138-kV Transmission Grid Improvements

TXU Electric Delivery operates the largest distribution and transmission system in Texas, providing power to three million electric delivery points over more than 100,000 miles of distribution and 14,000 miles of transmission lines. In 2001, TXU Electric Delivery asked Burns & McDonnell to assist in the design of transmission system upgrades to replace aging lines and increase transmission capacity to meet growing demand throughout the system. Today, Burns & McDonnell continues the relationship with TXU Electric Delivery with participation in a wide variety of transmission line projects from those under design to those currently in construction.

• Detailed engineering
• Scheduling
• Estimating
• Procurement
• Construction support
• Environmental studies

Burns & McDonnell transmission line engineers have done extensive work for TXU Electric Delivery including such projects as green field 345-kV lines, rebuilding 138-kV lines, reconductoring 138-kV lines, and various 138-kV relocations. The 25-mile Anna Switch to Farmersville 345-kV line, an ERCOT-driven project supporting the growing Dallas-Fort Worth metroplex, was designed by Burns & McDonnell as a quadruple circuit line to be installed in phases beginning with a single circuit. By structurally analyzing and proposing modifications to a 6.5-mile section of lattice towers in this project, Burns & McDonnell was able to work with TXU Electric Delivery engineers and grid management to develop creative ideas to string or rebuild this 6.5-mile stretch of line during the summer of 2001 to expedite the project and minimize the number of outages. The remaining 18.5 miles of the project was granted a Certificate of Convenience and Necessity (CCN), constructed using hybrid steel/concrete poles and energized in June 2002.

Burns & McDonnell has been heavily involved in helping TXU Electric Delivery rebuild and improve its 138-kV transmission system. This work has typically consisted of projects that require detailed engineering, scheduling, estimating, material procurement, construction support and environmental studies. 

A few of the projects Burns & McDonnell has completed or is currently working on are listed below:

• Round Rock-Round Rock South 138-kV and Round Rock-Round Rock Westinghouse 138-kV were reconductor jobs, both of which are located in an environmentally sensitive aquifer zone. These two projects required Burns & McDonnell’s and TXU Electric Delivery’s environmental departments to team up with our transmission line engineers to ensure due diligence.
• Primrose-Wedgwood 138-kV and Handley-Everman 138-kV are double circuit transmission lines that were designed to be rebuilt with new structures and new conductor on existing right-of-way.
• Paris-Commerce 69-kV/138-kV is a good example of how we are helping TXU Electric Delivery improve grid reliability by designing a new double circuit transmission line for both voltages on the same structure.
• Whitney-Walnut Springs 138-kV and Seldon-Walnut Springs 138-kV are single-circuit transmission lines designed and constructed in existing right-of-way that contained sensitive bird habitat. This existing habitat was closely monitored throughout construction by on-site Burns & McDonnell environmental inspectors who followed state regulations required to minimize disturbance.
• Allen Switching Station-McKinney Substation 138-kV double-circuit transmission line, in the heart of the booming north-south corridor north of Dallas, was constructed to supply current and future energy demands as this busy metro-plex continues to expand. 

Burns & McDonnell is in various stages of designing and supporting approximately twenty 138-kV transmission line projects for TXU Electric Delivery.

To date, Burns & McDonnell has engineered over 250 miles of 138-kV transmission line for TXU Electric Delivery that have been constructed and placed in service. Projects representing over 120 miles are either in design or under construction. The lines have ranged from less than a mile to 34 miles with an average length around 12 miles.

• Provided preliminary engineering and cost estimates
• Prepared all drawings necessary for construction
• Worked within TXU Electric Delivery’s data management system to create project budgets and forecast spending
• Secured all necessary permits such as highway and railroad crossings, U.S. Army Corp of Engineers, etc.
• Coordinated and managed geotechnical investigations
• Prepared bid packages and bid project to TXU Electric Delivery approved contractors.
• Worked with TXU Electric Delivery engineers to accommodate company standards.
• Provided construction support and coordination of line clearances with TXU electric delivery grid management
• Worked to ensure that all CADD work is compatible with TXU Electric Delivery’s electronic project database
• Provided project close-out drawings and documentation for permanent TXU Electric Delivery files
• Coordinated and conducted pre-engineering, pre-construction, and other various project meeting
• Coordinated and managed aerial and ground surveys
• Worked with TXU Electric Delivery’s construction management team to create, update and support project schedules
• Worked with TXU Electric Delivery right-of-way agents to secure easement rights for new projects
• Ordered complete project material using TXU Electric Delivery’s electronic procurement system and standard material list
• Worked with TXU Electric Delivery’s data management system to manage and update project budgets