The Cordero Rojo Mine is located approximately 25 miles south of Gillette, Wyoming. In 2012, the mine extracted and shipped about 39.2 million tons of low-sulfur coal, primarily to electric utilities in the west, midwest and southeast US. When the mine needed a structural plate crossing (one of the State’s largest), Big R was selected to design and manufacture a Super•Cor Arch with Vist-A-Wall Headwalls and Wingwalls.
Working with first-time crew and uncertain site conditions
Our 40+ years of experience came in handy as this was the first plate and headwall structure for the mine’s own crew. Corrosive backfill properties, extreme loads and limited cover all added to the complexity of this project.
The crossing was over a high-flow drainage area that was prone to severe flooding and the backfill material was Scoria — a coal mining waste material with uncertain electrochemical properties when saturated. It had not been used for this type of application before.
Special coating selected for Scoria backfill
Our design and fabrication teams worked closely with the consultant and, after reviewing many options, an elastomeric asphalt coating was applied to the structure below and just above the 100-year flood elevation.
Close controls on schedule and good communication with the owner’s team allowed for a pretty smooth delivery of product. Plus, with a little extra on-site assistance from Big R, the owner’s crew assembled the arch and wall structures with relative ease. Post-project feeback has been very positive.