The new Chelsea Street Movable Bridge is a vertical-lift bridge that spans the Chelsea River and serves heavy traffic movements between the cities of Boston and Chelsea, as well as frequent navigation by commercial tankers servicing fuel facilities along the river. The new, signature drawbridge replaced a structurally deficient structure, which was determined by the U.S. Coast Guard to be unreasonably obstructive to navigation.
As part of its contract with the City of Boston, HNTB also completed design services, including environmental permitting, and incorporating environmental requirements into the construction contract specifications. During construction, HNTB oversaw compliance with environmental permit conditions, including reporting and coordinating with environmental resource and regulatory agencies. HNTB prepared all state and federal environmental review documents associated with construction of a new Chelsea Street Movable Bridge, which spans Chelsea Creek.
At the time of its opening, the new Chelsea Street Movable Bridge was the largest permanent lift bridge built in Massachusetts.