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back to article First rigid airship since the Hindenburg enters trials

The first rigid airship to be built since the 1930s is about to commence trials in California: and the Pelican prototype also features a new technology, never yet flown, which could finally change things for lighter-than-air craft and see the leviathans of the skies make a serious comeback at last. The 230ft-long, 18-ton …

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Anonymous Coward

Re: I wonder how much helium they waste

"The other suicide method that has intrigued me.... "

Interesting hobby you've got there. Is there a monthly publication that followers buy?

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Re: I wonder how much helium they waste

I actually mentioned it in the original post - alt.suicide.holiday FAQ.

It's not a monthly publication, somehow people only wanted the one issue, and after that all their mail was returned...

And it is quite interesting. Suicide was never 'sinful' until the god botherers got the idea that part of you - the soul - isn't yours, it's part of a cosmic godhood that you are just renting, and don't do anything bad with, or you go to the hot place. Greeks and Romans viewed suicide very differently.

There are lots of different methods documented in the FAQ, some are crazily efficient, some are crazily inefficient, and most suicide attempts use the inefficient ones - either they don't know better, or they don't really want to die.

Eg, hanging, you can hang yourself quite easily - and asphyxiate to death with a crushed windpipe. It's excruciatingly painful, and if discovered before you pop your clogs, unlikely to work. Alternatively, buy the right rope, tie the right knots, fall the right distance for your weight, and your neck will snap instantly, with almost no chance of failure.

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Re: I wonder how much helium they waste

I thought the most "interesting" suggestion in that FAQ was jumping off a bridge while tied on - and strategically wrapped - with piano wire.

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Anonymous Coward

Re: I wonder how much helium they waste

"Cato the Younger, who disembowelled himself - ripping out his own intestines rather than let a doctor tend him - rather than live under the despot Caesar."

You know, I crave liberty as much as the next guy, but I think I'd pick 'Live in comfort and wealth under the despot' over 'Die a slow, agonizing death in exchange for mad post-mortem street cred and a guaranteed spot on the Wikipedia 'notoriety' list'.

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A few points

Shear stresses brought about by opposing storm cells.

Quite a problem without satellite surveillance.

Easy to shoot down by AAM.

More so than you might think. In WWII Zepplins were the terror weapon. Machine gun fire did not down them because they make very small holes in a very big skin. It was when both sides switched to tracer rounds and ignited the H2 that they started to drop.

And a dirigable would make quite a gunship.

One of the less appreciated things about airship operations was (AFAIK) that they had no flight simulators for pilots to practice on.

Keep in mind that a truck tire is also an "inflatable gas bag" and tires on carrier aircraft can run into the 100s of psi. So building a lightweight pressure sphere (best shape for high pressure) which does not have to be weather proof (as it's inside the body) should not be too difficult for say 10 atmospheres. Likewise using membranes to separate toxic propellants from driver gases which might dissolve in them is known in the pressure fed rocket field. Making lightweight highly impermeable gas tight membranes is well within the SoA. So using the same bags for air and Helium (on opposite sides of the membrane) is certainly possible and expelling the air should be quite fast.

The question is how big (and how heavy) a compressor do you need to get the responsiveness of the process to work?

I think their is huge potential for this. Imagine floating at near zero speed and watching Eagles or Falcons circling it the way dolphins follow ships.

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Re: A few points

Another problem with WWI Zeppelins for the Allies was the height at which they flew compared to the wood, linen and wire aircraft of the time.

An Airco DH2 in 1915 took about 25 minutes to reach 5,000 ft. In the time it took to achieve an interception, the Zepppelin could have unloaded its bombs and be flying - even higher - for home.

As anti-submarine patrols, the British put a lot of non-rigid airships into the air. How about using an airship to as escort shipping in pirate zones.

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Re: A few points

"As anti-submarine patrols, the British put a lot of non-rigid airships into the air. How about using an airship to as escort shipping in pirate zones."

