The Norwalk River Railroad Bridge opened in 1896 and carries roughly 175 Metro-North and Amtrak trains a day on the New Haven Line, the busiest rail corridor in the United States. Its four-track swing span has jammed open more than once. CTDOT’s $925 million replacement swaps it for two independent 240-foot vertical lift spans, each rising about 60 feet on lift towers 145 feet tall, with fixed approach spans east and west. Building two independent structures instead of one is what lets rail traffic keep moving while each half is replaced. The design was chosen after evaluating more than seventy replacement configurations, and it’s Connecticut’s first CM/GC project.
Project Scope
Replacement of the 1896 four-track swing bridge, 565 feet total span, carrying about 175 daily Metro-North and Amtrak trains.
Two independent 240-foot vertical lift spans, each lifting about 60 feet, on 145-foot towers.
Fixed east and west approach spans over the Norwalk River.
Utility relocation, staging areas, wetland restoration and vessel relocation.
High tower removal beginning in autumn 2026.
South span installation over winter 2027-28; north span installation over winter 2028-29.
Why It Matters
Movable bridges on active rail are the hardest assets in the North American network to replace, because the replacement window is measured in hours of track outage rather than months of closure. Two independent lift spans doubles the machinery, the towers and the maintenance obligation forever, and it is still the cheapest option once you price a New Haven Line shutdown. That trade is the whole design.
Connecticut is also using the project to learn a delivery method. CM/GC brings Cianbro and Middlesex into design development rather than handing them a finished set, which is how the constructability of a winter span installation over a tidal river gets tested on paper first. HNTB has the bridge design, WSP the programme management and inspection. Funding is 80% federal and 20% state.
Project Team & Details
| Developer | Connecticut Department of Transportation |
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| Owner / Client | Connecticut Department of Transportation |
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| Consultants | HNTB (Bridge Design)
WSP (Program Management, CEI) |
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| General Contractor | Cianbro Corporation / The Middlesex Corporation (JV) |
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| Status | Under Construction |
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| Delivery Method | CMAR |
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| Funding Source | Public (Federal) |
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