In 1918, after the end of the First World War, there was a boom in adventure in Europe and the United States. At the time, travel across the Atlantic and around the entire globe became common, but such travel was usually done by cruise ship, which was extremely slow—it would take more than a week just to cross the Atlantic.
The First World War greatly promoted the development of aircraft technology, but large passenger planes capable of crossing the Atlantic Ocean have not yet come out. At this time, another class of aircraft – airships (especially zeppelins) proved their ability to fly long-range.
Zeppelins were developed for military purposes. This airship was used by the Germans to carry weapons to bomb London. In order to achieve a journey across the ocean, the United Kingdom, France and the United States competed to develop civilian airships. Only post-war Germany was prohibited from developing military airships. German Zeppelin lobbying Americans: If we build you big airships, can you agree that our airship factory will continue to operate? Americans allow it.
With the restrictions finally being relaxed in 1926, Zeppelin began to build the largest and most modern airship in the world at the time, the transoceanic airship (hereafter referred to as “Led Zeppelin”). To show off the completion of the Led Zeppelin, Zeppelin Chairman Eckner and an experienced airship pilot embarked on an unprecedented airship trip. People waved to them wherever their airships went. After all, very few people went to the sky at that time.
As a result, Eckner became famous. After his miraculous “round-the-world airship trip” (which didn’t actually go around the world), big companies around the world wanted to invest in airships and let Zeppelin build them for themselves.
In order to maintain his leadership in airship production, Eckner decided to build the largest commercial long-range manned airship. This was actually the beginning of the aviation industry.
The airship was once a military tool (pictured in 1915)
On March 4, 1936, the largest zeppelin was ready for its maiden flight. However, even the engineers in charge of making the airship don’t know: How will such a huge airship behave after liftoff?
Although Zeppelin was a huge success within 25 years of its founding, it was the first time an airship of this size had been built. You know, this airship uses 28,200 square meters of air cloth alone.
The first test flight of the largest airship took more than three hours, but it did not fully verify all aspects of safety during the test flight. In fact, in order to prove the safety of an aircraft, multiple test flights are required: steering ability test, braking ability test, flight height control ability test, crash test and emergency evacuation test, etc. But for the largest zeppelin, multiple tests were not carried out. All seven of the airship’s test flights took place over land (not over the ocean) in Germany. This is not surprising, after all, the aviation industry was just getting started.
Still, the largest zeppelin began a 9,600-kilometer, four-day manned transatlantic voyage from Germany to Brazil. The flight turned out to be a success in the end. Why do you say “even”?
Zeppelins use flammable hydrogen to lift the airship. At the beginning of the design of the largest zeppelin, Eckner faced a major decision: Can he rely on hydrogen to provide the airship’s buoyancy? Or is it safe to use helium?
The density of the gas charged into the airship to create buoyancy must be less than the density of the atmosphere at the altitude of the airship, and hydrogen is the lightest chemical element, and hydrogen atoms are the smallest atoms. The natural form of hydrogen on the earth is gas, and the density of hydrogen is much lower than that of air, but nitrogen has the danger of explosion. Helium is the second lightest gas, but helium is an inert gas and is not as explosive as hydrogen. But hydrogen is readily available and cheaper. Using hydrogen to provide buoyancy, the airship can be made larger and carry more people on a limited budget.
Eckner knew that the Led Zeppelin was safer with helium. But in the 1930s, most of the world’s helium was produced in the United States. The United States actually monopolized the supply of helium, and European engineers were reluctant to import helium from the United States because of the high cost and import procedures. complex. Eckner was once shaken and felt that helium should still be used. But his last choice was still hydrogen, in part because Led Zeppelins have always used hydrogen and never had an accident.
Eckner was headstrong and decided to fill the largest zeppelin with hydrogen, which could be the blimp’s biggest fatal injury. But it wasn’t just Eckner’s decision that caused the catastrophe that followed.
In December 1935, Zeppelin technicians began covering the airship’s aluminum frame with aviation cloth. This process must ensure that the aviation cloth is very close and the position is accurate, otherwise the airship will not be able to fly smoothly. Led Zeppelin’s overlay technology is very effective and unique, all thanks to Horto, the company’s aeronautical cloth specialist. For 20 years, he supervised the air cloth coverage of more than 50 zeppelins. The covering technique he created made the air cloth covering the airship frame firm and waterproof. However, the coverage of the largest zeppelin was done without Horto, who was in the United States at the time.
Zeppelin manned airship maiden voyage scene
In the early 20th century, people watched airships
And the sheer size of the zeppelin wasn’t the only challenge. Another challenge was the wet and cold weather. This means that the aerocloth can get soaked with water and freeze over, which makes the aerocloth very stiff.
