Dirigibles on the rise - increased use and improved design of blimps

You won't believe what the Engineers at Zeppelin are Building these days

THE UNION PACIFIC RAILROAD RECENTLY placed an order for 58 new steam locomotives to meet the growing demand for freight shipments across the American continent. Western Union is opening scores of new telegraph offices; it seems that people drowning in cheap e-mail and faxes long for the drama and succinctness of the telegram. And even dirigibles are making a comeback: They may soon see service as airborne tour buses, flying cranes, and stratospheric cell phone antennas.

All those statements are surprising, but unlike the first two, the last one is actually true. Dirigibles, also known as airships, never deserved to go the way of the telegram or the steam locomotive; never deserved to be reduced to flying billboards like the Goodyear blimp. Public relations, ironically, had been part of their downfall: After 36 people died when the Hindenburg burned at Lakehurst, New Jersey, in 1937, it became hard to convince anyone that airships had a future. And in transoceanic passenger service--the business pioneered by the Hindenburg and its predecessor, the Graf Zeppelin--they surely didn't, once airplanes cut the crossing time from days to hours.

But the modern economy is creating many new niches, and in some of them being slow isn't much of a drawback--and being lighter than air is a decided plus. "Nostalgic as they are, airships could play a very interesting role in as innovative a sector as communications;" says Reimund Kuke, the engineer in charge of the stratospheric airship project at Astrium, a European aerospace company. "That's a charming business. And it may also be a very lucrative one, which is why so many people are giving it a try."

A century after they first took off, half a century after they became quaint, airships are coming back.

FROM THE ARCHIVES OF THE COUNT

Friedrichshafen, on Lake Constance in southern Germany, is a modern town, because like many German towns it had to be rebuilt after the war. Traces of its old resort atmosphere survive, though. Sometimes on summer evenings a brass band assembles by the lake, in knickers and felt hats, and the genteel blat of their horns winds through the streets and floats into open windows and drifts out over the water to die gently, oompah-pah paaaah, in the feather-bed air. It's easy then to imagine a zeppelin floating offshore--above and in silent harmony with the sailboats that are fanning in from all directions, now that it's dusk and the band is playing and the beer gardens are open on the shore.

On just such an evening a century ago, July 2, 1900, the first zeppelin took off here from a floating hangar. Count Ferdinand von Zeppelin built his hangar on the lake because he figured, wisely, that his airship might need plenty of room and a soft landing place. People lined the shore and circled the hangar in small boats to watch that first flight. It lasted just 17 minutes; the journalist on board barely had time to scribble a few weighty comments--"Everyone saw in it the supreme expression of the human will"--before Zeppelin made a forced landing on the lake, impaling his zeppelin on a buoy. But within a decade he had stayed aloft for 24 hours and had become a national hero. Airplanes then were still fluky gnats. At his funeral in 1917, Zeppelin was compared to figures like Galileo and Columbus, not the Wright brothers.

His great idea had been to make his airships rigid. Earlier dirigibles were kept in shape by the internal pressure of the lifting gas, like balloons--and like blimps, the only airships in active service today. When a blimp develops a large enough leak, even before it falls to the ground it becomes almost un-steerable; it starts to sag, changing from an aerodynamic cigar into a flopping banana. Zeppelins didn't have that problem. Their external envelope, of waterproofed cotton or jute, was held taut by a framework of aluminum rings and longitudinal girders, and the hydrogen itself was contained in a series of internal bags lodged between the rings. A zeppelin could lose one or two of those hydrogen cells and still be kept afloat by the others, and still keep its shape thanks to its rigid skeleton. It had to be big to lift all that aluminum--the very first zeppelin was 420 feet long, the Hindenburg 804 feet--but the skeleton allowed it to be big. A nonrigid dirigible of the size and speed of the Hindenburg would have been so deformed by the air it was plowing through that it would, again, have become un-dirigible.

It wasn't a technical shortcoming that killed zeppelins in the end. The Graf Zeppelin began transatlantic passenger service in 1928, flew around the world in 21 days in 1929, and was retired, after 590 disaster-free flights, in 1937, the year the Hindenburg burned--and two years before airplanes first carried paying passengers across the Atlantic. Even before the Hindenburg, the count's successors knew they should be filling their airships with helium rather than flammable hydrogen; had they been able to do so, airship history might have been very different. But the only source of helium was (and, for the most part, still is) natural-gas fields in Texas and Kansas, and the American government hesitated to supply helium to Hitler's Germany--especially after it annexed Austria in 1938, not to mention the military history of zeppelins, which had bombed London and Paris in World War I. In 1944, Allied planes bombed Friedrichshafen, flattening the Zeppelin hangars.