As a critical link along Amtrak’s Northeast Corridor, Stonington harbor lays claim to two century-old single span bridges on a causeway that were in need of replacement. Amtrak faced a unique challenge with these bridges because they needed to be replaced with minimal disruption to rail traffic while also being sensitive to the needs of the community.
Modjeski and Masters (M&M) determined that the most cost-effective and efficient way to replace both bridges was to use a “Slide-Out/Slide-In” accelerated construction technique. This required the new M&M-designed thru-girder superstructures to be constructed on temporary rail platforms parallel to the existing bridges. Once substructure modifications were completed, the old bridges’ superstructures were “rolled-out” and the new ones were “rolled-in” successfully with minimal rail traffic outage. M&M’s superstructure design brought an added benefit to the community –the shallow depth of the replacement structure provided a slight increase in vertical clearance. This allowed a new class of boats to pass underneath the bridges, thereby driving new business to local docks and growing the local economy.
For more information, see our project documentary film on YouTube: https://youtu.be/0ojaHzPzCzA
|Length of Spans|
|Length of Main Span||98 feet (East Br), 86 feet (West Br)|
|Total Project Length||975 feet|
|Tracks on Structures||2 tracks|