--- title: "How an 11-day steel runway in North Carolina in 1941 became a 72-hour airfield kit in World War II" url: https://badiyaa.com/marston-mat-pierced-steel-planking-runway/ published: 2026-10-15T04:30:00+01:00 modified: 2026-10-15T04:30:00+01:00 section: Tech publisher: Badiyaa --- # How an 11-day steel runway in North Carolina in 1941 became a 72-hour airfield kit in World War II Each Marston mat plank weighed 66.2 pounds and covered 12.5 square feet; nearly 2 million tons were made, and the idea survives in the Marine Corps' aluminum AM2 mat. The first steel-mat airstrip in the United States took 11 days to build in November 1941, on a low hill near the railroad stop of Marston, North Carolina. By the later years of World War II, engineering crews using the same interlocking planks were routinely clearing ground, laying the surface and launching aircraft inside 72 hours. The material became known as Marston mat, after that whistle-stop. The Army later filed it under a drier label, pierced steel planking or PSP. Its afterlife is still visible from Alaska to the Philippines. ## One plank, 66 pounds Each plank was a stamped sheet of 10-gauge low-carbon steel, 10 feet long and 15 inches wide, covering 12.5 square feet. Two pressed ribs split it into three channels, and each channel carried 29 flared holes, so a single plank had 87 of them. The holes cut weight, let rain drain away and gave the sheet extra stiffness around every opening. One long edge carried 30 hooks and the other 30 slots: crews dropped the hooks of one plank into the slots of the next, slid it forward about two inches and clipped it in place. A finished piece weighed 66.2 pounds, or 5.3 pounds per square foot, comfortably under the Air Corps ceiling of 7 pounds. One soldier could carry a plank; two could run with it. Usually the only tool needed was a sledgehammer. The design came from Gerald G. Greulich of Carnegie-Illinois Steel working with the Army Corps of Engineers. The first versions, tried at Langley Field in Virginia in the summer of 1940, were solid ribbed sheets. The punched holes arrived over the winter of 1940 to 1941. ## The 11-day test in the Carolina Maneuvers The proving ground was the Army’s Carolina Maneuvers of November 1941, weeks before Pearl Harbor. Engineers cleared and graded a patch of roughly 350 by 3,800 feet, shifted about 50,000 cubic yards of earth and laid a strip 150 feet wide and 3,000 feet long. General Henry H. “Hap” Arnold, head of the Army’s air arm, inspected it and praised it as “the year’s greatest achievement in aviation.” The strip worked for only a few weeks. After the exercise it was pulled up, loaded into 18 railroad gondola cars and shipped to Langley Field, and the place name went with it. One detail often lost in retellings: the site is usually described as next to Camp Mackall, but North Carolina’s state history records show work on Camp Mackall itself only started in November 1942, a year after the test. The camp, now used by the 18th Airborne Corps, has three 5,000-foot runways of its own today. ## The arithmetic of a 72-hour runway Our own calculation shows why the mat changed logistics as much as it changed construction. The 1941 test strip covered 450,000 square feet, which at 12.5 square feet per plank works out to 36,000 planks. At 66.2 pounds each, that is about 2.38 million pounds, or roughly 1,190 short tons, which means each of those 18 gondola cars carried around 66 tons of steel. A standard wartime runway of 150 by 5,000 feet needed 60,000 planks and, packed for shipping, weighed 1,986 tons. That single runway took up 41,600 cubic feet and 21 percent of a Liberty ship’s payload. The planks nested inside each other, so a bundle of 30 stood under 28 inches tall. Because they were dense, they were loaded low in the hold, with bulldozers and trucks stacked above them to come off first. Speed came with practice. Once crews had experience, a cleared, graded and matted strip with aircraft operating inside three days was not unusual; by 1943 teams were laying from both ends and the middle at once. In the Pacific, the planks were often covered with crushed coral or soil. A reference account puts a 200-by-5,000-foot runway within reach of a small engineering team in two days. ## Production on a war scale By December 1941 two factories had turned out about 4 million square feet. A year later 29 plants were making it. By early 1944 more than 180 million square feet, some 477,000 tons, had gone overseas, enough for 240 standard runways. Total wartime output reached almost 2 million tons, costing more than $200 million at 1940s prices. Damaged planks were not thrown away either: a 14-ton diesel reconditioning plant could straighten, clean and repaint 250 of them an hour, and one unit working out of Australia in 1944 refurbished about 50 million square feet. ## Where the planks are now Surplus mat went into roads, bridges and especially fences. The steel was rich in manganese and resists corrosion, which explains why stretches of it still stand as fencing and roadside barriers in the Philippines and Papua New Guinea. Racing teams in the US Southeast built car trailers from it, and Vietnam War-era planks were reused for border fencing in the 1990s. On Attu in Alaska’s Aleutian Islands, twisted strips still lie in the tundra. The military idea outlived the steel. Holes let vegetation and loose debris through, a hazard for jet intakes, so the Vietnam-era M8A1 dropped them, and the mid-1960s AM2 switched to an aluminum honeycomb core in a 24-by-144-inch panel. The Marine Corps still uses AM2. In a 2014 repair at Quantico, Virginia, Marines described panels of up to 24 square feet weighing as much as 140 pounds each, more than double the 1941 plank, with 146,000 square feet taking about a week to lay and replacement due roughly every five years. ## Further reading - [Wikipedia: Marston Mat](https://en.wikipedia.org/wiki/Marston_Mat) - [NC Department of Natural and Cultural Resources: Camp Mackall (I-34)](https://www.dncr.nc.gov/blog/2023/12/29/camp-mackall-i-34) - [US Marine Corps: Cherry Point Marines repair MCAF taxiway with new AM-2 matting](https://www.quantico.marines.mil/News/Article/518481/cherry-point-marines-repair-mcaf-taxiway-with-new-am-2-matting/) *Image: USFWSAlaska (Lisa Hupp/USFWS), Public domain via Wikimedia Commons* *This article was produced with AI assistance and reviewed by our Editorial Desk. [How we work](/editorial-policy/).*