What were the issues?

In December 2022 and January 2023, we experienced some damage of a small number of components of the Labrador-Island Link in couple different areas of the province. There were no customer outages as a result of these issues. The first component was Turnbuckles (3 of 1308 affected), which connect the energized line to the tower. This was the only component involving power flows. The remaining components do not interact with power carrying lines. These included tower peaks (2 of 3,223 affected), top plates (2 of 502 affected) and electrode conductors, or grounding wires (3 of 1,229 spans affected),

What did you learn?

Investigations determined that the turnbuckle damage was caused by galloping of the transmission lines over time–not a design flaw. The other issues were related to unbalanced ice shedding and ice overloading. Importantly, issues such as these, are expected and normal in the early days of operating any new asset.

Learn more about Galloping

What are you doing to address them?

Galloping of transmission lines is a common phenomenon. Most often utilities make adjustments to address galloping after the line is in service and the areas experiencing this phenomenon are identified. Although the issues we have found are small in number, we are taking a precautionary approach and replacing turnbuckles with a different, more robust piece of equipment. We are also adding components called air flow spoilers to the lines, which prevent the galloping. Hydro has implemented such measures on others lines in its history after they went in service. As customers on the island rely upon the Labrador-Island Link, we are taking this preventative step as a safeguard against potential future issues. For the ice related issues on the non-power carrying lines, we are proactively studying to determine if further action is necessary and will continue to monitor the impact of climate change on our operations.

What does this mean?

Experiencing issues in the early days of operation and again towards the end of the asset’s operation is normal for utilities. We expect this and plan for it. These issues are not wide-spread, and we do not expect any long term impact on our ability to provide reliable service for our customers as a result of them. We understand the importance of LIL in delivering reliable electricity for the Island and we are taking action now to mitigate against future incidents. Improved LIL reliability can be expected as we gain operational experience.