Rock salt storage facilities are dome-shaped so trucks can easily enter and exit the storage area without obstacles like trusses or roof supports, according to the BBC and the Dome Corporation of America. Domed structures have high interior spans that allow freedom of movement for bulldozers and dump trucks.
Wide front doors of storage facilities keep rain out. Salt is corrosive, so domed salt storage areas are made of materials that include protected concrete, wooden beams and roof shingles. A dome with a 150-foot diameter and 12-foot-tall concrete walls can hold more than 19,000 tons of sand. Larger facilities for municipal salt operations in Great Britain store between 2,000 and 3,000 metric tons of salt, according to the BBC.