Assonet River Bridge

The south coastal rail project is to provide a new southern line of the MBTA commuter rail system that will restore service between Boston and Southeastern Massachusetts. Phase 1 of the project will commuters to finally take a one-seat trip between Boston and Southeastern Massachusetts for the first time since the 1950’s. Bridges and culverts are being replaced on these routes to provide safe transportation for trains and commuters.

One phase of the project was to replace the Assonet River Railroad bridge. This bridge provided challenges for the designers, engineers, and contractors due to the location of the bridge which is located in the forest and near the Assonet River. To help assist in installation of the Assonet River Railroad bridge, the bridge was assembled off site.

After assembly the bridge was lifted by heavy duty transporters to the job site. During this timeframe the bridge was shut down for 11 days while workers demolished the old bridge, setting new precast, and replacing the The Assonet bridge in Massachusetts spans at 80’-0” in length, with the girders standing at 7’-0” in height. Hot-dip galvanizing was the coating specified for this project due to the coating durability and corrosion performance.

The MBTA wanted a bridge that will stand the test of time. Due the proximity of the Assonet River and the moisture that gets entrapped in surrounding area hot-dip galvanizing provided a safe sustainable coating system that won’t pollute the nearby river. If went with a wet paint system, the bridge will need to be repainted years down the road and this would have provided changes due to the accessibility of the bridge begin in the forest and the surrounding environment.

Having a galvanized bridge will allow future trains and passengers have safe commutes for years to come without worrying about the durability to the coating system.