January 5, 2026
Saving a Coastal Engineering Landmark Through an Integrated Approach
Article by Zeb Hutchison, Project Manager
Coastal railroad bridges usually just do their job, taking the weather and heavy train traffic without anyone really noticing. But when a century-old span over the San Luis Rey River in Oceanside, California, showed signs of significant corrosion, it became clear that action was needed to keep the second busiest intercity railroad corridor in the U.S. running safely.
The traditional, bid-build contract for the bridge’s repair might have suggested a rigid division of responsibilities: engineer designs, and contractor executes. In reality, the project operated in a more progressive delivery model. Because the contractor was involved early, the project turned into a hands-on problem-solving effort. Decisions were made quickly and practical solutions guided the work.
Facing a Century of Coastal Challenges
A century of service and relentless coastal exposure had taken its toll.
Bridge 225.4 stretches 704 feet across the San Luis Rey River, with four spans constructed in 1916 and three in 1925. Positioned over tidal waters and subjected to the corrosive effects of the Pacific Ocean, the bridge supports 66 daily trains, ranging from commuter to freight along the LOSSAN corridor. Inspections revealed extensive deterioration in critical bracing members, bearings, and gusset plates, creating a scenario that demanded both precision and urgency.
What the formal contract didn’t capture was the adaptive approach needed: many members could not be fully assessed until partially disassembled in the field and access itself posed significant challenges over tidal waters and a multi-use bike path. Success required collaboration between the bridge engineer and contractor long before the first steel member was replaced.
Engineering and Planning
Repair plans were based on thorough annual inspections and detailed field investigations.
The design team worked closely with field inspectors, verifying measurements and determining which members required replacement. Bearings, struts, and gusset plates were fabricated to ASTM A709 Grade 50W specifications, with final lengths confirmed on-site.
Early involvement was critical, and the proposed innovative bearing clip retrofits allowed the damaged bearings to regain capacity without full replacement. This early integration demonstrates the practical advantage of treating bid-build projects with CM/GC-style collaboration: solutions emerge faster, and construction risks are reduced.
Access, Fabrication, and Real-Time Problem Solving
Access challenges were among the most complex aspects of the project.
Temporary platforms were suspended from the existing bridge structure, designed to navigate environmental restrictions, live train traffic, and public pathways. Lead abatement crews first removed hazardous coatings from hundreds of locations, enabling accurate field measurements for fabrication. Custom-fabricated members, including gusset plates, struts, and bearings, were installed with precise fit, each one custom fit to match the field conditions at each location.
Material constraints and unexpected field conditions, such as oversized rivets and differences between original spans, required quick and adaptive problem solving. The engineering team collaborated to create field-verified solutions, including custom T-bars and bearing clips in lieu of full bearing replacements, keeping the project on schedule and within budget.
Even under conventional bid-build contracts, teams that embrace collaboration and adaptive thinking can achieve results usually associated with alternative delivery models.
Collaboration Under Live Operations
With trains passing over the bridge up to 66 times daily, maintaining safety was a constant priority.
Temporary bracing and constant coordination with the Roadway Worker in Charge ensured all work could proceed safely. Critical gusset plates were replaced during a pre-planned Absolute Work Window, maximizing efficiency and minimizing risk.
Perhaps most significantly, the access platforms revealed additional members needing attention, and these discoveries were addressed in real-time. This prevented delays and cost overruns, which is a practical demonstration of positive results when flexibility is embedded within a traditional bid-build structure.
Lessons for Infrastructure Delivery
Bridge 225.4’s repair shows that procurement type doesn’t need to limit problem-solving.
Early collaboration, integrated engineering, construction planning, and flexible on-site execution allowed a technically challenging project to succeed ahead of schedule and within budget. Traditional roles, such as engineer vs contractor, design vs construction, were intentionally blurred, with a “project-first” mindset driving outcomes.
Working closely with the agency, the team identified a clear path to complete the work four months early. That same collaborative approach also created opportunities to include additional work without an increase in price, reinforcing how early coordination and shared problem-solving can generate value beyond the original scope.
What Bridge 225.4 shows is that even within a conventional bid-build approach, close collaboration, thoughtful communication, and a willingness to adapt can deliver results that feel more like a partnership than a series of handoffs. For owners, it’s a practical lesson in the value of collaboration.
