Modjeski and Masters rehabs Union Station Tunnel in St. Louis

Mechanicsburg, Pa. — Bridge design and engineering firm Modjeski and Masters will perform engineering services required for rehabilitation and replacement of the oldest portions of the Union Station Tunnel in St. Louis. The work will help to maintain a viable alignment for Bi-State Development’s MetroLink commuter rail services and provide continued access to 18th and Clark Streets and surrounding destinations such as the St. Louis Union Station, the Peabody Opera House and the Scottrade Center. The project will employ a construction manager/general contractor (CM/GC) delivery model where the preliminary design team works with the CM/GC to complete contract documents and oversee construction.

Modjeski and Masters has collaborated with Metro to inspect and repair the Union Station Tunnel since 2005. During that time, Modjeski and Masters has become intimately familiar with the existing structure configuration, structural issues and drainage concerns. Modjeski and Masters also understands Metro’s safety concerns and desire to conduct work with minimal disruption to rail traffic. With this latest project, Modjeski and Masters will focus on rehabilitating and replacing the oldest portions of the tunnel.

“The rehabilitation of the Union Station Tunnel presents several unique technical challenges,” said Michael F. Britt, P.E., Senior Vice President and Director of Business Development at Modjeski and Masters. “With extensive experience working with contractors on behalf of owners to streamline the construction process and deliver projects more efficiently and effectively, our expert project staff is uniquely positioned to address these challenges and help Metro complete this project on time and under budget.”

Originally built in 1902 by the Terminal Railroad Association, the steel frame portion of the tunnel served as subway access for the 36 rail lines entering St. Louis Union Station. In 1929, the subway tunnel was lengthened to the west by extending the steel framing to the width of the overhead train shed and adding a concrete slab and column segment. When Metro initiated service in the 1990s, a two-cell reinforced concrete box culvert segment was constructed to extend the alignment west. Today, the Union Station Tunnel crosses beneath the St. Louis Union Station parking lot, five sets (four active) of excursion train tracks and 20th and 21st Streets.