In A Nutshell
The most iconic image of an airship is perhaps that of the Hindenburg, crashing as it’s engulfed in flames. That’s just one type of airship, however; the Hindenburg was perhaps the most popular zeppelin, characterized by its rigid metal frame. Blimps might look the same, but they lack the rigid internal structure of a zeppelin. There are also semi-rigid airships that contain only a partial frame, and it was one of these that was recognized as the first aircraft to traverse the frigid North Pole.
The Whole Bushel
Blimps, zeppelins, balloons, airships: They’re terms that are often used to refer to the distinctive, gas-filled aircraft that we see floating over football games and (occasionally) dramatically going down in flames. They’re actually distinctly different types of aircraft with a storied history.
The broad definition of an airship is a cigar-shaped balloon that is held aloft by the use of a lighter-than-air gas, is driven forward by an engine, and also has room for at least a crew and usually passengers. Some airships use helium; some use hydrogen. The different types are defined by their internal structure.
Zeppelins are airships with rigid internal structures, presenting a unique set of problems that aren’t found in other types of airships that lack this internal frame. Weight is perhaps the most important consideration in the construction of an airship, and even though zeppelins use lightweight materials like aluminum alloys, the addition of the extra weight means that they need to be large enough—more than 120 meters (390 ft)—to achieve a weight ratio that enables them to fly. Zeppelins by design can’t be small, as they would simply be too heavy to fly.
The first zeppelins were, of course, created by Ferdinand Count von Zeppelin. Originally, the giant airships were used as passenger crafts. (Less famous than its demise was the fact that the Hindenburg made 10 round trip flights across the Atlantic in 1936, ferrying more than 1,000 passengers between the United States and Germany in the years before World War II.) Once the war started, however, they were soon drafted into use as bombers.
Blimps are more common than zeppelins, and lack the internal structure. The balloon of a blimp keeps its shape solely because of the pressure of the gas inside. There are a couple of different stories on how they got their rather odd name. One suggests that it was given because “blimp” is the noise the balloon makes when it’s tapped. Another (probably more accurate) story is that the name comes from a combination of their “B” airship category status and the idea that without the gas pressure, the balloon is “limp.”
There is also another kind of airship, called “semi-rigid.” These have a partial frame, although most of the shape of the craft is sustained by the interior gas pressure. With carbon fiber being a more readily available material in manufacturing, these remain popular. In the 1920s, the Italians became the first to fly over the North Pole, and they did it in a semi-rigid airship.
Blimps were popular scout vehicles dating back to World War I. Blimps called Sea Scouts were used by the British to patrol coastal waters, and they saw significant advancements as the war progressed. Early Sea Scouts could stay aloft for around 10 hours, while later Coastal Class Airships could stay in the air for up to 22 hours. Even though blimps are generally smaller than zeppelins, they also had impressive carrying capacity not only for fuel but also for machine guns, communication equipment, and cameras. These blimps were also on the front lines of Britain’s defense against German zeppelins; the massive rigid airships were not only easy targets for faster, more maneuverable British planes, but they made quite a spectacle when they were shot down—ultimately leading to their discontinued use as war bombers.