P35.008: Enhancing Transmission Line Resiliency

Update the EPRI Transmission Line Reference Book: Conductor and Structure Motion (The Orange Book): Minor (editorial) updates are expected on the Orange Book in 2027, which intends to be released for the benefit of new members.

Provide Orange Book Overview & Single Conductor Aeolian Vibration Training: EPRI aims to continue the production of selected training modules covering key chapters in The Orange Book. These events intend to be held in conjunction with EPRIU4T.

Quantify Transverse Cascading Loads: While EPRI and other institutions in the transmission industry have conducted research into longitudinal cascading events, transverse cascading loads remains a knowledge gap. EPRI aims to build and operate a transverse cascading test line to quantify loads experienced by structures during these events and ultimately help engineers design against them. In 2026, EPRI aims to install a test line and perform exploratory tests to simulate transverse cascades to then execute upon in subsequent years.

Broken Wire Loads for Bundled Conductors: EPRI’s multi-year research effort to quantify the magnitude of broken wire conductors was conducted exclusively for single wire conductors. There is reason to believe that a bundled conductor configuration may offer some damping during a broken conductor event, which intends to significantly reduce the impact for many transmission lines. EPRI plans to conduct full scale tests and simulations to quantify this impact.

Reliability and Repair Methods for Damaged Traditional and Advanced Conductors: EPRI aims to produce research into suitable repair methods to address conductors that have been compromised. Reliability aspects, such as efficacy of bolted, compression or preformed product repair devices vs extent of conductor damage intends to be assessed. The guide also aims to address damage to advanced conductors.

Derive Lessons from Failure: With every structural or mechanical failure event, there is a potentially valuable lesson to be learned by line design engineers. Very often the events leading to failure are often multi-dimensional. When the root causes and possible preventative actions from these events are documented, they can teach engineers how to become better designers. In 2027, EPRI aims to add multiple case studies to its current guide on documented failures related to how structures have failed in the past and how future generations of engineers may use this information to achieve more resilient designs.

Optimal design and intervals for anti-cascade structures: Engineers are often confronted with the question of how long the intervals between anti-cascading, high-strength structures should be. EPRI aims to research the question from the perspective of risk adjusted cost of line reliability. Guidance on the appropriate design of anti-cascade towers intends to also be provided.

Rapid Response Emergency Tower: The Rapid Response Emergency Tower was developed under EPRI’s Technology Innovation Program in support of project 35.008. In 2027, EPRI aims to complete final production plans for the system based on lessons learnt from the prototype demonstrations in 2026.

Provide Tools and Resources on the Transmission Resource Center: The following calculators, tools, result summaries, and references are planned to be available on the Resiliency Transmission Resource Center: