Inspecting the Dynegy power plant chimneys takes three men, two ropes and really strong magnets.

On a foggy February morning, Cody Costello and Brandon Thein stand at the base of the Dynegy power plant’s Unit 6, a 500-foot-tall chimney just north of its twin, Unit 7, in Moss Landing.

The men are outfitted in heavy-duty harnesses that cross their backs, wrap over their shoulders and form an H across their chests. Their harness belts are heavy with tools including pulleys, leg lanyards and brick-sized magnets.

The day before, they dragged 10-pound, 500-foot-long ropes to the top of the chimney, inspecting it on the way up, then anchored the ropes for an hours-long rappel and inspection down the opposite side.

Today, at 8am sharp, they begin their ascent up the ladder on Unit 6’s south side. Costello takes the lead, climbing up rung after rung after rung, stopping only to clip and unclip into a safety slide rail next to the ladder. After Costello gets about 20 feet up, Thein follows. Over the next hour they inch toward the sky.

Costello and Thein are chimney men. They work out of the Pittsburgh-area office of NAES Power Contractors, a Washington state-based company that services power plants.

When asked if they ever feel fear, or a thrill, when climbing up or rappelling down a chimney, they couldn’t be more nonchalant.

“You just kind of go,” Thein says.

Costello just shakes his head, smiling.

They’re joined by NAES Chimney Division Manager Matt Schreckengost, who flew out from Pennsylvania to oversee the inspection. Here in Moss Landing, the team’s job is to check on the massive machinery that keeps our lights on. Each chimney releases exhaust from a generator with enough capacity to power 600,000 homes, making the plant a crucial source of power for the tri-county region.

Since Units 1 and 2 – smaller, more efficient generators – came online in 2002, Units 6 and 7 are mostly dormant, according to Rex Lewis, the plant’s managing director. They only kick in during peak energy use, like hot summer days and cold winter nights.

Still, the chimneys provide more than just power to the region. They have become a part of the Moss Landing landscape.

“They’re part of the history of the town,” Moss Landing Harbormaster Linda McIntyre says. “[For] a lot of the boaters, especially the old-timers, that’s their landmark to know they’re heading in the right direction.”

Lewis agrees. He says that when Units 1 and 2 were being built, the community wanted to ensure the chimneys remained. “There was a lot of concern from the vessel owners,” he says.

In a span of four days, the three men inspect every foot of the power plant’s chimneys, inside and out.

And to be clear: They are chimneys, not stacks. “Stacks have a single wall, towers are open, but a chimney has an independent liner,” Schreckengost writes in a follow-up email.

That’s news to Lewis, who’s worked there almost 41 years. “I call them stacks,” he says. “I’ll have to pass that on to our people.”

Only five employees at the plant are certified to scale the chimneys, mostly to replace light bulbs. Lewis, who has never done it himself, says those five were selected from a much larger group that volunteered for the privilege of looking out from the only skyscraper in the county.

“They say you can see forever,” he says.

The NAES contractors come out every three to five years to ensure the chimneys remain in peak condition. This year, the men spend two days inspecting each chimney, looking for anything out of the ordinary, like cracks in the cement or loose bolts on the ladder.

Once at the top, they set up a pulley and thread through the rope they dragged up. The worker at the bottom ties a second rope to the end of the first, so by the time the rope on top reaches the ground, the second rope’s been pulled to the top. One of the men puts the ropes through his harness, while the man at the bottom belays, ready to catch the rappeller in the event the rope slips.

The process for the inside is much the same. The belayer stands inside the base of 66-foot-diameter chimney, which is lined with rings of steel tiles that stretch to the 20-foot-diameter top.

“It’s like looking up through a straw,” Schreckengost says.

The worker rappeling down uses the magnet when he needs to pull closer to the wall. A small probe takes readings of the steel’s thickness to make sure it’s not deteriorating.

Like any other job, even this one can become a grind. But the perspective from the 500-foot-tall tops is a perk even Costello doesn’t tire of.

“It’s quiet and peaceful,” he says, “with a spectacular view of everything.”