Approved Croquet Hoops - Specification

1. Hoops

Standard Approval may be given to hoops of unstressed upright separation 3¹¹/₁₆ inches to 3¹³/₁₆ inches, and both Championship and Standard Approvals to those with separation in the range 3¹¹/₁₆ inches to 3³/₄ inches. The Championship range provides for a ¹/₁₆ inch clearance on all Championship Approved balls and the different upper limit of the Standard range accommodates a ¹/₈ inch clearance. By stressing the hoops in the ground it is expected that most designs will produce both ¹/₁₆ inch and ¹/₈ inch settings at ball half-height; the rules for Approval also aim to cover hoops of fixed width such as may be more suitable for use with artificial surfaces.

The requirements in Section 2(c) were revised in 2009 to recognise widespread use of hoops of greater upright diameter than ⁵/₈ inch diameter, problems with the production of cast iron hoops with ⁵/₈ inch, and a strong interest in the upper reaches of the game in providing hoops of significant challenge. The revision of the Laws in 2008 to increase the upward tolerance on the ⁵/₈ inch dimension to ¹/₈ inch was therefore interpreted in Approval regulations 2(c) and 2(e) to permit the use of ³/₄ inch diameter uprights and crown.

Hoops with Approval

Hoops that have current Approval are as follows:

• Omega Adjustable Hoop (Steel; Standard and Championship Approval, December 2000) (see our on-line shop).
• Jaques Championship Hoop (Cast Iron; Standard and Championship Approval, July 2005).

The design of a hoop system for use with artificial surfaces by R.H. Rawden of the Bury St. Edmunds Club was Approved in 2003.

Makers intending to produce Approved hoops are invited to make contact with the Chairman of the CA's Equipment Committee.

Manufacturers seeking Approval are required to submit one (non-returnable) fully finished hoop for testing, to arrange a Field Test at an agreed venue and for an agreed period, and to provide written assurance that the manufacturing processes are adequately reproducible. The Equipment Committee will be responsible for preparing a report of performance in relation to the stated criteria and will provide a check list of items for the Field Test. The report will include a general description of the hoop system and indicate whether the hoop is suitable for fixed or adjustable setting. Approvals will be announced in an appropriate manner by the CA. A hoop system may be accorded Approval in either or both of the Standard/Championship categories. The report will be made available to the maker and for an Approved hoop it may be published by the CA.

2. CA Standard and CA Championship Approval of Hoops

Notes of explanation are enclosed in square brackets. The specifications for Approval are derived from the requirements for clearances of ¹/₈ inch ('handicap setting') or ¹/₁₆ inch ('advanced setting') with any ball meeting the internationally recognised Championship Approval standard - i.e. diameter 3¹⁹/₃₂ - 3²¹/₃₂ inches.

(a) Construction

• 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.

(b) Height

• 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.

(c) Upright diameter

• The diameter of each upright should lie between ¹⁹/₃₂ and ³/₄ inches (15.1 and 19.1 mm); minor deviations at the top and bottom are permitted. Hoops with uprights formed from well-made ³/₄ inch bar will be deemed to fulfil the requirements for Approval.
• 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).

(d) Uprights parallel

• The inner surfaces of the uprights must be approximately parallel and of separation between 3¹¹/₁₆ and 3¹³/₁₆ inches (93.7 and 96.8 mm) for Standard Approval or between 3¹¹/₁₆ and 3³/₄ 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:
  3¹⁹/₃₂ (min. ball) + ¹/₈ (handicap setting) - ¹/₃₂ (hoop tolerance) = 3¹¹/₁₆ inches
  3²¹/₃₂ (max. ball) + ¹/₈ (handicap setting) + ¹/₃₂ (hoop tolerance) = 3¹³/₁₆ inches
• Championship Approval:
  3²¹/₃₂ (max. ball) + ¹/₃₂ (min. clearance) = 3¹¹/₁₆ inches
  3²¹/₃₂ (max. ball) + ¹/₁₆ (adv. setting) + ¹/₃₂ (hoop tolerance) = 3³/₄ 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.

(e) Crown

• The crown must be straight, at right angles to the uprights, and have a diameter between ¹⁹/₃₂ and ³/₄ inch (15.1 and 19.1 mm).
• Any logo must comply with these limits.

(f) Field Test

• 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.