As the Hindenburg came in to land at Lakehurst, New Jersey, it caught fire and, with hydrogen tanks in use, a huge explosion followed.
In the evening of May 6, 1937, the German airship Hindenburg was approaching Lakehurst, New Jersey, preparing to land. The ground crew stood ready as the ship reduced its speed, dropped its landing ropes, and prepared to connect with the mooring mast. Suddenly there was a flash of light and before anyone could assess what was happening a gigantic fireball erupted and the whole ship was engulfed in flames. In a few minutes the Hindenburg was reduced to a smoking mass of flames and molten metal.
In 1937, Hitler was at the height of his power in Germany and the zeppelin Hindenburg was the biggest airship in the world. As flagship of Germany’s lighter-than-air fleet Hitler wanted to use it in a regular service to the United States to demonstrate the benefits of this new mode of travel. The Hindenburg had made the Atlantic crossing several times in the previous year and this was its first trip in 1937.
With its huge size, almost as long as the Titanic, and with enough width and height to provide lounges and dining rooms, it offered a new and luxurious style of air travel. Everyone knew that the gas used to hold the airship aloft was hydrogen, inexpensive to produce and very effective, except that it was highly flammable. A single match or a bullet could easily set off the kind of explosion that occurred at Lakehurst.
This may have been the reason for premonitions of doom that were expressed before the flight left Frankfurt. These concerns affected some people so much that they cancelled their plans to travel. Seven million cubic feet of hydrogen was needed to hold the 242-ton ship in the air and the presence of this huge quantity of a flammable gas might also have caused fears.
The much safer gas to use in zeppelins was helium, more expensive to produce than hydrogen but not flammable. Germany would probably have used helium had it been available. In the 1930s the United States had control of the world’s supply of helium and was not willing to let a country like Germany have access to it because of all the military buildups taking place in Europe.
The debate over helium versus hydrogen was not an easy one to settle and most German authorities finally relied on years of experience with hydrogen-filled airships to support sticking to this gas. It was sixty times cheaper than helium to produce so that was a big factor even if there had been no problem with supply. Helium had only 90 percent of the lifting power of hydrogen, because it was a slightly heavier gas, and Germany was anxious to mount the biggest cargo possible.
It even changed the passenger terminal city for the Hindenburg from Friedrichshafen to Frankfurt because the latter was a thousand feet lower in elevation. At the higher air pressure that this change provided the airship could carry an additional seven tons of payload. To avoid the risk of an explosion when releasing gas to allow descent, which had previously led to two explosions, stored water was used instead.
The Hindenburg was a new airship. Its first flight took place in 1936. It was a luxury, air-conditioned vessel with twenty-five two-berth cabins to accommodate its fifty passengers. Passengers could live aboard in a style of luxury unmatched in all earlier airships. It was like living in a first-class hotel. Along both sides of the passenger deck was the promenade with seats and with slanted windows that gave clear views of the landscape below. It was always a spectacular scene as the vessel was only 650 feet above the ground or sea level. Passengers boarded the ship via a retractable set of stairs as far as the lower deck, then by a staircase to the top deck. The Hindenburg could travel 8,000 miles without refueling at a speed of 80 mph.
The material used for the sides was cotton or linen as these were found to have better resistance to wind and rain than any other materials. A varnish and several coats of aluminum paint completed the outer shell. Everywhere inside the ship the lightest materials were used for framing, usually aluminum. The ship’s brain was the control car, located on the bottom of the vessel close to the front.
Two of the key officers always on duty were the rudder and elevator men. The former kept the ship on a fixed course while the elevator man watched four instruments dealing with horizontal and vertical shifts, elevation, and hydrogen pressure.
Hindenburg was the first of the zeppelins to allow smoking but the rules for smokers were strict. There was a revolving door that served as an airlock through which people passed to reach the smoking-room. Asbestos lined the walls of this room and no passenger could leave until the cigarette was extinguished in a water-filled ashtray. No one was ever seasick on this airship; its motion was so smooth that often passengers refused to believe it was in the air, quite a contrast to today’s big planes.
One popular game that related to the airship’s stability saw people competing to see how long a pen or pencil could be stood on end without falling over. Ernst Lehmann was the captain, a man with long years of experience on zeppelins stretching back to World War I days. As the airship traveled across the Atlantic on its fateful final voyage everything seemed to go well. The weather was good so speed was maintained at 60 mph. This meant crossing the Atlantic in three days. At Lakehurst, New Jersey, there was some delay due to bad weather but the rain and wind had gone by the time the Hindenburg touched down.
No one was prepared for the chaos and destruction that followed the spark from somewhere as the nose of the Hindenburg approached the mooring mast. The landing ropes had been thrown down and ground crew was steadily drawing the ship to the ground. Suddenly the whole structure collapsed and fire was everywhere. Some jumped to the ground, others waited until the ship dropped farther down, risking getting incinerated in the process.
One passenger called it a medieval picture of hell. Some had no chance of escape and were caught in the flames. The whole conflagration started and was all over in half a minute. Captain Lehmann, who ran back into the flaming fuselage more than once to rescue people, was so badly burned that he died soon after being taken to hospital. Thirty-six people lost their lives and many were injured.
