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The Second Age of Airships
The Telegraph has a story about a new generation of airships. It says "It's a new vehicle. It's a hybrid because we're combining helium lift, aerodynamic lift, a hovercraft landing system, and vectored thrust... If you can get beyond the word airship — because that has a lot of history — people think about them differently."
we'll have peak helium.
http://news.slashdot.org/story/10/07/05/2159215/Price-Shocks-May-Be-Coming-For-Helium-Supply?from=rss
A libertarian shat on my carpet once. Claimed the free market would sort it out. -Ford Prefect(8777)
Hydrogen is safe as long as you don't coat the outside of your airship with rocket fuel.
I will forever associate the word "airship" with Final Fantasy VI. Damn you, early-mid 1980's birth!
Living With a Nerd
Is this really how we should be using the Helium we have left on Earth?
If you can get beyond the word airship — because that has a lot of history
Ya, "history", all the bad kind
I work for the Department of Redundancy Department.
Arrogant prick. Seriously, you think the problem with your world changing brilliant idea is the name? No, the problem is that it sucks. To quote Archer "You combine all the comforts of a cruise ship with a slightly faster method of travel.", its a dumb idea. Thats the problem.
So basically, -1 troll/offtopic is really slashdots way of saying "I hate that you thought of something before me."
Half as dense as helium (so twice the lifting power), orders of magnitude cheaper, and far, far safer than a jet plane carrying aviation fuel.
It's not difficult to design safe(*) hydrogen airships nowdays. There's no excuse, other than irrational fear, for restricting airships to using expensive helium.
Jolyon
* - safe, as in the risks are at a similar, or lower, level than comparable forms of transport in everyday use.
Please read my Canon EOS tech blog at http://www.everyothershot.com
Much better
"If you can get beyond the word airship..."
Why would you want to? Airship is an awesome word.
Wouldn't you like to own a private airship? Call up your buds "hey man, wanna come over and watch the Superbowl? Yeah, we'll be hanging out on the airship. I'm planning on floating in circles over the lake at a few hundred feet. I get a 60 inch flat screen, two kegs, and a party sub. Bring your sister."
Cool!! Airships! Does this mean we all get brass goggles and leather aprons and other Steampunk essentials?
We need way more retro-future stuff like this! That's freakin' awesome.
Next, zombies in London. :-P
Lost at C:>. Found at C.
Every science magazine since the 1950s has felt obliged to talk about the "blimp renaissance" once a year, along with a "promising prototype".
I'm still waiting for the news of a prankster somewhere that flies a large RC blimp with a picture of Osama on it.
It's going to be a Glorious Ride!
Or maybe not
He picks a name that abbreviates to HAV. Hmmm Haich - Aiii - Veee... HIV!
Seriously...
Monorail!
the preceding comment is my own and in no way reflects the opinion of the Joint Chiefs of Staff
They are not the first trying to revive the airship. Several years ago, CargoLifter was developing a "second generation airship". Despide heavy subsidaries they've gone insolvent, because the engeneering required to create an actually useful airship is not exactly trivial, and the list of potential customers is astonishingly small. Well, at least they left a damn big hangar that now contains a nice amusement park.
The other problems with hydrogen are (a) that it leaks out of just about everything even faster than helium does and (b) your safety statement is utterly unproven - because nobody has recently built full size airships and compared the safety record to current winged aircraft, which are quite extraordinarily safe. Historically, airships in the 1930s might have been safer than airplanes - but since then airplanes have had over 70 years of technical advancement which have paid off massively.
From scarped cliff or quarried stone she cries "A thousand types are gone, I care for nothing, no not one."
... I won't have to dodge chocobo droppings, I'm all for it.
Imagine all the people...
The only form of transportation I think could be better that trains is some combination of low-altitude flying pulled by engines on the ground. 100% electric, safety provided by ground, weight of engine, fuel, guidance, etc, supported by ground. Needs some kind of "rail", but fast-switching rails now can be as flexible as roads.
Build your own energy sources from scratch. http://otherpower.com/
Sure, there is a place on this planet (or just above it) for airships. However, trans-atlantic passenger service isn't one of them.
