By Andy Cooke
The one airship disaster that everyone knows: "Oh, the humanity!"
In OTL, this was the final straw that broke the zeppelin's back. The fiery crash of the LZ 129 Hindenburg on May 6, 1937 at Naval Air Station Lakehurst in New Jersey, captured on newsreel and with live commentary.
I ask three questions in these PoD articles: What happened? Why did that disrupt airship use? What could have happened instead?
What happened
On its 63rd flight, the LZ129 Hindenburg, pride of the Deutsche Zeppelin-Reederei corporation - and pride of Germany - flew from Frankfurt in Germany to New Jersey in the USA. The trip took three days, slowed by headwinds, but was smooth. However, the captain and crew were concerned about weather at Lakehurst, which had been struck by thunderstorms on the 6th of May.
After flying over New York, Captain Pruss held off away from the Naval Air Station, flying around the coast until weather conditions improved. As the evening wore on, a window of good weather became apparent, and the Hindenburg made its landing attempt.
With inconstant and changing wind, the approach was difficult. Having been forced to "go around" once as the ground crew were not yet ready, the second approach was even more challenging. At the last minute, the wind shifted yet again, all the way from easterly to south-westerly. Unwilling to carry out another go-around due to concerns that the weather might deteriorate again, the Captain ordered a sharp S-turn to face into the new wind direction (swinging out to port to give it some manoeuvring space before a tight turn starboard to line up). Meanwhile, it had been having some trim issues, its tail being heavy on approach - possibly due to accumulation of rainwater. Standard venting of hydrogen from the bow and dropping of water ballast from the tail was carried out, and crewmen sent forward to weigh down the bow some more.
The landing lines were dropped and it looked, at this point, to be a routine landing. A few minutes later, as it was being drawn down, witnesses reported seeing the outer cover fluttering, some others reported a dim blue flame, others a muffled thud, and the Hindenburg burst into flames. The fire raced over the ship and it crashed in a tangled, incandescent heap, in just over 30 seconds.
As the ground crew turned to sprint away, their chief, "Bull" Tobin, roared, "Navy men! Stand fast!" Just over a decade earlier, Tobin (a registered airship pilot) had survived the breakup in mid-air of the USS Shenandoah, riding one of the three broken sections to the earth. The newsreel film captured the moment when the sailors turned and ran back towards the burning ship. Meanwhile, in the control car, Captain Max Pruss carried radio operator Willy Speck out of the wreckage. His clothes on fire, he went back in to rescue more survivors, until being physically restrained in order to save his life. Burned badly enough to be given the Last Rites, he somehow survived.
Thirty-five of the 97 on board died, along with one of the ground crew.
The disaster was captured on newsreel, and, famously, by a radio commentator. Herbert Morrison's words were broadcast around the world, including the now iconic line, "Oh, the humanity!"
The precise cause of the accident is still unclear, despite numerous attempts to "prove" what might have happened. Sabotage, lightning strike, rocket-fuel-like-coating igniting... were all proposed from time to time before being ruled out. It is possible that a line snapped during the tight turns, cut through a gas bag, and allowed a mix of hydrogen and air to build up under the cover, becoming more flammable as with the R101, but this is contested as well. The spark could have come from static electricity, or a malfunctioning engine, or St Elmo's fire - even this is not truly known.
Why did this end up disrupting airship use?
The first instinct is to raise both eyebrows and simply point to the pictures.
But that isn't really fair: there had been many airship flights by this point and the only commercial passenger deaths on any rigid airships were, well, the ones here. In the same year, there had already been three heavier-than-air airplane crashes, resulting in 22 deaths, with 11 survivors. The year before, 6 airplanes had crashed, killing 71 with only 4 survivors. In the nineteen-thirties as a whole, up to that date, 22 airplanes had crashed, killing 204 people, with only 27 people surviving the crashes.
More than a million miles of travel had been carried out on more than 2000 flights of commercial zeppelins over 30 years, carrying tens of thousands of passengers; none had yet crashed. Not a single passenger had been injured. Until now. Even so, the survival rate from the crash was impressive in comparison to heavier-than-air crashes, the safety record still, overall, excellent... so why did airships lose out while airplanes thrived?
