DYWIDAG launches their strongest stay cable system yet

DYWIDAG has successfully developed and tested a new Ultra-High-Strength (UHS) stay cable system, set to be deployed on Yodogawa Bridge in Japan. Created in close collaboration with Sumitomo Electric Industries Ltd (SEI), this solution combines UHS strands, with advanced corrosion protection, to meet the evolving demands of bridge engineering.

“Modern bridge engineering not only addresses the needs of durability and structural stability” says Werner Brand, Technical Director of Mega Projects at DYWIDAG, “but also increasing demands on sustainability, which can be achieved using ultra-high strength products, with improved service time.”

A system to meet modern demands

As cable-stayed bridge designs have evolved, the limitations of traditional strand technologies become more apparent. Longer spans, higher loads, and a desire for extended service life, require improved cable systems, and DYWIDAG's engineering team have designed a stay cable solution to push performance boundaries - without compromising durability or safety. The system is based on epoxy-coated, wax-injected, and PE-sheathed strands from SEI, delivering a tensile strength of 2233 N/mm² and an ultimate load of 335kN. That represents a 20% increase over standard stay cable systems.

“This increase in strength allows a reduction in material quantities for steel, wax and PE,” Brand adds, “faster installation cycles and even a reduction in the diameter of the outer stay pipe, reducing the wind load on the cables, with potential savings on the overall structure.”

A new benchmark in performance and protection

Epoxy-coated strands have been used in DYWIDAG post-tensioning systems on more than 50 projects since 2005, adapted to include triple corrosion protection: an epoxy-coated strand core, wax-filled cavities, and an outer polyethylene sheath. This multi-layered approach ensures long-term durability, even in harsh environmental conditions, while minimizing maintenance needs.

“The filled epoxy coated strand has superior resistance against axial and bending fatigue loadings without the risk of inter wire fretting,” Brand explains.

These features align with international standards and are fully compliant with fib Bulletin 89. As a result, the system is ideally suited for use in demanding infrastructure projects that require superior mechanical and environmental performance.

Testing was conducted at MPA Braunschweig and TVFA Vienna and included:

• Static tensile test using DG-UHS-E 75 anchorages

• Fatigue and subsequent tensile testing

• Leak-tightness validation using DG-UHS-E 31 anchorages.

All tests were completed with zero wire breaks, significantly exceeding project-specific and international requirements. The result: one of the most robust and fatigue-resistant cable systems on the market today.

Real-world application: Yodogawa Bridge, Japan.

The system's first deployment will take place on the Yodogawa Bridge, a major infrastructure project, led by SMCC, and owned by NEXCO. It marks the beginning of a new chapter in stay cable technology - one where high performance, corrosion resistance, and global collaboration come together.

“Thanks to our project partners in Japan for the great Japanese-German cooperation,” Brand concludes.

By combining innovation with proven systems and testing protocols, DYWIDAG's cable-stayed bridge solutions help deliver safer, stronger, and smarter structures worldwide.

For more details or to explore how DYWIDAG’s stay cable systems can support your next project, get in touch