What's the difference between the Boston Celtics and the Boston Bruins? About 6 inches. I'm not talking player height here: That's the difference between the wooden floor the Celtics race up and down on and the icy rink the Bruins zip across.
The Celtics and Bruins share Boston's Fleet Center, the same way they shared the old Boston Garden. The basketball court sits atop the skating arena. But how do you go from one to the other?
It takes about four hours and a crew of 30. It also takes careful planning. The seasons for pro basketball and pro hockey overlap. Basketball runs from November to June, and hockey from October through June (if your team is in the playoffs). Sometimes, there's a Celtics game on a Friday night, and a Bruins game the next afternoon.
"It can get real hectic," says Joao Rebelo, event-production manager of the Fleet Center. "Sometimes we have a matter of hours to transform the arena from basketball to hockey."
The changeover begins the minute every Celtic fan has left the 18,854-seat basketball stadium. Now it's time to turn it into a 17,565-seat ice-hockey arena. A photographer and I got to watch it happen the other night (and morning). An exciting Celtics game against the Miami Heat had ended with the Celtics' Antoine Walker sinking a three-point shot in the last seconds of the game. By the time the stadium was clear, it was 11:30 p.m. Time go to go work.
"Men!" Mr. Rebelo shouted, forming a megaphone with his hands. "Let's do this!"
First the goals come down. Next the parquet floor comes up. It's the same storied floor that was in the Boston Garden, though it's been repaired and boards have been replaced over the years.
The floor is like a giant wooden puzzle. But this puzzle's pieces are interlocking squares of oak beams. Each one weighs 180 pounds. Exactly 988 screws must be unscrewed before the floor can be stored under the bleachers on giant carts.
Each time the playing surface is taken up, a carpenter examines it for damage.
"This floor takes serious abuse," says Fleet Center carpenter Arnando Madeira. He's decked out in work-stained white overalls. "Giants like Patrick Ewing and Alonzo Mourning trample on the court night in and night out, and it gets banged up when it's being stored."
The first arena to have a basketball court on top of a hockey rink was the second Madison Square Garden in New York. It was built in 1925. Basketball's New York Knicks played there, along with hockey's New York Rangers.
The second was Boston Garden, built in 1928. The Garden was torn down after the Fleet Center was finished in 1995. Today, many arenas worldwide can host basketball one day and hockey the next, with rock concerts and tennis matches in between.
One night's glowing-orange surprise
After the parquet floor is gone, black sheets of plywood that were laid over the entire surface of the rink are removed. Sometimes the ice is dirty because trash can fall through the cracks. (Unlike the parquet, the plywood isn't screwed together.)
"Once we pulled up the planks and there was this enormous orange stain on the ice," Rebelo recalls. "It was glowing!"
The stain was frozen orange Gatorade that ballboys had spilled during a Celtics game. The spot had to be carefully scraped off.
After all the ice is revealed, it's swept with brooms. When the peanut shells and other trash have been collected, it's Zamboni time. Zambonis are trucklike machines that scrape off a wide, thin layer of ice. They also spray a layer of water on the ice that freezes quickly to renew the icy surface.
The cement underneath the ice is filled with pipes. Glycol, a refrigerant, is cooled and pumped through the pipes. The cold glycol cools the concrete, which freezes the ice. The ice is melted only twice a year: once when the hockey season is over, and once because of elephants. (Can you guess why? The answer is at the end of this story.)
The surface temperature of the ice can be controlled. For hockey games it's a chilly 16 to 18 degrees F. But when there's an ice show - like "Disney's World on Ice" - it's slightly warmer: 21 degrees F. Warm ice is better for doing tricks because it's more slippery. Colder ice is better for hockey because it gives skaters more traction.
How do they put those lines on the ice?
"People usually don't believe me when I say this, but all the writing, lines, and ads are painted on," Rebelo says. "They're embedded in the ice about three-quarters of the way down."
First, the rink is flooded with a thin - less than 1/4 inch - layer of scalding-hot water. Hot water freezes faster because the water molecules are farther apart. Hot water also has less air dissolved in it than cold water. Less dissolved air means smoother ice that's more dense.
Then Rebelo and his crew spray-paint the whole surface of the ice with water-based white paint! When the paint dries, another thin layer of water is applied and freezes.
Now the lines, logos, and ads are painted on. For logos and ads, special stencils are used. Each stencil has thousands of tiny holes in it. The stencil is placed on the ice, and the paint is applied right on the stencil. The paint seeps through the holes onto the ice.
"It's a lot like paint by numbers," Rebelo says.
When that paint dries, it's time for more ice.
Although the ice on the rink appears to be very thick, it's only about 1-3/4 inches. That's slightly thinner than the average college dictionary.
The ice is melted and drained when the hockey season is over. It also has to be melted when the circus comes to town. The elephants, motorcycles, clowns, and cages must be grounded on cement.