TriAxis Services 

TriAxis Engineering, Inc. provides design services and studies for the electric utility industry, with specialized design expertise in electrical power systems for renewable generation facilities. TriAxis also supports designs for airport electrical systems. TriAxis develops design drawings and specifications to direct the construction of new facilities. TriAxis produces reports and provides guidance and/or oversight for planning studies, valuations, project development support, and construction management. TriAxis typically works directly for an electric utility, industrial client, or an independent power producer; however, we have experience working as the contractor’s engineer for design/build (EPC) projects.

Completed TriAxis projects are located throughout the U.S. and the Pacific Islands, with the majority in the Pacific Northwest. Experience lists for specific project areas are available on request.

Substations and Switchyards

TriAxis has in-house design and drafting capabilities to produce complete construction packages for our typical substation projects

  • One-Line Diagrams
  • Overall Project Scoping
  • Preliminary Cost EstimatingSKelso
  • Site Layout
  • Fencing, Ground-Grid, Oil Containment Design
  • Sections and Elevations
  • Foundations, Steel Support Concepts, and Structural Loading
  • Equipment and Bus Design
  • Schematics, Three-Line Diagrams, Interconnect Diagrams, and Point to
  • Point Diagrams
  • SCADA Interface Design
  • Communication System Interface Design
  • Conduit Layout, and Circuit and Conduit Schedule
  • Lightning Shielding Design
  • Insulation Coordination and Strength Design
  • Equipment and Construction Specifications
  • Bid Documents for Equipment and Construction
  • Construction Cost Engineer’s Estimate
  • System Protection Design
  • On-Site Construction Management and Monitoring
  • Spill Prevention, Control, and Countermeasure (SPCC) Plans
  • Arc-Flash Calculations and Mitigation


Transmission Lines

TriAxis performs all the following design services for transmission line projects.

  • Route Selectionwestland mcnary4
  • Economic Conductor Size and Type Selection 
  • Structure Selection and Design
    • Wood structures
    • Steel Structures
    • Concrete Structures
  • Survey, Photogrammetry, LiDAR, and Geotechnical investigations are subcontracted as required to firms local to the project area or already engaged by the project owner.
  • Basic Design Calculations
    • Ruling Spans
    • Sags and Tensions
    • Clearances
    • Galloping
    • Environmental Loading
    • Insulation
    • Grounding and Lightning Performance
    • Structure geometries
    • Maximum span lengths
    • Conductor Vibration and Mitigation
    • Guy and Anchor Calculations
    • Structure Embedment Design
  • PLS-CADD Plan and Profile Design
  • Construction Assembly Drawings and Material Lists
  • Stringing Charts
  • Construction Specifications
  • Bid Documents and Bid Evaluations


Distribution Line Design

manzana35kvMany of TriAxis overhead transmission line projects included the design of distribution underbuild. We also provide designs for new distribution pole lines, re-builds, and upgrades. Our distribution line design experience ranges from 2.4-kV to 34.5-kV, underground and overhead, and single-phase to three- phase circuits. Because every project is different, and each utility has its own unique practices, we maintain a comprehensive library of AutoCAD distribution construction unit assembly drawings to make design modifications easy and more efficient. 

Distribution line design requires all of the design steps and calculations discussed above for transmission line design. However, distribution design is often more involved due to practical constraints and multiple service locations along any given line section. Centerline surveys are seldom available or economically justified, and consequently the layout and height selection of poles, guys, and anchors require field design and staking. The required distribution field design engineering skills are only learned through years of practical experience.


Interconnection of Generation Projects

TriAxis is uniquely qualified to support both utility-side and generator-side interconnection projects. We have provided feasibility and system impact studies for utilities and have acted as the developer’s engineer in the interconnection process. Our understanding of the needs and requirements of electric utilities and the goals and constraints of generation developers allows us to work effectively to find the best possible solutions that work for all parties, avoiding misunderstandings.

This ability to understand the needs and requirements of both parties makes us especially valuable to developers as they wade through the interconnection process. Our understanding of the typical issues of effective grounding, protective relaying, isolation and disconnection, harmonic impacts, and code requirements is of great value to clients.