On March 4, 1936, the largest zeppelin flew for the first time with only a few crew members and no passengers on board. Minutes after the airship took off, the crew noticed vibrations in the aeroclothes on the boat, and as soon as the airship returned to the ground, they searched for a solution. The solution they eventually found was to apply two coats of special paint to the aviation cloth on the entire top of the airship. However, this paint is highly flammable.
Despite being painted, the issue of air-cloth vibration on the airship was not resolved. But neither the added drag due to the painting nor the vibration of the aerocloth seemed to affect the overall flight performance of the airship, and they were unaware that the vibrations would be transmitted to the airship frame. So these issues are ignored. However, the hazard of air cloth vibration has already appeared on some smaller airships before, and this hazard will be magnified on larger airships.
During the first test flight of this huge airship, problems caused by omissions in the construction of the airship appeared many times, and these omissions were related to the hurried construction of the airship. This rush goes back to 1929. This year, Wall Street in the United States collapsed, and economic depression occurred worldwide, and Germany was no exception. Eckner thus faced a budget shortfall. In 1933, he turned to Goebbels, the head of Nazi propaganda, for funding to complete the construction of a huge airship. Goebbels immediately agreed, which he saw as one of the best opportunities for publicity, and invested heavily in the construction of the airship.
In 1936, this huge airship was built. Goebbels immediately affixed a huge swastika to the airship. The airship’s test flight was supposed to take place on the high seas, but Goebbels ordered it to make several short flights across Germany to promote the strength of the Nazis.
Passengers entering the airship
Led Zeppelin Around the World (1929)
In order to give a quick return on investment, Zeppelin decided to conduct the first commercial flight of a huge airship, under the circumstances that various preparations, especially safety preparations, were obviously insufficient.
Nine months after the construction of the largest airship, it successfully completed 34 transatlantic voyages, carrying nearly 3,000 passengers and a total flight mileage of 320,000 kilometers. The flights, which appeared to be smooth sailing, lurked a fatal problem: a giant hydrogen bladder was about to burst, and no one noticed.
In December 1936, the huge airship underwent its first overhaul. After a successful first year of test flight, 10 new cabins were installed inside the airship to increase the number of passengers and the luxury of the airship. To do this, one of the airship’s 16 hydrogen bladders needs to change shape. The airship repair report, which was discovered only recently, said that when workers pulled out the hydrogen bladder, they found wear on the top, meaning the bladder could be leaking. The wear was due to vibrations in the airship’s air cloth, which loosened the ropes holding the airbags in place. The loose rope rubs against the airbag’s airbag, resulting in thinning of the airbag in some parts. The report also noted that while the damaged airbag was repaired, the ropes that held it in place were simply tied back and not secured.
Dining area of the largest zeppelin
So far, even if the damaged aviation cloth is repaired, the vibration problem of the aviation cloth has not been solved. A few days after the aerocloth was repaired, Zeppelin began the countdown for the next flight of the giant airship. The company’s senior engineer, Lehman, realized the airship was in danger, but he kept silent so as not to offend his superiors. In 1937, the airship was flown by several captains, one of whom was Lechmann.
The contents of a letter, also recently uncovered, indicated that Lechman knew at the time that the airbag was damaged and that it had been improperly repaired. He told a reporter the secret information at the time and said he was very concerned about it. He decides to sacrifice himself in an effort to prevent disaster from happening. He also said the crews were incapable of dealing with the problems, which he might have been able to deal with.
Airship interior corridor
Control room inside the airship
restaurant on airship
Airship cabin interior
On May 3, 1937, Lechman boarded the giant airship. Analysts said Lechman was aware of the airship’s problems, but should not have expected a cataclysm.
partial to late
At noon on May 5, 1937, the airship was still 1,600 kilometers away from its destination. The destination of the flight was the Lakehurst base in the United States, chosen because of its proximity to the city. However, Lakehurst often experiences sea fog and severe weather.
Pushing forward 20 years, many people believed that airships were the future means of international travel, so the US Navy decided to build an airship base in Lakehurst, which also marked the climax of American airship research and development. Lakehurst has the world’s largest airship hangar, built to accommodate giant airships like Zeppelin’s largest.
U.S. Navy airship (age unknown) flying over New York City, USA
Despite the size of the Lakehurst airship base, one major problem with this location is the unpredictable weather here, due to its proximity to the North Atlantic. It stands to reason that the safe location of the airship base should be more than 160 kilometers inland away from the coast, and Lakehurst is less than 23 kilometers away from the coast. In 1927, an American manned airship was blown upright by a hurricane here. Fortunately, the air flow calmed down a few minutes later, and the airship rolled over and landed, causing damage to the boat. While the accident sparked concerns, the site continued to be used without another accident in the ensuing 10 years.
At 11:30 am on May 6, 1937, the base headquarters received a severe weather forecast. At this time, there are still 6 and a half hours before the huge airship arrives here. The airship was delayed by the time it reached the east coast of the United States due to strong countercurrents. There was supposed to be a one-hour window during which it was clear and windless over Lakehurst. In other words, if the airship arrives on time, it will land safely.
