by Lisa Meiman
On the night of June 19, severe thunderstorms, some with tornadic activity, rolled across South Dakota, damaging and destroying more than 120 Western structures across the state’s 380-mile width.
Wood H-frame structures faced winds exceeding 80 mph, and in some areas, more than 120 mph, causing them to snap and split like popsicle sticks; some were ripped entirely from the ground.
The storm did not discriminate: 60-year-old original structures suffered the same fate as two-year-old ones, and guyed “storm structures” failed alongside them. In total, six Western lines were out of service following the storm.
With both wholesale and retail customers out of power due to damage on the Western system, line crews from South Dakota, North Dakota and Montana responded the next morning, patrolling known affected areas and preparing to repair and replace the structures as quickly as possible. End-use customers were energized within a few hours, powered by the local cooperatives who hoped for mild weather to keep demand low.
Robust, redundant system streamlines repair
South Dakota’s system is particularly robust. A few structures replaced in muddy soup-like conditions relieved the load from local cooperatives near Wall, June 23, and all other power was able to be re-routed on redundant paths, allowing crews to methodically repair and replace structures when conditions allowed.
Through July 1, UGP crews, joined by Rocky Mountain crews from Brush, Colorado, and Gering, Nebraska, traversed the state, repairing and replacing structures in three waves: the first crew would remove or ‘wreck out’ the damaged structures, and the second would erect the new H-frames. Then, the crews would return to each structure to attach the cross arms, x-braces, insulators, conductors and all other equipment. Even after the lines are returned to service, cleanup of the demolished structures and negotiations with landowners regarding damage needs to be accomplished.
By the fourth of July, four of six lines were back in service. A fifth will return to service the week of July 6. Crews will then move on to the remaining 230-kilovolt New Underwood-to-Maurine line, which needs 36 new structures. Soggy ground prevented crews from accessing the line earlier even though a 230-kV line is typically a higher priority. Because no residents or businesses were out of power, crews waited for the ground to dry, making it easier to work and also mitigating damage to the land around the structures.
Storms are unpredictable; the responsiveness, dedication and quality of Western’s crews are not. When the power goes out, they respond immediately, in often inclement conditions, to bring power back to customers and help them get their lives back to normal as quickly as possible.
See more photos of the storm repair at Flickr.