‘You go to Richmond Park International. At 11 o’clock on Thursday you get on board the SkyCat200. There are hundreds of staterooms on it and you dinner dance your way across the Atlantic. At two o’clock on Friday afternoon you’re getting off at the East River in New York. You’ve travelled 3,000 miles overnight and there’s no jet lag.
Or, you could get on an airplane, be in New York in a fraction of the time, and spend the rest of the day recovering from jet lag.
Realistically, SkyCats would be most useful in the transport of heavy loads – the largest SkyCat can carry up to 200 tons – to harsh environments
That's more like it. If you attack problems like heavy lifting, surveillance, even tasks like fighting forest fires, you don't have to sell it by saying "it's a hybrid"
At that time they tested a full-sized airship against a range of artillery including a Russian mounted machine gun filled with .22 calibre armour-piercing incendiaries and a SAM-7 surface to air missile. What they learnt was this: the airship is almost invincible to attack. Helium is an inert gas, so it doesn’t explode.
Did the test include shooting at the crew? I'm sure they'll find that sitting nearly motionless over a well-armed enemy does not make airship pilots invincible.
I need trepanation like I need a hole in the head.
Nope, still peak oil. The envelope of an airship can still be filled with hydrogen (made from fossil fuel) or with air (heated with fossil fuel). Some analysts claim that the problem with LZ 129 Hindenburg wasn't that it was filled with H2 as much as that it was painted with solid rocket fuel.
You can call anything ecological now. BP successfully marketed themselves as an ecological energy company. They should stop calling these "airships" and call them "super-ecological-airplanes", quoting fuel usage compared to jets.
Build your own energy sources from scratch. http://otherpower.com/
I bet it catches on just as fast as the metric system in the US!
Until we get lots of airships all contending for airspace directly at the destination
Then how about a compromise: You can keep building dedicated facilities where these airships land, but unlike with ships, you don't have to locate them all on the coast. I've got a name for them: "airports". Because airships can use shorter runways, an airport on a given amount of land can probably service much more traffic than an airport built for conventional jet airliners.
Now imagine the costs if the thing must always take off at constant load. It would be like old sailing ships that had to fill up with gravel ballast to make safe return trips (because if they returned empty the wind could simply push them over.) Currently an Airbus 380 can transport about 150t of freight one way, and if it makes the return journey empty, OK it is a wasted trip but it requires less fuel for takeoff, which is significant on short hauls.
If you try to solve the problem by having pumps to transfer gas from the envelope to storage tanks, to control the buoyancy, you have to factor in the cost of ferrying around the pumps and the tanks. It is not impossible, but it would be complicated and expensive and require extensive safety testing before it could be certified. Much of the simplicity relative to an airplane would be lost - and you still end up with something that requires as much or more room as a 380 - a helicopter replacement this is not.
From scarped cliff or quarried stone she cries "A thousand types are gone, I care for nothing, no not one."
At 20,000 feet, what would an RPG fired by an insurgent do to the thing? That doesn't seem high enough to avoid ground-to-air fire, and without the maneuverability of a fighter jet, or even helicopter...
GENERATION O98346: The first time you see this, copy it into your sig and remove a random number from the generation. T
If you can get beyond the word airship
It's not an airship you stupid thick-headed Saxon git!!! IT'S A BALLOON! Do you hear!? Airships are for kiddy-winkies!!
.
Don't forget the Shenandoah, R38, Roma, Akron and Macon. The Los Angeles was the only rigid US airship that didn't go crashing into the earth or sea and that is only because we the good sense to ground it before it had to chance to take out another crew. I can think of no other mode of transportation with such a failure rate and in the end it has only done Goodyear and Goodrich any good.
I hate to rain on this guy's parade, it is an awful neat one, but what advantage does it serve? In war it is the definition of slow moving target. For surveillance we already have satellites and they don't require a crew of airmen, massive hangers that rival the wonders of the ancient world and they run well under an airship's budget. Travel? For the speed and price why not take a cruise; the last time I check a lighter than air craft doesn't have room for a waterslide, chorus line or multiple all-you-can-eat buffets.
Don't get me wrong, it is terribly fascinating idea. If you said, 'Hey, you wanna take a ride on a airship, here are the tickets', I'd jump at it, but just because it is an interesting idea doesn't mean it was a good one.
It is not a blimp it is a rigid airship!
