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Boeing-Skyhook Airship Faces Technical Challenges
waderoush writes "Since the Hindenburg disaster, dreams of giant airships capable of lifting heavy cargo have been restricted mainly to Popular Science covers
(with the notable exception of the Cargolifter AG failure) — until Boeing and a Canadian company called Skyhook announced on July 8 that they're building a 300-foot-long, helium-filled craft that will lift loads of up to 40 tons and carry them 200 miles. But an aeronautical engineer at the University of Washington cautions that there are still some big problems to be worked out with mega-airships, including their stability in turbulent weather."
Unless we run out of helium.
http://www.wired.com/wired/archive/8.08/helium.html
"At our current rate of consumption, Cliffside will likely be empty in 10 to 25 years, and the Earth will be virtually helium-free by the end of the 21st century."
You mis-understand me. "people are trying to build an airship" is news-worthy even if they were built every day. But that's not this article's focus. This article focuses on how some other people (not the airship builders) mention problems with airship design. This article is about raining on someone else's parade.
What makes it particularly stupid is that these people who are predicting the builders' failure are doing so in an industry where virtually nothing has been done for decades. So essentially they are using antiquated data to argue against current endeavours. That's not only mean, it's retarded -- in the correct sense of the word.
At a rest stop in ohio, I noticed a sign about the crash of the shenandoah, an earlier version of these. Still, high time they came back. Skyhook is a brilliant name for it.
They should give Randall Munroe a free ride.
http://www.roadsideamerica.com/story/10432
America had four zeppelins of its own in the 1920s and 1930s. One -- the Los Angeles -- was built by the Germans, flew successfully for a decade, and retired with dignity. The other three -- the Shenandoah, Akron, and Macon -- were built by Americans, and each crashed less than two years after its first flight.
The first, and the only one to crash on land (and thus be suitable as a tourist attraction) was the Shenandoah. In September 1925 it was ordered to conduct an ill-advised publicity tour of midwestern state fairs. Less than 24 hours into its flight "the strongest airship in the world" was caught in a thunderstorm, torn to pieces, and scattered across the rolling hills of Noble County in southeastern Ohio. Amazingly, 29 of its crew of 43 survived.
Well a plane crash-landing from 100 ft. is usually going a couple of hundred miles per hour, getting to zero from that speed usually involves quite a bit of force.
A blimp crashing from 100 ft. while be going at much slower speeds and thus your chance of survival will be greatly enhanced.
Actually, chances of surviving a fire on the ground in an aircraft are quite low. Most of the fatalities in air crashes come from people who burn to death shortly after impact, rather than the impact itself.
I'm also reminded of numerous crashes which happen quite close to the ground which result in massive casualties--Tenerife, in particular, comes to mind. The greatest loss of life in aviation history came about because of a collision on the ground.
One of the things that makes airline accidents so deadly isn't necessarily the altitude, but the speed and the fact that these things are carrying so much damn fuel. I wonder which has more energy, the envelope of the Hindenburg or your average passenger jet fuel tank...
(Incidentally, airships can crash land from quite high altitudes with minimal ill effects. Because they're lighter than air, and contain so much lifting gas, even sizable holes leak quite slowly in comparison to the envelope volume, and the airship drops slowly. Fatal airship crashes have usually involved loss of control, rather than a sudden loss of lift; even the Hindenburg, with the entire envelope aflame, crashed rather gently.)
Nice comment. Except for the part where you make the assumption that the ship is neutral with it's cargo. The article is talking about a ship that is neutral without it's cargo. Then it as rotors, just like an helicopter, for lifting the cargo. The rotors are compensating for the weight of the cargo. To go down, just slow the rotors. When you unload, the ship just stay there.
Try to read the article next time ;-)
One of the things that makes airline accidents so deadly isn't necessarily the altitude, but the speed and the fact that these things are carrying so much damn fuel. I wonder which has more energy, the envelope of the Hindenburg or your average passenger jet fuel tank...
Interesting question. I did some quick googling and math. I wasn't particularly careful, so corrections are welcome.
The Hindenburg had a gas volume of 200,000 m^3, at 0.089 kg/m^3 standard density of hydrogen gas, that is a total hydrogen load of 17,800 kg. Hydrogen has a high energy density of 143 MJ/kg.
A fairly heavily loaded 747 will be carrying 136,000 kg of Jet-A at 43 MJ/kg.
So, the 747 has more than twice the energy onboard, although smaller jets would be rougly equal, all depending on the fuel load. I also did not include the diesel onboard the Hindenburg (or its rather flammable aluminum paint).
One significant difference between hydrogen and Jet-A burning is that the hydrogen is going to rise once the gas bags rupture and not hang around on the ground like Jet-A.
Worst...sig...ever!
I thought most of the casualties were from people jumping -- the people who stayed with the wreckage as it settled to the ground were mostly ok.
-b.