By James L. Fouss PhD P.E.
The early research behind corrugated-wall plastic drain tile.
By James L. Fouss PhD P.E.
The year 2015 was the 50th anniversary for the beginning of the corrugated-wall high-density polyethylene (HDPE) plastic drainage pipe manufacturing industry in the United States. Working for the United States Department of Agriculture, Agricultural Research Service (USDA-ARS), Soil and Water Conservation Research Division at Ohio State University, my former colleague Norman R. Fausey and I conducted research to develop new subsurface drainage materials and methods of installation that could potentially be installed faster and at a lower cost than clay and concrete drain tile.
The first phase of our research began in 1960 and focused on installing a circular plastic liner within a mole drainage channel with an attachment behind the blade of a mole plow. In field experiments, the plastic mole liner was found not to be strong enough for long-term stability under soil loading. In January 1965 we received a sample of a small diameter corrugated-wall HDPE plastic tube used for underground electrical conduit from Haveg Industries of Willington, DE. It was manufactured with corrugation equipment developed in Germany. Narrow slots were sawed into the tubing corrugations for drainage water entry and a modified attachment was fabricated to pull behind the mole plow for installation.
Installation with the drain plow proved successful, fast, and easy, plus the structural stability of the corrugated-wall tubing under soil loading was found to be excellent after several months of field testing. In December 1965, a technical paper on our early field research with the corrugated plastic drain tubing was presented at the first National Drainage Conference held in Chicago, sponsored by the American Society of Agricultural Engineers (ASAE). The paper was published in the ASAE Drainage Conference proceedings and has often been referred to as the foundation paper that attracted the drainage tile industry’s attention to begin a new revolutionary era for manufacturing corrugated-wall plastic subsurface drainage pipe materials.
We continued our research by developing design criteria for the corrugated-wall plastic drain tubing. To obtain corrugated plastic tubing for testing with our trial corrugation profile, and fabricated with three types of plastic resins (PVC, high-density polyethylene and polypropylene), we contracted with Armco Steel’s corrugated metal pipe division to have corrugation molds made and test tubing fabricated. Armco arranged with the German firm that had developed the corrugation equipment to have the special molds made and the tubing fabricated with a three-inch diameter. Those three-inch diameter pipes were used to conduct laboratory deflection resistance tests for evaluating the corrugated-wall plastic pipe design method; the design procedure was validated. In 1967 the first commercially manufactured corrugated-wall HDPE drainage tubing in the U.S. was four inches in diameter, the same as the recommended diameter for clay or concrete drain tile used for subsurface drain system laterals.
In companion development work, we designed, fabricated and tested a floating-beam type drainage plow mounted on a crawler tractor to install the plastic drain tube at a maximum depth of six feet. An accurate method of controlling the drain depth and grade when installing corrugated plastic tubing with the high-speed plow was required to make the method acceptable to the industry and especially contractors. In the late 1960s we developed a prototype Laser-Beam automatic depth and grade-control system for the high-speed drainage plow. Field-testing and two field demonstrations in 1971 for drainage contractors and industry representatives showed the successful operation of the Laser-Beam controlled plow installing corrugated plastic drainage tubing. The innovative technology was fully adopted and commercialized by the drainage industry over the next few years.