Richard G. Weingardt, P.E., received an overwhelming response to his column in the February 2007 issue of Structural Engineer. The column, titled "The stunning Millau Viaduct: Engineers take second billing again," also touched off a dialogue about which structure deserves the title of "highest bridge."

The following letter was received from Ken Ross via e-mail:

I have read "The world’s highest bridge is not in France," by Richard G. Weingardt, P.E. (published in the September 2005 issue of Structural Engineer and available in the archives on www.gostructural.com), where he discussed the Millau Viaduct and the Royal George Bridge in terms of the world’s highest bridge.

Another contender for "world’s highest bridge" is the Hegigio Gorge suspension bridge, in Southern Highlands province in Papua New Guinea. It was completed in December 2005, and carries oil and gas pipes across the gorge on a deck that is 393 meter (1,290 feet) above the river. The higher tower on the southern bank is 35 meters higher, at 428 meters (1,404 feet) above the river. By those criteria, the Hegigio Bridge is higher than both Millau and Royal Gorge. I know because I recently retired from Kellogg Brown and Root in Australia, where I was the principal design engineer for the bridge.

Weingardt responds to Ross’s comments below:

The Hegigio Gorge suspension bridge only carries pipe lines and doesn’t allow for the movement of any kind of traffic. For it to be considered a bridge in the traditional sense would require a pretty loose interpretation of the definition of a bridge. However, it’s an extremely exciting and impressive structure, deserving some kind of recognition.

Weingardt will continue to explore this topic in the June 2007 issue of Structural Engineer in his column, "What structure holds the title of ’highest bridge in the world’?"