Mesa Associates, Inc.
Power Delivery Transmission Lines

Transmission Lines

Mesa's design engineers have over 650 cumulative years of transmission line design experience and possess the skills and experience necessary for any overhead or underground transmission line project. Mesa has completed over 1,000 transmission line projects for various utilities throughout the Southeast. These projects typically range in nominal voltage from 46-kV through 500-kV with the majority of services being provided for 161-kV transmission lines.

Mesa is highly qualified to meet any challenge from conceptual design studies through final engineering, design, and project management services. Mesa's highly qualified and experienced staff of engineers, designers, environmentalist, surveyors, and realty specialists, coupled with our unique strategic teaming agreement and our utilization of specialized transmission line optimization software, will allow us to provide a full range of services extending from beginning to end for various transmission line projects.

Our unique base of expertise along with our past experience and familiarity with transmission line industry practices and transmission line standards, will allow us to efficiently provide the following range of services for transmission line projects.

Our Transmission Line Services Include:

Transmission Lines

Feasibility Studies

The Transmission Line Design Group has expertise in performing feasibility studies for evaluation and comparison of alternatives and to provide an economic project assessment. The study leads to decisions on design philosophy and criteria, configuration, operational aspects, ratings, and economics.

Physical aspects and system performance are often addressed simultaneously in optimizing the transmission line project. Specific studies that we conduct as part of the feasibility study include:

  • Ambient Environment Considerations
  • AC vs. DC Economics/Performance
  • Insulation Coordination
  • Selection of Voltage Level
  • Underground vs. Overhead
  • Structure Type Evaluation
  • Conductor Parameters
  • Current Carrying Capacity
  • Cost and Economic Evaluation

Right-of-Way Design and Acquisition

Mesa has a highly qualified and experienced staff to supply cutting edge technology to provide the following services related to the survey and acquisition of right-of-way for transmission line projects.

  • Topographic Surveys, Aerial* and Ground
  • Subsurface Investigations and Core Borings
  • Right-of-Way and Centerline Selection, Aerial* and Ground
  • Property Owners Identification Information
  • Center-Line Staking, Bench Marking and Construction Survey Requirements
  • Legal Descriptions and Property Maps
  • Expert Testimony
  • Title Research
  • Title Abstracts
  • Property Buying

Mesa, in cooperation with various Aerial survey companies, can provide airborne laser-scan survey, color digital imagery, and black and white digital imagery in various combinations and with various software and processes to create transmission line location and engineering products.

Transmission Lines

Conceptual Engineering and Design

Mesa’s staff is proficient in performing conceptual designs to optimize the plans chosen from the feasibility studies. Computer methods covering areas such as field effects, structure loading, sag and tension, and ampacity are used extensively.

Also, particular client design preferences, and operational and maintenance practices are considered. The results are documented in a Design Criteria Document (DCD), which includes a summary of design criteria, study results, conceptual structure outlines, and other pertinent information. The DCD serves as an overall plan guide document for subsequent detailed engineering and design.

Mesa has experience in performing various studies for the conceptual design phase that includes:

  • Insulation Selection
  • Capacity
  • Corona and Field Effects
  • Sag and Tension Calculations
  • Cost Estimates-Economics
  • Shielding
  • Foundation Parameters
  • RI/EMF/Corona Analysis
  • Structure Type Selection
  • Conductor and Shield Wire Selection
  • Special Conductor Clearances
  • Power Loss Study
  • Grounding System
  • Audible Noise
  • Hardware Selection Criteria

In the past three years, Mesa has completed over 4,000 miles of Transmission Line rating analyses for various utilities from the southeast to west coast.

