March 11, 2009

The ABCs of Curling - I

illum_i is for Ice, upon which the game of curling is played. The playing surface of a sheet of curling ice is between 146 and 150 feet long, and between 14 feet 6 inches and 16 feet 5 inches wide. Most clubs have four or six sheets of ice (well, it's only one big sheet, usually, but it's got multiple playing surfaces laid out on it). While there are some curling clubs that share an arena with an ice skating or hockey rink, most clubs have their own facility. Curling ice and Hockey ice are different enough to make sharing a rink undesirable.

First of all, hockey ice is usually much thicker than curling ice - more than double the thickness in most cases. Ice that thick used for curling results in very heavy conditions. The curlers have to throw the rocks really hard to get them to the other end. When a high profile curling event, like the Brier, is held in an ice skating facility, the ice makers will spend several days slowly scraping down the ice surface until it is thin enough to make good curling ice.
The other big difference between skating ice and curling ice - the one most people immediately notice upon stepping onto the playing surface - is that curling ice is not smooth. The surface is "pebbled" by sprinkling water droplets on it from a specially designed watering can.
Running Surface
Likewise, the bottom of a curling stone is not smooth either. Or flat. As seen in the picture to the right, the surface is concave, and only a thin circle of stone actually touches the ice. This circle, about ¼ inch thick, is roughened, or sharpened, or textured (depending on who you talk to). The result of the rough running edge of the rock, and the pebble on the ice is a significantly reduced surface area of rock and ice actually in contact with each other.

Reduced surface area translates to reduced friction, and allows the rock to travel as far as it does. If you were to try and throw a smooth bottomed stone across smooth ice, you'd have a hard time gettting it to go fifty feet, much less the one hundred and fifty needed to get to the far end of the sheet.

<- Start at the beginning.