Laney Find New Tech Solution For Challenging Crossing

Longest U.S. Direct Pipe Project To Date
By Jeff Griffin, Senior Editor | March 2014, Vol. 69 No. 3

Texas-based contractor Laney Directional Drilling recently employed Direct Pipe technology to make an underground wetlands crossing on a segment of a major pipeline project in the Northeast United States.

It was the longest application to date of the process in the United States.

The Direct Pipe (DP) process is described as combining the advantages of horizontal directional drilling and microtunneling. DP technology and equipment for the project was developed and manufactured by Herrenknecht AG, Allmannsweier, Germany.

Laney used the DP trenchless method to install 1,350 linear feet of 42-inch diameter steel pipe to cross Aquashicola Creek in Monroe County, PA. The crossing was in a conservation wetlands easement considered a habitat for bog turtles, a critically endangered species.

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The project owner is Williams with the DP segment a part of the Palmerton Loop pipeline project. Laney was the prime contractor. GeoEngineers provided design consultation and on-site construction representation with Laney’s engineering division providing a feasibility analysis and initial design oversight. Laney also handled construction services for the DP crossing. The installation also was supported by mainline contractor, U.S. Pipeline.

Use of Direct Pipe technology was necessary because of recognized environmental, geological and topographical concerns, said Alan Snider, P.E., Laney vice president of engineering.

“Aquashicola Creek flows through a valley with steep ridges on either side,” Snider explained. “That made topography of the area challenging for directional drilling. An HDD design would have to be significantly longer in order to get the pilot bore under the creek at a sufficient depth to alleviate risks of hydraulic fracturing and inadvertent returns.”

A longer crossing route also would have added logistical issues regarding the pipe stringing area, Snider continued. Complex subsurface conditions included rock, shale with layers of gravel, and cobbles which would pose additional challenges if directional drilling was used.

Alternative solution