Hello Airplanes? It's blimps... congratulations you win.
-If you have not watched Archer, you have missed out.
would be cooler if it could also be a flarecraft in ground effect.
THL phish sticks
I think the acronym for Hybrid Air Vehicle has a lot of potential.
It is unwise to ascribe motive
Did the test include shooting at the crew? I'm sure they'll find that sitting nearly motionless over a well-armed enemy does not make airship pilots invincible.
WTF?!
the preceding comment is my own and in no way reflects the opinion of the Joint Chiefs of Staff
Why would I want to? It's a wonderful word.
> because that has a lot of history
Yes. A fine one.
Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
You win.
– Archer
Seriously - no Archer fans here? My god this so the Skytanic!
Danger zone anyone? Anyone?
-CF
Lockheed's P-791 airship has been flying around Palmdale for several years now. This is a product of Lockheed's Skunk Works. It is slightly heavier than air, and those four "feet" are lift fans. This has advantages and disadvantages. It takes fuel to stay up, for one. On the other hand, takeoff and landing are easier; the craft can land on a runway and taxi as a hovercraft. No mooring mast required.
The P-791 looks far more controllable than any previous airship. Rudders and elevators are ineffective at low speed. The P-791 has four propellers, each fully and independently steerable in two axes, plus speed, and maybe blade pitch. Plus the four lift fans. So it is controllable in all six degrees of freedom, even at zero speed. With classic airships, having twenty controls to manage by hand would be hopeless. With flight control computers, it's possible, once the airship has been characterized. That's really what flight tests of the P-791 are for - figuring out the control strategies. In the video,it's clear that the propellers are all being steered independently, which indicates computers and sensors are busily working to stabilize the beast. This is probably an easier job for the Skunk Works controls team than any of the stealth fighters they've done, all of which are unstable in all three axes.
The Zeppelin NT has a similar, but less flexible system, with three steerable fans plus a lateral tail rotor, all controlled by a fly-by-wire system. I suspect that the Skunk Works put more degrees of freedom into their prototype than are really needed, so that they could experiment with different control strategies and find the best way to control their unusual craft.
The Zeppelin NT has a compressor system, so they can reduce lift by compressing some helium into a high pressure tank and letting some of the ballonets deflate a little. This is preferable to dumping ballast or helium.
"football pitches" Huh?
"silver and crockery" you mean dishes, right?
"frolicking dogs" Whaddya?
"mug of Lady Grey" Tut, tut!
"mulish lay people" We call em Lusers
"sheep, a duck and a cockerel" a Whaterel, do you mean a chicken?
"too Byzantine for a computer to process" would it have killed you to say complicated?
"22 calibre armour-piercing incendiaries" I think you meant 22 millimeter
I killed da wabbit -Elmer Fudd
Even if it runs on renewable energy, isnt there a Heluim shortage that will make it dependent on a scarce non renewable "propulsion" source?
The best test environment is production. - Me
chrome://browser/content/browser.xul
Nope! We should ban this right now!!!
RIP America
July 4, 1776 - September 11, 2001
If Helium rises because it is less dense, would it be possible to force a balloon open, using some sort of supports, and end up with essentially a balloon filled with nothing, and thus able to rise? Or is this beyond current material science?
That would be something I would be interested in.
There's a couple of folks who make nice livings taking folks on their sailing ships around during the vacation season and off season, they just do there thing. Work 4 months off 8.
RIP America
July 4, 1776 - September 11, 2001
Instead of running from it, they should embrace the "airship" designation and use a steampunk motif for all styling, both interior and exterior. I'd be more likely to buy a ticket.
I mean... these ships are supposed to fly over the entire planet right? I guess pirates would love to shoot them down.
So if I understand it, the thing does not have enough buoyancy to stay aloft without its engines, or enough engine power / the right shape to stay aloft without the helium. So what we have here is a disaster that can happen if either component fails.
Nullius in verba
WTF is a hovercraft landing system?
Do you throw out the eels to slow down your descent?
Low speed. Less maneuverability than an airplane. Lame.
Frink: Nice try floyd, but you were designed for scrubbing, and scrubbing is what you shall do.