The airship was originally expected to arrive at 6:00 a.m. and the airship was cruising at 100 kilometers per hour. However, due to the obstruction of strong airflow, the airship slowed down by half. In the strong wind, the air cloth wrapped around the airship trembled violently. The captain radioed the Lakehurst base that the airship would be delayed, so the base personnel rested and stood by. But as the wind slowed, the airship continued to accelerate on its way. By 4 p.m. that day, the airship was approaching the Lakehurst base.
The weather was generally not good at this time, but it was calm for a while, providing the airship with a chance to land. However, the actual arrival time of the airship was two hours earlier than the revised notification, and the ground crew did not arrive. Generally speaking, the landing of a giant airship requires the assistance of more than 300 ground personnel. The ground personnel need to hold the rope dropped by the airship and pull the airship to land.
Because there were no ground personnel, the airship had to temporarily turn around the base, waiting for the notified ground personnel to arrive. At this point, the weather got worse, with lightning and thunder. At 5:12 p.m., the base command signaled to the airship: The weather has calmed down and a landing is recommended. But in reality, he misjudged the weather. This is not surprising, since the weather observation equipment at the time was backward, and modern weather radars did not exist at all.
When the airship was about to land, there was not only lightning over the base, but also a lot of humidity. If the airship leaves the base and flies away, there is still a chance of averting disaster. But that would cause the airship to fly back to Europe later. And Zeppelin couldn’t take that risk, because the airship was contracted to take 70 passengers from Lakehurst to Europe on time. The airship’s upcoming return trip is very important for the Zeppelin company. Those passengers who are about to take the airship to Europe are all dignitaries who are going to London to attend the coronation of King George IV of England.
The ground personnel saw the airship explode, but there was nothing they could do
Although the storm was still increasing in intensity, Zeppelin landed the airship in the storm. At this time, the atmosphere is charged, which may cause the hydrogen gas in the airship to explode. But in order to reduce the buoyancy of the airship, the crew began to deflate the airbags. As the airship descended, its tail sank due to the loss of gas, and the head of the airship cocked. In order to restore the airship to a level state, the crew expelled 1 ton of water from the airship’s ballast tanks to the outside of the boat. As a result, the airship is stable, but no longer in the landing attitude. As a result, the captain took an extreme measure – a sharp turn at full speed, in order to restore the airship to the landing attitude. It now appears that the sharp turn likely caused the aluminum frame inside the airship to overbend, loosening the otherwise unsecured airbag tethers.
During an investigation in 1937, it was believed that the loose cord had worn the airbag and caused the leak. But now experts believe that the airbags had actually leaked in strong storms before this, which could explain why the tail of the airship sank because it lost its buoyancy.
The airship is likely already leaking. Just as the airship and landing mast were lined up, the captain made another wrong decision. There are two types of airship landing methods: high landing and low landing. The captain decided to land high, that is, throw two ropes from the nose of the airship to the ground for the ground personnel to grab.
At 7.12pm, the first landing rope was thrown down in the rain. At this point, the airship was more than 60 meters above the ground. As everyone knows, the airship will get static electricity from the air during flight in the atmosphere. The ground personnel knew very well that they could not directly grab the airship’s landing rope, otherwise they would be electrocuted as the electric charge on the surface of the airship moved down.
Just 4 minutes after the first airship landing rope reached the rain-soaked ground, the airship suddenly exploded. Until now, no one knew whether lightning or static electricity ignited the hydrogen in the airship. While 62 passengers and crew miraculously survived, 36 people died in the accident. Lechman was also seriously injured in the accident and died the next day.
It appears today that there was not a single factor responsible for this major airship accident. The tragedy also marked the end of the golden age of airships.
The spectacle of the giant manned airship flying over the city is a thing of the past
Zeppelin and Zeppelin
A silent zeppelin in 1917
In 1784, the Frenchman Jean-Pierre Blanchard made the first airship. In 1900, German inventor Zeppelin successfully proved the great potential of mechanized airships, that is, from simple lift-off and drifting with the wind to autonomous flight that is not afraid of strong winds.
At the heart of the Zeppelin philosophy is the airship’s protective aerocloth covering: a series of airbags that provide the airship with enough buoyancy to carry thrusters, people and cargo. The higher the number of airbags, the larger the airship and the higher the load. Even an airship has multiple thrusters, which is a major breakthrough for Zeppelin.
Schematic diagram of the structure of the zeppelin airship
Airship interior (detail)
The largest zeppelins are over 240 meters long. The airship’s single airbag is larger than the largest balloon to date. The airship has a banquet hall, parlor and library, which is not only spacious but luxurious. The airship even has a promenade deck and a piano on the deck. In short, the various facilities on the cruise ship are all on this airship.