Hoops, like balls, come in a variety of sizes and shapes depending on where they are being used and price paid. Typical inexpensive backyard (garden) hoops may be made with thin, plastic coated wire. They are quite often seen bent into a round arch. They provide a target to shoot through and are the least expensive. The height of this class of hoop offers about 3" - 4" in the ground and only about 8" of hoop to shoot through. From that entry point, the steel used to make the hoops become thicker in diameter, ranging from 1/4", 3/8" 1/2" and a full tournament size hoop uses 5/8" diameter steel. The amount of hoop underground is also critical. That is what anchors it from deflecting as a ball hits it or plays off it. A full size tournament hoop may have up to 10" below ground and large carrot shaped base or large fins to prevent movement.
The opening of a hoop - the amount of space the ball has to pass through can vary. Many recreational sets are wide at 4-1/2" to as much as 5". Along with the ball being as little as 3", the ability to pass through the hoop is quite easy. At the opposite end of the scale, top level tournament hoop clearance can be set as tight as 1/64".
Below, is a description of hoop constructions from the Croquet Association in England. These specifications have also been adopted by the World Croquet Federation for top level tournament play.
ENSURING HOOP SPECS
Croquet hoops may be approved by the equipment testing committee of the Croquet Association (CA), based in England.There is no requirement that tournaments use approved hoops but they should comply with the specifications as set out by the CA. These are outlined below.
FOR CONSISTENT TOURNAMENT PLAY
- A hoop comprises two vertical uprights joined at the top by a horizontal crown and must be provided with a means of anchorage at the base of the uprights.
- The uprights and crown should be straight and the anchorage system must not hinder free passage of the ball.
- The uprights and crown must be constructed of solid metal of adequate hardness and the hoop must be rigid.
- The hoop must be capable of a setting in which the top of the crown is between 11.5 and 12.5 inches (292 and 317 mm) from the ground.
- The diameter of each upright should lie between 19/32 and 21/32 inches (15.1 and 16.7 mm); minor deviations at the top and bottom are permitted.
- Three measurements are to be made for each upright: high, low and mid length: all diameters must lie within the allowed range. Here and subsequently, high = approx. 13/4 inches from underside of crown; low = approx. 13/4 inches above base of upright.
- The high and low points avoid minor deviations at the top and bottom of the uprights and approximate respectively to a ball radius from the underside of the crown or the ground (13/4 inches = ideal ball radius minus 1/16 inch).
- The inner surfaces of the uprights must be approximately parallel and of separation between 3-11/16 and 3-13/16 inches (93.7 and 96.8 mm) for Standard Approval or between 3-11/16and 3-3/4 inches (93.7 and 95.25 mm) for Championship Approval. For a set of hoops the separations must not differ by more than 1/16 inch (1.6 mm).
- Three measurements of the separation between the inner surfaces of the uprights of an unstressed hoop are to be made at high, low and mid length: all three measurements must be within the allowed range and the difference between the largest and smallest measurement shall not exceed 1/32 inch; for a set of hoops the difference between the largest and smallest of the 18 measurements should not exceed 1/16 inch.
The ranges are derived as follows.
- Standard Approval:
3-19/32 (min. ball) + 1/8 (hcp setting) - 1/32 (hoop tolerance) = 3-11/<16 inches
3-21/32 (max. ball) + 1/8 (hcp setting) + 1/32 (hoop tolerance) = 3-13/16 inches
- Championship Approval:
3-21/32 (max. ball) + <1/32 (min. clearance) = 3-11/16 inches
3-21/32 (max. ball) + 1/16 (adv. setting) + 1/32 (hoop tolerance) = 3-3/4 inches]
The uprights between the high and low positions will be tested for coplanarity: when one upright is in contact with a plane surface, no point of the relevant length of the other upright may depart from the plane by more than 1/16 inch.
- The crown must be straight, at right angles to the uprights, and have a diameter between 19/32 and 21/32 inch (15.1 and 16.7 mm).
- Any logo must comply with these limits.
- The hoop must be capable of being set firmly in suitable ground.
- Evidence of satisfactory performance in setting, durability, and play with Championship Approved balls must be available.
- A check list will be prepared to ensure that the Field Test has appropriate scope.