The LEMV will hover above Afghanistan at 20,000ft, equipped with the sort of super-powerful cameras that can read a signature on a letter from four miles away. It will be, Taylor says, ‘an unblinking eye’, recording every move made on the ground. In theory, no one will be able to plant a roadside bomb – a device which has claimed the lives of so many British soldiers – without the cameras seeing who did it and, more importantly, where they came from. And, if the LEMV is a success, it could prove to be a tipping point, ushering in a new age of airships.
Talk about big brother... Still, I suppose nobody has considered the possibility that it may just get shot out of the sky by those with a grudge?
This is obviously nonviable airship. Just looking at it shows the problems. It should look like a wooden British Warship (cannons included) with numerous propellers sticking out the top. And the designers name must be Cid.
Who would win this election: Andrew Weiner vs Andrew Weiner's weiner.
Great read that goes into this concept in detail. http://www.johnmcphee.com/deltoid.htm
Let's see... this is about the fifth "Second Age" of the airship, isn't it?
Let me guess. They'll be fusion powered and piloted by AI? Oh, and don't forget the emergency jetpacks!
The Secret Nose Blimps are a myth. Where did you get such a silly idea. You probably believe in yeti, black helicopters, the Face on Mars, Art Bell, and Stan Lee.
Just to be clear, the agents knocking on your door having nothing to do with your mention of Secret Nose Blimps.
Politics is the art of looking for trouble, finding it everywhere, diagnosing it incorrectly and applying the wrong fix.
however there not practical for common use. It's like having the speed of a train, and all the disadvantages of a ship.
The Kruger Dunning explains most post on
Oh teh humaniteez!
Have gnu, will travel.
I forget the super famous author, but in the book Diamond Age this very thing is done to help hold up large buildings. The enabling technology is nanotech capable of manufacturing large diamond bladders (both strong and airtight) then using pumps, then nano-pumps, to vacate the volume enclosed in the very rigid shapes before the pump aperture itself is sealed with diamond by the nanobot construction methods.
The only practical reason that this is impractical today is the lack of that nano-deoposition in real space. To date we cannot create a structure that is strong enough to remain voluminous but empty under 14.5lbs per square inch large enough to provide nontrivial lift without using materials heavier than the volume of air displaced.
But someday... yes... with the right materials a "simply empty" or "nearly empty" rigid sphere/elipse/etc could be used as a lifting device.
Actually, at much larger scales, one could make a "giant greenhouse" that could lift itself based on air temperature differences with no vacuum or specialized lifting gas at all. But these things would be "small city" sized. (See R. Buckminster Fuller for details of this sort of floating city.)
Innocent people shouldn't be forced to pay for inferior software development.
--"Code Complete" Microsoft Press
Airships in the sky seem to be the hallmark of alternate realities. Having lots of them in our sky could confuse things.
(1) one only needs the "modern" technology of the "compressor" to re-compress the gas into dense storage cylinders. They _used_ to vent the gas because the compressors and storage were more expensive and heavy than the cheap replacement gas. Modern technology can solve this really easy. You can fit 80 cubic feet of air (so probably like 100 cubic feet of helium) into a scuba tank, and it would be quite heavy thereafter. Intelligently done, a large number of flexible ballon-like bladders and one or two semi-rigid (pressurized) bladders would be easily sufficient to change the overall displacement of an airship by up to 50 percent without even getting into "high" pressures (e.g. more than three atmospheres or so in the pressurized fixed-size bladders). It's not rocket science, its basic pressure mechanics and displacement.
(2) many of the craft being discussed are only "mostly buoyant", with vectored thrust and lifting bodies etc, so that the static weight of the craft is neutrally boyant, then only the thrust to lift or fly the cargo is spent. E.g. the goal is to make the weight of the _vehicle_ free. Think of the helicopter. Right now we have to maintain thrust to lift the copter and the people, which uses far more fuel than just lifting the people.
(2a) once you are lifting only the cargo weight, crashes are lots safter as something with the weight of the cargo but the drag profile of the whole vehicle will have a much lower in-atmosphere terminal velocity, unless of course someone decided to shape it like a giant dart pointing straight down. 8-)
So, Good Sir Nay-Sayer, yes, if nobody actually thinks about the problem, then ballast becomes a hassle. But then again, if nobody thinks about breaks, a speeding car is quite a problem as well.
