Transmission Lines

Description

With a goal established that by 2020, 33% of all energy in the state of California was to come from renewable sources, the Tehachapi Renewable Transmission Project was developed by Southern California Edison to deliver wind energy from the California desert, to the urban center of Los Angeles. Tri-State was subcontracted by Wilson Construction Company to install 1030 foundations throughout Los Angeles and San Bernadino Counties that would make up Segments 7 & 8 of 250 mile transmission line project. From the installation of the foundation in the fall of 2010, Tri-State tackled the strict environmental regulations, a variety of difficult drilling conditions, and the challenges associated with working in the second largest metropolitan area in the US, until the last foundation was installed in March of 2013.

  • Date Published: 07/29/2016
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  • Client: Southern California Edison as a subcontractor to Wilson Construction
  • Website: SCE

Description

Dominion’s Meadowbrook-Loudoun is a 65-mile 500-kV transmission line (part of the Trail Project), located in northwest Virginia, southwest of Washington D.C. The project crosses some rugged uplands, as well as a corner of the Manassas National Battlefield Park. As subcontractor to The L. E. Myers Company, Tri-State installed 1,960 foundations for a mix of monopoles and 4-legged towers. Foundations ranged from 3’-12’in diameter. This project presented some rugged access along with the need to keep the right-of-way and road accesses extremely orderly. As the elevation rose up toward the Appalachian trail, the rock was extremely hard, requiring days of work with air hammers and core barrels.

  • Date Published: 03/09/2016
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  • Client: Dominion Power as a subcontractor to The LE Myers Company

Description

Arrowhead-Weston is a 220-mile transmission line connecting Duluth, Minn., with Wausau, Wis. The project, built by Wisconsin Public Service and owned by American Transmission Company, included 1,564 structures, with foundation sizes ranging up to 13’-dia. by 62 feet deep. Unique challenges included boulders the size of trucks, blasting granite near existing poles, and managing water use and disposal along the right-of-way.

  • Date Published: 03/09/2016
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  • Client: Wisconsin Public Service as a subcontractor to MJ Electric

Description

After the need was determined for an electrical interstate system connecting Minnesota, South Dakota, and Wisconsin the CAPX2020 initiative was born.  CAPX2020 was broken up into several segments and managed by various owning power companies.  Tri-State was contracted to complete much of the Hampton – La Crosse 345 kV Transmission Line by Xcel Energy.  From June 2014 to December 2015 Tri-State worked closely with Xcel Energy to install over 700 foundations running from La Crosse to Alma, WI and then from Rochester to Hampton, MN. 

  • Date Published: 03/06/2016
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  • Client: Xcel Energy (Northern States Power)
  • Website: http://www.capx2020.com

Description

Starting in the spring of 2012 crews began work on the mammoth 1352 foundation project from Center to Grand Forks, ND.  The Minnkota Power owned 345 kV transmission line spans the Missouri River in the west then continues through the farm fields and prairies to bring electricity to the communities of eastern North Dakota and western Minnesota.  Finishing in February of 2014 it became the largest transmission project Tri-State had ever completed at a total contract value of over $70MM.

  • Date Published: 03/06/2016
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  • Client: Minnkota Power
  • Website: Articles

Description

One of the largest and toughest jobs in Tri-State’s 60-year history, CP&L’s Middletown-Norwalk included 45 miles of 345-kV. Line in Middlesex, New Haven and Fairfield Counties in Connecticut.  Tri-state’s portion (as subcontractor to Par Electrical Contractors) required 610 foundations, and nearly 23,000 cubic yards of concrete.  The soils included a driller’s nightmare menagerie of rock types:  sandstone, basalt intrusions, schist, quartz veins, diabase, metadiabase—with unconfined compressive strengths as high as 58,000-psi.  Overall, the project involved drilling 6,730 cubic yards of these rock types.  The aggressive schedule called for all this to be completed in 16 months.  Tri-State completed the job on time, under budget.

  • Date Published: 03/06/2016
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  • Client: Connecticut Light and Power as a subcontractor to PAR Electrical Contractors