A mechanical failure of a sheave in the south tower of the 76-year-old, 2,804-ft-long Sarah Mildred Long Bridge on Aug. 21 has led to a permanent closure—10 weeks before construction of its replacement would have closed it anyway.
The steel-truss lift bridge carries 14,000 daily vehicles on the U.S. Route 1 Bypass over the Piscataqua River between Maine and New Hampshire. After two days of investigation, engineers from the New Hampshire Dept. of Transportation, MaineDOT, Hardesty & Hanover and contractor Cianbro determined the bridge would not be safe for operation without repairs that would cost $1 million and take at least six weeks.