SAFETY experts have designed a new fence which could save the lives of three-day eventers.

Five riders, including rising star Simon Long of Bradford on Avon, died in falls at horse trials in 1999.

The 38-year-old, from Westwood, was crushed to death by his horse, Springleaze Macaroo, when they fell during the cross-country round at Burghley Horse Trials.

An inquiry into all horse trials was called by the British Horse Trials Association after Mr Long became the fourth rider to die that summer. A fifth was killed weeks later.

All the riders died when their horses somersaulted after hitting rigid fences.

Now scientists at the Transport Research Laboratory have devised a 'smart' fence which will be fully tested at horse trials in Scotland in May.

But Mr Long's parents, Michael and Olive, believe changes already made have had an effect.

Mr Long, who now runs his son's Hudds Farm Livery Stables said: "We are convinced they have already modified jumps because there haven't been any more deaths since 1999.

"They must have modified the space between jumps and their heights."

Their son, who was an experienced three-day-eventer, fell at the Sunken Water fence, designed by Captain Mark Phillips.

An inquest in July 2000 heard that Mr Long's death was an accident.

At the inquest, coroner Gordon Ryall said: "The only change that might have brought about a different result in this case would have been if the fence gave way on impact."

The new 'smart' fence does not give way, but has breakable metal pins inserted between the top pole and the uprights supporting it.

The device is designed to fragment when a horse's hooves collide with the top pole.

When the pin shatters the pole drops by 4in, stopping the horse from somersaulting.

Laboratory testing showed that it was virtually 100 per cent successful in eliminating the somersault which has been responsible for most deaths and serious injuries.

A BHTA spokesman said: "We are confident this pin will reduce the risk to safety and ultimately save lives."

Former British world champion eventer Ginny Elliott, who has worked closely with the engineers, was badly injured in a somersault fault in 1992.

She said: "I do not believe I would have fallen had this fence been in use."