Updates & Events

Info for members about events, updates, and results

Task: Resolving Underclearance Spans Workshop
Task Description:

  • Utilities oftentimes have a need to mitigate or raise underclearance transmission lines. These issues may arise due to line uprate projects, land development in transmission right-of-ways, or a variety of other sources.
  • In partnership with EPRI Project 35.013, Overhead Line Ratings and Increased Power Flow, a workshop was planned to discuss utility experience and present a variety of solutions for resolving underclearance transmission spans.

Update:

  • The Resolving Underclearance Spans Workshop was held on May 25th, 2023 with approximately 50 utility member attendees. Three North American utility engineers gave presentations discussing utility experience on this topic and EPRI presented 18 clearance resolution solutions.
  • In 2024, EPRI plans to publish a technical report expanding upon the topics discussed at this workshop.

Video Updates

Engagement Opportunities

Meeting Date Location Information
Overhead Line Design Task Force March 10-13 (In-person)
March 17-20 (Virtual)
Charlotte, NC Meeting Materials
EPRI Overhead Transmission Program (P35) New Supplemental Launch Webcast April 3
2:00 pm - 3:00 pm ET
Webcast Webcast Information
Online Training for Orange Book April 24
2:00-3:30 pm ET
Webcast Register Here
EPRI R&D Project Update Webcast: Composite Structures, Line Design, Increasing Line Resiliency (P35.005, P35.007, P35.008) May 29
2:00 - 3:00 pm ET
Webcast
Training: Calculation of Overhead Line Loads- Session 1 June 4
2:00-3:00 pm ET
Webcast
Training: Calculation of Overhead Line Loads- Session 2 July 9
2:00-3:00 pm ET
Webcast
Overhead Transmission 2026 ARP Rollout #1 July 17
10:00 am - 11:00 pm ET
Webcast
Overhead Transmission 2026 ARP Rollout #2 July 24
2:00 pm - 3:30 pm ET
Webcast
Overhead Line Design Task Force August 18-22 (In-person)
August 25-29 (Virtual)
Charlotte, NC
EPRI End of Year Webcast: Composite Structures, Line Design, Increasing Line Resiliency (P35.005, P35.007, P35.008) November 13
2:00-3:00 pm ET
Webcast
Red Book Training September 29-October 2
8:00-4:30 pm ET
Charlotte, NC

Anticipated 2025 Deliverables

In 2025, a mix of ongoing research initiatives together with new research areas will be undertaken.

Deliverable Type Date
Conductor and Structure Motion Reference Book (The Orange Book) Reference Book December 2025
AC Transmission Line Reference Book: 200 kV and Above (The Red Book) Reference Book December 2025
AC Transmission Line Reference Book: 115–400 kV Compact Line Design (The Blue Book) Reference Book December 2025
Optimal Pole Material Selection Guide Technical Update December 2025
Overhead Line Design Guide: Extra-High-Voltage Line Design Checklist Technical Update December 2025
Safe Design Tension of ACSS Conductor Technical Update December 2025
Online Training Seminar: The Orange Book Workshop December 2025
Calculation of Overhead Line Loads Workshop Workshop December 2025
Transmission Line Workstation Gen 2 (TLW-Gen2) v13.0: Design and Vibration Modules Software December 2025

2024 Deliverables

Product ID

Name

Type

3002029583

EPRI AC Transmission Line Reference Book (Red Book): 200 kV and Above: 2024 Edition

Technical Update
3002030852

EPRI Red Book Application Suite

Technical Update
3002030375

Transmission Pole Material Selection Guide: 2024 Edition

Technical Update
3002030266

Cost Effective Measures for the Resolution of Under-Clearance Spans

Technical Update
3002030376

Safe Design Tension of ACSS Conductor: 2024 Edition

Technical Update
3002030115

Optimal Line Tension Calculator Op10 v2.5

Pre-Software
3002030117

7. Transmission Line Workstation Gen 2: Design Modules Vibration (TLW-Gen2) v12.0

Software
3002029583

Determination of NESC C2-2023 Clearances – Module 1

Training Workshop
3002029583

Determination of NESC C2-2023 Clearances – Module 2

Training Workshop