Fact or fable?
That was the question I kept privately asking myself Sunday as the collapse of the fabric roof of the Metrodome, home of the Minnesota Vikings in Minneapolis, coincided with a very public event — the Tree of Life Holiday Concert by the USD Department of Music, followed by a reception and treats and lots of talk at Sanford Vermillion Hospital.
A major topic of conversation as Vermillion citizens gathered to sip wine and munch on hors d'oeuvres at the hospital Sunday evening is the similarities of the "old" DakotaDome on the USD campus and the present-day Metrodome, which, it turns out, is only about two years younger than the Vermillion structure. Both buildings have suffered with a breach or two in their suspended fabric roofs, thanks to heavy snow and high winds. The DakotaDome's Teflon-coated fiberglass roof, which had the consistency of very stiff canvas, ripped under the force and weight of snow and wind twice in its early life.
The Metrodome, since opening in April 1982, has had its similarly constructed roof, suspended over the large structure thanks to a lot of hot air and metal struts, fail for the fifth time, counting Sunday's dramatic tear.
Sunday's bursting of the Metrodome's bubble caused a lot of the people enjoying Sunday evening's fellowship to dust off the DakotaDome's own stories of adventure. Besides failing twice, the roof of the 30-year-old USD suffered what best can be termed a near miss.And thus, the tale, the myth, the legend or perhaps, a story based on pure fact could be heard repeated among long-time Vermillionites Sunday. It's a story that combines a bit of engineering ingenuity with the natural pioneer spirit of South Dakota.People in Vermillion, or in South Dakota for that matter, weren't used to having such a space-age type of structure as the DakotaDome, with its seemingly magic floating roof, as part of the local landscape three decades ago.Surely a cure to the roof's ills, at a time when it seemed close to failing, would involve some super-secret chemical polymer to hold the Teflon fabric together. Turns out the chemical solution likely was a follow-up to one of the most successful "instant" remedies applied during one of those early times the DakotaDome's roof was ailing.
In the time it takes to load a shotgun and pull its trigger, the fabric covering of the structure was saved from what likely could have been substantial damage.
A flaw in the building's covering was allowing heated air that usually was trapped between the fabric roof's inner and outer layers, thus keeping it inflated, to escape. The hot air melted the snow that had gathered on the DakotaDome's top during a winter storm. The melting water began to form an ever-growing puddle in the fabric. The more the snow melted, the more water gathered, causing the Teflon panels to strain against the water's weight.USD officials were told by consulting engineers to shoot the roof, so to speak, to save it. And this is not a made-up story. Jack Doyle of Vermillion, now retired after many years of service as a legendary coach and athletic director at USD, witnessed it all.
"It actually did happen," Doyle said in a phone conversation Tuesday. "There was a big snowstorm that came up, and they decided to shoot a hole in the roof to relieve the water that was accumulating up there."
And Doyle revealed an unexpected gem to this story, a nugget of ironic truth that explains why this cure was such the talk of the town in Vermillion last Sunday, the day of the latest Metrodome roof failure.
"At the same time that our roof was saved, the one went down in Minneapolis the same night," he said. "It was very productive to put the hole in the roof to relieve the pressure that was building up there."
Doyle can't remember the year of the miracle shotgun cure to the DakotaDome roof. It's safe to say it likely was sometime in the early 1980s. The Metrodome's roof received severe winter weather-related damage in 1981, 1982 and 1983. High winds tore the Minnesota building's fabric roof in 1986. Last Sunday marked the fifth time the Metrodome's roof has failed. It also is the most significant deflation the building's top has experienced in its 28-year history.
"I was there (in the DakotaDome) the night it happened; I saw how the shotgun put a hole in the roof," he said. "It wasn't that big of a hole, and then it was repaired, naturally, to keep the air inside after the water had drained. It saved the roof."
Everyone was wondering why the roof didn't come down in Vermillion when the same night, it went down in Minneapolis," Doyle said. "That was the reason why."
The roof's instant relief to its threat from Mother Nature took only one round from the shotgun. "There was just one shot that took place," he said. "The insurance company wasn't very happy when they heard that a shotgun blast made a hole in the roof of the DakotaDome, but I think they realized when the one came down in Minneapolis that night, and ours just had a little hole in it – I think they were pleased that the decision to use the shotgun was made."
For approximately the last decade, USD officials have not had to worry about the DakotaDome during a fierce winter storm. The dome received a $13 million steel roof in 2001, allowing the university to eliminate the concern of snow build-up on the structure's roof.
"It's really a blessing that we have a permanent roof on that building now, because a tremendous amount of pressure was put on the facilities people in the winter to try to remove snow from the fabric roof," Doyle said, "and it was very, very dangerous."