A company in the United Kingdom has created a jump design to lessen the severity of cross-country falls. In 1999, several U.K. riders died from accidents on cross-country jumps. The resultant study committee hired the Transport Research Laboratory (TRL), an expert in transportation safety, for scientific investigation, data analysis, accident investigation, and engineering.
From available video coverage of 100 falls and intensive equine anatomical studies, TRL created a mathematical model of a horse and a crash-test dummy. The key conclusion of their study was that significant injuries resulted from rotational falls. In this sort of fall, the horse hits a fixed obstacle between knee and shoulder, overturns, drops the rider at the base of the jump, then falls on the rider. The speed is low enough that the rider is not thrown clear. The study concluded that if the top rail could give way as much as 20 cm (eight inches), the horse would have a few fractions of a second to free up its front legs and prevent the rotation, if not the fall.
Barriers International created the “frangible pin” to meet this criteria as well as other sport-specific parameters. Frangible is defined as “capable of being broken.” However, a frangible pin fence does not mean a breakaway fence. The set-up will only give way if the top pole is hit with sufficient downward force equivalent to the horse’s weight plus momentum. Monitoring in competition has show that horses can hit and land on a frangible pin fence without breaking the pin.
A frangible pin fence, at this point in development, is always a post and rail jump of some type–