I had been researching and experimenting with hydrogen for several months when I decided to look into purchasing a tank of H2 because my production capacities were so small (on the hobby level - measured in milliliters per minute).

I went to my local welding (industrial gas) supply shop where I researched prices and such. Earlier I had bought a six foot weather balloon for storage and thought perhaps I could save the tank deposit (several hundred dollars) if I brought the weather balloon down to the store and had them fill it for me and just pay for the hydrogen.

They looked at me like I was crazy and informed me that it was FAR too dangerous. That hydrogen was HIGHLY EXPLOSIVE. I was shocked. These guys were supposed to be professionals who knew their stuff when it came to gases.

Hydrogen is FLAMMABLE. It burns at a low temperature similar to propane. It can be explosive but only under certain unusual conditions. Hydrogen dissipates (and rises) very quickly, much faster than any other gas making explosions from leaks and such almost impossible. A hydrogen/air mixture above 4% will burn but the mixture must reach 14% to become explosive.

In other words, you would have to try pretty hard to get a tank of hydrogen to do anything harmful unless you were really, REALLY stupid (say opening the valve in a tightly enclosed area for several minutes and then lighting a match). On the other hand, any idiot can walk into any gas station and fill a gas can unsupervised. Anybody want to guess what the comparative dangers are? I did not bother to correct or even argue with them about it because I still wanted the hydrogen and did not wish to alienate them in any way. But it was certainly an eye-opener.

HYDROGEN fire | GASOLINE fire  Infra-red image enhancing was used to make the hydrogen fire visible. Only a few hundred cubic feet was burned through a small induced leak. It took less than two minutes and the car's interior was completely undamaged. This is the earliest photographic image of the disaster I have found so far. The fire has engulfed cells #1-8 (of 16) and the top of cell #9 has ignited. The white area above the skin fire may be steam formed by over three million cubic feet of hydrogen that has already burned. The dark area above the front of the steam cloud may be the newly ignited hydrogen from cells #7-9 This one is taken a few seconds later and from a different angle (Note the two falling objects that can be seen in both photos).

I've done quite a bit of research since this incident. There is actually no consensus about what actually caused the Hindenburg disaster but the majority agree that hydrogen was not the probable cause. Hydrogen's burning temparature is relatively low and the flame ranges from blue to invisible. I have roasted marshmallows with H2 and it burns very similar to propane when used to cook. What follows is my own synopsis and opinion based on my research.

Most of the passengers and crew of the Hindenburg became aware that something was wrong when they felt a slight 'thump'. I believe that this was probably the point at which the hydrogen contained in cell number four (of sixteen counting from the aft) ignited and 'exploded' (causing the gentle 'thump'). The skin fire (probably started by a static electricity discharge when the steel mooring lines were dropped grounding the airship) was already in progress.

Eye witnesses on the ground report that the airship maintained trim and altitude for some seconds after the skin fire was well underway. Passengers and crew report that she began to list right after the 'thump'. This was when she lost structural integrity due to the pressure loss in cell four. Cells three and five ignited some seconds later and the airship began it's gentle descent with the bow slowly tipping upwards. The first photo (at right) was taken some seconds later as cells 1 and 2 as well as cells 6-8 are burning.

I believe it is even possible that the hydrogen contained within the Hindenburg when the skin caught fire actually mitigated the disaster somewhat if anything. Two-thirds of the passengers and crew survived. Most of them were forward of and below the initial fire. The majority of deaths occurred among those who jumped from the Hindenburg when it was still several stories up.

1. The burning hydrogen used oxygen that couldn't be used by the larger skin fire lessening it's intensity.

2. Hydrogen fires rise quickly. This pulled both oxygen and heat upward from the burning airship. This may have actually helped several crew members survive, based on and interpretting some of their actual testimonies of what they saw during the thirty-two seconds between the time the fire ignited near the top of cell number four (of sixteen counting from the aft) and the time the airship hit the ground.

3. Water is the main by-product of any hydrogen fire. The Hindenburg carried over seven million cubic feet of hydrogen. It ended up as about half a million liters of water. That's more than the amount of water in a 25' by 50' (by 12' depth) swimming pool. This accounts for the 'warm rain' many eye-witnesses on the ground reported.

4. Pieces of the skin survived the disaster. They were used in the research done by Bain. It seems unlikely that anything could have survived the inferno seen in the film footage, unless perhaps small portions were doused with water...

Witnesses said that the bow actually even bounced slightly when she hit the ground indicating that it probably still contained a fairly significant amount of hydrogen in her forwardmost few cells at that point.