Another seawall wasn’t the answer. Even if the design team merely wanted to rebuild the 50-year-old sheet-pile wall to protect the Massachusetts Bay Transportation Authority’s largest bus maintenance facility, doing so would require relocating two large transmission lines running behind the existing bulkhead or cantilevering the wall. And a new Charlestown wall on the tidally influenced Mystic River likely would need replacing in another 50 years, says Paul Schuman, a senior staffer for the project’s lead engineering firm, Simpson Gumpertz & Heger.
“Building a new wall is often the typical choice in these situations,” Schuman says. “Our choice was driven by the replacement cost of the steel wall in the future.”