The fire burned on long after the airship was a mass of tangled wreckage. Diesel oil from the engines kept it going. An attempt was made to rescue some of the mail and there was some success. People in Germany and across the United States received badly charred letters a few days later. Some looting occurred because the police did not cordon off the area for a few hours.
The conclusion as to cause was simple, the ship was destroyed because it had hydrogen. Suggestions of sabotage were given serious consideration but were later dismissed. The fact that a storm had passed over the area just before the ship arrived gave confirmation to the idea that a static electrical charge had built up between the outside of the airship and any metal structures within.
It was discovered that the fabric cover, unique to the Hindenburg, was a poor conductor, thus allowing an electrical charge to build up. Immediately after this tragedy, the fabric of other airships was checked and, where necessary, changed to ensure good conduction. Other changes in the aftermath of the Hindenburg explosion saw hydrogen being removed and helium put in its place on all airships. At the same time, new regulations were put in place to anticipate electrical discharges. The electrical gradient between ship and ground was always thereafter measured at landing time.
Perhaps if the Hindenburg had decided to get to ground first instead of the mooring mast the story might have been quite different because the size of the electrical charge would have been less. In any case, this one event changed the history of aviation. The zeppelin never regained an important role in air travel and production of new airships was stopped soon after 1937. Sixty-four years later, Friedrichshafen was once again in the news as a new eight million dollars, helium powered, zeppelin was built there for low altitude tourist trips around central and southern Europe.
Germany’s alternative to the growing demand for luxury travel across the Atlantic in bigger and more luxurious liners came to a sudden end when the Hindenburg caught fire. A comparable shock had come twenty-five years earlier with the sinking of the Titanic and, as a result, new rules about safety were introduced at that time for all ocean liners. The demand for ways of moving from place to place greatly increased after World War II and, because there were large numbers of people leaving Europe for short or long stays at countries around the world, faster ways of traveling were demanded.
In the final years of World War II, jet fighter planes came into use. Immediately after the war this type of plane was seen as the answer to faster modes of travel. By the early 1950s commercial travel by jet planes had started. Like all new developments in the technology of air travel there were risks of failures. To use jets in warfare was quite different from long distance usage with large numbers of people. The wartime ma- chines were light and their length of time in the air on any one sortie was only a few hours.
It was a very different challenge to fly a big airliner on jet engines halfway around the world. Britain was a pioneer in this new way of air travel and in 1952 the De Havilland Company launched the first turbo-jet airliner, the comet. It was a thirty-six-seat jet and it could fly from London to Johannesburg, South Africa, at speeds of 500 mph. The British Overseas Airways Corporation (BOAC) adopted it at once and in less than a year comets were flying around the world. Other airlines were equally eager to buy these new jets and De Havilland soon had a waiting list of five for every comet that came off the assembly line.
The trip from London to Singapore was one of BOAC’s longest routes and comets were particularly welcome on it because they cut back substantially on the time taken. One comet was flying that route in 1953 and had stopped over in Calcutta en route. As it took off on May 2, 1953, to continue its flight to London everything seemed normal. Six minutes later communication with the control tower was lost. The plane had gone down less than ten miles from the airport and all forty-three on board were killed. This was BOAC’s first fatal crash in five years and the fact that it happened to one of its newest planes was a big shock. Commentators insisted that some unusual weather much have caused the accident. One newspaper concocted a story of a downdraft meeting an updraft of air just where the comet was flying. Many believed it.
Another long-distance route flown by BOAC was London to Johannesburg so comets were popular there too. For eight months after the tragedy near Calcutta, nothing occurred to make BOAC change its activities. The comet continued to be enormously popular. Then, on January 10, 1954, a comet from London, one that had stopped over in Rome, took off from there to continue its journey to Johannesburg. There were thirty-five people aboard.
These numbers seem small by today’s standards but the 1950s were years that knew nothing about the jumbo plane or even smaller jets of the kind we know now. Jets were still quite new ways of traveling. An Italian fisherman saw this jet shortly after its takeoff while it was high in the sky, then watched it plummet down into the sea near the Island of Elba, about one hundred miles from Rome. BOAC immediately grounded all of its comets and proceeded to conduct a full scale inspection of its entire fleet.
Following a meticulous series of examinations, flights resumed in March of 1954 but within a few days another comet went down, this time on the London–Johannesburg route. Commentators and officials now began to ask big questions. Newspaper reports wondered about the basic safety of the comet, asking whether there might be something wrong in the design that no one had yet recognized.
A major salvage operation was launched to recover the wreckage of the jet that went down off the Island of Elba and the results were very surprising. There was no evidence of fire, explosion, or engine failure. The only possible explanation for the crash was the condition of the fuselage. It had been ripped apart in several places.
Intensive tension and pressure tests on the materials being used in the comet’s fuselage finally revealed what was wrong. The materials were inadequate for long distance travel at high altitudes. The jet’s fuselage was fine for short-range military fighters at low altitudes but it could not cope with repeated pressurization, speed, and high altitude over long distances.
The career of the comet came to an abrupt end two years after its debut. Sometime later it was redesigned with better materials but by then other manufacturers like Boeing had captured the jet plane market and the comet was no longer the only choice available.