Growing Momentum for Press-Brake Tub Girders in Short Span Bridge Construction

Photo: Press-brake tub girder in Geauga County, Ohio. Photo Credit: Nelson Bridge Systems

Press-brake tub girders (PBTGs) continue to gain momentum as an efficient, durable and cost-effective solution for short-span bridge construction. With growing interest from bridge owners and engineers, companies such as Delta Steel and Nelson Bridge Systems are expanding their capabilities to support the design, fabrication and delivery of these innovative steel bridge systems.

Developed through research and collaboration supported by the Short Span Steel Bridge Alliance (SSSBA), press-brake tub girders offer several advantages over conventional bridge systems, including reduced fabrication requirements, lightweight construction, high torsional stiffness and opportunities for accelerated bridge construction.

The technology uses structural steel plate that is cold-formed into a shallow trapezoidal tub section using a press brake. By forming the primary girder section from a single plate, the system reduces welding requirements while providing an efficient structural shape. PBTGs can be fabricated using weathering steel or galvanized for corrosion protection, depending on project requirements. They can also be incorporated into modular bridge systems to simplify transportation and installation.

Expanding Fabrication and Supply Capabilities

Delta Steel, a structural steel service center and member of The Infra Group, recently expanded its capabilities to offer press-brake tub girder forming and processing services. At its Fort Worth, Texas, facility, Delta Steel offers forming capabilities for girders up to 60 feet long, using AASHTO M270 (ASTM A709 GR 50) steel plate up to 1/2-inch thick. These capabilities enable the company to provide formed tub sections, processed plate and fabrication-ready components to bridge fabricators. The investment provides another source of formed steel components for PBTG projects, helping expand the supply chain available to bridge fabricators and contractors.

 Nelson Bridge Systems LLC, established in early 2026, provides engineering and fabrication services for PBTG bridge projects. With Senior Bridge Engineer Guy Nelson, P.E., S.E., the company builds on extensive experience with PBTG technology and offers standardized girder designs and fabrication services for bridge owners, designers and contractors. In a recent company update, Nelson Bridge Systems reported receiving purchase orders for 14 bridges involving 147 PBTGs. The company has completed fabrication for eight projects, delivered and installed six projects and reported that five bridges are now open to traffic. Nelson Bridge Systems also reported receiving fabrication approvals from five state departments of transportation.

 The complementary capabilities of these companies demonstrate how collaboration across the steel supply chain can support continued adoption of PBTG technology. In a recent project update, Delta Steel highlighted its work forming steel tub girders for Nelson Bridge Systems using AASHTO M270 (ASTM A709 GR 50).

Recent Bridge Projects Demonstrate the Technology

Several recent projects highlight the practical applications of press-brake tub girders.

Cherry Hill Road Bridge – Washtenaw County, Michigan

Nelson Bridge Systems supplied six galvanized PBTGs for the replacement of the Cherry Hill Road Bridge over Fleming Creek. The project replaced a deteriorating concrete box beam superstructure with six 18-inch-deep steel tub girders supporting a concrete deck.

The lightweight PBTG superstructure allowed the existing bridge foundations to be retained while accommodating current design loading requirements. According to Nelson Bridge Systems, this approach reduced replacement costs and helped shorten construction.

The bridge reopened to traffic on August 8, 2026, following approximately three months of construction. Additional project information and photographs are available in Nelson Bridge Systems’ project case study.

Geauga County Bridge – Ohio

Another recent project in Geauga County, Ohio, illustrates the coordination between Delta Steel and Nelson Bridge Systems. According to a Delta Steel project announcement, the bridge replacement utilized 10 U-24 steel tub girders for an overall bridge length of 69 feet, manufactured from 3/8-inch AASHTO M270 (ASTM A709 GR 50) steel plate, along with more than 200 additional fabricated components.

The project replaces an existing concrete bridge and demonstrates the coordination of material sourcing, plate processing, forming, fabrication and field installation needed to deliver a completed PBTG superstructure. Bridge construction started May 29, and the complete bridge opened to traffic on October 1, for a total of 126 days of construction.

Smith Road Bridge – Will County, Illinois

In Will County, Illinois, Nelson Bridge Systems recently reported the installation of 15 galvanized press-brake tub girders for the Smith Road Bridge over Long Run Creek.

The replacement structure includes three spans with an overall bridge length of approximately 103 feet and utilizes 12-inch-deep steel tub girders supporting a concrete deck. The project illustrates the versatility of PBTGs for multi-span bridge applications.

These projects demonstrate the adaptability of PBTGs for local bridge replacements, particularly where reducing superstructure weight, simplifying construction and minimizing long-term maintenance are important considerations.

Building on Years of Research and Development

The growing availability of PBTGs builds on more than a decade of research, development and industry collaboration. In response to a 2009 challenge from the Federal Highway Administration to develop economical, modular steel bridge solutions, the SSSBA organized a national task group to investigate innovative short-span bridge systems.

Led by researchers at West Virginia University, the effort resulted in the development and testing of shallow press-brake-formed steel tub girders. The SSSBA subsequently supported additional research, experimental testing, standardized designs and educational resources to advance the technology.

The history and development of PBTGs is documented on the SSSBA website, including the construction of the first PBTG bridge in the United States in Buchanan County, Iowa, in 2015.

SSSBA has also supported extensive experimental research addressing structural performance, fatigue, live-load distribution and other design considerations. These efforts have resulted in a comprehensive collection of PBTG research reports available to bridge engineers and researchers.

Today, PBTGs have been used in bridge projects across numerous states, providing bridge owners with another option for efficient steel bridge replacement.

Resources for Bridge Owners and Engineers

As additional companies develop capabilities to support PBTG projects, bridge owners and engineers have access to an expanding network of suppliers, fabricators, and technical resources. The SSSBA maintains a comprehensive collection of press-brake and folded-plate girder resources, including research, project case studies, design guidance and educational materials.

For information on available suppliers and fabrication services, visit the SSSBA Supplier Directory, which includes companies offering press-brake and folded tub girder products and services.

Additional information is available from Delta Steel and Nelson Bridge Systems.

The SSSBA also offers complimentary project assistance to bridge owners and engineers interested in evaluating steel solutions for their next bridge project.