Staff Sgt. Joshua Lisowski, 786th Civil Engineer Squadron pavements and heavy equipment operator "dirt boy" uses a jackhammer to break off pieces of a failed repair of a core sample, while Airman 1st Class Greg Sims, 786th CES dirty boy, sucks up the debris with an oversized vaccuum called a air blast sweeper at Ramstein Air Base, Germany, Aug. 15, 2011. A core sample is a piece of the pavement taken off of the runways and taxiways. It is used to test the resiliency of the material and determine how much life is left and if restrictions need to be made. This was one of many tasks completed by the 786th CES between 10 p.m. to 6 a.m., when the Ramstein Airfield was shut down. (U.S. Air Force photo by Staff Sgt. Travis Edwards)