Frangible Pins: Making Cross Country Jumps Safer

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--an oxer (two verticals jumped as one unit), a vertical, a triple bar, or even a corner. A steel sleeve is insert into the upright post. A special aluminum pin is inserted in the sleeve to support the top crosspole. The pin is designed with a narrow 20mm neck that shears under sufficient pressure. Each upright is built to allow the top pole to drop 40 cm, creating the required 20 cm in the center.

During the initial trial period in 2002, 29 fences were jumped by 2,344 horses in nine events of various levels and geographies in the UK. The pins broke once. Further testing was done at 12 events and complete load testing and monitoring at two events. To date the pins have broken four times.

The pins have been used twice in the United States, in the fall 2002 Fair Hill CCI three star and 2003 spring Rolex Kentucky CCI four star events. No pins were activated.

The UK plans on requiring the use of frangible pins in all appropriate post and rail type fences built from this year forward and in all appropriate existing fences by the start of 2006. Plans for use of the pins in the United States are under discussion. The pins are of moderate cost, but must be installed correctly to function properly and prevent further harm. For example, the crosspole must be roped at an angle to allow the pole to drop yet retain the pole once it has fallen. Other design elements include a catching block, a spacing block, and an infill that does not block the pole.

Although the pin system was designed to address rider safety, there will be a benefit to horses in preventing or mitigating catastrophic falls. According to Tim Hadaway, Sport and Technical Manager of British Eventing, "Eyewitness accounts of a couple of the situations where the pins have broken so far have clearly suggested that potential serious injury to horse as well as rider has probably been averted."

Hadaway stresses that other work is being done on cross-country safety, "This is one possible solution for certain situations."


About the Author

Katherine Walcott

Katherine Walcott is a freelance writer living in the countryside near Birmingham, Al. She writes for anyone she can talk into paying her and rides whatever disciplines she can talk her horses into doing.

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