High winds in late afternoon on Friday, Sept. 15, 2006, snapped a 2,500-foot-long pulley-type high-line crane system that spanned Black Canyon and was used to transport heavy materials for the building of the new bypass bridge below. The snapped cable, in turn, toppled the two towers standing 300 feet tall on both sides of the canyon that held up the cable.
Luckily, the reported 100-mile-an-hour winds that swept down the canyon that day had stopped work on the project, so only a skeleton crew of construction workers was on the site and no one was injured in the mishap.
One of the towers crashed down on US 93, all tangled in cable and spreading debris around. The highway was completely closed for four days, but luckily again, no cars were impacted or people injured. None of the completed work on the bridge was damaged either, which seemed, initially anyway, like good news.
It took until late October to clean up after the accident and open the whole highway.
The bridge project was about halfway completed when the accident occurred, well on its way toward its scheduled 2008 grand opening. Now, however, it looks like the time required to replace the towers and cable-crane system will delay the project by two years and drive up the cost of the project.
When completed, the bridge will be nearly 2,000 feet long and 900 feet high, and will replace the bridge over the Colorado River on the dam itself. The new bridge is being built to withstand winds of up to 100 mph. Apparently, the cables and towers weren’t.
