Glass bridges can crack, but may still be safe

World Today

Cracks Appear in New Glass Skywalk at Yuntai Mountain ResortCracks Appear in New Glass Skywalk at Yuntai Mountain Resort

The news this week that a glass bridge in China cracked has many fearful that these new tourist attractions are unsafe.

The crack at the Yuntaishan glass bridge in central China’s Henan province on Monday led to a panic. Staff members said it was caused by a heavy thermos that was dropped by a visitor, which broke one of the layers of glass. The area is now closed for repairs, but authorities said that similar incidents have occurred before, with no threats to public safety.

Chinese authorities cited a 2014 crack in the glass walkway at the Tower Bridge in London. Interestingly, that crack developed when someone dropped a bottle of beer on the glass panel and then a someone walked over it wearing stiletto high heel shoes, which caused it to shatter even further, the Daily Mail reported.

Tower Bridge officials said the crack was just on a panel covering thicker glass below and posed no risk to visitors, CNN reported.

Bill Karren, a principal at Lochsa Engineering in Las Vegas, Nevada, said that if designed and built properly, glass bridges are not dangerous.

Karren designed Skywalk at The Grand Canyon, a 70-foot U-shaped cantilevered bridge over west rim of the Grand Canyon, which hovers 4,000 feet above the ground.

The bridge was built with inner and outer beams designed to resist wind and vibration forces. The beams were then covered with five composite layers of tempered glass totaling 2.79 inches thick.

While he can’t comment on the cracked bridge in China as he does not know the details, Karren said engineers take into account issues of wind, vibration, and weight.

He said whether a glass bride is safe or unsafe depends on the “design, usage, and maintenance” of the bridge.