BY SUSAN WARE

The doubledeck Allenstown-Pembroke Bridge, which carries Route 3 traffic across the Suncook River, failed a state inspection on Friday, Aug. 3, forcing the opening of the new replacement bridge on Tuesday, Aug. 7.

The inspection was prompted by the collapse of a Minnesota bridge on Aug. 1. The following day the Federal Highway Administration ordered an immediate inspection of all bridges across the country. The bridge that collapsed was a deck truss design, and the U.S. has 750 of these bridges. In New Hampshire, there are four.

In addition to the Allenstown-Pembroke Bridge, inspectors focused on the Queen City Bridge, Manchester, the Ashland-Bridgewater Bridge and the Sarah Mildred Long Bridge that spans the river between Portsmouth and Maine.

“The Allenstown-Pembroke Bridge is just not a good structure. It has required constant monitoring and we have had to add strengthening supports many, many times,” said Mark Richardson, the head of the state Bridge Design bureau.

The bridge gets heavy use and for the past few years has been in place while a new bridge is constructed next to it.

While the new bridge was scheduled to open at some point this month, the inspection on Aug. 3 changed those plans.

Richardson made the decision to have crews work through the weekend to finish the new bridge so that traffic could use it and the old Allenstown-Pembroke Bridge could be closed on Tuesday, Aug. 7.

“Because we had so many concerns once we did the close-up inspection, there was no other choice but to close that bridge as soon as possible,” said Richardson.

The access to the old bridge has been blocked off with barrels and barriers, and traffic is moving over the smooth pavement of the new bridge.

Richardson said a contractor has been selected to remove the old bridge, and that a date has not been set yet.