By Amelia Tarallo
Hometown Weekly Staff
When people drive over bridges, they tend to avoid thinking about their structural safety. But every engineer knows that every bridge needs a tune-up here and there to ensure its safety. The Elliot Street has been driven over by thousands over the last 162 years since its creation, which has made it a historical marker and a crucial connector between Needham and Newton. With businesses, emergency vehicles, and civilians, making up hundreds, if not thousands, who rely on the bridge for daily use, it was a no brainer that the bridge needed a tune-up that wouldn’t sacrifice its historical qualities.
What was unexpected was that the team responsible for fixing it would be awarded Best Project of the Year by the American Public Works Association (APWA) in the category of historical restoration/preservation under $5 million.
The original bridge connecting Needham and Newton on the site was built in 1714. Following that bridge’s decline, a new one was built in its place in 1857. This is the bridge people see today. With its stone arches, the bridge is a classic example of the architecture of the time. But deteriorated stones and gaps between stones had made the bridge less stable, and resulted in a reduced load capacity.
Knowing the importance of keeping these two towns connected by the bridge, officials in Needham and Newton began working together on a solution to fix it. Needham took control of the design portion, while Newton controlled the construction.
Work on the bridge began in May of 2016, when the bridge was partially closed. Complete closure of the bridge began in July 2017. Officials knew they would only have a short amount of time to finish their work for the sake of the bridge’s usual passengers. The bridge was reopened on December 12, 2016, safer and with some added features.
The construction of the bridge was approached with the goal to keep most of the original structure intact. “The bridge was supported by scaffolding and wooden forms to support the arches over the river while the pavement and earthen fill was removed from the top of the arches and bridge structure,” explained Needham Town Engineer Anthony L. Del Gaizo. “Then, micropiles were drilled into the bedrock to pin the bridge to its underlying foundation. Next, reinforcing steel was added to the void within the interior of the bridge structure and tied to the micropiles. Concrete was then poured in layers up to the bottom of the electric conduits proposed to be placed within the bridge. Curbing and sidewalks were installed. The conduits were installed and the final layer of concrete poured … The method used was dubbed the ‘root canal’ approach.” The last step of the project was adding vehicular and pedestrian railings, neither of which had been included on the bridge before construction.
From the start, people working on this project knew that it was going to be unique and a challenge to complete. They have been rightfully recognized by the APWA for their hard work and unique strategy for saving the historical Elliot Street Bridge. With the project completed, the Elliot Street Bridge will exist for at least another seventy years.
It’ll be interesting to see what the next generation of engineers come up with to preserve this historic spot.