The last two movies I’ve seen (The Aviator and The Very Long Engagement) both feature pre-Hindenburg blimp explosions. I had thought that dirigibles used helium almost exclusively before the Hindenburg, and that it only used hydrogen because the U.S. would not sell helium to Germany. Had hydrogen been used as fuel before in inflatable aeronautics?
IANABE (I am not a blimp expert) but hydrogen is easy to manufacture (thus cheaper than helium) and doesn’t leak as easily as helium. I belive it was the filler of choice for all blimps in that era.
Try looking at http://en.wikipedia.org/wiki/Airship.
I certainly had the impression that everyone used to use hydrogen until a few explosions scared people enough to pay for helium (or planes).
Hydrogen gives greater buoyancy than helium, but has the obvious disadvantage of being combustible. However, the Hindenburg fire wasn’t a hydrogen explosion - it was caused by static electricity triggering a fire in the flammable lining material.
(BTW, neither hydrogen nor helium are fuels for airships - they just provide a lighter-than-air balloon.)
[nitpick]Hydrogen wasn’t fuel in the Hindenburg, just the lifting gas. It used diesel engines for propulsion.[/nitpick]
I’m pretty sure all the airships built before WW II except those built in the US used hydrogen (the observation balloons used in the US Civil War used it as well).
Germany flew many rigid airships, all used hydrogen - including the ones used in bombing raids over England in WW I. It must’ve been fun flying with hundreds of thousands of cubic feet of flammable gas while people are shooting incendiary bullets at you. Oh, and no parachutes on board, either. They’d add too much weight. :eek:
Britain had a number of airships over the years, including the R-100 and R-101, which used hydrogen. Norway’s Norge (first aircraft to fly over the North pole) and Italy’s Italia used hydrogen.
I’m sure there are others that I’m not remembering.
naita, iirc, pretty much only the US flew blimps (ie non-rigid airships) in that period, including hundreds used in WW2 used very successfully for coastal and submarine patrol. They used helium. The airships flown by other countries were larger rigid airships filled with hydrogen. The US had a few large rigid airships too. They used helium as well.
There were hundreds of rigid airships flown, the vast majority by Germany. Hindenburg (LZ-129) was the second to last built. The Graf Zeppelin II wasn’t completed until after the Hindenburg disaster. It was decided to not carry passengers unless it could be inflated with helium, which the US has a near monopoly on. The US wasn’t willing to sell any to Germany out of concern it might be used for military purposes. The Graf Zeppelin II flew a number of propaganda flights, but eventually was dismantled and recycled into fighter planes for the war.
Eric
German zeppelins all used hydrogen from the Count’s first efforts at directible balloon flights, through the First World War, right up through the Hindenburg explosion.
Any discussion of the Hindenburg includes the comment that the U.S. prohibited sales of helium to Hitler’s Germany, a point that is both true and irrelevant as the Germans were quite confident in their ability to use hydrogen safely and they never even considered asking to buy helium for the Hindenburg.
I have not previously encountered Santos L Halper’s observation that the Graf Zeppelin II was restricted from passenger use unless it could be flown with helium. That is certainly plausible and may account for the way in which the U.S. prohibition is always mentioned in discussions of the Hindenburg disaster. However, the U.S. helium restrictions had nothing to do with the Hindenburg 's use of hydrogen. Of approximately 250 hydrogen lifting dirigibles between 1900 and 1937, I have found fewer than a dozen that actually burned–and the Hindenburg appears to be the only one that burned without being subjected to wartime anti-aircraft fire. Hydrogen, being so light, vents upward rapidly and most of the wartime zeps that were shot down did so without burning when anti-aircraft fire destroyed their structural integrity.
A good point, and one that’s often overlooked. Those who were burned in the Hindenburg disaster were, AFAIK, burned by the diesel fuel for the engines, not by the burning hydrogen, which was well above the passenger compartment.
I recall a NOVA episode from some years back, in which there was a discussion about using hydrogen for automobiles. Some people expressed concern about carrying such a flammable gas in a moving vehicle. The demonstration set up by the NOVA folks consisted of two tanks of fuel, one gasoline, the other hydrogen, each with the same energy value (i.e., the hydrogen tank was quite a bit larger). Next to each tank was an open flame. From a distance, they fired a rifle bullet into each tank. When the gasoline tank was hit, a fairly spectacular fireball ensued, in short order. When the hydrogen tank was hit, it wouldn’t ignite. They fired a few more bullets into the tank - still no flames. The hydrogen, of course, was rising so quickly, it wasn’t in proximity to the open flame long enough to catch fire. Very impressive demo.
