By: Culvert Tech
Project Summary
The 2026 NCSPA Member’s Choice Award and Special Application Award winner transformed a six-month concrete concept into a record-setting corrugated steel railway underpass completed in just 72 hours. The project became the largest closed-section corrugated steel structure ever constructed in Türkiye and Europe. This record-setting railway overpass and highway underpass in Türkiye became the largest closed-section corrugated steel structure ever constructed in Türkiye and Europe. The finished structure measures 42.7 feet in span and 29.7 feet in rise, creating the largest closed-section corrugated steel installation ever constructed in Türkiye and Europe.
Intro
Some projects save money. Others save time. This award-winning project accomplished both.
Submitted by Culvert Tech, the project delivered the largest closed-section corrugated steel structure ever constructed in Türkiye and Europe while reopening an active railway line after just 72 hours of closure. Fabricated by Hengshui Yitong and constructed by ODF Yilmazlar Insaat, the project transformed what was expected to be a six-month concrete construction effort into a rapid-installation corrugated steel solution.
Located in Cankiri, Türkiye, the crossing allows a newly constructed highway to pass beneath an active railway corridor that serves nearby industrial operations. Because railway service could only be suspended for 72 hours, project stakeholders needed a solution capable of meeting an extremely aggressive construction schedule.
Working with the General Directorate of Highways of the Republic of Türkiye and Turkish State Railways (TCDD), Culvert Tech developed a corrugated steel solution that met the demanding schedule while creating a record-setting structure.
A 72-Hour Window Changed Everything
The project site sat at the intersection of a newly constructed highway and an active railway corridor. The railway serves industrial operations by transporting raw materials and coal, making extended closures impossible.
To keep both transportation networks functioning, the General Directorate of Highways of the Republic of Türkiye and Turkish State Railways (TCDD) established a strict protocol. Railway operations could be suspended for no more than 72 hours before service had to resume.
That requirement immediately eliminated many conventional construction approaches.
Projects with tight construction schedules often drive owners toward solutions that reduce installation time, one reason engineers continue to utilize corrugated steel structural plate systems for complex transportation crossings.
When Concrete Wasn’t Fast Enough
Project planners initially evaluated a reinforced concrete underpass. Preliminary studies showed the concept was technically feasible, but the schedule was not. Construction would require approximately six months to complete.
With only a 72-hour railway closure available, the team needed a different solution.
Culvert Tech proposed a corrugated steel railway underpass that could be assembled rapidly while still providing the strength required to support railway loading conditions above. The approach eliminated months of construction activity and dramatically reduced disruption to rail traffic.
This focus on accelerated construction mirrors lessons learned on the Yellow Mill Channel Bridge Rehabilitation Project, where steel infrastructure helped minimize impacts to critical transportation routes.
Engineering Europe’s Largest Closed-Section Structure
Culvert Tech completed the engineering design and project development for the crossing. The final structure measures 13.02 meters in span and 9.04 meters in rise, creating the clearance necessary for highway traffic while maintaining structural performance for railway operations above.
The project pushed corrugated steel design into new territory.
Upon completion, the structure became the largest closed-section corrugated steel installation ever built in both Türkiye and Europe.
The achievement demonstrates the capabilities of modern buried bridge and underpass systems and highlights how corrugated steel can be adapted for unique infrastructure challenges.
Assembly, Backfilling, and Restoration in Three Days
Once railway possession began, every phase of construction had to proceed without delay.
Crews completed excavation, structure assembly, backfilling, and railway track reinstatement during the limited closure period. When the 72-hour window expired, the railway reopened according to the schedule established in the project agreement. What had been estimated as a six-month reinforced concrete construction effort was completed during a single railway possession period.
The ability to install large structural systems quickly remains one of the major advantages of steel infrastructure. Prefabricated components arrive ready for assembly, helping reduce field construction time while maintaining quality and performance.
A similar approach helped deliver challenging transportation improvements on the Deep Corrugated Structural Plate Arch in New Mexico, where steel provided an efficient solution for difficult site conditions.
A New Transportation Connection for Türkiye
Today, motorists travel beneath the railway through a spacious corrugated steel underpass while trains continue operating overhead.
The completed crossing provides a safe and reliable connection between transportation corridors without compromising rail operations. More importantly, it demonstrates how innovative steel solutions can overcome constraints that would otherwise delay project delivery for months.
The project joins a growing list of award-winning transportation improvements, including the Stone Arch Culvert Rehabilitation Project, where steel solutions helped preserve critical infrastructure while accelerating construction.
Why This Project Earned Two NCSPA Awards
This project earned recognition because it delivered results that conventional construction methods could not realistically achieve within the owner’s schedule constraints.
By converting a six-month concrete concept into a corrugated steel railway underpass completed within a 72-hour closure period, the team delivered a practical, innovative, and record-setting transportation solution. The result not only met the owner’s requirements but also established a new benchmark for rapid infrastructure construction using corrugated steel.
That combination of innovation, engineering, and execution earned both the 2026 NCSPA Member’s Choice Award and the Special Application Award.