Section 2: Equipment
2.1 Curling Stones
Curling stones are made of dense, polished granite. The majority of competition stones are crafted from granite quarried on Ailsa Craig, a small volcanic island off the coast of Ayrshire, Scotland. The two granite types — Blue Hone (extremely rare, used for the running band) and Common Green — are prized for their low water absorption and consistent hardness. Some stones are also sourced from Trefor, Wales.
- Weight: No less than 17.24 kg (38 lb) and no more than 19.96 kg (44 lb), including handle and bolt (Rule R2(a)).
- Circumference: No greater than 914 mm (36 in) (Rule R2(a)).
- Height: No less than 114 mm (4.5 in) (Rule R2(a)).
- Running band: A narrow, concave annular ring on the bottom of the stone — the only part that contacts the ice. The concavity reduces friction and allows the stone to curl.
- Handle: A gooseneck handle bolted to the top, used to impart rotation (turn) during delivery. Handles are colour-coded to distinguish the two teams.
Each team uses a set of eight stones with the same handle colour, individually identified by visible markings (Rule R2(b)). If a stone is damaged and becomes unsuitable for play, it is replaced; if no replacement is available, a stone already delivered in the end is redelivered (R2(b)). If a stone breaks in play, the teams use the Spirit of Curling to agree where the pieces should be placed, and if agreement cannot be reached, the end is replayed (R2(c)).
2.2 Brooms and Brushes
- Purpose: Sweeping the ice surface ahead of a moving stone to influence its speed and trajectory.
- Construction: Modern brooms use a carbon fibre or fibreglass shaft with a fabric pad head. Traditional corn brooms are rarely used in competition.
- WCF Approval: All broom heads must comply with WCF specifications. Directional fabric, waterproof coatings, or any material that deposits debris on the ice is prohibited — the brush head must not deposit debris in front of a moving stone (Rule R8(a)).
- Stabiliser broom: The delivering player uses a broom or stabiliser (delivery stick) in the non-throwing hand for balance during the slide.
2.3 Footwear
- Slider shoe: Worn on the sliding foot (left foot for right-handed deliverers). The sole is coated with Teflon or a similar low-friction material to allow a smooth glide during delivery.
- Gripper shoe: Worn on the hack (push-off) foot. The sole features a high-traction rubber coating for grip on ice.
- Slider guards: Removable rubber covers placed over the slider sole when not delivering, to prevent slipping while sweeping or walking.
2.4 Additional Equipment
- Stopwatch: Used by the skip or vice-skip to time stone speed (split times between hog lines) for weight judgement.
- Measuring device: Used by officials to determine which stone is closest to the tee when it cannot be determined visually, per Rule R2(i).
- Eye on the Hog: Electronic sensor embedded in the stone handle that detects whether the stone was released before the hog line. A green light indicates a valid release; a red light indicates a violation.