Diesel-powered HDS 1000 DE pressure washers recently teamed up with the National Park Service to clean presidential sculptures at Mount Rushmore. Performed over a 4-week period this past summer, the cleaning project blasted dirt and unwanted vegetation from the massive, granite sculptures of former U.S. Presidents George Washington, Thomas Jefferson, Abraham Lincoln, and Theodore Roosevelt, each of which stands about 60 ft. high. Goals of the project were to remove algae, moss, and other organic stains that could corrode the underlying rock of the sculptures. Cleaning was to be performed solely with, without using any chemical supplements. To begin the cleaning, helicopters transported 5 pressure washers and companion hoses to the mountain top, along with rope harnesses and drinking water for the cleaning crew. In turn, a fire brigade filled a pool with water to operate the high-pressure cleaners, which sprayed water onto the sculptures via rotary nozzles. Crews used a companion dirt blaster and boiling water to remove stubborn stains, along with a smoother, flat jet for gentle cleaning of sensitive areas. The high-pressure washers allowed workers to vary the water quantity, temperature, and distance from the nozzle to the surface. Each washer features a 9-hp. diesel engine, ready to deliver 870 to 3,000 p.s.i., at flow rates up to 4 g.p.m. All cleaning work at Mount Rushmore was successfully completed on schedule. For added appeal, the washers lightened the surface of each sculpture to make the monuments stand out from their natural background. Companys line of pressure washers includes portable, skid-mounted, and stationary models, in diesel-, gas-, or electric-powered versions.