Key Takeaways
- NWPX Infrastructure successfully installed the world’s first intentionally curved steel microtunnel using its patent‑pending Permalok® Radial Bending Joint.
- The technology enables 72‑inch OD steel casing pipe to follow a 5,500‑foot‑radius curve while preserving weld‑free, press‑fit installation benefits.
- The field trial, conducted beneath New Jersey’s Pleasure Bay for an emergency wastewater conveyance project, spanned approximately 1,290 linear feet of curved pipe.
- The breakthrough expands trenchless design options, reduces disruption, and lowers costs for complex underground infrastructure.
- NWPX Infrastructure highlights its continued leadership in innovation and commitment to quality, accountability, and teamwork across its North American manufacturing footprint.
Introduction to the Groundbreaking Curved Steel Microtunnel Installation
On June 10, 2026, NWPX Infrastructure, Inc. (Nasdaq: NWPX) announced the completion of the first field installation of its patent‑pending Permalok® Radial Bending Joint, a breakthrough that allows steel casing pipe to be laid along intentionally curved alignments during microtunneling operations. This achievement marks a historic shift from the long‑standing limitation of straight‑only steel casing in trenchless projects, opening new possibilities for navigating congested urban environments, existing utilities, and natural obstacles without costly reroutes or extensive surface disruption. The successful deployment demonstrates that curved steel microtunneling is no longer a theoretical concept but a proven, field‑ready solution.
Technical Features of the Permalok® Radial Bending Joint
The Permalok® Radial Bending Joint builds on the company’s established press‑fit connection system, retaining its core advantages: weld‑free assembly, reduced field labor, and compatibility with existing microtunneling boring machines and jacking systems. The joint incorporates a specially engineered radial flex segment that permits controlled bending while maintaining the pipe’s structural integrity and sealing performance. By preserving the proven Permalok® design, the innovation avoids the need for specialized welding equipment or extensive re‑training of crews, facilitating rapid adoption across the industry.
Technical Specifications of the First Installation
The inaugural installation utilized 72‑inch outer‑diameter (OD) steel casing pipe manufactured by Northwest Pipe Company, a subsidiary of NWPX Infrastructure. The pipe was laid along a 5,500‑foot‑radius horizontal curve, covering roughly 1,290 linear feet beneath New Jersey’s Pleasure Bay. This radius represents a tight curvature achievable only through the radial bending capability of the joint, demonstrating that large‑diameter steel casing can conform to complex alignments without compromising strength or durability. The project was executed as part of an emergency wastewater infrastructure effort for the Two Rivers Water Reclamation Authority.
Advantages Over Traditional Straight‑Line Casing
Historically, steel casing pipe used in microtunneling has been restricted to straight runs, forcing engineers to design projects around underground obstacles, utilities, waterways, and existing infrastructure—often resulting in longer alignments, deeper shafts, or costly surface disruption. The Permalok® Radial Bending Joint eliminates these constraints by allowing the pipe to follow horizontal, vertical, diagonal, or compound curves while maintaining the same installation efficiency as conventional straight sections. Consequently, projects can achieve shorter overall lengths, reduced jacking forces, and minimized surface impact, translating into lower material costs, faster schedules, and less community disturbance.
Project Context: Emergency Wastewater Infrastructure in Pleasure Bay
The curved installation was undertaken to resolve a critical setback in an emergency wastewater conveyance project beneath Pleasure Bay. Original tunnel plans were interrupted by unforeseen subsurface conditions, leaving a gap that needed to be bridged without extensive excavation in a densely populated neighborhood. By deploying the Permalok® Radial Bending Joint, construction crews were able to navigate a tight footprint, intercept an abandoned tunnel from the original exit shaft, and complete the conveyance line efficiently. The solution provided by Hazen and Sawyer’s design and executed by Northeast Remsco Construction showcased how the new technology can rescue stalled projects and restore essential services swiftly.
Statements from Leadership and Industry Impact
Scott Montross, President and Chief Executive Officer of NWPX Infrastructure, emphasized the significance of the milestone: “This is one of the most significant advancements in steel microtunneling in decades. The successful installation of the Radial Bending Joint demonstrates that curved steel microtunneling is no longer a concept, but a proven reality. We now have field‑proven technology that can fundamentally expand the possibilities for infrastructure projects that were previously too complex, too disruptive, or too costly to construct.” Industry analysts note that the innovation could catalyze a wave of redesigns for urban utility upgrades, storm‑water management, and subway expansions where space is at a premium.
Company Profile and Manufacturing Capabilities
Founded in 1966, NWPX Infrastructure, Inc. is a leading manufacturer of water‑related infrastructure products headquartered in Vancouver, Washington. Under the Northwest Pipe Company brand, the firm is the largest producer of engineered water transmission systems in North America, supplying steel casing pipe, bar‑wrapped concrete cylinder pipe, pipeline system joints and fittings, reinforced precast concrete products, lined precast sanitary sewer structures, water distribution and management equipment, pump lift stations, wastewater pretreatment, and stormwater quality solutions. The company operates 14 manufacturing facilities across North America, a footprint expanded recently through the addition of lined and engineered precast production lines to increase capacity and regional availability. NWPX’s core values of accountability, commitment, and teamwork drive its ongoing focus on quality and innovation.
Conclusion and Future Implications for Trenchless Construction
The successful field deployment of the Permalok® Radial Bending Joint marks a turning point for trenchless technology, proving that large‑diameter steel casing can accommodate intentional curves without sacrificing performance or installation ease. As municipalities and utilities confront aging infrastructure and growing urban density, the ability to route pipelines around existing obstacles with minimal surface disruption will become increasingly valuable. NWPX Infrastructure’s innovation not only addresses immediate project needs—such as the Pleasure Bay emergency wastewater fix—but also sets a precedent for future designs that prioritize flexibility, cost‑effectiveness, and community impact. Stakeholders interested in learning more or arranging demonstrations can contact Aaron Wilkins, Chief Financial Officer, at 360‑397‑6294 or [email protected], and visit the company’s website at www.nwpx.com for additional details.