Chelsea Street Bridge is a 450-ft span 225-ft tall Vertical Lift Bridge. The bridge replaced the previous structurally deficient, functionally obsolete, through truss drawbridge at this location which accommodated only a 95-ft channel clearance which was barely sufficient for the tankers that used the navigational channel. The 450-ft span placed the lift towers on land and its wider footprint allowed the older bridge to remain in place and continue to carry traffic through a significant duration of the new bridge construction. Sena Kumarasena, Ph.D., PE served as the Project Manager and Lead Engineer since 2006 (original design completed in 2002 by others) for pre-construction preparation and construction-phase services. Construction-phase challenges included simultaneous in-house design review led by Sena resulting in many design revisions needed on the original design along with proactively implementing the changes to ensure project success and managing the resulting schedule and cost impacts by working collaboratively with the contractor and the bridge owner agencies, City of Boston DPW and MassDOT.