Could They Ever Return?

[stratplans]

Earlier I mentioned The Big Lifters, a science fiction work by Dean Ing (1988). I managed to reread it (and enjoyed it more than the first time). Here is his vision of a modern airship:

Not a cigar...a lifting body.

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His solution for ballast was lightweight compressors to quickly store gas instead of venting it, although he also had some stores of water that could be jettisoned...most likely as a "suspenders AND belt" approach. One of his applications was both retrieving and loading containers from/on moving freight trains, and delivering it in-stride to waiting short-haul trucks. Trains would have to stop at freight yards less often, bringing rail response times down significantly (ObFilk: Dave Clement, The Grain Trains), and reducing the need for long-haul trucks. In the book, the latter goal drove development of the Big Lifters.

Not many details about structure (beyond composites, with some inflatable structural components--calling Dr Schlock!) or power plants, though double-walled ballonets for fuel gas storage were mentioned. Ing envisioned a million cubic feet displacement for his story. He thought the props would be roughly 18' (6m-) in diameter. The sexiest propulsion was an auxiliary rocket assist, using hydrogen heated by ground based lasers, concentrated by synthetic sapphire into thrust chambers. (OBTW, magnesium alloys are a BAD IDEA in that scenario .) This would be used at strategic points in a route, say for clearing mountain ranges when loaded. Note, this system was a plot device with an ulterior motive. In atmosphere, you might as well use a jet or a rocket, if the fire risk is as manageable as an airliner's.

My own guess, having seen container ships and the versatility of the Big Boxes (& having lived in one ), is that compartments and cargo would be fully modular, & could be dropped in an emergency. Combination cargo chutes and retro-rocket systems, such as those used by Soviet airborne forces, could mitigate such drastic actions. Chute-worthy passenger seats could further reduce the landing jar--Blackhawk helicopter seats, though Spartan and lughtweight, are designed to absorb some impact.

Other SF with food for thought on LTA transport are The Anarch Lords, 1981, by A. Bertram Chandler, and C.C. MacApp's Prisoners of the Sky, 1969.

[PaulGazis]

I'll have to reread Dean Ing's novel. It's been far to long. Thanks for the suggestion!

I believe several hybrid lifting body airships have been built and flown over the past 30-40 years. AN early ship that got a lot of publicity was the Aeron 26. This flew in 1971, an looking at the shape, I can't help but wonder if it severed as one of the inspirations for Dean Ing's work. John McPhee described the project in some detail The Deltoid Pumpkin Seed. Like all of McPhee's work, this well-written, fun to read, and gives a good summary the issues.

The Aeron 26

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The thing looked way sexy -- more like a spaceship than an air vehicle. Whenever I see photos, I can't help but wonder where the Energy Cannons go

[Farfri]

There appear to be several hybrid concepts out there, but nothing that looks to promising.

Conceptually I love the idea of using an airship as a fire tower.

A few ideas that came to mind while I was at work today.

The concept from Sky Captain, and from the USS Akron of a flying aircraft carrier. Honestly in the modern military environment I don't feel they would be vulnerable. Most of the weapons used in air-air combat are missiles fired from beyond the horizon. This means that the aircraft with the most ECM wins. Add to that the amount of weaponry one could mount on an airship, I think it could be a formidable weapon. Just don't get hit.
Military advantages to an Airship, long loiter time, able to refuel and rearm fighters, mobile command and control center, possible able to deploy and repair drones.
One could probably sheath the hull in a layer of LEDs to provide adaptive camouflage, alternatively cover her back in solar panels to charge a set of batteries, so that the ship would not have to refuel.
Final military advantage that comes to mind is the fact that a lighter than air ship can be completely silent. Given modern stealth technology I imagine that one could develop a stealth Dirigible for troop landings, if one was motivated.

A more realistic use would be in the civilian market. There are places that trucks are unreliable due to poor roads. A lumber clearing company could clear an area, land an airship at night, load her with felled lumber, and lift ship once the sun warmed her cells.
I don't know how well they work in excessive cold, but a dirigible could likely make a much safer trek to the northern towns in Alaska than driving semis across melting ice sheets.
Pretty much, if you put on any of the 'dangerous drive' shows an airship would be good there.

-Jack

[Kona]

A more realistic use would be in the civilian market. There are places that trucks are unreliable due to poor roads. A lumber clearing company could clear an area, land an airship at night, load her with felled lumber, and lift ship once the sun warmed her cells.

Good idea! I googled it, and there appear to be some applications for logging, but it’s not very well developed yet. The biggest advantage of air logging is the low impact on the forest environment, and airship, or balloon, logging uses much less fuel and produces less pollution than helicopters. It’s certainly practical, and it would be preferable economically if the government stepped up ecological impact restrictions or offered incentives.

[PaulGazis]

I agree. The applications that seem to keep coming up over and over again are surveillance, exotic luxury cruise ships, sightseeing flights, heavy cargo transport to areas without a transportation infrastructure, and logging. The former will almost certainly happen, since people are already using tethered aerostats and free balloons for a wide variety of data collection purposes. And for the latter, the existence of commercial services that fly heavy lift helicopters like the CH54/S64 suggests that there should be a demand.

To compete with heavy-lift helicopters, a ship would need at least a 10 ton payload. This might work out to something half the volume of the Flying Cloud, about the size of the later WW-I German military zeppelins. I'm sure people are thinking about it...

