Going With the Flow

“Imagine someone standing on a skateboard, and the ground moves under them. They could feasibly stay upright, and not fall,” explains Dr. Leon Kempner, a Principal Civil (Structural)

A base isolated transformer with flexible conductor
A base isolated transformer with flexible conductor in Seattle (BPA photo)

Engineer with the Bonneville Power Administration (BPA). “Base isolation technology works much the same way, putting transformers on platforms with isolators that are flexible, allowing a transformer to ride out a quake.”

In his 47-year career at the BPA, Dr. Kempner has flown to the scenes of multiple large-scale earthquakes, including Japan, Chile, and Northridge, California. He examines electrical towers, substations, and transmission lines, looking for what has stood up to a quake’s force, what has collapsed, and why. He has learned equipment designed and built to roll with an earthquake’s movement can remain up and continue to function even after a quake. Much of the West Coast lies along the Cascadia Subduction Zone, which is expected to cause a massive earthquake here at any time.

Knowing how crucial electricity will be to recovery after a massive quake, Central Lincoln’s engineers have been absorbing Dr. Kempner’s applied research, and are using his findings.

“Dr. Kempner has shown that substation transformers mounted to a platform, and placed on flexible base isolators could ride out a tide of rolling earth during a quake,” says Shamus Gamache, Central Lincoln’s Engineering Supervisor. “We’re eliminating porcelain insulators, since they are likely to shatter during an earthquake. And we’re using flexible conductor, instead of the usual rigid busbar.”(Busbar is a metal strip or “bar,” used to connect high voltage equipment in substations.)

Substation transformers are very expensive, but are critical to electricity delivery, and it takes a year or more to manufacture a transformer, so protecting them is crucial. A massive, new 140,765-pound substation transformer is on its way to the Central Coast. “That’s more than 70 tons!” Shamus exclaims. “The same weight as 10 school buses.” Our engineers have calculated a 3” thick galvanized steel platform will be strong enough to support this mammoth, and it will be Central Lincoln’s first transformer to be installed using Dr. Kempner’s research.

A recent recipient of one of the BPA’s highest honors for an employee, Dr. Kempner thinks about his life’s work, and smiles shyly. “After a major earthquake in this area, I’ll either be a hero, or a hermit. I hope I’m a hero.”

The Columbian provides a video on Base Isolated Transformer Testing on their YouTube channel, giving more information about the BPA’s earthquake and infrastructure research.