A few months ago, I asked for opinions on whether the new, circular Grand Canyon glass viewing platform and the Hegigio gas-line structure in New Guinea should be labeled as record-setting bridges. The quantity and quality of your responses suggest that many structural engineers take record-giving seriously. One reader wrote, "Who cares?" He then suggested that rather than calling attention to the tallest or highest bridges, "… why not have records for the strongest highway bridge, the first cable-stayed bridge, or first orthotropic all-steel bridge?"

Although most respondents thought the Grand Canyon structure noteworthy, not a single one considered it a bridge. Said Jeffery Perrier, "A bridge spans some barrier and allows traffic to cross. The Grand Canyon Skywalk doesn’t span anything. It ends up where it started and should rightly be classified as a cantilevered observation platform with a hole in the middle of it." Regarding Hegigio as a bridge, he wrote, "It is actually an elevated pipeline and doesn’t support traffic. If, however, they decide to build a maintenance catwalk along its length, [its classification as a bridge] might get dicey."

Joseph Siccardi didn’t even need that caveat. "Hegigio, although a utility structure, is a bridge because it ’spans’ a major natural barrier." Robert Goodman said, "The New Guinea structure is truly a masterpiece of engineering—pure, simple, and functional, and a noteworthy example of true design. It is a bridge that serves a purpose very well, and it deserves recognition." Jim Simmons added, "Because of its utility purpose, Hegigio is a ’pipeline’ bridge versus a ’vehicular,’ a ’pedestrian,’ or a ’railroad’ bridge. By its utility, the loadings may be different, but the design is the same. Call it a bridge!"

Those in agreement with Siccardi, Simmons, and Goodman made up 46 percent of the respondents. About 54 percent agreed with Perrier and dismissed calling the New Guinea structure a bridge in the traditional sense. Said Randy Wintz, "Hegigio does cross something, but it does not carry people. If it were to be considered a bridge, then how can you not include any rope or cable across a void?" Jonathan Waldrop said, "The Hegigio structure delivers goods via pipe, but does not provide passage. Bridges need to provide passage; therefore, it is not a bridge."

Dan Broekhuizen wrote, "The Hegigio Gorge structure is in a gray area. While it technically does span across a river, it doesn’t have a deck for pedestrians or vehicles. If it is put on any list with other bridges, it certainly needs an asterisk that says ’No deck for pedestrian or vehicular crossing. Bridge carries mechanical systems only.’"

In agreement, Keith Steurer wrote, "Structures should be classified based on what purpose they are actually serving. The Skywalk [or Skybridge], for instance, should be the record-holder for the world’s tallest cantilevered pedestrian platform, and the Hegigio should be the world’s tallest clear-span utility bridge. I would avoid using the term ’highest’ because it could mean elevation above sea level rather than distance between deck and the surface below. Case in point, climbers on Mount Everest build temporary ’pedestrian bridges’ each year to cross gaps in the glaciers and rocks. These are much higher than any other bridges in the world!"

Perhaps Helmuth Wilden hit the mark when he wrote, "How about something absurdly simple like ’Unique Structure Awards.’ With this title, any really unique structure that does not easily fit into an already existing category can be named."

In summary, those supporting Hegigio as being a bridge rank the world’s highest "in-distance-above-the-surface-it-crosses" bridges as 1) Hegigio at 1,290 feet, 2) Royal Gorge at 1,053 feet, 3) Beipanjiang River at 918 feet, and 4) Millau Viaduct at 891 feet. If the New Guinea structure is eliminated from the bridge category, the other three move up in rank and the 78-year-old Royal Gorge suspension bridge stays in the top spot. In any case, France’s Tarn River viaduct retains the title as the world’s tallest bridge from its base to the top of its tower, even though, Goodman, in a tongue-in-cheek chide of the French, said the Millau entry should include the caveat, "… it has roadway but no railway provisions."

Why do we have structural records, anyway?—to bring outstanding engineering achievements to the public’s attention. I believe more rather than fewer record-setting structures need to be spotlighted. Structural engineers should be just as adamant as their architect counterparts in getting their record-breaking and award-winning projects publicized on a regular basis.

Richard Weingardt, P.E., is CEO and chairman of Richard Weingardt Consultants, Inc., a Denver-based structural engineering firm. He can be reached via e-mail at rweingardt@gostructural.com.