Sgt. Joshua Jelinek, the lead instructor for the Assault Climbers Course, observes the one-rope bridge to ensure it has been properly assembled and is safe for use at Camp Lejeune, N.C., April 12, 2016. These bridges allow Marines from the 22nd Marine Expeditionary Unit to conduct cliff assaults, and move supplies and themselves safely across a river or cavern. - Sgt. Joshua Jelinek, the lead instructor for the Assault Climbers Course, observes the one-rope bridge to ensure it has been properly assembled and is safe for use at Camp Lejeune, N.C., April 12, 2016. These bridges allow Marines from the 22nd Marine Expeditionary Unit to conduct cliff assaults, and move supplies and themselves safely across a river or cavern.