A Sun-Times series spotlighting the people and professions that keep Chicago thriving. Labor movement profiles are made possible by the Chicago Federation of Labor.

From the ankles up, Steven Moore is casually dressed for his office job.

He’s a power engineer coordinator for the Chicago Transit Authority — essentially the supervisor of a team of electricians responsible for one zone of the Red and Green lines south of 22nd Street.

When poring over payroll, proposals and budgets at a desk, there’s no need for a hard hat or flame-retardant apparel. But there’s a reason Moore wears tall, rubber-soled work boots every day: if a certain kind of emergency arises, he’s poised to provide boots-on-the-ground help to fix it.

“You never know when you’ll be needed,” said Moore, 53. “Think about it. Some of these [train lines] have been energized ... for 24 hours a day, seven days a week for decades. Sooner or later, it’s gonna break. So we have to be there when it does.”

There are few people more essential to the everyday operation of Chicago’s “L” trains.

Electric workers are key to a system in which all 2,300 daily trips that zip across the system’s 224 miles of track are powered by a regulated current of electricity.

The process doesn’t happen magically.

ComEd sends 12,000 volts of AC power to 64 different substations, which is converted to 600 volts of DC power and fed through hundreds of miles of cables to the third rail on the tracks. Railcars are equipped with special “shoes” that transfer the current into the engines that power the train.

A lot of factors can cause things to go wrong, including equipment failure, power outages and inclement weather. The system can be especially tricky to maintain given the patchwork quality of the technology that powers Chicago’s “L” trains, some of which dates back to the World War II era.

“We’re actually using some tech from companies that went out of business 30 years ago,” Moore said. “We use the word ‘retrofit’ a lot because we have to get old equipment to properly interface with the new.”

Moore, a member of IBEW Local 9, is working constantly to do just that. Recently, fluctuating voltage was causing some trains’ computer systems to crash, leading to costly delays. He and a colleague studied the problem and proposed installing new hardware that uses an uninterruptible power supply (UPS), also known as a battery backup, to adjust to the voltage hiccups.

It worked, and the devices are now being installed in areas where the electric grid isn’t as robust.

Moore said he finds it satisfying to identify an issue and think up the solution that solves a systemwide problem. Not bad for a guy who spent his 1991 rookie year with the transit agency performing odd jobs like cleaning up cigarette butts discarded by coworkers.

The next year, Moore enrolled in a 12-month-long journeyman training program through IBEW Local 9. The CTA soon promoted him to lineman, a tradesperson who installs and repairs electrical transmissions and power distribution systems.

Workers have a slang term for the gig — “tunnel rat” — because it involves so much spelunking through the city’s subterranean corridors. It’s a job that comes with downsides, like spending time with real rats in dark tunnels and the risk of bodily harm. For a lineman, avoiding touching the electrified third rail and dodging 57,000-pound train cars is not child’s play.

Still, Moore loved the job so much, he did it for nearly 23 years.

“Most people just see trains at the stations, but we get to see a whole other city under our city. It’s tunnels and transformers and all of this gear that’s making all of this infrastructure work,” he said. “Really interesting stuff.”

Since 2016, when he accepted a promotion to supervisor, Moore doesn’t get to spend as much time in Chicago’s little-seen underground world. But when he gets a call and learns a substation has caught fire or a train’s electrical system has gone haywire, he’s more than ready to step into action.

The proof is in the boots.