Standard Drawings and Specs

assembliesTriAxis works with electric utility clients, developers, public utilities, and cooperatives to develop standard engineering assembly drawings and construction specifications specific to the client’s specific needs.

TriAxis is experienced with developing pole top assembly configurations and material items that comply with all electrical requirements, code clearance requirements, as well as APLIC avian protection recommendations.







Electrical Utility System Studies

TriAxis performs electrical distribution system studies such as Long Range Plans and Short Range Construction Work Plans. TriAxis uses Aspen Distriview software to build system circuit models and perform circuit analysis. TriAxis utility system planning involves estimating load growth and construction cost, and merges the resulting system technical Studiesrequirements with optimized improvement recommendations and the utilities operation and maintenance goals.

TriAxis provides the following types of studies for our utility clients:

Load Flow & Voltage Drop A Load Flow & Voltage Drop study is necessary to compare actual line loads with rated capacities, and to determine if service voltage levels are within the required limits. Using ASPEN Distriview and other software tools, TriAxis provides radial and network electrical system analysis. We can quickly build a new electrical model from system circuit maps using standard system network parameters, or we can use a client’s existing system model database and software. Using load data, we can then examine the normal and contingency voltage drops in an electric system.

Fault Current Studies are needed to:

  1. Compare equipment fault current ratings with the actual fault current available under different types and locations of system faults, and
  2. Coordinate the operation of circuit breakers, reclosers, sectionalizers, and line fuses.

TriAxis uses ASPEN Distriview to build a simplified circuit model for quick answers or to construct complex models with multiple sources, radial and looped lines, in normal and contingency configurations, for comprehensive studies.

Protective Device Coordination

Proper protective device coordination can prevent damage to equipment. At the same time, it can reduce both the extent and duration of system outages by sectionalizing the area of the trouble. TriAxis adds protective devices and their settings to the system software circuit model and examines the interactions and coordination of these devices. Protective device time current curves (TCCs) are produced to document the intended coordination of their operation.

Protective Relay Settings

In addition to examining existing system-wide protective device settings, TriAxis can provide recommendations for substation and switchyard relay setting changes, replacements, and complete sets of relay setting sheets for common protective relays. TriAxis has experience with Basler, ABB, Cooper, Siemens, and SEL relays. Where requested, TriAxis can prepare equipment-specific electronic settings files for use by clients.

Arc Flash Studies

Using ASPEN Distriview models, TriAxis has prepared both detailed and general arcflashstudies. Arc hazard assessments look at high-, medium- and low-voltage systems and the protective devices and working practices typically encountered. TriAxis has developed recommendations for arc-flash management programs and personnel protective equipment policies. TriAxis has also developed utility-specific hot-line tagging programs for use in protective relays to implement arc hazard reduction programs. Several industrial clients have had TriAxis perform detailed arc-flash hazard assessments for compliance with codes and standards. In some of these projects, TriAxis has used SKM software, at client request, when performing the studies. TriAxis has a license for SKM software.

Short- and Long-Range Capital Improvement Plans
TriAxis has provided clients with system studies that estimate and then examine the impacts of future load growth patterns, service area annexations, and general system expansion.

TriAxis can also perform studies to recommend cost-effective maintenance replacements, which improve system efficiency.

These studies always include much client input and collaboration to plan changes and mitigation strategies. To plan future capital needs, a Short- or Long-Range Capital Improvement Plan must be based on accurate construction cost estimates. TriAxis staff has extensive experience turning project concepts into constructed projects. We regularly provide order-ofmagnitude, budgetary, and construction cost estimates. Using our current construction pricing information, and the experience of staff, we find our estimates to be consistently in agreement with actual construction costs.

