Last weekend, the old bridge carrying River Street over MBTA commuter rail in Mattapan, MA was demolished and replaced. The new span was constructed at an adjacent site. Prior to closure, new abutment walls were cast in front of the existing walls. Utilities were relocated to a new, separate utility bridge to the north of th existing birdge. River Street was closed on Friday night, April 13. The existing bridge was demolished, and precast concrete abutment caps were placed on the new abutment walls. On Sunday, the new span was rolled into place using self-propelled modular transporter (SPMT) units. Highway work for the approaches was also accelerated through use of precast concrete approach slabs.
Owned by the Massachusetts Department of Transportation, the bridge was designed by Fay Spofford & Thorndike of Burlington MA and the prime contractor was P. Gioioso and Sons of Hyde Park MA.