Titan Tech Culvert Saw and Culvert Expander

Situation: Increase Productivity of Culvert Repairs

Titan Tech of Boise, ID has been in the drainage culvert repair business for decades. Their visionary team identified an opportunity to produce and market a custom equipment system that would make the process of repairing culverts under roads faster with less impact on traffic. The idea consisted of two primary elements: the Culvert Saw and the Culvert Expander. Titan Tech team members were fully subscribed with the everyday work of the company, and the company had not developed this type of equipment before, so it made sense for them to seek an outside product development team to turn their culvert saw and expander concept into a new equipment design system to rehabilitate corrugated metal piping.


The culvert saw is pulled through the culvert from one end to the other. As it moves, it cuts the bottom of the culvert. Once the saw is pulled through, the culvert expander is pulled through. As the expander is pulled through, it expands and rotates. The expander opens up the existing culvert sufficiently to allow a new culvert to be pulled through the old one. Companies that work in the culvert repair business use a fairly standard set of tools and equipment to get the job done. Most of the tools on site are hydraulic. To maximize adoption of the new industrial system, it would be important for the new culvert saw to be compatible with the most common equipment, which meant using hydraulic systems.  The sawing system would need to be small enough to fit inside a culvert pipe, but have enough cutting power to cut through the corrugated steel pipe itself. The expander would need to be powerful enough to expand the existing culvert, but small enough to be fit inside the culvert as well.

Approach: A New Industrial Equipment Design

As a starting point, the SGW Designworks team spent time on-site with Titan Tech observing their existing processes. With a clear understanding of the environment,  equipment used and the role of the new saw + expander, the custom design could begin. Initial design in 3D CAD allowed the team to explore a number of different configurations. Once the general configuration for both the saw and the expander were defined, component selection began. In this case, selection of the hydraulic motor on the saw was especially critical, and the design of the plumbing subsystems were challenging. For the expander, the forces that the system would generate approached 1MM pounds. This meant tremendous loads on internal mechanisms. Finite element analysis and simulations were used extensively to iterate the design. Initial prototypes were developed and tested. After small changes based on testing, a final phase of work focused on design for manufacture ensured that the entire system was compatible with manufacturing constraints.

Outcome: Faster Repairs, Decreased Traffic Impact.

Titan Tech is using the system today, replacing culverts under roads – often with no impact to traffic on the road. Titan Tech was able to get from concept to a fully functional system that is working in the field, in less than 18 months. By engaging SGW Designworks, they were able to do this without adding internal r&d or engineering resources.