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 | Meeting Materials |
| 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 |