U.S. standards for keeping bridges from collapsing when hit by ships hail from a different era. They rely on half-century-old West German experiments on model ships for a key mathematical formula. Their minimum specifications cite the danger of empty 195-foot barges breaking loose from their moorings and drifting into bridges, a threat that seems quaint compared with the hulking 985-foot container ship that strayed off course after an electrical failure and toppled the Francis Scott Key Bridge in Baltimore last month. (Photo: Jonathan Newton/for The Washington Post)
