Last week's answer

Question: Spanning the sheer granite cliffs of the Arkansas River in Colorado, the iconic Royal Gorge Bridge opened in 1929 and stood for over 70 years as the world’s highest bridge (and remains the highest in the U.S. at 955- feet). Despite its incredible height and 1,260-foot main span, the bridge was completed in just six months without any central support piers in the gorge floor. What unusual structural feature did engineers use for the bridge deck to help absorb wind loads high above the canyon floor?

Answer: A walkway deck constructed of more than 1,000 wooden planks that are deliberately spaced with small gaps to allow high mountain winds to vent straight through.

Crews left a half-inch gap between each of the 3-inch thick and 1-foot wide planks in order to allow snow to fall through the deck and for airflow through the structure in order to eliminate any aerodynamic forces. 

Source: American Society of Civil Engineers