Transforming a swimming pool into a curling track was a challenge for Beijing-2022

Ice can just be ice. But not in curling.

The frozen slabs created for elite competitions like the Olympics are the product of a detailed process, led by a team of experts who have to meet the very specific demand of ensuring that a heavy stone, helped by athletes who furiously sweep the ice in front of it, slips. gracefully for a clue.

Even under the best conditions, in facilities built especially for the sport, work is stressful. In Beijing, the complications are immensely greater.

International experts in creating ice worthy of an Olympic curling event have faced an even more complicated challenge than they have faced in the past: transforming an Olympic swimming pool at the Chinese National Aquatic Center into ice rinks ready to welcome international curling athletes.

“It was something that had never been done before,” said Hans Wuthrich, chief ice production technician for the Beijing Winter Olympics, the fourth edition of the Games and one of the numerous elite competitions he has worked on in his career, which has already lasts decades.

Chinese officials have bragged about Beijing’s status as the only city to host both the Summer and Winter Olympics — and the feat was accomplished, in part, through recycling sites built for the 2008 Games.

Curling competitions take place at the beehive-shaped swimming park that in 2008 was known as the Water Cube, and where Michael Phelps won eight Olympic gold medals for the United States. For the Winter Games, the location name was changed to Ice Cube. But preparing him for competition was much more complicated than a simple name change.

A first challenge was to build an infrastructure that would sustain the ice. The pool was occupied by a system of scaffolding, topped by a layer of concrete.

Then came the ice – and an initial obstacle. The common water used in the cube had a reading of 375 parts per million of dissolved solids such as salts, minerals and ions. This amount is acceptable for drinking water, but when the water is frozen, it is not suitable for curling. Impurities affect the ability to make ice sheets as smooth as needed.

The construction team used filtration systems to purify the water. But when the process ended, it was too pure for human consumption.

“If a person were to drink it,” said Mark Callan, the second-in-command of the ice-making team for the curling events, “they would suffer internal burns.”

Outdoors, water freezes from top to bottom, creating a highly inconsistent surface. Indoors, “you have to take the process very slowly,” Callan said, “and allow the water to freeze from the bottom up.”

When the top layers are frozen, white ink, marks and logos are added. In total, the ice is 10 centimeters thick.

The next obstacle is air. The building was too dry – “which is kind of ironic,” Callan said, “since it’s a swimming pool.”

The team installed a system of humidifiers that release a constant mist around the ice rink. But that wasn’t enough. Wuthrich is proud of the solution he found: filling a smaller pool, not far from the ice, with hot water. “Everyone thought we were completely crazy,” he said in a Twitter post, accompanied by a photograph showing the scene.

Even after the ice is frozen to their specifications, technicians continue to worry about the details, monitoring the ice and the atmosphere around it at a granular level: too hot, too cold, too wet, not too wet, texture not enough for the stone to slide. Any deviation can have a disproportionate impact on competition.

“We worked to the nearest thousandth of an inch,” Wuthrich said after his team finished preparing the ice for the women’s tournament.

The precision of the work contrasts with the idea that, among the Olympic sports, curling is one of the easiest. It is a widely accessible sport and, in amateur clubs, practitioners seek above all beer and fun.

But at the Olympic level, athleticism and strategy dominate the sport, and knowing how to read the ice is essential to victory. Ice matters as much as stones and brooms.

“It’s a game of skill, not luck,” Callan said. “And if we can’t deliver consistent conditions, players’ technique starts to lose importance and luck becomes more important – it’s our job to make sure that doesn’t happen.”

Wuthrich and Callan – plus a third coach, Shawn Olesen – were drawn to this highly specialized career because of their passion for curling. They have other jobs. Wuthrich, who lives in the Canadian province of Manitoba, owns a gardening business and a plant nursery; Callan, who lives in Glasgow, Scotland, is the sales director for the company that makes the stones used in elite curling competitions from granite quarried from a Scottish island.

As satisfying as their work seems to them, they also recognize the pressure that comes with it.

“It’s the pinnacle of everything, and as an ice maker, it is for me too,” Wuthrich said of the Olympics. “You have to be on the lookout all the time. If any little thing happens, it has to be fixed. You have to create the best lead possible, because people have fought for 20 years to get to an event like this.”

One night before the final rounds of games, the three coaches — and their team of nearly two dozen Chinese volunteers, most of them college students — began their ice prep routine.

The team used an ice scraper to level the slopes; Callan carried a backpack filled with water and equipped with a shower head. Walking backwards along the slopes, he sprinkled water droplets to create the texture that allows the stones to slide and rotate across the smooth surface.

Then they used a device known as a stone thrower, which allows them to throw multiple curling stones across the lanes to simulate a match. They wanted to leave the ice softened for the players.

The last step was a test done by Callan with a stone. Under the terms of their contract, they have to create ice in which a stone can move between 1.2 and 1.5 meters in 24 or 25 seconds. Their goal is to keep the surface temperature of the ice at minus five degrees Celsius.

The days are long, and they seem to be getting longer. Wuthrich walks about 10 kilometers a day at work; because he takes care of the texture of the track, Callan walks 12 kilometers.

They start at 6am each morning. Lately, problems have been piling up, which means they often work until 1am.

On Monday night, as the South Korean women’s team walked to open a five-point lead over Japan, Wuthrich left the ice for a moment and sat down. He imagined being back at home in Manitoba with his two dogs. He relished the mental image for a few moments, but was soon back on the track, where the teams were still in contention, shouting and deciding strategies.