160728-N-IK959-018 GREAT LAKES, Ill. (July 28, 2016) Chief Warrant Officer Trevor Davis escorts Secretary of Defense (SECDEF) Ashton B. Carter and Rear Adm. Stephen C. Evans, commander of Naval Service Training Command, through a simulated missile-damaged berthing compartment on the U.S. Navy’s largest simulator, USS Trayer (BST 21). Trayer is a 210-foot-long Arleigh Burke-class destroyer replica where recruits go through Battle Stations, a grueling 12-hour culmination of basic training and the last evolution recruits accomplish before they graduate. (U. S. Navy photo by Scott A. Thornbloom/Released)