ASW has been a running theme of US Navy work.

People keep thinking what a huge radar scanner you can skin inside the envelope without turning it into a fuel hog.

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Happy

Possible military use??

Naval early warning aircraft for those 'this week it's vertical takeoff only' QE class aircraft carriers? Like a 'copter, but can go higher and has massively greater endurance.

If the baddies can shoot it down if its 10,000ft above the carrier, then your CAP's failed and the carrier is then not going to be a lot safer, is it?

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Blau Gas

The Zeppelins got round the problem of burning-off fuel by powering the engines using Blau Gas, a hydrocarbon mixture with neutral boyancy.

http://www.airships.net/lz127-graf-zeppelin/design-technology

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Fly with Helium, but Burn Hydrogen

They should investigate a mixed helium / hydrogen concept: The hydrogen could be burned off in transit to lower buoyancy as required.

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Anonymous Coward

Why bother to land?

I think we need a flying aircraft carrier!

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Optional

Surely the idea here is that it would not be flown into a warzone? I'm not convinced they are trying to create it to fly into active warzones where they do not already hold the air. Take the Iraq war as an example, within 1-2 days of the conflict there was little/no threat of planes being shot down (although it did still happen, didn't it). Given the load something like this could hold, landing even close to where you'd like to be will still be a better idea than trying to get everything in using conventional planes (Considering cost/how much this can move) i'd have thought.

If it's largely hardware (vehicles, etc) then it can move on it's own after you land, if not and it's equipment then it's just loaded up and moved after landing via vehicles. I'm not convinced you'd even bother trying to fly something like a C130 into an active warzone where you don't already hold air dominance so i don't see this as being much different really.

If your against an opponent who has a reasonable air force/surface-air defence, i don't think this is "that" much more vulnerable than any cargo plane and if you are going to fly it over SAMs, etc then you deserve to have it shot down.

Just what i reckon...

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Hot Helium anyone

You can get much more lift from helium, and use less of it if you heat it up. No one ever seems to follow this idea up. BTW you can make helium in a fusion reaction, the only problem is the radioactivity....

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Re: Hot Helium anyone

BTW you can make helium in a fusion reaction, the only problem is the radioactivity....

And the cost.

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The main problem with airships is not the one addressed here.

And it is essentially that the strength to weight of available materials limits their size if they are to handle anything more than quiet air conditions.

Even carbon fibre wont substantially make a large airship capable of carrying a decent load, feasible.

There may be a very small niche market - as the Goodyear blimps have exploited - for the ability to remain stationary for long periods. But its a very small one.

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Lakehurst is waiting...

The hangars - and railroad tracks to offload freight - are still maintained at the former Lakehurst Naval Air Station, now Joint Base MDL, in New Jersey...

http://www.nlhs.com/hangars.htm

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The thing about bicycle tyres

is that they can hold quite high pressure, up to 140PSI, only because they are less than an inch wide. Increasing the diameter increases the surface area that this force acts on, and thus the stress on the tyre carcass.

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Bah!

Helium? If only Bill Clinton had not sold off the massive Strategic Helium Reserve in the late 90s this would be a zero-cost option. I wonder what we now use the big underground caverns the helium was kept in for?

Also: Military gasbags? Strikes me this is not only a double entendre but more importantly a stupid idea waiting to be demonstrated. If I have the facts straight, military sites needing emergency supply have these things called "bullets" zooming around. Military "bullets" are designed to go right through a human being (the bods that drew up Geneva Convention believing this was less cruel than having the "bullets" lodge inside a soldier apparently). I imagine the so-called parabellum "bullets" would have no trouble whatsoever in riddling the internal gas-cells of this machine, making the lift/ballast question moot as the entire ship became what we call a "frame tent" (albeit a leaky on thanks to the holes punched in it by the "bullets").

