J. D. Hair & Associates is a consulting firm whose mission is to provide its clients with value through the artful application of technology. We are the industry leader in the design of horizontally directionally drilled pipeline crossings and have been key members of design teams for some of the most significant and challenging pipeline projects ever completed. Our engineers are comfortable conducting surveys in the field, performing design in the office, monitoring construction at the jobsite, or presenting the results of a research project. We are based in Tulsa, Oklahoma, but work on projects throughout the world. 

Since its founding in 1987, JDH&A has consulted on more than one thousand HDD crossings in locations ranging from Alaska to Australia. Included among our clients, who have been located on every continent except Antarctica, are Fortune 500 energy companies, major international design and construction firms, local utilities, and HDD contractors.

JDH&A's leadership position in the specialized field of HDD crossing design is demonstrated by its experience. We invite you to take a few moments to review the selected projects presented on our website. We think you will agree that our firm's HDD design capabilities are unparalleled in the HDD Industry.


See other selected projects that we have been a part of here - Projects


    Lake Sakakawea, North Dakota 2015-2016

    Lake Sakakawea is the third largest man-made reservoir in the United States at 23.8 million acre-ft. The water body, due to its size and topography, has discouraged many previous pipeline routes. Consequently, it's no surprise that the lake was the primary obstacle of this 91 mile dual product pipeline system. JDH&A provided design and construction monitoring services for two state-of-the-art HDD crossings of Lake Sakakawea between January 2015 and September 2016. Both crossings had drilled lengths exceeding 11,000 feet and extended to depths of more than 500 feet beneath the bank elevations.

  • natural gas Transmission pipelines

    nexus project, midwest u.s. 2015-2016

    To meet the growing market for natural gas in the Upper Midwest, the Nexus Gas Transmission system will move over 1 billion cubic feet of energy products per day. Many waterways and wetlands lie along the proposed 36-inch pipeline route forcing trenchless methods such as HDD and Direct Pipe to be pursued. JDH&A provided feasibility assessment, design, and associated engineering analysis for eighteen trenchless crossings between June 2015 and August 2016.



    Due to rising costs from maintenance and rehabilitation, two aerial bridge crossings were decommissioned and replaced by parallel running lines installed by HDD. The decommissioned bridges were built in the 1950's and carried over 500 million cubic feet of energy products per day. JDH&A provided design and construction monitoring for the replacement HDD crossings between May 2015 and May 2016


    GTA PROJECT, ONTARIO, 2012-2015

    Due to the population expansion in the Toronto metropolitan area, the existing pipeline infrastructure had not kept up with the rising demand for gas. Enbridge’s solution was to add approximately 30 miles of 36-inch and 42-inch pipeline to increase the capacity of natural gas being brought into the city. Most of this new line was installed in tight utility corridors throughout the greater Toronto area. With many roads, major highways, sensitive waterways, and high volumes of utilities to be navigated, HDD and Direct Pipe proved to be valuable assets during planning, design, and construction. JDH&A provided design and construction monitoring for the twenty HDD and Direct Pipe installations on the project between May 2012 and December 2015.

J. D. Hair & Associates, Inc.

2424 East 21st Street, Ste 510

Tulsa, OK 74114-1723


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