Innocent people shouldn't be forced to pay for inferior software development.
--"Code Complete" Microsoft Press
Airships are slow; there is no way around it. They have huge cross sections and drag is a big factor. If your airspeed is 30knots going into a 30knot headwind your ground speed is 0knots. Even a moderate wind of 10knots will decrease your speed by 33%. Crosswinds are a similar issue. An airship can spend much of its forward speed compensating for winds.
Mass is also an issue. Large airships are docked to towers to keep them on one place for loading and unloading. This docking process is very precise. It is somewhat like porcupines kissing; too fast and the tower gets knocked over and/or the airship damaged, too slow and you never get there. Winds complicate the matter. Many accidents have happened due to strong gusts or wind dieing at inopportune times.
Then there is landing area. Each airship needs a circle at least the radius equal to the length of the airship as it needs to be able to swivel into the wind. You could put the airship inside a hanger but that maneuver it tricky (can not be done in windy conditions) and the hangers are huge/expensive.
Depending on the winds, the airship may note get out of the hanger, get loaded, get launched, reach the destination, get tethered and or get unloaded. This makes flights very unreliable in even moderate weather.
I just love how the article says that airships will save lives in Nunavut. I am sure that sending 200 tons of stuff that the locals can not afford to buy will really help the situation. Throwing stuff at people is not the solution to social issues.
You know, it may sound like blasphemy, but there are other credible metrics other than the all mighty dollar.
People routinely get on big-ass vehicles that go nowhere to have a good time, have a few drinks, and generally enjoy the novelty of not slaving away 24x365.
bizarre, ain't it?
the preceding comment is my own and in no way reflects the opinion of the Joint Chiefs of Staff
The main determinants of fuel consumption are: 1) speed; and 2) the surface area of the front of the vehicle (since that determines how much air must be pushed out of the way). Since airships are very large, they will never be fuel efficient unless they travel very slowly. If they travel very slowly, then we must ask: why not use a train or a ship? Trains and ships will always have vastly greater carrying capacity, because they don't require helium to lift their cargo which has modest lift for a given volume.
In short: if speed is not important, then trains and ships will always be far cheaper and carry far more; and if speed is important, then airplanes will always be faster and more fuel-efficient at high speeds.
Airships are neglected because they suffer from fundamental limitations and therefore have few uses.
Granted, airships may find niche uses. Airships do have several advantages: first, they can hover for long periods; and second, they require little infrastructure (like long landing strips, ports, or train tracks). Since they can hover for long periods, they have found a use as floating advertisements, and they may find a use as floating observation vehicles for the military. Since they don't require infrastructure, they may find a use in transporting cargo to areas which lack airports, train tracks, or ports. But they will never take over the bulk of transport between major areas, because of fundamental limitations of the technology.
Every few years, someone starts a company to revive the airship. The venture always fails, because o
f fundamental limitations of airships that will always prevent widespread adoption. Perhaps some com
pany will eventually succeed, but they will succeed in a niche market, not widely.
The parent of my parent post brings up putting rocks in sailing vessels as argumentative support, he is wrong for at least two reasons.
(1) Many modern non-sailing vessels still use ballast. The problem isn't old-timey nor is it "solved", nor is it _really_ the same issue as buoyancy with respect to airships. In a seagoing vessel the problem is that a non-trivial amount of the vessel must remain "above" the water over which the vessel must remain buoyant. As such, to remain upright, as cargo is loaded above the waterline, one must add weight below the water line to keep the ship upright. In an airship the entire ship is "submerged" in the air, so the issues are much simpler. That is, an airship and a submarine are in the same domain, but an airship and a sailing ship are not.
