“When (the pieces) show up to the job site on a flatbed truck or trailer, we can pick them up like really big Legos and put them in place really quickly,” he said. “You almost have an instant bridge.”
The same technique was used in the state’s “Fast 14” bridge replacement project during the summer of 2011. The state replaced 14 bridges over Interstate 93 in Medford in just 10 weeks.
Complicating things in Andover, however, is the fact that freight and passenger trains move under the North Main Street bridge.
For cars, “we can usually create detours, temporary roads. Cars can make turns and traverses. Trains can’t,” Watters said. “Trains don’t like when we’re picking up steel beams over their head and they’re running at the same time. So this steel beam work that I’m talking about is going to have to work either at night when there’s shutdowns in the train service or on some weekends.”
While there will be impacts to traffic with the shifting and merging of lanes during construction, emergency vehicles will still be able to travel north from downtown Andover during the project, according to Hopkinson.
“You’re putting a fire truck on a 10-foot lane. They may have to stop traffic or slow traffic down in order to safely travel through there,” he said. “We looked at that and the folks at the safety complex seem to think they can work with that. We’ve addressed the safety issue. There should be none.”
To help emergency vehicles cross the bridge during construction, emergency workers will control area traffic lights to let traffic move through the bridge without interference, Public Safety Officer Chuck Edgerly said.
Sweeney Court, a small neighborhood with a driveway feeding right onto the southern end of the bridge, will also be impacted by the construction. When the northbound side of the bridge is being replaced, a new, temporary entrance will be created for those residents to access their property, according to Watters.