.21-1 Jockey Safety Vest.

A jockey safety vest shall:

A. Cover the torso, front and back, from the collar bone to the hip bone;

B. Be of uniform material and thickness over the whole of the vest, except for localized:

(1) Variation due to pattern, for example, quilting,

(2) Thinner areas to aid fit, for example, under the arms, at fastenings and at edges, and

(3) Thicker areas in regard to particularly sensitive areas of the body, for example, the spine; and

C. Equal or exceed a minimum shock absorbence rating of 5 according to the specifications established by the British Equestrian Trade Association (BETA) which are as follows:

(1)) Use a critical height apparatus to measure the maximum deceleration on impact of a striker consisting of a spherical indenter weighing 5.9 (+/- 0.05) kilograms with a diameter of 215 (+/- 2) millimeters,

(2) Condition the vest and the striker for a minimum of 3 hours at 23 (+/- 2) Centigrade,

(3) With the vest lying on a smooth, flat, massive concrete base with the inside of the vest facing the striker and positioned so that the striker will impact on an area of typical thickness, not reinforced by additional material, raise and release the striker starting at a height of 0.2 meter and increasing the height by increments of 0.2 meter to a height which will result in a deceleration of over 300 gravity units (1G=9.81 ms-1) as measured by recording the signal from an accelerometer throughout the impact from the time before the striker impacts the vest until the accelerometer returns to the same level as before the impact,

(4) Record the gravity units measured at each height increment on a line graph which has the gravity units in ascending order as the vertical axis and the release height in meters in ascending increments as the horizontal axis,

(5) Plot the height in meters at which the deceleration reached 300 gravity units, and

(6) Multiply the height obtained in C(5) of this regulation by 10 to calculate the shock absorbence rating.