[ASIDE: One of the things the boat commander of a submarine must watch for is rolling over during initial dive. In surface operation, the sub is a surface ship, and its center of gravity is below its center of buoyancy just like any other ship. In underwater operation the center of gravity must be above the center of buoyancy or it won't sink below the surface. That moment when the two must cross is tricky, as they must "cross", not "pass each other". That is, if say the port side takes on ballast faster, the center of gravity would pass to the port of the center of buoyancy and the ship would roll. The normal way to make this happen most safely is to be under-way at the time of submersion or surfacing so that the wing-like bow planes and rudder etc. can be used to counter any small tendency to roll. The single most dangerous submarine maneuver is the static (non-moving) submerge. It is virtually never done as messing it up is expensive in both lives and equipment. Surfacing is safer than submerging as "blowing" the ballast tanks can right the ship very quickly if it starts to roll, and can be done before reaching the surface. That leads to that really dramatic "breaching" thing where a significant fraction of the sub leaves the water entirely before crashing back to the surface. Dramatic, "safe", but again, hard on the men and gear. (I hear it's fun though... 8-)]
(2) Ballast was much more spoken of, and "tricker" in the age of sail as the power source (the wind) wanted to push the ship over anyway. Additionally, _letting_ or even encouraging the wind to push the ship over a little (e.g. heeling) could lead to increased speeds and efficiencies.
(3) Ballast in seagoing vessels is more important and variable because you want enough to stay upright, but each little bit more than that sinks the ship a little more, causing more of it to interface with the viscous watter instead of the less-viscous air.
(4) Water can not be meaningfully compressed. Things "denser than" water also cannot be meaningfully compressed. (e.g. compressed enough to substantially effect displacement.) Air and lifting gas is eminently compressible. Consequently airships, in issues of both displacement and buoyancy, are completely dissimilar to anything seagoing (except a scuba diver in a wetsuit 8-) so none of the natures and limits you (grandparent poster) mention really apply as such.
Innocent people shouldn't be forced to pay for inferior software development.
--"Code Complete" Microsoft Press
You only _really_ need the compressors and at the cargo terminals anyway.
Land ship. Hook up hose. Re-compress the gas with a target displacement smaller than that needed to lift the empty ship. Take off cargo. Load on cargo. Vent gas to desired buoyancy. Fly away.
Keep the gas on the ship. Keep small compressors on the ship for in-flight tweaking. Use shore power and shore compressors for the big changes.
Heck, "vent" the gas to an empty (e.g. partial vacuum) ground-station holding tank and you can probably offload the gas faster than you can get the cargo unstrapped.
These are not hard issues at all, and involve less "dangerous or difficult logistics" than refueling.
Innocent people shouldn't be forced to pay for inferior software development.
--"Code Complete" Microsoft Press
is my suggestion for a new term that avoids the Hindenburg stigma. Imagine having an Air Yacht that you kick around the world in. Plenty of room for friends, complete freedom to come and go as you please. Saw a story about a guy who did that in Paris at the turn of the century, travelling from his rooftop to friends' rooftops in his private dirigible.
Do what you can, with what you have, where you are.
The age of the airship was pretty much over by the time the Jet engine was developed. Seems like most of the modern airships eschew jet engines. High speed, high altitude air ships that never have to come down into the more turbulent layers of the atmosphere. I'm smoking crack.
Years ago I did a public radio piece on this ... here was my conclusion:
"Is this new Zeppelin a true revival? Most likely its just a symptom of what's called "helium head" disease. To be a "helium head" means you've fallen in love with lighter-than-air travel - airships, blimps, dirigibles, or zeppelins. And in them you see an instant and easy solution to nearly all the world's transportation problems. This disease of helium-headiness has afflicted humankind for over a hundred years -- and likely will continue for as long as humans move about the globe."
The complete piece is at: http://www.engineerguy.com/comm/4477.htm
So what happens if a terrorist gets a hold of one and runs it into the freedom tower (aside from USA invading another OPEC country)?
Do they just bounce off or actually cause any damage?
They'll all be designed with Linux on the desktop. And the best bit is, we'll have plenty of helium from all the fusion power plants!
If you were blocking sigs, you wouldn't have to read this.
You are partially right on that. A 80cf scuba cylinder is rated to 80 cubic feet of air, not helium. Helium storage would actually be significantly higher. The scuba tank is rated based on what walls of the cylinder can handle as outward pressure. Helium is going to have significantly less outward pressure than normal air. I would bet that you could double the amount of helium stored.
What you are thinking about is available on most jet flights and is called "First Class". Well, you do have to go through airports, but at least they let you out of the plane while the others are required to "please stay seated".
