Testing a bridge cable for weakness.
Credit: NPR

With Pres. Obama’s AMERICAN RECOVERY AND REINVESTMENT PLAN in place, one of the items South Carolina has to look forward to is “enacting the largest investment increase in our nation’s roads, bridges and mass transit systems since the creation of the national highway system in the 1950s.”

On that note, we sure could use some funds for all the road construction that’s been going on around here. As far as bridges go, our only suspension bridge also happens to be the newest one in town (for now) – but if a suspension cable ever broke on it, it would be a complete disaster.

The Cooper River bridge
falling down.

According to Raimondo Betti, professor of civil engineering and engineering mechanics, who is leading an experiment that tests bridge cable weaknesses, one suspension cable failing on a bridge such as NY’s older Williamsburg, Brooklyn, or Manhattan Bridges would cause the failure of the entire bridge. “You can imagine what could [happen] if one of these bridges needed to be closed for a major repair. This would mean that the city basically shuts down,” Betti said.

We all know things are much better now with our new bridge: it’s so wide that a wreck in one lane could be averted by moving over to another, where in the past, we were all tied up for hours, and the question of the day was: ‘Which way do I go home?”, and forget about before the Mark Clark was built, you might as well cancel dinner.

The idea is that the sensors would alert engineers and maintenance personnel immediately when a cable becomes weak – because sooner or later, every bridge will have it’s day.

This short video shows a mockup the Columbia University engineers have built to test sensors they imagine being placed within the suspension cables while being built.

Thanks to our beautiful new bridge here in Charleston, we won’t have to worry about stress tests of this magnitude during our lifetime, but it’s good to know there’s a plan in place for older bridges.