Idylwood-Tysons Underground Path A Direct Pipe

Michels Trenchless, Inc. helped meet growing energy demands in the Washington, D.C. area by completing a project to install an underground electrical transmission line. Michels Trenchless evaluated conditions and various methods to determine the highest probability of success after a horizontal directional drilling attempt was vacated. Michels Trenchless performed a 3,376-foot long Direct Pipe® installation of 42-inch sacrificial steel casing beneath I-495, I-66, Washington Metropolitan Area Transit Authority Railroad, and Historic Washington and Old Dominion Trail.

Michels crews worked within the confines of a constricted overhead utility right-of-way to execute the project in varying geologies, including clay, silty sands, and mica flakes. The installation was completed in 200-foot sections to 42-inch sacrificial steel due to overhead utilities.

Michels Pipeline, Inc. worked on a small site to assemble sections of the steel casing and provide lift and welding operations during installation.

Michels Power, Inc. developed and assisted with implementation of a plan to ground equipment and temporary structures and mitigate risks posed by several power lines above and next to the jobsite.

Upon completion of the Direct Pipe® installation, an HDD rig was mobilized to pull a 36-inch HDPE casing into the sacrificial casing. With the HDPE casing in place, the 42-inch sacrificial casing was retracted, and 230 kV cable conduits were installed inside the HDPE casing.