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Canada Is Using Lasers and Robots to Study a Mysterious Curling ‘Frankenbroom'

At stake is nothing less than the future of curling.
Image: Martin J. Smith

Inside a slightly shabby building on the outskirts of of Kemptville, near Ottawa, the World Curling Federation (WCF) has gathered a world-class team of scientists and premier curling talent to unravel a scientific mystery that is rattling the foundations of curling.

At stake is nothing less than the future of one of the world's oldest team sports.

The aim of the tests at the so-called World Sweeping Summit, which runs from Wednesday to Friday, is to understand how controversial new brush heads—some have dubbed them 'Frankenbrooms'—and new sweeping techniques are able to manipulate the trajectory of curling stones in radically unprecedented ways.


Under the scrutiny of scientists from the National Research Council of Canada, Olympic medalists and world champions tested 50 brooms from different manufacturers along with a variety of sweeping styles as we journalists looked on.

As an Australian, I was probably the least familiar with curling among my fellow scribblers. Like so many sporting dilettantes, the extent of my exposure comes from watching the odd Olympic competition on TV. Thanks to Motherboard, I was confronted with a steep learning curve.

NRC's Louis Poirier (left) analyses data with curler Emma Miskew. Image: Dan Gamache/National Research Council of Canada

To achieve the sort of consistency that is demanded by scientific rigour, stones were propelled down the ice using a robotic stone thrower that resembles a squashed Mars rover.

Al Cameron, Curling Canada's amiable media relations director, likened it to the "Iron Byron" robotic machine that is used to measure the performance of golf clubs by replicating the same swing, at the same angle and force, over and over.

I watched as two-time world champion and Olympic gold medalist, Canadian Ben Hebert, scrubbed the ice in front of a stone with a furious rhythm. Hebert, along with fellow athletes—and there is no doubt, curling requires a remarkable degree of athleticism and finesse—took turns at sweeping, directed by the rather insistent voice blaring out of the public address system.

An array of sensors was positioned on the ice, including a laser scanner that built a detailed picture of the ice surface each time the brush passed. Other sensors were attached to stones to measure their distance, path, speed, temperature, acceleration and rotation.


Periodically, an instrumented broom was given to the athletes to capture the pressure being applied to the ice, as well as the frequency of the sweeping action.

Image: Martin J. Smith

Armed with a wealth of fresh scientific data from the testing, the WCF will be drafting new regulations. These will be proposed by the WCF board in July, and voted on by the membership in September. Depending on the outcome, the new regulations could be in effect well before the 2018 Winter Olympics in Pyeongchang, South Korea.

Until a few years ago, change in this sport could be measured on geological timescales. Meaning hardly at all. Then brush-head manufacturers began introducing new brush materials. The most effective brushes employed 'directional fabrics' that are smooth in one direction, and coarse in the other. These were often coupled with hard inserts that allowed sweepers to apply greater pressure to the ice, creating grooves for the the rocks to follow.

Almost overnight, the game was thrown into turmoil.

"The last couple of years we've had a revolution in the sport. Manufacturers have come up with some products that lets you do some fancy stuff to the rocks," said Hebert.

Testing the sweeper's force and frequency with Christine Urech. Image: Dan Gamache/National Research Council of Canada

Sweepers were suddenly able to control of the stone in dramatic ways. They were able to curl the rock more, straighten it, or even slow it down. The paucity of rules and regulations didn't prohibit the new style of brushes from being used, although the WCF did temporarily ban them in competition.


"None the manufacturers are at fault. A couple of them came up with a product that was deemed too good for the sport," said Hebert.

Curling broom and stone on the ice sheet. Image: Dan Gamache/National Research Council of Canada

Two-time world champion Emma Miskew said that it's about bringing the game back to its roots, where skill is paramount.

"It got a little out of hand this season where it became more of a line-calling game and a sweeping game as opposed to a throwing game," explained Miskew. "We don't want it to be about the fabric on your broom head. We want it to be about throwing it [the rock] well."

Part of the mystery is why it has taken this long for someone to apply some serious science to how sweeping works. After the ban on directional materials was put in place, sweeping techniques that were developed to take advantage of them persisted.

According to some players, even with legal brooms, sweepers are able to control the rocks as effectively as the with the banned directional fabric brushes. It was abundantly clear that without some quantifiable data to confirm exactly what is happening, any policy changes would be based on guesswork.

Image: Martin J. Smith

Enter the NRC. The question is, why is the government agency committing scientists and technical resources to answering this question, when surely there are more pressing ones.

"The NRC has a long history of working with the Canadian athletes in both summer and winter Olympic-type sports," said the NRC's Christa Homenick. "Our goal is to support Canadian manufacturing. The majority of broom manufacturers are Canadian."

Homenick told me that the research falls under what is called a fee-for-service project where the client, in this case the WCF, covers the costs.

What the WCF does with the NRC findings is up to them. The challenge is is to decide what is in and what is out. Where the line is drawn will have important implications for this sport.