At its M.L. Hibbard Renewable Energy Center in Duluth, Minnesota Power uses a truck dumper to unload trailers full of hog fuel (wood chips or shavings from sawmills). The hog fuel is used to produce steam for the adjacent paper mill and to generate renewable electricity. When the structural steel on the 25-year-old dumper had reached the end of its repairable lifespan, Minnesota Power decided to replace it with a new truck dumper designed to lift both the truck and trailer during unloading, reducing the time to detach the full trailer from the truck and unload it.
Because the larger dumper required a stronger foundation and larger hydraulic power unit, Barr provided structural, mechanical, and electrical engineering design services to help install the new dumper, hydraulic power unit, and hydraulic-power-unit building. To develop layout and design, we conducted a 3D scan of the site and equipment. Our work also included preparing a demolition plan to remove the old dumper, working with the client and truck dumper fabricator to specify the new dumper, designing concrete foundations for the new truck dumper, and providing controls and electrical design for the hydraulic power unit. For the hydraulic-power-unit building, we designed the concrete foundations and hydraulic piping, plant air piping, and HVAC. In addition, Barr provided on-site construction observation.