Bell full-face helmet

Ask any neurosurgeon and he will tell you that the living human brain is nothing like the firm, grey, formalin-preserved specimens you see in glass jars in anatomy labs. It's light pink in colour because of the blood coursing around it, and it has a consistency something like thick porridge. It's so soft, in fact, that it can't support its own weight.

Even within its cushioning cerebrospinal fluid and meninges, and the hard, tough shell of the cranium, this delicate structure is, unsurprisingly, susceptible to damage as a result of the high forces involved in car accidents. Susceptible but not exactly vulnerable, since the tolerance of the human animal (young, healthy examples, at any rate) to high decelerations is remarkable — as the redoubtable Colonel John P Stapp of the US Air Force proved in a series of hair-raising experiments conducted first at what is now Edwards Air Force Base in California and then at Holloman AFB, New Mexico, over a period of seven years from 1947.

The best known statistic from Col. Stapp's final, 10 December 1954, ride on Sonic Wind I, the rocket sled that fired him and other human guinea pigs across the desert with ever increasing ferocity, is that it blasted him from zero to 632mph in five seconds, making him the fastest man on earth. But the sled's top speed and the 5.8g average acceleration provided by its 12 solid fuel rockets weren't the significant part of the test, which was intended to simulate the forces involved in ejecting from an aircraft at supersonic speeds. That came at the end of the run, where the sled hit a water splash designed to decelerate it with even greater force. On that last outing Stapp was brought to a halt in a time of 1.4sec, an average deceleration of 20.6g 3T with a peak of over 40g. He suffered temporary loss Z; of vision and had to be removed from the sled on Ia stretcher, but he made a full recovery and lived to the impressive age of 89. Without such innate F resilience human beings could never have gone Emotor racing, or competed in a host of other rought and-tumble sports.

For obvious reasons, the focus of helmet design at that time was on enhancing protection of the brain. The hard outer shell was intended to function as a kind of secondary cranium, providing limited protection against penetration, while the compressible lining within acted to reduce the deceleration experienced by the brain if the head impacted anything in the course of an accident This, and the fact that helmets for motorsport followed the example of helmets designed for aircraft, which had to allow access to the mouth and nose for an oxygen mask, meant that open-face designs were universal. In retrospect, it seems surprising that racing drivers didn't quickly call for something better, because there is much else a motorsport helmet can and should do.

The romantic images of drivers with blacked faces, relieved only by two pools of clean, goggle-protected skin around the eyes, hide the fact that it wasn't only exhaust fumes from the car in front which flew up at them. Dan Gurney, who was to play a key role in promoting a better helmet design, still clearly recalls one frightening example.

"I was in Frank Arciero's 4.9-litre Ferrari and I was trying to overtake a car ahead of me which fired a stone from under a rear tyre. It went right through the windscreen. It was more akin to a bullet than a pebble. I thought, 'That would've really smarted!" Gurney had already contrived a leather face mask to give improved protection, but it wasn't until he went to watch some dirt-track motorcycle racing at Ascot Speedway in Los Angeles that he found a complete solution already in use. In dirt-track racing the problem of flying stones was even worse — "like a fire-hose full of them" — and the bikers had an altogether superior defence against it: the full-face helmet, introduced by Bell Helmets, which extended the protection under the eyes, over the nose and mouth and down to below the chin.

Instead of the rider having to wear goggles, a fixed visor provided eye protection. Gurney realised that here was a ready-made solution to the racing driver's similar problems. Although he wasn't the first to wear a full-face helmet in a racing car — his protege Swede Savage, - an ex-biker, beat him to it in 1967 — Gurney it was who brought the design to everyone's notice when he wore it for the first time at the Indy 500 in 1968 and, in F1, at the Nurburgring that same year.

He was an instant convert. "I wasn't the shortest guy in racing, so I normally caught my share of things in the face. The full-face helmet was just so much better — like you were driving a coupe instead of an open roadster. I didn't know if it would work in the rain but, with anti-fog treatment on the visor, it turned out to be better in the wet, too. It was such a big leap forward it was sensational." Other drivers took a little more convincing, although within a couple of seasons most saw the light. Why the delay? "Human nature and the reluctance to change was part of it. Then there was concern about whether it would fog up under these often difficult conditions in the rain, but it turned out it didn't. And some people are claustrophobic — I think there was also some concern about that"

Welcome as it was for drivers not to have their faces peppered with flying stones, the full-face helmet deserves to be regarded as much more significant a development than that As the letter from surgeon Alistair Gray in our November issue emphasised, a full-face helmet can make the difference between escaping unscathed and sustaining injuries that can cause permanent disfigurement.

You often hear talk of the world of motorcycling contributing technologically to car design, but the idea of it contributing anything to safety seems faintly ludicrous. The full-face helmet is the exception.

The only piizzle is: Bell never patented it. Thanks to Don L'Heurervcfor his help in preparing this feature