Cracked welds delay new N. Washington St. Bridge a year

State officials say new span will not open until 2025

COMPLETION OF A NEW North Washington Bridge in Boston will take at least a year longer than expected because of mysterious cracks that developed in welds at steel connection points.

Jonathan Gulliver, the Massachusetts highway commissioner, said the tiny cracks were first discovered by state inspectors about a year ago.

Works was halted and an investigation revealed that some of the cracks didn’t appear until weeks after the weld work was completed. Others were found in materials at the fabrication shop prior to shipment to the bridge site. Overall, 192 cracked welded connection points were discovered and are now being fixed one at a time.

“This is a serious issue for a bridge like this,” Gulliver told the Massachusetts Department of Transportation board of directors on Wednesday. “We want to make sure things are safe.”

Gulliver said the new bridge is not expected to be completed until March 2025.

The bridge, sometimes called the Charlestown Bridge, spans the Charles River connecting Charlestown and the North End. The bridge dates to 1898, and was deteriorating badly when a $177 million contract was awarded to J.F. White Contracting to install a temporary replacement bridge, tear down the original bridge, and build a new bridge with two travel lanes in each direction, an inbound bus lane, and separated bike and pedestrian paths.

The temporary bridge, with two inbound lanes, one outbound lane, and a sidewalk, will remain in place during construction, so existing traffic patterns will remain unchanged.

Gulliver said the delays will drive up the cost of the project significantly, but he said it’s not clear yet who is responsible for the additional cost.

“It’s complicated and there’s an ongoing investigation to see where things went wrong,” Gulliver said. “From our opinion at MassDOT, we do not have any fault in this.”