Line Design

Over the years, we’ve applied our line design expertise to helping a number of communities improve the efficiency of their electrical energy distribution.  Each transmission line design project is separate and unique.  Terrain, easements, materials and construction standards all factor into the solution.
  Distribution line
One of the first steps is developing a design criteria document for the proposed project.  The criteria will include detailed design requirements regarding the following:
  • design voltages
  • structure types & configurations
  • insulators
  • conductor (transmission, distribution & neutral)
  • loading conditions
  • tension limitations
  • structure overload factors and strength reduction factors
  • galloping
  • clearances
  • right-of-way
  • plotted sags
The design criteria are loaded into the modeling software while three-dimensional models are constructed for each pole configuration.  A digital terrain model (DTM) is then constructed based on the information provided by the survey team.  The orthophotography can then be draped over the DTM to make a realistic 3D view of the project corridor.
A Finite Element Analysis is performed on each structure in accordance with the predetermined design criteria.  The model is fine tuned by changing components in an effort to minimize cost while maintaining the desired reliability.  Attention to detail and matching form with function all integrates to provide the optimized design for each situation.
Our line design capabilities and services include but are not limited to …
  • developing construction standards and drawings in accordance with NESC and RUS
  • preparing Preliminary Design Phase documents (outlining line design specifications and drawings
  • preparing Final Design Phase drawings, including those for civil/structural analysis and review
  • using PLS CADD for all transmission and sub-transmission design
  • designing whatever steel structures and foundations are needed at strategic locations
  • coordinating system load and switching requirements during line construction/load transfer
  • developing specifications for the purchase of major equipment, including poles (both steel and wood), insulators, wire, cable, and switches
  • issuing major equipment specifications for long-lead items such as switchgear and transformers
  • developing construction specifications
  • preparing the construction bid package and participating in the construction pre-bid meeting
  • assisting with vendor selection
  • supporting the Construction Phase with onsite project inspection and technical site reviews
  • witnessing factory acceptance tests of major equipment
  • providing complete testing, commissioning, and training
  • preparing Post-Construction Phase “For Record” documents

If you’d like to know more about our electrical power line design capabilities and what they can do for your community, contact Spectrum Engineering