Structure Retrofit The information below taken from the "Air Force Research Laboratory Air Expeditionary Forces Technology Division". Structure Retrofit The success of the LINE-X® PAXCON® retrofit was so significant that the Air Force Research Laboratory decided to tackle an even tougher problem - improving the blast resistance of lightweight modular structures. We applied the LINE-X polymer to both the outside and inside of a 10-foot by 20-foot construction trailer. 500 pounds of ammonium nitrate-fuel oil (ANFO) explosive were used to generate 12 psi pressures on the trailer. As can be seen above, the trailer walls underwent large deflections and the LINE-X polymer protective coating had some tears in the membrane, but virtually no wall fragments entered the occupied space. Structure Program Based on the successful proof-of-concept testing done on the LINE-X PAXCON, the Air Force Civil Engineer urged AFRL-Tyndall to aggressively pursue a LINE-X polymer retrofit program with a goal of issuing field guidance on retrofitting lightweight structures by summer 2000. These types of structures, characterized by timber stud walls, exterior aluminum siding and interior veneer-plywood paneling, are widely used during extended deployments, such as our forward installations in Southwest Asia.