.
Expensive to build, sure, but why expensive to operate if you’re getting almost all your fuel for free from the jet stream? That’s the major premise of the OP, that using the 150 mph jet stream to carry stuff for free would offer tremendous savings, especially in a world where oil costs are going nowhere but up over the foreseeable future. Sure, you’d have to use fuel to steer the zepp and to get it up to jet stream height, but a jet has to burn fuel to keep it airborne for EVERY INCH OF ITS JOURNEY.
Weather could only be a problem when taking off and docking, because the jet stream, as I understand it, operates above the weather. Over the hurricanes and such. The window for causing problems would be relatively small.
If as Chronos says, hydrogen isn’t all that combustible … something I have trouble with … then cheap hydrogen for lift solves the expensive helium problem. But I’ll have to ask Chronos for clarification found several scientific sites that describe hydrogen as “dangerously combustible” such as this one.
The fact it’s 7 miles up IS a problem.
Zepps and blimps never operated at high altitudes, and still don’t. You don’t see the Goodyear blimp over Denver very often, do you? There are issues of gas expansion to deal with, and you’ll need pressurization for any human occupants and certain types of cargo and that will add considerable weight and expense. Pressurized jets use the jet engine to collect outside air - what will you use? You’ll need a good heater, too, not having that jet engine to use as a handwarmer. I suppose you could just limit things to robot controls (no humans required) and cargo that can tolerate low temps and pressures.
Next problem - the jet stream doesn’t stay put. It shifts around, sometimes quite a distance over a matter of days. This has plagued long-distance ballons throughou the 20th Century. It causes problems for airlines. The jet stream can abandon one path to take up another hundreds of miles away. This makes keeping a regular schedule difficult at best.
Finally - how do you intend to get down? You’ve achieved the bouancy to reach the jet stream, that’s great. In order to get down you need to reduce that bouancy either by adding weight (impossible) or reducing lift. How do you reduce lift? By venting your lift gas… you see, you can’t just fill the thing once and forget it, you have to keep topping it off after each trip. Maybe you could somehow collect the gas and compress it into a smaller volume until it then exceeds the density of air… but again, you’re looking at storage tanks, compressors, motors, and plumbing all of which have weight, take up room, reduce profit-generating payload, and some of which needs to be fueled.
That’s now called “cluster ballooning”.
Doesn’t matter if the helium is in one big container or a lot of little ones - it’s still going to require a certain amount/density of gas to lift a certain weight, and it’s going to cost money.
**Or, use a hollow, rigid sphere of multiphase carbon materials, or nanotube material, & pump all the air out.
**
Think about it.
If the jetstream path varied even more than a mile or two (and I’d bet any amount of money that it does), then you’re going to have all sorts of logistical problems that come up. I subscribe heartily to Murphy’s Law. You’ll be forced down occassionaly in some virtually inaccessible place, have unforseen expenses with hiring extra trucks and people to get the cargo from the different spots, unhappy customers whose cargo was delivered after deadlines because you hit bad weather, etc. The combination just from my own ideas is enough to make me try to make money some other way.
Someone on this board said (arguing very convincingly) that this isn’t possible; that there’s no material strong enough - which makes sense - we’d be talking about making a fully rigid ballon capable of being evacuated, with a total mass of materials less than the equivalent volume (i.e. one balloon-full) of air.
Wasn’t someone toying with the idea of a heavy-lift airship for moving military equipment overseas? Of course, I think I might have read about it in a Maxim, so I could be wrong.