Senior Airman Chase Lyman, 28th Civil Engineer Squadron heavy equipment technician, uses a tamper machine during construction of a retaining wall outside the 28th Bomb Wing Headquarters building at Ellsworth Air Force Base, S.D., Sept. 8, 2014. The tamper is used to compact soil in order to provide a solid foundation for the wall. (U.S. Air Force photo by Senior Airman Anania Tekurio/Released)