You might not see it, but $64 million in upgrades began last week inside the McNary Dam.

Andritz Hydro was awarded a contract by the U.S. Army Corps of Engineers last October to rewind 10 of the dam’s generator units.

Andritz Hydro is a global leader in customized plant systems and services for hydropower, pulp, paper, steel and other specialized industries.

The project involves disassembling and reassembling the 10 generators before 2014.

Ryan Bliss, USACE project engineer said gearing up for the “rewind” has cost $2 million to make sure everything is ready.

“We’ll shut down the first two units, then pull out the rotors mid-July, finishing those two between December 25-31,” Bliss said.

To get to the coils, the 750-ton rotors will be removed by two powerhouse cranes.

Teams will work in two groups, in 10-hour shifts, to make the repairs.

“It’s pretty specialized work, only a handful of companies have their own crews that can do it,” said Dee Dee Lingo, USACE electrical planner.

Lingo is familiar with the rewinding process, having been part of seven others including the Bonneville Dam.

“It will be very hectic, and they may have to work on them on a staggered schedule, so the cranes aren’t removing two rotors at once,” Lingo said.

The crews will also have to keep track of the generator parts labeling and measuring each to avoid mixing them up.

“They might seem the same, but some parts are custom fit to their own unit,” Lingo said.

While the coils are removed, the Corps will isolate the affected generators so power can still be generated.

“It’s like remodeling your kitchen and bathroom at the same time, and very unique that we’re doing this two at a time,” said Dave Coleman, USACE McNary Dam operations manager. “Normally you only do one at a time.”

Coleman said repairs are needed now because of the winding coils’ age.

“All of them are about 50 years old, and you don’t want them to fail, so we’re being proactive in repairing them,” he said.

Failures could cause the generators to go out of phase and shut down, forcing the dam to possibly spill a unit of water for the effected generator, meaning a loss of revenue.

That loss, Coleman said, would also effect other dams in the Bonneville Power Administration’s system, due to McNary’s “linch-pin” status, making the three-year repair project vital for the region’s hydroelectric production.