Robot bridge inspector looks for defects

摘要

WHEN the I-35W bridge over the Mississippi river collapsed in 2007, killing 13 people, it was because of defects in steel plates. Such tragedies might be avoided with the help of a robot that makes bridge checks easier. Surveying a road bridge used to involve drilling to check the concrete and steel structures hidden underneath the road. Although radar has simplified the work since the 1980s, sending out teams of people to check bridges is still expensive and can require extended road closures.