Kingdome Considered Icon By Some Engineers

Imagine this: the Kingdome as a national landmark. Of course, you probably thought that debate (and the Dome) were finished. Which means you didn't visit San Francisco lately.

That was where the first-ever Structural Engineers' World Congress (SEWC '98) just took place. It lasted five days, involved 1,700 folks, 50 countries and 20 organizations. While spouses from Estonia, Italy, Britain and China toured nearby Napa's vineyards, engineering's key celebrities were holding court. Some exchanged heated words about our ill-fated icon.

Perhaps the most opinionated came from Princeton's David Billington. Readers may know Billington from his PBS TV series ("Great Projects in Engineering") or from a letter The Seattle Times published last June. In it, he begged salvation for the Kingdome, comparing its plight to that of the early Eiffel Tower. Billington's missive deemed our Dome "the most impressive concrete-roof structure in the world . . . a national historical landmark."

In the orbit of the congress, Billington himself is a landmark, as author of the classic text "Thin-Shell Concrete Structures." That, of course, is what the Kingdome actually is: a vast shell of separate concrete shapes placed in a special geometry. Its roof is nine full acres of unsupported concrete, 5 inches thick - and made out of "hyperbolic paraboloids."

This is engineer-speak for pie-shaped, double-curved shells. Billington feels the Kingdome's create "the most dramatic roof structure of any large covered stadium anywhere." But the Dome is also, for America, the culmination of a historic, worldwide movement.

The shell roof form was developed in Germany during the early 1900s. In 1913, Breslau's Centennial Hall became the first structure whose concrete roof surpassed the span of the Parthenon. The engineering system that achieved such a marvel was refined, then exported to America. It was promoted here by a single engineer: 29-year-old Viennese native Anton Tedesko. He evangelized the "shell" from a Chicago firm, for whom he created watershed buildings: the Brook Hill Dairy Farm at the 1933 Chicago World's Fair, a 1936 sports arena in Hershey, Pa. and, in 1941 in San Diego, seaplane hangars for the Navy.

Other "shells" blossomed in other cultures; the genre also grew in Germany, Italy, Spain and Mexico. There are famous names associated with this revolution: Ulrich Finsterwalder, Pier Luigi Nervi, Eduardo Torroja and Felix Candela. But, in America, shells became respected largely because of Tedesko. During World War II, they provided large spans and high clearances; later, they were tapped for signature civic projects such as airports, auditoriums and Olympic stadiums.

Tedesko eventually settled in Seattle; he died here in 1994 at the age of 90. But his legacy certainly lives. The year he died, his daughter Suzanne accepted his first posthumous honor: the University of Vienna's "Founder's Award." (To celebrate its 175th anniversary, the college chose a single graduate - Tedesko - to honor its legacy.) Last year, Tedesko's innovations were again celebrated at Paris' Pompidou Center.

Not least of his remarkable accomplishments was NASA's Launch Complex 39. This was the facility that finally put a man on the moon and that now resides as a landmark on the National Register. David Billington sees Tedesko as one of only two American "thin-shell" visionaries. The other? Seattle's Jack Christiansen, lead engineer for the Kingdome.

In San Francisco, Billington sang that stadium's praises. "The Kingdome is a work of real structural art. That is not the same thing as architecture. Real structural art grows out of different design motives, such as the desire to control forces and reduce costs."

When it comes to those costs, Billington can cite the dollars. "The final Kingdome costs were $800 per seat. The Montreal Olympic stadium, which is concrete and built near the same time, and which contains seats for as many people, cost $13,750 per seat. And that was without any roof."

One of his themes at the World Congress was education. "It's essential to study structural art like the Kingdome. If you're going to study literature over centuries, you look to the great artists - not merely writers of merit."

The fact the Kingdome was getting its due in San Francisco came as surprising news to Jack Christiansen. But, says Christiansen (who did not attend), it puts no sugar on a bitter pill. "But what is a change is to hear informed discussion. I've talked and talked and talked; I've supplied endless materials. But nobody's listening; I've had to put it out of my mind." There is a silence. "I just didn't have another choice."

Then he becomes animated again. "I'll tell you, that building is a 21st-century structure. It's much more historic than what's going to replace it!"

Two other speakers at the congress agree. They are Thomas Boothby, of Pennsylvania, and Barry Rosson, of Nebraska. The duo presented a rallying call to preserve thin-shell concrete, and bemoaned the demolition of two "classic" structures. One was the 1968 New Orleans Exhibition Hall (on which Christiansen worked); the other, Denver's 1969 "Paraboloid," created by I.M. Pei and Tedesko. The Kingdome, these authors told their listeners, might be next.

Informed that it is next, all were horrified.

Boothby argues that the Kingdome is irreplaceable. "It was the last major thin-shell built in this country, and it's the biggest. Later sports stadiums went to inflatable roofs, then they went to retractable roofs with large steel structures."

But what about those people who just . . . don't like it? "Well, these are very much structures of a certain period. They exude an optimism about construction. Filtered through '90s tastes, they can certainly seem outdated."

He sighs. "But people recognize that cycle in music or fashion. You may not like bell-bottoms. But: do you eradicate all of them?"

Matthys Levy is a different sort of dome expert. In 1990, he supervised the Georgia Dome, a structure whose roof is constructed out of faceted fabric. Until Britain unveils its Millennium Dome, Levy's Georgia peach will remain the ruling macrodome.

Levy understands the world of Tedesko and Christiansen. "When I was younger, I did lots of thin-shell concrete. These structures were very popular from the '50s to '70s." He agrees that some shells are structural art, yet Levy remains reticent about the Kingdome. "Nervi and Candela were on the cutting edge; there's really not much more you can do with concrete. It's true the Kingdome is one of a kind. But is it an icon? I would need more research."

For that, at the moment, Levy is a little too busy. After finishing Argentina's La Plata soccer stadium, Korea's Pusan Dome and the Shanghai Stadium, he is about to tear down and rebuild London's Wembley stadium. It will be, he assures, a state-of-the-art facility. But - is that what they'll be saying at SEWC 2020?