Also also: Helium diffuses out of most expanding rubber-like materials very quickly as every kid who has been given a fairground balloon knows. This idea of pumping it around in bike tyres seems to be uninformed wrt the ugly facts.

Also also also: For all the hoo-ha about Hydrogen's dangerousness when compared to Helium, it provides twice the lift for a given volume of gas. Have any kind of studies been done on the weight of fire mitigation tech vs half-the-lift, or are we firmly in the land of the No Nuke mentality here?

Also also also also: Airships suffer from a problem specific to the mode of lift generation, namely that the air density upon which the local lift depends can vary suddenly with no warning, and it can do so non-homogeneously over the length of the envelope, all of which is part of the lifting structure (unlike a conventional aeroplane). Airships of old were *extremely* vulnerable to this problem - irrespective of the lift gas chosen - because of their enormous length and the fact that the sun shining or not on bits of the envelope can locally heat or cool the lift gas and cause it to change its lift properties.

These craft are only meta-stable at the best of times. Submarines have similar issues but their medium and buoyancy techniques have the advantage that changes introduced are usually fairly slow affairs, easy to correct for in the comparatively dense medium of the sea. Not so with airships that can move quite quickly through the air in any direction should the conditions change.

There's a rather neat eyewitness account from the control gondola of an airship launch in the January 1925 issue of National Geographic that demonstrates that even with a crack crew and officers who knew what they were doing, something so "simple" as casting off from the mooring mast was an operation fraught with complications. I recommend it to all.

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IT Angle

Vacuum Spheres (little ones)

Why not make spheres filled with nothing and then fill the airship with these?

C'mon, surely this is possible? And if not, why not!

Can a clever person calculate how buoyant a vacuum filled ping-pong ball would be (ignoring its inability to withstand the pressure)?

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Unhappy

Re: Vacuum Spheres (little ones)

It's maximum lift is the density of the air at sea level.

The idea is employed in the "The Diamond Age."

The problem is that air pressure is surprisingly strong when it's not balanced.

As the container gets bigger the surface area over which it acts (on the container) gets bigger.

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Anonymous Coward

If it springs a leak like from enemy fire, does it zoom around the atmosphere uncontrollably like a balloon?

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Go

Interesting!!

Looks great, but if it works out then I expect a sudden uptick in flying saucer sightings. Several points follow:

Regarding capturing water from the engine exhaust for use as extra ballast, wouldn't it be easier to just capture it from the surrounding air using a condenser of some sort, rather than adding something to the exhaust system that might affect engine performance? Then again, I guess a condenser for external air could be weighty, and would probably not work well in very dry environments, whereas the engine exhaust would always have a certain amount of water in it from byproducts of combusting hydrocarbons.

Agree with previous posters that a hydrogen-based airship would probably not work very well in a military environment. Helium could be bad enough if someone was shooting at the airship and hit the ballast system.

Something like this ship might work beyond the military for extraction of lumber from remote areas, which is sometimes done by helicopter now. Maybe even airlifting agricultural produce like coffee beans, or precious metals/ores from remote sites?

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FAIL

the sad thing is, I know DoD isn't kidding

I'm the first to concede I ain't no combat veteran. H3ll, I wasn't even combat-arms. So my opinion is light in the balance. But the idea of being transported anywhere-- but especially into action-- with something covered with...fabric...any kind of fabric...no matter how high-tech, in my opinion...and virtually hollow...is A Really Bad Idea...and frightening to the core.

The sad thing is, I know The Puzzle Palace isn't kidding. Some wingnut, uniformed or otherwise, there actually thinks this is a concept worth millions of dollars of investigation if not R&D. And moreover, said wingnut even has found people more authoritative to rubber-stamp the deal!

"Military intelligence"...

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FAIL

Helium from where ??

All the Helium on planet Earth comes from a single mine in Delhart, Texas...

The US Congress in 2011 released the strategic hold on the reserve...

Enabling this harebrained project and ensuring the end of commercial Helium...

