For the longest time, the motorsports industry was fairly fixed on the use of 3-inch belts for driver safety harnesses. The prevailing wisdom was that a 3-inch belt helps spread the load more broadly in the event of a crash.
However, a closer look at the origins of motorsports safety indicate that the prevalence of 3-inch belts had more to do with availability and the state of the textile industry than anything else. To find out more, and to learn the current state of the art in harness safety, we got in touch with Ben O’Connor, vice president of sales for Impact Race Products.
The use of 3-inch belts started, like so many other things in motorsports, when soldiers came home from World War II and started racing on the dry lake beds and drag strips, and then on road courses in the 1950s. O’Connor explained:
“It’s hard to undo some 60 years of usage in the industry in terms of perception of 3-inch versus 2-inch. A lot of it goes back to the earliest days of motorsports safety,” O’Connor said. “When people started putting restraints into vehicles, it most likely was the result of military surplus, which at the time, they were 3-inch. That was just what they used, but that was more due to the textile industry being what it was, and finding the strength in the webbing in the materials that were used.
“There’s been a push within the industry on the safety manufacturers and some of the sanctioning bodies,” he continued. “Dr. Terry Trammell with IndyCar is one of the key people in pushing the 2-inch restraint. NASCAR very soon afterward adopted it as well.”
Modern webbing used in today’s harnesses, particularly the polyester-based webbing is much stronger than it was early on. Today’s 2-inch webbing meets any of the most stringent SFI and FIA standards. Yes, it could be argued that wider belt is superior at spreading the load, but the wider belts have some issues of their own.
Lap belts cross the hip bone at the what’s known in medical terms as ilium. Using 2-inch belts allows the belt to be tighter because it fits into a natural pocket in the center of the ilium. That’s really critical in terms of driver safety because the lower part of the body, across the pelvic area strengthened by the large pelvic bone has the largest load-carrying capacity in the body. Keeping the hips and butt more tightly in the seat in the first place helps prevent it from accelerating in a frontal event, which is safer than trying to stop a driver’s body after it’s already begun to accelerate out of the seat.
Because of their width, 3-inch belts can ride up and over the iliac crest, the hip bone you can feel with your hand right by your belt line. By keeping the belt below the iliac crest, it helps prevent the belt from coming up above the crest in a forward event and maybe creating some internal injuries in the abdomen, O’Connor said.
“Objects in motion stay in motion, so you want to eliminate the start of that motion,” O’Connor said. “You want to arrest it as soon as possible, so again, the closer you can keep the body in the seat, the less chance it has to gain speed moving out of the seat before it hits the laps, and more consequently, the shoulders, which, in an abrupt stop, is what causes those basilar skull fractures (HANS) devices were designed to prevent.”
In fact, it was the use of frontal head restraint devices — FHR or HANS devices — that ushered in greater acceptance of 2-inch belts, O’Connor said. The “channels” for the shoulder harnesses on an FHR device weren’t wide enough and 3-inch belts often would not be fully contained. Some early harnesses designed for HANS devices featured 2-inch-wide shoulder straps where they ran through the FHR device, then sized up to 3-inch straps below that. IndyCar and NASCAR now have adopted 2-inch belts as standard. You can’t run 3-inch belts in either sanctioning body anymore.
“So, they’ve (NASCAR) really been, in this country anyway, at the forefront of safety advancement along with IndyCar,” O’Connor said. “Just having the resources to do the testing and validation has been invaluable. Fortunately, everyone benefits from that research that NASCAR does because that stuff starts at the pro levels and it trickles down to every-day racing.”
Of course, as research continues on how systems interact with the human body, so too does other technology. For example, cam locks have become commonplace. Latch-and-link locks have been in use for decades, and they offer a secure connection for all five or six points of a race harness, but cam locks are superior. Say you’re pulling out of the paddock and you notice you forgot to connect a shoulder strap. With cam locks, all you have to do is snap the tang into the center lock. With latch and link, you have to disconnect all the straps and start over again.
Specific to Impact’s new 16.5 Pro Series cam lock harnesses, new technology includes adjusters built right into the tangs that click into the cam lock. It eliminates the issue of having a floating adjuster that can get caught on the openings in the side of a racing seat when you try to tighten the belts.
Impact also changed the design of the adjuster itself. It’s more of a roller style, with a wedge-type lever release. It’s smooth and easy to tighten, so a driver, by himself, sitting in the car, is going to find it easier to tighten with this type of restraint than with traditional adjusters.
“It’s always been a common problem that needed to be addressed. This really resolves a lot of those typical issues that drivers deal with when they’re trying to get properly restrained in the vehicle,” O’Connor said.
“We do have, I guess you could say, on staff, a professional driver, Robbie Pierce of Jimco, and a Trophy Truck driver in the SCORE series. He’s the former owner of the company, but he’s still a consultant for the company, and very active. He worked on this project.”
Impact’s tensioner technology isn’t necessarily new, but it is notable because it reduces the need to retighten the belts while you’re out on track. It uses a wedge-shape tensioning device. The higher the load, the further it drives that wedge into the adjuster in clamping on the webbing. When it’s time to get out, the clasps release by lifting up on the lever.
Belts rated by the SFI Foundation expire two years from the date of manufacture, Why? Well, as fabric ages, its strength can decrease. Factors such as ultraviolet light, frequent use and high cockpit temperatures each can play a role in the degradation of the harness. Also, any belt that undergoes a serious crash should be replaced due to stretching, so if your harnesses are due to expire soon, 2-inch belts are worth considering.
“All the major manufacturers are in support of this movement toward 2-inch belts. This is not unique to us,” O’Connor said. “It’s something the entire industry is on-board with, at least all that I know of.”
