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® pipe for the Casino Waterline & Highway 57 Service Line project near St. Michael, ND" />
Shortly after completing a record-breaking directional drill of 4,800 LF of 24" Fusible C-905® pipe for Standing Rock Rural Water in South Dakota, King Contracting (KCI) of Lincoln, NE installed another long directional drill using Fusible PVC® pipe in North Dakota. In October 2009, KCI successfully completed a 3,900 LF continuous directional drill under Devil's Lake for Spirit Lake Rural Water using 8" Fusible C-900® pipe. The directional drill was part of the Casino Waterline & Highway 57 Service Line project near St. Michael, ND.
Devil's Lake, one of central North Dakota's major attractions, occupies over 90,000 acres and is over 200 miles long. With the continued increase in the lake level, a road raise project was going to cut off the existing water supply line to the Spirit Lake Casino, one of the Tribe's primary businesses. Due to concerns with re-installing the pipeline in the road right-of-way, the most direct and economical way of conveying water to the casino was to have the new alignment cross under Devil's Lake.
Bartlett & West designed the directional drill of 3,900 LF to complete the crossing. Two thermoplastic pipe materials were specified for the HDD section: 8" DR14 DIPS Fusible C-900® pipe and 10" DR7.3 IPS HDPE pipe, providing similar flow, pressure, and critical buckling pressure to handle the length and depth of the drill.
KCI selected Fusible C-900® pipe based on the advantage in safe pull force-to-weight ratio of Fusible PVC® pipe. The specified Fusible PVC® pipe weighed ~43,000 lbs, while the HDPE pipe weight was ~73,000 lbs. This yielded a safe pull force/weight ratio of 1.1 for Fusible PVC® versus 0.7 for HDPE. Given the length and complexity of the drill, KCI based their decision on minimizing risk.
Pullback was completed in approximately 16 hours, requiring an intermediate fusion of two 1,800 LF sections due to limited layout space. KCI used a 22" reamer, ballasted the pipe during pullback, and measured a maximum pull force at the drill rig during pull back of 25,000 lbs. (~ 50% of the rated safe pull force of the pipe). Jame Todd, Project Manager with Bartlett & West, stated: "This was a very important project for the Tribe as their casino is basically situated on an island. With the constant raising of the roads there was no good alternative to locate the water pipeline. By using Fusible PVC® pipe and completing a 3,900 LF directional drill under the lake bed, we were able to design a project that would not be impacted by future fluctuations of the lake and/or road projects."