Like we need more kinds of spy in the sky equipment, that uses irreplaceable stuff...

Best use for these things is un-manned, with Hydrogen lift gas...( WW2 barrage balloons )...

Let them be blown up occasionally by enemy ground fire...save the Helium...RS

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WTF?

Re: Helium from where ??

"All the Helium on planet Earth comes from a single mine in Delhart, Texas..."

No it does not. You are simply wrong.

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Tustin it is. Used to live and work next door in Irvine. Helicopters hangared there COULD (but AFAIK didn't ) hover inside.

http://boingboing.net/2012/09/02/an-airship-boom-in-southern-ca.html

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Joke

"Helicopters hangared there COULD (but AFAIK didn't ) hover inside."

Well, for that they'd have needed a vaguely suspect-looking eastern european guy standing next to the kiosk to run the remote control and look bored.

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What a nice target!

Big, slow and ugly, somebody with a slingshot will be able to shot it down - not mentioning a ZSU-23-4, loaded with HE fragmentation rounds..

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excess lift after load drop?

Easy. Put the entire load in a single container, like Thunderbird Two. Land. Release the container. Shoot skywards like a greased weasel.

If this were a military operation getting the hell out of Dodge double quick would be a good thing wouldn't it?

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WTF?

well, here's a 1988 book that took COSH and added more scope!

Try reading Dean Ing's _The Heavy Lifters_ for a more advanced (imo) and larger rigid airship with more utility- dynamic ballonets for balance- though military use would be rather dumb [or desperate] unless you had more than your payload in point defense! (BTW, bigger can really be better with Lighter Than Air designs)

(for a taste of possible why's, try the same author's _Systemic Shock_ [and keep reading, it's the first of a trilogy! ])

Another possible COSH method can be found in S. M. Stirling's _On the Oceans of Eternity_, [2004, 3rd book in that trilogy] where they use a fixed set of lifting gas bags, and a section that's a variable lift hot air balloon. granted, it's a tricky bit of engineering- but they were working with limited amounts of tech hardware, albeit with knowledge of 20th century tech.

both concepts use the simple idea of neutral-density fuel gases so running the engines doesn't affect static lift. (yes, that does make for low-energy-density fuels, but there are always tradeoffs... see _the Grantville Gazette, volumes 41-44 for LTA airship design possibilities in the _1632_ universe- and some history of airship propulsion that may be surprising to many)

I think the "radical airship firm Aeros" folks lack some of the ability to think big found in the _Troy Rising_ trilogy by John Ringo.

Why would one want to build things like this for military use? big bucks, limited quantities, more chance of a relatively small (in commercial terms) vulnerability to kill all chances of a payoff.

Go commercial application first- lower bucks per each but once proven, potentially a *lot* more volume of units. *then* harden some for the assault mode...

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Meh

Re: well, here's a 1988 book that took COSH and added more scope!

On paper anything can be made to work.

They have actually built it.

Try doing that some time. Reality is trickier than it looks.

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Dirigibles? In a battle field zone?

So the only weakness was not being able to off-load cargo? Slow, large, easily holed (and so downed) by anyone with something little better than a pea-shooter. Seems like a winner.

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Lift

Airships do not fly by hydrostatic lift: they all need aerodynamic lift too. As they rise the atmosphere gets less dense but the airship doesn't, unless it drops ballast, in which case it has to vent gas to come down again. So airships are filled and ballasted to float just above ground level, and use aerodynamic lift for climbing and cruising.

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Military applications?

As far as delivering troops and cargo into a combat zone, I can't see a possible use for this. Too big, too slow and nothing that can't be replicated with fixed/rotary wing aircraft. Perhaps if it was stealthy, maybe for insertion of special operation forces with their equipment to the middle of nowhere where there aren't full-blown hostilities.

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Coat

How about bring airships back for commerial cargo and passenger use. It would be a great to tour the world.

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