Nevertheless, you can still build airships without helium. See http://www.flyingkettle.com/outline.htm [flyingkettle.com] . Steam airships have some potential advantages such as being able to make more lift gas on their own, and can reduce lift by venting without losing a huge amount of valuable gas. The envelope can also act as the condenser for steam engines, thus making such engines light enough for use in the air.
The lifting body and wings allow the craft to operate under a much wider envelope of loads and buoyant lifts. A huge problem with airships is maintaining desired buoyancy despite variations in temperature, altitude, barometric pressure, fuel expenditure, and condensation or icing loading - helium is too expensive to vent when the airship is light and cannot be generated in filght as can hydrogen, hot air or steam*. Being able to descend or ascend without losing ballast or lift gas and to operate without massive ground crews and facilities should significantly reduce the operating expense associated with helium airships.
*Steam is potentially the most economical lift gas since it gives 60% of helium lift or 200% of hot air lift, is essentially free if generated as a by-product of a steam engine, and the airship envelope acts as a condenser for the engine, reducing weight. This makes both the lift gas and propulsion much more efficiently produced than helium bags or IC engines See www.flyingkettle.com for more details.
[Pasted together from my responses the last two times "new" airships were on Slashdot]
"Is life so dear, or peace so sweet, as to be purchased at the price of chains and slavery?" - Patrick Henry
The real problem with the Hindenberg fire was the painted cloth outsides catching fire. The Hydrogen made a nice POOF and losing it helped the ship fall, but if you had a fire like that in a helium-filled Zep, it'd fail just about as fast.
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
Gasoline burns hotter than hydrogen, but thanks to the Hindenburg crash video, we don't have hydrogen cars either.
Gasoline burns, hydrogen explodes. There's a difference. And the issues with hydrogen cars are a multi-paragraph post that I don't feel like writing right now, but (lousy energy density, present impossibility of storage, no infrastructure) are the main reasons, not lingering Hindenburg memories. Who on earth modded GP Insightful?
Wrong and Wrong.
Gasoline explodes AND Hydrogen explodes.
Gasoline burns AND Hydrogen burns.
E.G.- Gasoline EXPLODES inside your Car's IC engine. Surprise! That is how a gasoline engine works.
But you can burn it on a wick- but you had better be careful when the flame creeps down to the container of gasoline and air. That's why we don't use gasoline in coal-oil lanterns.
As well, Hydrogen will burn, if it is controlled by a small nozzle such as a welder's torch.
And- Why we do not use Hydrogen in cars? IT's TOO DAMN EXPENSIVE! And hard to make and control!
Gasoline is quite easy to make from Catalytic crackers. You can do this to make Hydrogen also, but whats the point?
You are still stuch refining fossil fuels. AND AND- Hydrogen is a shitload harder to store and control than Gasoline!
And guess what? At STP, there is much more hydrogen in a gallon of gasoline, than in a gallon of hydrogen.
Figure THIS one out!
I haven't read Scientific American lately.. Are BMW and Shell still inserting those ridiculous "Hydrogen Cars - The FUTURE!" advertisements? The SciAm ad agency must be giggling all the way to the bank...
.
- aqk
F U
Don't fly them over the ocean, they look particularly vulnerable to sharks.
Slowly waving my hand - "This is not the sig you are looking for."
> > "Gasoline burns, hydrogen explodes.
And yet Hydrogen can support combustion in a gas-jet nozzle while gasoline, in the form of a Fuel-Air explosive device can (guess what?) be exploded:
http://www.youtube.com/watch?v=GmRASCHJe2Q
(David Bowman, EVA near HUGE Monolithic Win-PC in orbit around Jupiter) "My God - its full of Malware!"
> > "There are just too many potential sources of ignition (sparks from machinery, static discharge) for it ever to be safe enough for flight, if we hold it to the same standards of safety that commercial jets are.
Then I guess that Boeing holds to different standards than do you!
http://business.timesonline.co.uk/tol/business/industry_sectors/transport/article3675188.ece
'"John Tracy, Boeing's chief technology officer, said: “For the first time in the history of aviation, we have flown a manned airplane that was powered by a hydrogen battery.
Boeing said that hydrogen fuel cells were unlikely to power the engines of large passenger jets but could be used as backup or auxiliary power units onboard."'
(David Bowman, EVA near HUGE Monolithic Win-PC in orbit around Jupiter) "My God - its full of Malware!"