Detailed Engineering and Design

Mesa has completed hundreds of detailed engineering and design projects ranging in nominal voltages from 46-kV – 500-kV with the majority of our work being associated with 161-kV. Examples of specific tasks, for both new and existing lines performed by Mesa on a routine basis include:

  • Plan and Profile Development
  • Structure Design and Analysis
  • Insulator Assemblies
  • Structure Grounding Design
  • Supporting Hardware Selection
  • Aircraft Warning System
  • Sag and Tension Data
  • Material Specifications
  • Permit Procurement
  • Structure Spotting
  • Line Optimization
  • Guys and Anchors
  • Foundation Design and Analysis
    (Poles and Towers)
  • Structure Load/Clearance Diagrams
    (Poles and Towers)
  • Conductor Vibration Analysis
  • Swing Clearance Calculations
  • Environmental Assessments
Transmission Lines

Transmission Line Design Optimization

Mesa achieves transmission line optimization through the use of our transmission line experience coupled with computational software to help reduce project costs to its clients. Programs such as PLS-CADD and Multi-span Design, and other software are used extensively in developing design alternatives and problem solutions.

Mesa’s transmission line design staff is trained in using automated design tools such as AutoCAD 2007, MicroStation Ver. 7.1, MicroCadam Ver. 13.1, and ProEngineer Ver. 15. We have several copies of the latest version of PLS-CADD installed in the Chattanooga office to be used for various projects.

PLS-CADD is one of the most powerful and comprehensive programs available anywhere for the structural and geometric design of overhead transmission lines. It integrates in a seamless environment all aspects of transmission line design, including terrain modeling and rendering, route selection, manual or automatic minimum cost spotting, sag-tension, clearance and strength checks, material list generation and plan and profile drafting.

To compliment PLS-CADD, we have structural design optimizing capabilities using programs such as PLS-Pole (Wood, Steel, and Concrete) and PLS-Tower. Additionally, we have other optimization design software available, such as Mesa’s MULTISPAN and RateKit Ver. 3.9, a thermal ratings tool.

By using customized in-house AutoCAD programs and data files generated by an electronic survey data collector, we are able to automatically generate an AutoCAD drawing of the profile for a transmission line survey.

We have custom software that will automatically generate the structures, sags, and associated information on an AutoCAD drawing once the line is designed and counts poles by class and height. Software has also been developed to automatically generate the Structure List Drawing and link it to the Plan and Profile Drawing.

Mesa in cooperation with various aerial survey companies has developed a fully integrated remote mapping and design program to be used in route selection for new transmission line projects and uprating existing transmission line projects. In these applications, a survey using laser technology of the proposed transmission line corridor or of the existing transmission line is performed and the data collected is directly downloaded into design/engineering software such as PLS-CADD for detailed route selection and/or rating analysis required for specific projects. Furthermore, the data collected from the aerial survey can be directly converted to GIS/Facilities Mapping applications.

Transmission Line Upgrades and Uprates

Mesa’s staff is experienced in various transmission line upgrade and uprate projects typically ranging in nominal voltages from 115-kV to 500-KV. Additional capacity is frequently obtained by various methods including higher operational ampacity, increased operating voltage, conversion of AC lines to DC operation and higher order phase transmission.

In these cases, Mesa conducts detailed consultation prior to study commencement to ensure proper understanding of operational constraints and practices. Mesa performs studies to evaluate the options as follows:

  • Ampacity at High Temperature
  • Working/Ground Clearances
  • Field Effects
  • Insulation Coordination
  • Sag and Tension Limits
  • Structural Analysis
  • Facility Layouts
  • Cost Estimates

As indicated earlier, Mesa in cooperation with various aerial survey companies has developed a fully integrated remote mapping and design program to be used in uprating existing transmission line projects.

Construction Interface, Support, and Management

Mesa has a unique combination of highly experienced employees with electric utility service who have had many hours of actual field experience coordinating with construction and maintenance personnel. This experience base has provided us a unique ability to assist utility or contractor construction personnel in resolving unanticipated issues or circumstances identified during the construction phase of transmission line projects. Additionally, Mesa has highly qualified transmission line construction management personnel that can provide management and supervisor services to both utility and/or their construction contractor.