U.S. Army soldiers with the 65th Engineer Battalion install culvert denial systems along Highway 1 in Helmand province, Afghanistan, March 24, 2014 The system is comprised of two metal-bar grates that are placed at either ends of the culvert and held together by tension force cables, with an anti-tampering device secured to the grates. The device can detect any type of disturbance from vibrations to heat and will initiate a camera to record any tampering with the system.