The era of hydrogen-filled airships came to an end on one tragic night in 1937, when the German passenger airship LZ 129Hindenburg caught fire and was destroyed during its attempt to dock, causing 35 fatalities. Now, half a century after the disaster, one undeserved legacy still remains. Any mention of the Hindenburg disaster immediately brings to mind the word hydrogen; and hydrogen, disaster, danger and death are all too often considered intimately related.
Although the Hindenburg disappeared in a ball of flame, it has been conclusively shown since then that the hydrogen gas giving the great ship its buoyancy was not the source of the fire. It has been proved that the real danger to the airship was the aluminum powder and nitrate doping used on the outer skin to reflect sunlight and reduce interior temperatures. Most of the passengers were burned by the diesel fuel used to power the engines and by the burning fabric cover that gave the airship its shape.
A little research into the Hindenburg tragedy will reveal that even though it contained 200 000 m3 of hydrogen - it did not explode. 32 passengers who perished either died from burning diesel fuel or jumped to their deaths. Those 77 who lived, rode the Hindenburg to the ground as it burned. It took 37 seconds for complete destruction. If the hydrogen had actually exploded it would have happened all at once and no one would have lived through it. Although it is certain that hydrogen contributed to the burning rate, the lack of confinement prevented an explosion. The energy content of the 200 000 m3 of hydrogen was equivalent to over 68 000 L of gasoline and was stored above the passengers. One can only imagine the terror and death the spilling and igniting of this quantity of gasoline would have caused.
So why do people remember so well the Hindenburg tragedy? Since 1937 many flights, ships, trains, buses and cars crushed with much more fatalities, sometimes reaching thousands of lives. The answer is coming from the popular culture. An English rock band Led Zeppelin, widely considered one of the most successful, innovative and influential rock groups in history. They are one of the best-selling music artists in the history of audio recording; various sources estimate the group's record sales at 200 to 300 million units worldwide. A photograph of the burning LZ 129 Hindenburg, was used on the cover of the band's debut album and extensively on later merchandise. This explains why people still remember the Hindenburg disaster and relate it with hydrogen.
When hydrogen is compared realistically with other fuels in common use, the safety issue so on becomes a non-issue. Proper system design and safety engineering will ensure that a future hydrogen economy will be accepted by the general public and perhaps gasoline and other fossil fuels will be seen in the negative light that once shone unfairly on hydrogen. Future generations may still recall the Hindenburg; but, by then, the word hydrogen will be synonymous with clear air and energy freedom, rather than death and disaster.