Miller Park roof delivers comfort for fans, pays dividends at the Brewers box office

The Miller Park roof has delivered in the clutch just over 4,000 times for Milwaukee Brewers fans for 17 seasons.

The 12,000-ton structure with five moving panels keeps fans warm and dry, especially on days like Monday's home opener, which is expected to see temperatures in the upper 30s.

"Before the first pitch is thrown, I can tell you what the Brewers' most valuable asset is — the roof," said Mike Duckett, executive director of the Southeastern Wisconsin Professional Baseball Park District.

The roof has scored at the box office for the team, which is drawing some 1 million additional fans per year, on average, compared with County Stadium. Last year, nearly 2.6 million fans attended Brewers games.

That's for a team that in 17 seasons at Miller Park has racked up about the same record on average (76.9 wins, 85.1 losses) as the Brewers did during their last 17 years at County Stadium (75.8 wins, 82.1 losses,), according to a report prepared for the stadium district board.

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As the Miller Park landlord, the district maintains the roof, a protocol that includes logging every move. As of Friday, the panels had opened or closed 4,014 times since Miller Park opened, according to stadium district records.

"On a scale of 1 to 10, the roof is operating at a 12," Duckett said.

"I've been very pleased with the roof," especially once early problems with the structure and machinery were resolved, said Rick Schlesinger, Brewers chief operating officer. "The stadium district has delivered on its promise to fans and us."

After a few rocky early years, both landlord and tenant agree that the roof is performing well, and there are no significant issues on the horizon.

Construction costs and debt for Miller Park was paid for with a 0.1% sales tax in the five-county area. The tax is expected to end in either late 2019 or early 2020.

For years, the Brewers and the stadium district, using the sales tax money, set aside money in an escrow fund to cover future maintenance — especially for the all-important roof. That fund currently has a balance of about $21 million.

RELATED: Miller Park sales tax generated nearly $31 million last year and could be retired in 2019 or 2020

Taking care of the roof requires ironworkers, engineers and, yes, roofers.

On a recent cold March morning high above the stadium floor, a team of roofers clambered up and down the panels hauling away large pieces of gutter-type metal damaged by snow and ice.

Duckett said that's a routine part of upkeep following the poundings that the roof receives during Wisconsin winters.

"Over time, things are going to get stretched and tugged and the gaps are going to line up a little bit differently," he said. "We're constantly chasing leaks."

A closer look at the roof membrane on the right field panels reveals a network of patches from over the years. Duckett said a good spring rainstorm helps workers determine where such patches are needed.

Massive structure

The structure is made up of 8.5 acres of commercial roofing with a mile of flexible gaps. Duckett said the size of the roof is comparable to the roofs of 5,000 single-family homes.

Special attention is paid to the mechanical parts, especially the 10 electric-powered "bogies," engines that haul the panels along the outfield track.

Early in the life of Miller Park, the roof panels would be opened or closed ceremonially at the end of games, accompanied by the dramatic theme to "2001: A Space Odyssey." That ended following the first season after loud noises were heard from the "pivot" where the panels join behind home plate.

"It was metal on metal. That's how bad it was," said roof supervisor Mike Brockman, noting that the issue was never a safety problem. "We stopped doing it for show."

The pivot bearings were replaced, and after the 2006 season, the bogies were replaced and upgraded from two-wheel to four-wheel engines with a "beefier design," said Brockman, an engineer with the Sigma Group who works as a contractor for the stadium district.

"In essence, the entire drive mechanism of the roof was replaced," Duckett said.

The district has spare parts for the bogies including chains, motors drives, bearings and grease.

"The life of these new bogies and the new pivot bearings will outlast the building," Brockman said.

Moving the roof is not as simple as pressing a button in the control room, visible to the public on the loge level behind home plate.

A team of five people — four from the Brewers and a stadium district supervisor — participates in each move. Workers walk along the tracks ahead of the bogies to ensure they are clear. Others walk alongside the engines as they pull along the roof panels.

"We look at the rails. We look at the bogies and we listen to it as it moves," Brockman said.

A network of 60 sensors monitors stress, surges and any significant changes to the structure, Duckett said. That includes unusual stress placed on the bogies or if the engines require more power than usual to do their work.

"The sensors all have to be in the 'go' zone for the roof to move," Duckett said. "We want to be careful, follow the rules and make sure we're safe."

"They watch to see if it's experiencing more of a strain than it should," he said. "Fortunately, there's been very few of those."

These days, roof moves are kept to a minimum. Last season, the panels moved 204 times, the third-lowest since the stadium opened. The high was 301 in 2003.

Most roof moves don't happen during games, but when they do, the umpires make the call.

And, of course, the fans realize they're seeing something special.

"I call it the dance of pointing fingers," Duckett said of the reaction of fans as they notice the roof moving. "It has to move 10 to 20 feet before people start noticing — and then you see them all pointing."

Schlesinger said the roof has made the Brewers a regional team.

"We know we will start on time and that there will not be a rain delay," he said.

"It can be 40 degrees and rainy outside and it's 68 degrees and dry in here. I can't tell you what a luxury it is for our fans, our staff and our players."

Schlesinger said ticket sales are running about 20% ahead of last year. Season ticket sales are up 18%, group sales up 11% and individual ticket sales are up 12%.

"The roof was clearly our greatest challenge" when Miller Park was designed and constructed, Duckett said.

"It's clearly our greatest reward."