Airships (1999)

It’s one of the most familiar newsclips of the 20th century: the giant airship Hindenburg approaching the mooring mast in New Jersey, the sudden rush of fire, the announcer choking out “the humanity, the humanity!” as the Hindenburg settles to the ground in flames.

Many people think giant, passenger-carrying airships died forever with that crash. But guess what? They’re about to make a comeback.

Whereas airplanes rely on the rush of air over their wings to generate lift, airships rely on giant bladders filled with extremely light gas: hydrogen in the ill-fated Hindenburg, non-flammable helium ever since.

Airships float in air the same way boats float in water. Archimedes’ Principle states that an object will float if it weighs less than the weight of the fluid it displaces. That means a large volume of gas that weighs less than the same volume of air can be used to lift heavier-than-air stuff like people.

The ancestor of the airship is the balloon. Ever since the Montgolfier brothers of France made the first balloon ascent in 1783, balloonists have been at the mercy of the wind. As a result, early balloonists immediately began experimenting with propulsion systems (hand-cranked propellers, for instance). They quickly realized the balloon would be easier to steer if it were shaped like a cigar.

Henri Giffard of France made the first powered airship flight in 1852, when he mounted a three-horsepower steam engine on a 44-metre oblong balloon and flew 27 kilometres, but it took the internal combusion engine to really make airships practical. By the early 20th century, when airplanes struggled to stay aloft for a few minutes, giant airships were making journeys lasting hours or days.

There are three kinds of airships: rigid, semi-rigid and non-rigid. The giant airships of the past were rigid airships, which get their shape from an internal frame that holds giant gas bladders inside. Because of the weight of the frame, early rigid airships had to be a minimum of 120 metres long. The biggest, like the Hindenburg, were twice that size.

That, as much as the hazards of hydrogen, is what did them in. No one fully understood the stresses on such gigantic airborne structures, and there were a number of high-profile accidents in which airships broke apart in mid-air. As a result, nation after nation shelved plans for vast fleets of airships.

Germany came closer than any other country to achieving that dream. Tens of thousands of people flew around Europe and across the Atlantic in the big ships, commonly called “zeppelins” after Count Ferdinand von Zeppelin, whose firm that built most of them.

Even after the rigid airships disappeared, though, semi-rigid and non-rigid airships continued to serve a variety of functions.

A non-rigid airship, or blimp, is a balloon with propellers; a semi-rigid airship is a non-rigid airship with a rigid keel. Unlike rigid airships, a blimp’s shape is maintained by the pressure of the gas inside it. (The word “blimp” supposedly echoes the sound made by flicking a finger against the taught skin of a non-rigid airship.) The best-known blimps today are the ones that appear over major sporting events.

During and after the Second World War, the U.S. Navy used blimps to watch for submarines and to carry large radar dishes aloft. Recently, blimp-based radar has been used to watch for cruise missiles, and there’s been talk of creating a 460-metre-long airship to carry large tanks and cannon. Airships are also useful as stable aerial platforms for scientific research.

But most exciting of all are plans for new passenger-carrying airships. In South Africa, funding is in place to build a 132-metre airship, the Nelson, that could carry up to 150 regular passengers (or 44 in first-class luxury) at 90 kilometres an hour and an altitude of 500 feet.

In Germany, meanwhile, Zeppelin has built its first rigid airship in decades, the Zeppelin LZ N07. New technology means it shares little but its shape with its ancestors. For one thing, the 12-passenger, helium-filled craft is only 75 metres long, thanks to today’s lightweight synthetic materials. As well, its three engines, located at the tail, can be rotated for maneuvering; that, plus additional maneuvering thrusters in the nose, means the LZ N07 requires only three people on the ground. (The Hindenburg, by contrast, needed 228!) A Swiss sightseeing firm has already contracted to buy the new Zeppelin; many other companies are interested.

Who knows? Perhaps, 60 years after the fiery sunset of the last great age of airship travel, we’re about to witness the dawn of a new one.

Permanent link to this article: https://edwardwillett.com/1999/08/airships-1999/

Leave a Reply

Your email address will not be published.

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Easy AdSense Pro by Unreal