Petty Officer 3rd Class Chance Keifer, a construction mechanic with U.S. Naval Station Guantanamo Bay's Naval Mobile Construction Battalion 4, greases the tracks of a land excavator at the Seabee's equipment yard, Aug. 26, 2008. NMCB 4 supplements Joint Task Force Guantanamo's constructions needs, as well as commands, whenever called to do to so. JTF Guantanamo conducts safe and humane care and custody of detained enemy combatants. The JTF conducts interrogation operations to collect strategic intelligence in support of the Global War on Terror and supports law enforcement and war crimes investigations. JTF Guantanamo is committed to the safety and security of American service members and civilians working inside its detention facilities.