Marston Mat, more properly called pierced (or perforated) steel planking (PSP), is standardized, perforated steel matting material developed by the United States at the Waterways Experiment Station shortly before World War II, primarily for the rapid construction of temporary runways and landing strips (also misspelled as Marsden matting). The nickname came from Marston, North Carolina, adjacent to Camp Mackall airfield where the material was first used.[1]