Plow Pulling Installation of Steel Pipelines

Installation of composite pipelines via plowing has been an accepted industry standard for decades. By applying similar principles from composite pipe plowing we wanted to see if steel pipe plowing was viable and had similar benefits of increased production during the installation and remediation phases. The biggest challenge to overcome was the lack of flexibility that steel pipe has when compared to composite style pipes. Composite pipe can be plowed via an enlarged chute, similar to a cable, with a specific bend radius that is larger than the minimum bend radius of the pipe. We developed a pipe pulling method which functions as a hybrid of a horizontal directional drill (HDD) and conventional plowing method. The plow is modified and fitted with a specialized expander head, and the steel drag section is installed inside the expander head. The plow then installs the pipe, which is set up as if it were an HDD pullback, by pulling it into the ground. General findings were that installation of steel pipelines is possible using the pipe pulling method. Installation efficiency increases varied and were heavily dependent on right of way alignment. The best utilization of the method was on long sections. This is due to the travel time between sections, setup, and take down making up the majority of time required versus actual plowing. This constant setup time is very consistent between long and short sections. The longest section of pipe installed was just over 3,100 linear feet (install plowing time 1.5 h) versus the shortest section of 300 linear feet (install plowing time 0.25 h). Right of Way (ROW) restoration time and effort was dramatically reduced using the pulling method. Conventional plow rip was restored via track packing. Topsoil stripping was not required, allowing vegetation regrowth and complete restoration after three weeks in summer condition. Soil saturation affects the restoration, with dryer soils causing more plow rip heave, versus wetter soils leaving more significant rutting that requires clean up. The steel pull method, while deemed successful, has limitations and cannot be applied to all pipeline installation projects. Soil conditions, ROW alignment, terrain, and pipe coating material will all impact production gains. The paper also discusses steps to mitigate some of these factors to make the method applicable to a wider range of projects.