Roberts Street Railroad Bridge Replacement

Lunda Construction Company, the heavy-civil arm of Tutor Perini, has started work on replacing the Roberts Street Railroad Bridge over the Mississippi River in St. Paul. The existing structure is a 113-year-old vertical-lift truss spanning 189 feet. Its replacement is a 215-foot rolling bascule truss. Construction began in July 2026 with substantial completion targeted for December 2029.

Project Scope

A rolling bascule doesn’t swing on a fixed pin. The span rotates and rolls rearward along a curved track under counterweight, which is the move engineers reach for when tower height or approach geometry rules out a vertical lift. Beyond the movable span itself, the contract covers replacing six steel approach spans, rehabilitating the existing concrete piers, demolishing timber protection walls on both sides of the navigation channel, and driving a new steel pile protection wall at a new support pier. A 38-foot-diameter sand-filled crash bumper provides marine impact protection. A concrete platform for a new bridge operations building is also in scope.

Why It Matters

The existing bridge has to keep carrying trains and keep opening for barges for the duration. That constraint drives everything. Crews are staging around a live movable span on a federally maintained navigation channel, which means the U.S. Coast Guard controls when the channel can close and for how long. Movable rail bridges over commercial waterways are among the more specialized jobs in American heavy civil, and the pool of contractors who self-perform this kind of work is small. A three-and-a-half-year schedule on a single crossing reflects how little of it can be accelerated.

Project Team & Details