An hour and 40 minutes before a 7:30 p.m. tip-off between the 76ers and the Sacramento Kings on Jan. 29, Sixers shooting guard Matisse Thybulle popped his head out of the tunnel from the locker room into the bowl of the Wells Fargo Center.

Instead of soaking in the typical serenity of an empty arena during the moments before warm-ups, Thybulle was greeted by throngs of changeover crew members putting the finishing touches on the arena after a 1 p.m. Flyers game earlier that day.

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The crew still had the north and south risers and the visitors’ bench to set up, but the court was ready for the shootaround a whole 10 minutes ahead of schedule.

“[The players] don’t really see the behind-the-scenes stuff that goes into making sure they can play that night,” Arianna Alosi, the facilities director, said.

On days of a hockey and basketball double-header, the turnover from ice rink to court must happen in a three-hour window between games. There are a thousand things that can go wrong and little time for error, so the workers stay focused on their tasks, even as players pop in.

Blake Malcolm, the senior director of event services, and his team try to organize the two hockey teams (home and away) and two basketball teams so that their schedules don’t collide with each other’s or with the changeover crew’s. However, curiosity often draws players and coaches out early to check out the transformation from rink to court.

If all goes well, by the time fans flood in, most people will never know how much work went into making sure the 76ers aren’t playing basketball in a hockey rink.

Practice makes perfect

The Wells Fargo Center changeover crew has a maximum of three hours to pull off what vice president of operations Tim Allen refers to as the “controlled chaos” of a quick change from ice to court or court to ice.

“We rehearse this and we go over it and we refine our systems every day for these types of things,” Allen said.

When going from hockey to basketball, the changeover crew of between 150 and 175 people from a variety of trades operate within a window between the final horn of the Flyers’ game to 90 minutes before tip-off of a Sixers game.

According to Allen, it’s easier to transition from basketball to hockey (remove the court to reveal the ice underneath) than it is from hockey to basketball (build the court on top of the ice).

Meanwhile, transitioning from lacrosse to hockey, which involves rolling up the turf and removing the decks that protect the ice, is the simplest changeover the crew oversees.

Malcom estimates that the Wells Fargo Center does eight to 15 doubleheaders (two sporting events on the same day) each year.

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The ice

The very first step in transforming the Wells Fargo Center is taking care of the ice.

Hockey rinks are made just once a year, and it’s a multi-day process. To put it simply, there is a room full of refrigeration equipment that connects to a massive pipe system that runs underneath the concrete floor. The pipes carry glycol, which keeps the concrete frozen, and water is then layered over the concrete. Once created, the ice’s temperature hovers between 20 and 23.5 degrees.

Throughout the year, it’s a constant process of clearing off snow during game days with the Zamboni’s blade and replacing what they took off after games by laying water down with the Zamboni.

Optimally, the ice depth should be about 1.25 inches, although the crew can work with one inch. If it gets down to 0.75 inches, it’s “sweaty palms for me at that point,” said ice manager Chris Jennings.

On non-game days, they can spend up to 16 hours working on the ice. But on a doubleheader, they simply clean off the ice and then cover it up. It gets covered by plastic sheets that are an inch thick and cut to fit the rink.

Jennings said he compares the ice surface to grass so people understand what goes into maintaining it. They keep it “warm,” about 24 degrees, so that it doesn’t dry out. Ice, like grass, is healthier when it is regularly watered.

As soon as cleaning’s finished, the Zamboni doors come off so everyone else can move in. Jennings and his team shift to a supporting role, typically helping remove the rest of the glass.

The court

An NBA regulation rim stands 10 feet above the court. Not 10 feet and a half inch. Not nine feet and 11 and a half inches.

When it comes to building out the court on top of the ice during the changeover process, perfection is the end goal. The court surfaces, the scoring systems, and the rims must be precisely constructed to avoid mishaps during the game.

The Wells Fargo Center has three different basketball courts, each broken down into more than 250 panels — the main Sixers court, the City Edition Sixers court, and the Villanova court. The courts are about three inches thick and sit atop blocking so it isn’t directly on the cold floor.

To eradicate the risk of condensation on the court with the cold sheet of ice lying beneath it, the Wells Fargo Center has massive air conditioning units that regulate the temperature above the court.

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When arenas have had trouble in the past, it isn’t because the ice beneath the court melted.

“It’s going to look like a gallon of milk is coming up through the floor if anything catastrophic were to happen,” Jennings said.

