The historic 6,442‑foot‑long Eads Bridge has carried rail traffic across the Mississippi River in St. Louis since 1874. To support MetroLink’s operational needs, the agency advanced a $7.6 million effort to install a new East Riverfront interlocking system that controls single‑track train movements over the bridge. STV provided design services to modernize the bridge’s structural, track, and communications components while preserving its architectural character, in accordance with requirements from the Illinois Historic Preservation Agency.
What challenges did STV address?
Upgrading a modern signal and communications system within a 19th-century structure required careful integration of new equipment with historically sensitive elements. The bridge’s age, geometry and location above an active waterway added complexity. The interlocking system had to be designed to support reliable, safe single‑track operations without affecting the historic fabric of the bridge.
What solutions did STV deliver?
STV designed a 29‑foot ballasted steel girder span to support new trackwork and equipment for the asymmetrical double‑crossover interlock. The team advanced structural, trackwork and communications system upgrades, providing designs that met operational needs while respecting preservation requirements. STV also delivered signal house improvements and new contact system components. The firm completed 30 percent of the design–build assignment in less than three months and finalized the full design and bid package within an additional three months.
How does this project benefit the region?
The upgraded interlocking system strengthens MetroLink’s operational reliability and safety while maintaining a vital connection between Missouri and Illinois. The project supports efficient train movement across one of the region’s most iconic structures and helps protect the long‑term functionality of the light rail system.
Key stats and accolades
- 6,442‑foot‑long historic Eads Bridge
- 29‑foot ballasted steel girder span for new trackwork
- Asymmetrical double‑crossover interlock
- 30 percent of design completed in under three months
