Initiated in Scotland around the later medieval times, curling is a game played between two teams of four members each. It is a winter sport, principally similar to bowls.
The curling feet an ice sheet has two tees placed 38 yards apart that have circles of a 6 feet radius around each. The aim of the game is to send more and more stones nearest to the tee. Each team is given 8 to 10 stones. At the end of the game, the stones closest to the tees, add up as points. A curling tournament is called Bonspiel. It is a major winter sport in Canada, Europe and to some extent in the US. The international governing body for curling is in Scotland and is called ‘The World Curling Federation’. This body has given standards on the basis of which official curling equipments and fields are to be prepared.
Let us first have a look at the curling playing surface or curling sheet. This sheet has to be as flat and level as possible. The length should be 146 to 150 feet while the breadth or width has to be 14.5 to 16.5 feet.
At each end of the sheet, there is marked a target called the house. This is made of three concentric rings of paint or vinyl different in color. The diameter of the rings is generally used to define them which are available in different a diameter that is four foot, eight foot and twelve foot rings. These help in analyzing the proximity of the stone to the tee, a stone should at least touch the outermost ring or it does not score at all. These rings are a mere visual aid to the players and do not affect scoring much. Two lines drawn length wise and width wise divide the houses into quarters. The lengthwise line drawn from the centre of the sheet is called the centre line and a tee line drawn 16 feet from and parallel to each backboard intersect at the point that becomes the centre of the house. This centre is known as the button. Along with this there are two hog lines, these are drawn 16 feet from and parallel to, each back board.
Hack is present around twelve feet behind each button. This hack serves as an object that can be used to push against while making a throw. The use of rubber lined hoes which are present on the either side of centre line and two fixed hacks is made in Indoor rinks.
The distance between the inside edge and the centre line or the front edge of the hack line is not more than three inches. Even a single movable hack can be employed.
Another important factor for the field is the ice. In curling clubs, an ice maker or even a team of them is especially employed to take care of the ice temperature and air humidity levels. Generally, each ice sheet has multiple sensors embedded in them to keep track of the surface temperature and probes to measure humidity. The surface of the ice should ideally be around 23 °F. Another important part in the preparation of the field is the formation of pebbles. These are made by spraying water on the field, these water droplets freeze into pebbles and aid the curling of the stone. The stone curls inside or outside because of its contact with the pebbles.