Staff Sgt. Daniel Graham, 4th Civil Engineer Squadron firefighter, attaches a mechanical advantage system to help add tension to the main line during rope and confined-space rescue training, Oct. 30, 2017, at the training tower at Seymour Johnson Air Force Base, North Carolina. This simulation was part of a 10-day training, which certified about 15 firefighters from the 4th CES on various rescue operations. (U.S. Air Force photo by Tech. Sgt. David W. Carbajal)