Once the ice decks are laid down, the changeover crew installs each panel of the court. Naturally, during the construction process, pieces of the court often get banged up. Carpenters are on standby with tools to fix nicks and scratches, ensuring the court is laid down to perfection.

Compared with the hockey setup, the floor of the basketball bowl is much smaller from a square-footage perspective. The changeover crew brings down risers over dashers, lays down courtside decking, and sets up chairs.

“That center line has to be completely perfect,” first-year apprentice carpenter Delfino Moreno said. “If anything is off, even by an inch, it’s really noticeable, like with the rugs or the chairs.”

The Wells Fargo Center preaches a “center of the bowl out” mentality — “If you can’t get it right in the center of the bowl, it doesn’t matter what you’re doing back [on the concourse] ... [It] does matter, but it matters a lot less if the basketball court’s not down,” Allen said.

The tech

When the score table gets wheeled out and positioned between the empty spaces awaiting the team benches, electricians and technicians converge, maneuvering colorful wires and devices around.

The score table is “the hub of technology,” Allen said, and it’s where some of the most complicated work happens during the changeover.

“You think about basketball and the ref blows the whistle,” Allen said. “All the clocks’ve got to stop. And you know, a rebound goes up, and [that] stat gets sent to New York. So there’s a real onset of technology, which we embrace, but it also adds to the things that we have to do.”

Allen started working at the Spectrum in 1985, and the rising role of technology over the years has changed the process significantly. More steps get added every year.

“But since we embrace it, it becomes part of our lift,” Allen said. “There’s unity in our lift. It’s an ‘us against the world’ mentality. It’s a massive lift every night and we’re united by it.”

In addition to setting up the score table and the scoreboard, they also have to place the increasing number of gadgets, like the various cameras that track stats, in the right places and make sure they’re all connected.

The scoreboard graphics change from orange to blue, as do the banners around the bowl. Other teams, like the broadcast crew, also reach out to the changeover crew, who help make sure the sight lines are good for the TV cameras.

Staying on schedule

If fans attend both basketball and hockey games on the day of a changeover, they should be able to feel the difference between the two setups simply by closing their eyes.

Every detail of the changeover is intentional, down to the different temperatures in the bowl.

During a Flyers game, the arena is 60 degrees and 40% humidity in ideal conditions. Sixers games are warmer — 68 degrees — and less humid — 20%.

“It doesn’t matter what the temperature is outside,” Allen said. “We have the equipment to produce fresh air and keep our temperatures and humidities exactly where we want them.”

From putting up the proper advertisements on the dasher boards to ensuring the doors of the Zamboni tunnel are equal, there are checks and balances for each part of the changeover process. Everyone has a role, and they stick to it, making sure they complete it efficiently. Alosi said that they’re a “fan of overcommunication,” so that there aren’t any mix-ups the day of a quick change. Alosi is in charge of scheduling everyone who’s a part of the changeover, and she schedules down to the minute.

“But you have to understand, in the sports industry, nothing stays on schedule,” Alosi said, and the first changeover of the year proved that statement true.

Competing against the clock

When the Flyers-Kings game went to overtime on Jan. 29, the changeover crew started to sweat a little. Each second that went by without a game-winning goal was a second lost in the already tight window for turning over the Wells Fargo Center for the 76ers game that night.

As soon as Jennings’ crew finished cleaning the ice, the rest of the changeover crew jumped. Workers scurried and managers called out the remaining time and tasks. Colorful language filled the air as an extra second was wasted trying to get chairs to connect or a minute was spent trying to get a plank to fit in a tight spot.

The Wells Fargo Center during a quick change is a high-stress environment. Yet people keep coming back for more. Allen said there are people, both laborers and supervisors, who have been with them for decades.

Those veterans work alongside people of all ages, including those in the pre-apprentice program. Moreno, now a carpenter, completed his apprenticeship during the pandemic. There were no fans, and he was allowed to do only manual labor until he passed his test, but even then he was drawn to the “puzzle” of putting together the court and the team that does it. A year later, that fascination hasn’t waned.

The camaraderie turns the stress into a game. Every night, they’re racing against the clock. They also compete against one another as they complete tasks, trying to do them quickly yet perfectly.

Every lift, whether it’s a quick change or not, is challenging, Allen said, so you have to have good people. As they go about transitioning the Wells Fargo Center from one event to the next, they have to remember to laugh.

And if no one else ever recognizes they’re there, then they’ve succeeded.

“We never want to be the show,” Allen said. “We want no activity out there during the event. We don’t want to impact game play at all.”