Electric and Magnetic Field (EMF)

TriAxis routinely performs power line Electric and Magnetic Field (EMF) analysis for project permit applications, Environmental Impact Studies, and Environmental Assessments. TriAxis has assisted numerous utilities, developers, and environmental/permitting consultants with the descriptive text, figures, and EMF analysis graphs for overhead and underground lines with voltage ratings from 12.47-kV to 500-kV. Our contributions to the power line sections of these documents normally include calculations of audible noise and radio/TV interference, in addition to EMF. Overhead line projects are often built in the proximity of existing lines. To present the “before and after” impacts, TriAxis models and analyzes the existing EMF levels, and then models and analyzes the configuration of existing facility with the proposed facility added. The calculations are summarizes in graphs for the Right-of-Way cross-section, and in tables for the closest receptors. TriAxis maintains two EMF calculating tools: Power Line Systems EMF Calculator Module, and Bonneville Power Authority “Corona and Field Effects” program. Because the BPA program provides corona effects, it is more often used than the PLS program.

Because the design of overhead lines is a core business for TriAxis Engineering, we are able to provide intelligent plain-language responses to review questions raised by permitting agency staff and their consultants.



TriAxis has provided Spill Prevention Control & Countermeasure (SPCC) Plans for dozens of substations, municipal yards and storage facilities in the Pacific Northwest, and BC Hydro and Manitoba Hydro in Canada. We have completed over 100 SPCC Plans for utilities in Oregon, Washington, Wyoming and Alaska.

Our SPCC Plans:

  • Meet the requirements of 40 CFR 112
  • Are practical and useful to the first responder of an oil spill
  • Are developed with an appropriate level of effort and a competitive overall cost
  • Provide a review of each site, recommend oil catchment and containment facilities that may be required, recommend practical solutions, and rank any future improvements on a benefit vs. cost basis
  • Provide AutoCAD layout drawings of the Utility’s facilities based on the best available USGS maps
  • A site-specific map is typically prepared for each facility as well as an overall map that shows the locations of all of the utility’s substations and applicable storage yards.


General Consulting Support

engineering support

In addition to small and large studies as indicated above, TriAxis provides general engineering support to utility engineering and operation departments and provides on-call troubleshooting support. 

General Engineering Support

We are regularly asked to provide general consulting, technical support, and special technical investigations, unrelated to designs in progress. TriAxis answers questions and assists our clients to solve problems related to relay operation, protective device coordination, power quality, hardware selection, and other engineering and operational issues related to in-house design projects. TriAxis has prepared and presented expert witness testimony on behalf of clients for several cases in state and federal courts.


TriAxis provides on-call and on-site support to many utilities where the need for maintaining full-time engineering staff is not warranted, or where the additional expertise provided by an outside consultant is occasionally needed. We regularly provide help in locating distribution system faults from relay data, changing relay settings to accommodate a new situation or switching arrangement, identifying causes of protective device mis-operations, and providing guidance or options


Airport Electrical Design

Astoria AirportTriAxis provides all required electrical design services for airport lighting and signage up-grades and new airport construction. Airports utilize specialized equipment with unique electrical requirements. TriAxis maintains its expertise in current airport lighting and signage equipment. For a typical airport design project we provide planning advice, develop electric system layouts, and size power supply centers, cables, conduits, vaults, and handholes. TriAxis also provides control panel, electric vault, and equipment interconnection schematic and wiring diagrams, construction specifications, and bills of material. Our expertise includes standby power systems and general apron lighting design.








Additional Services:

Due-Diligence Reviews

Due-Diligence Reviews

TriAxis has the experience and expertise to provide independent review of plans, specifications, workplans, and construction schedules pertaining to substation or transmission line construction projects. This service is sometimes necessary to secure long-term project financing.

Project Development Support
TriAxis regularly provides assistance to Independent Power Producers in the development stage of generation projects. IPPs have used TriAxis to provide guidance for economical and practical arrangements for substations, transmission lines, and utility interconnections. We have provided help in contract provisions and negotiations for power sales, transmission wheeling, and interconnection construction. TriAxis has also represented the IPP as the Owner’s Engineer through EPC bidding and construction.

Utility Valuations
The TriAxis group has performed several utility property inventories on the behalf of utility clients, and has developed opinions of value based on replacement-cost-new less physical depreciation.