There are a number of factors. Firstly, there's something called the Availability Heuristic. Simply put, it is that we tend to rate things as more probable and more common, the easier it is for us to recall examples of them. This is fairly sensible in most day-to-day life, but can skew our risk estimates. The Hindenburg disaster was prominent in everyone's mind for a long time - it's still, to this day, readily recognisable and immediately associated with airship travel. Most other air crashes, especially back then, were not. Accordingly, we all think "dangerous - hydrogen - crash - burn to death" when we think of zeppelins and hydrogen airships. This is not helpful for encouraging passengers, especially with the uncertainty over what actually caused the disaster.
Secondly, airships still only had a tentative hold as a travel option. Only Germany was operating passenger airships, with the retreat of the British Empire from airships following the R101 disaster. There were other investors, in America as well as Germany, keenly watching the Hindenburg to decide whether to invest further funds to expand. The loss of the Hindenburg with such publicity destroyed that precarious option. In addition, the Nazi regime made it harder to sustain any support for a system solely operated by Nazi Germany.
Thirdly, heavier-than-air airplanes were improving steadily. Although still shorter range, cramped, and unreliable, the capital investment for an airplane was significantly lower, and the speed at which you arrived was far quicker. Airships were already aiming for the "luxurious" and "comfortable" end of the market - which found it far easier to refrain from travelling.
The economics were also very difficult to sustain. They didn't make sense for smaller airships; you had to scale to very large size for it to be plausible to use them - with consequentially large aircrews, groundcrews, and support costs. Huge hangars plus masts were needed, as well - and in the case of any accident, dozens of people could be killed (this element was far more important in 1937 than today, when hundreds of people at a time travel in airliners).
So the age of the airship died on that field in New Jersey.
What could have happened instead
Without the cause of the disaster being known, it's difficult to suggest what specific event could have averted the crash. Not making sharp turns? Grounding the ship properly on landing?
There is one thing that's obvious, though: had the Hindenburg used helium instead of hydrogen, it wouldn't have burned. People are often surprised to learn that the Hindenburg was actually intended to use helium as a lifting gas from the moment it was designed.
Unfortunately, the Germans could not get a source of helium. Only the United States produced sufficient helium to export, and, in 1927, they had passed a law prohibiting helium exports. The designers had hoped to convince the Americans to waive that law, but the rise of the Nazi Party made such negotiations difficult. The economic depression didn't help matters, and the lesser lifting power of helium made hydrogen look more and more attractive in comparison as the difficulties continued. After all, they'd used it for decades already, with no passengers ever harmed - maybe other countries might have problems, but they knew what they were doing and could be safer. And it did allow for more lifting capability and more range.
After an interim design where they minimised the helium requirement by designing a double cell, with hydrogen in the centre, surrounded and protected by non-flammable helium, Eckener (the chief designer), reluctantly went for hydrogen, allowing them to add more cabins into the bargain.
But what if the United States had agreed to export the helium? Or the Germans had found another source?
In the 1960s, helium was found in Poland, largely by chance, as a byproduct of intensive surveying for oil and gas. Had these surveys occurred before the Second World War, it is very possible that this source, practically on Germany's doorstep, would have bypassed the problems. Hindenburg would have flown with less range and fewer passengers (but still retained transatlantic range), and would have been immune to the disaster that destroyed her.
The successful record of the airship would have encouraged more investment - after all, as mentioned above, investors were poised. Even with World War II looming, airship production for comfortable long-range travel could have continued in the United States.
With that said, however, the advancement of long-range airplanes during World War II would still have happened as in OTL, pushing airships into a niche. That niche, though, could well have been sufficient for luxury skyliners to still be ploughing the skies today, at one or two thousand feet altitude, cruising slowly over the land and seas, almost in the role of Sky Safaris. With the climate considerations today, they might even be in the middle of a full-scale resurgance, with people willing to take two days flying across the Atlantic in exchange for far-reduced carbon emissions.
Especially as the feasibility of electric airships is significantly greater than that of electric airplanes.
Andy Cooke has written the sci-fi Endeavour trilogy (The End and Afterwards, Diamond in the Dark, Beyond the Sunset) and the political alternate history Lectern books (The Fourth Lectern, The Fifth Lectern), published by SLP