Sports

Curlers Are Finicky When It Comes to Their Olympic Ice

By JOHN BRANCH

VANCOUVER, British Columbia — The other ice surfaces at the Winter Olympics, from the bobsled track to the speed-skating oval, are designed to be smooth and fast. But at the Vancouver Olympic Centre, Hans Wuthrich will try to make his ice perfectly bumpy.

Wuthrich is an icemaking expert hired to create the playing surfaces for curling. His work, more than that of the four other so-called icemeisters at other arenas, will be scrutinized inch by inch, water drop by water drop.

“Most people who have never been involved in curling have no idea how much is involved,” Wuthrich said.

Curlers demand a perfectly level surface pebbled by tiny frozen drops of water. But they also tend to be hypersensitive human weather stations, even worrying about the on-ice effects of uneven air flow through the ventilation system far overhead. Inconsistent air, a speck of dirt or a warm hand inadvertently placed on the ice can steer a 44-pound curling stone off course.

“For a curler, the smallest little thing makes such a difference,” said Wuthrich, who was born in Switzerland and makes a living operating a landscaping business and nursery in Manitoba. “Other guys will tell you that for their sports, too, but for us it’s just a little more finicky.”

Four raised curling sheets — 150 feet long, with bull’s-eye targets known as houses at each end — will be built atop a slab of ice on a rink. Wuthrich will use foam for a border (“Very high density, so it doesn’t suck up that much water,” he said), filling it, in layers, with about three-quarters of an inch of ice. When the raised sheets are complete, they will be divided by blue carpet for competitors and officials.

Members of the Brazilian curling team practice in Canada earlier this year. Curlers demand a perfectly level surface pebbled by tiny frozen drops of water. Yannick Grandmont for The New York Times

Flat ice is imperative, more than in any other event. Water expands a little more than 9 percent when it freezes, he said. And refrigeration pipes buried in the concrete of the rink, Wuthrich said, create almost imperceptible waves in the ice. That is why curling sheets are leveled with a blade that measures the cut to a hundredth of an inch.

“Once you get it absolutely perfect, contoured, then you do the pebbling,” Wuthrich said.

It is what makes curling ice truly different — a top layer of raised, flat-topped dots.

The ice is misted with tiny droplets of water from a sprinkler-style head. There are about 40 different sizes and types of pebbling, Wuthrich said, the choice dependent on the size of the rocks and the pounds per square inch they exert on the ice.

What slows curling stones is friction, and pebbling allows the stones to glide across the ice more easily. The stones slowly erode the pebbles, which is why resurfacing occurs between each match.

“They almost melt them but not quite,” Wuthrich said.

When the pebbling wears down, the friction increases and the stones curl more. The bigger culprit is the sweeping that curlers do in front of a stone to direct it to its desired resting place.

“Ice is fastest when you have it up at about 28, 29 degrees,” Wuthrich said. “Normally we keep curling ice about 23, 24 degrees. If you have a brush going in front of it, the friction of the brush, you’re actually heating up the surface, right? So now you’re getting your rock to travel faster.”

In a sport of precision, curlers frown upon touching a knee or a hand to the ice, since the body heat might alter the ice surface. They worry about dirt from people’s shoes, even the lint from the carpet.

“There’s always going to be an excuse of some kind,” Wuthrich said good-naturedly.

There will be no excuses from Wuthrich. He is the one icemeister allowed to have bumps on his ice, as long as they are perfectly done.