While there’s a tiny trace fraction of helium in the atmosphere, the only place it occurs in a proportion high enough to extract is in natural gas – specifically, the natural gas from the Louisiana-Texas fields, which apparently have a much higher concentration than the European and Middle Eastern natural gas fields.
Hence the U.S. had close to a monopoly on commercial helium in the 1930s. And it was considered a strategic resource, so export sales had to pass the approval of FDR, Cordell Hull, and Harold Ickes, three toughminded men.
Hydrogen is, contrary to initial impressions, quite safe to use for lift – so long as there is no leak where it mixes with atmospheric oxygen, and so long as open flames or sparks occur nowhere near any such mix that does occur (e.g., controlled venting of hydrogen from the top of the airship to descend).
I’m not sure whether it was the Zeppelin company (which was anti-Nazi) or the (Nazi) government of Germany that made the decision regarding the Graf Zeppelin II, but it was decided that they would try to get helium rather than run it on hydrogen after the Hindenburg disaster, and Ickes prohibited sales of helium to the Germans. This was a reaction to the disaster, and there were still those who argued – correctly – that hydrogen was safe.
(There was a controversy about ten years ago to the effect that the Hindenburg disaster was intentional, anti-German sabotage, not the result of a “natural” explosion. Someone posted here, the last time we “did” LTA airships, that the powdered-aluminum paint used was also passably explosive, and quite likely had more to do with the fire aboard the ship than the hydrogen did.)
The Hindenburg disaster is a powerful example of the power of a single image. We all have seen that one horrific picture of the airship exploding and that one image affects everything we think about airships. Objectively, the fireball in the picture wasn’t the result of hydrogen and the accident itself wasn’t the fault of hydrogen. The net loss of life was relatively light. Had that one picture not existed, airships might have gone on a lot longer, even if all other events surrounding the Hindenburg had happened the same way.
Compare this to the Challenger accident. Again, a single image, or in this case, a few seconds of video, changed everything. Had the same accident happened, with no one watching, events may have unfolded differently.
The Titanic accident had much greater loss of life, but the trans-Atlantic steamship industry survived and continued for many years. The Titanic had no single, mind-searing image. In modern times, we have the 9/11 disaster. This is another event that unfolded before our eyes with incredible, unforgettable images. Airline travel has yet to really recover. How many people today, as a result of 9/11, shudder when they think of the 800 passenger capability of the new Airbus A380?
Hydrogen didn’t bring down the airship industry. A single picture did.
Sorry. Upon rereading, I see that I strayed a bit from the topic.
It’s completely OT per the question, but I’ll note that the Graf Zeppelin II did also fly the couple of intelligence missions probing the Home Chain set of British radar stations in 1939.
In all this interesting discussion, we never did get around to answering the thread-title question, though Santos L Helper (Santos-Dumont, given the topic? ;)) touched on part of it.
European nations used hydrogen, easily produced by reduction from a variety of hydrogen-bearing substances. The U.S., after an initial experiment with a hydrogen-inflated ship went up in fire, switched to helium, for which we had a near-monopoly.
After an assortment of problems with their craft experienced in various nations, only the U.S. and Germany had functional airships in the mid-1930s. After the Hindenburg explosion, the Graf Zeppelin (I, LZ-127) was retired, and as noted above, the Graf Zeppelin II (LZ-130) made only a few flights before being dismantled in 1940.
The U.S. Navy continued to fly blimps until the 1960s, but its sole surviving rigid airship, the Los Angeles (ZR-3), was effectively mothballed (I believe it did make a couple of flights) and was also dismantled early in World War II.
Well, the shutle program continued for quite some time after Challenger. It’s only ended (or at lesat gone on extended hiatus) after the recent Columbia disaster which was watched by… nobody.
For a better example of a spectacular image (well, several) killing a promising technology, I nominate the McDonnel Douglas DC-10. It’s a reliable design, with many examples still flying, but production ceased in 1988 because of public unease and not any design flaw.
Your point is well taken, but it seems to me that the response to the Challenger accident involved much more public input because it was such a public accident. In the case of Columbia , the investigation and re-engineering seem to be less noticed by the media. I would attribute that to the fact that Challenger created a spectacular image while the loss of Columbia did not lend itself so well to video and photography.
I know that the DC10 was killed by a series of mishaps, but I don’t remember a particular event. What, in your view, was the singular event that doomed the DC10’s viability?