Getting a handle on curling stones not easy at Tournament of Hearts in Calgary

The honour system is in play at the Canadian women's curling championship when it comes to hog-line violations.

The honour system is in play at the Canadian women’s curling championship when it comes to hog-line violations.

A curler delivering a stone must release it before it reaches the hog line. Sensors in each stone’s handle determine whether the rock is released in time because of a magnetic strip embedded in the ice under the hog line.

A green light in the handle indicates a legal delivery, while a red light indicates a violation and the stone gets pulled.

But handle sensors were disabled at the Scotties Tournament of Hearts in Calgary’s WinSport Event Arena after five hog-line violations in the second draw.

“Some spots were prematurely lighting up,” said Curling Canada’s chief ice technician Greg Ewasko. “We deemed that it’s not really fair to the curlers.”

Ewasko’s initial theory that magnets in the arena floor to affix short-track speedskating pylons might be the culprit has been replaced by the possibility that rebar in the floor contains ferrous metal with magnetic properties that interfere with the handle sensor and the ice magnet.

“We found out that there’s no magnets that are embedded into the concrete for speedskating. What we are thinking is the handles are attracted to ferrous metals, like rebar, with some magnetic components in it,” Ewasko said. “We won’t really know until we take the ice out.

“When they make a floor for hockey or curling, the concrete has rebar in it. Because there’s so many thousands of rebar, they could have a few pieces in there made back in the day that have ferrous metals.”