[polycopter]

The U.S. military wants them to return, maybe:

http://www.washingtonpost.com/wp-dyn/content/article/2010/02/15/AR2010021503088.html

[Thalass]

I'm an aircraft maintenance engineer for an airline in Australia, fixed wing aircraft sadly, but my coworkers and I have been talking about this for a while. (On and off, in between discussions on wind turbines, electric cars, etc)

I think that with a modern composite structure, a good strong modern fabric (racing yachts use woven kevlar, don't they?) outer hull. Efficient diesel generators, and several (six or seven) strong electric-driven propellers or ducted fans that pivot to provide maneuverability... Then it could work. I favour the hybrid airship model, with at least some lift being aerodynamic, where one of the guys at work favours pure lighter-than-air. In civilian applications, the airship would be flying from a modern airport anyway, so issues with ground crew numbers and such aren't that bad. We have three guys seeing in one aircraft, two to push it back. A hybrid airship shouldn't be much different.

With gimbaled pivoting electric motors you would avoid the issues of low speed maneuverability that the Flying Cloud has. And also you could probably fly these in to airports after noise curfews are in place for other aircraft. 50 tons of cargo in at 2am without a sound! (almost haha).

A modern airship ought to be quicker than the classic airships. Even at 250km/h, it would take eleven or twelve hours to get from Perth to Sydney - longer than an airliner's 5 hours, but not too bad. And the alternative is three or four days by bus/truck or train! To cross the pacific (refueling at Haiwai'i) would take two days, I think. (I can't remember the numbers at the moment). All up it may take four days of flying and airport transfers to reach your destination (Perth to Toronto in this case) but I'd much rather spend a few days in a comfortable chair, watching movies or reading a book or something, being nicely refreshed when arriving at the next airport and not having as severe jetlag - than spending 36 hours in a cramped cattle-class seat, getting no sleep and being stressed out at a foreign airport, taking a week to get over the jetlag! haha.

I think it's not a matter of engineering, but finance and public opinion. No doubt if someone tries to introduce an airship on a passenger (or freight) route, someone else will jump up and down and cite the Hindenberg disaster.

Wow, that was alot more convoluted than I thought it'd be. Oh well, bring on the new age of the airships! I'd love to be an engineer on board one. Much better than being stuck on the ground.

*Edit - hope that's ok.

It occurred to me today that a major advantage that a cargo airship would have over conventional air cargo is that since the cargo bay probably wouldn't be pressurised, and so there is much more freedom in the shape it could take. Which means instead of using aircraft cargo boxes (wikipedia tells me they're called "unit load devices"), you could use intermodal containers taken directly from a truck or wet ship or whatever. You'd still be limited to a small number of them (the max weight appears to be just over 30 metric ton each (!), more than I thought it would be), but a large ship might carry ten or twelve (say, 360,000m^3 of helium for the cargo alone, plus airframe, engine, fuel, etc. Quite a large airship!), and would still be quicker and much more flexible than a train.

it'd be an impressive sight!

[Sintaqx]

One very interesting bit of technology I have been looking into is the Vacuum Balloon. It's a very old idea (circa 1670) but with a modern twist using modern materials. The basic premise is that a contained vacuum will displace the air around it without providing any weight for the lifting agent, therefore it will float. The tough part about construction of a vacuum balloon, however, is you need to brace it against atmospheric pressure rather than containing a lighter than air lifting gas at a higher atmospheric pressure. Unless my math is completely bonkers (completely possible given the late hour I scribbled down these figures) a vacuum dirigible measuring around 300' by 65' by 65' with a 4/5A vacuum contained would be neutrally bouyant at sea level at Standard pressure with a gross weight of 80 tons. Decreasing the atmospheric ration increases lifting capacity, 1/2A would give you an effective ceiling of 18,000 feet with the same payload. Lifting capacity changes by the cube of the surface area, so the bigger you go, the lifting capacity rises at an incredible rate. I used the 4/5 ratio because it is the same standard ratio that a hot-air balloon uses, and nearly the same principle.

Edit: Small error in the calculations. The indicated size would have a 15000lb max gross weight at 4/5A. A ship the size of the Graff Zeppelin (50' radius, 776' length) would have a 91000lb max gross weight at 4/5A. Though if you could sustain a pure vacuum in an area that size it's lifting capacity would be an astounding 456000lbs (neutral bouyancy, sea level @ std pressure) with a usable payload of 226000lbs to 18000'

[PaulGazis]

... Lifting capacity changes by the cube of the surface area, so the bigger you go, the lifting capacity rises at an incredible rate...

I suspect that this principle, applied in reverse, is one reason why airship development has languished. For conventional airplanes, lift scales as surface area while weight scales as volume, so all other things being equal, smaller planes can have proportionally higher lift. (They're also slower, have less range, use more fuel to carry a given amount of cargo, and more vulnerable to weather, but that's another matter.) This makes airplanes cheap to develop. But with airships, smaller vessels have proportionally less lift -- indeed, for the Aeron prototypes, the effect of the lifting gas was so negligible that they dispensed with it entirely in the Aeron 26 (see my earlier post). Ships much smaller than 300,000 cubic feet can't carry much of anything. This means one has to start big, with prototypes in the ten to hundred million dollar range, which is a tough row to hoe. Or ho. Or however you spell that darn word.

Several groups have almost pulled it off over the years. And three Zeppelin NTs are flying -- I can look up on a sunny day and watch the Eureka pass by overhead. For that matter, if The Flying Cloud attracts 100 million readers, and each one contributes a dollar, maybe we can build the real thing!

Well, heck, a man can dream

[Kona]

Well, whaddya know...

http://www.techmagnews.com/us-looking-t ... istan.html
http://forum.pakistanidefence.com/lofiv ... 86703.html
http://www.wired.com/dangerroom/2008/07 ... ater-want/