USA Luge finds balance between speed and control with Norton Abrasives technology
February 2014 - Supine on a sleek slice of fiberglass tucked between shoulders and knees, a luge athlete battles G-forces and the friction generated by the sled’s steels sliding over the ice, to beat a clock calibrated to 0.001 of a second.
This minuscule unit of time could be all that determines whether the 10-person U.S. luge team wins the medals they seek. Team USA will compete this month in the 22nd Winter Olympics in Sochi, Russia with one goal—to go as fast as possible. A partnership with sponsor Norton Abrasives could give team members an edge that will help tip the scales. “Races are won, lost and tied by the thousandths of a second—faster than you can blink your eye,” says Gordy Sheer. Sheer, a 1998 Olympic silver medalist, is the director of marketing and sponsorships for USA Luge, 
Lake Placid, N.Y. “We were silver by 0.02 of a second. Put another way, four miles of racing can come down to a matter of inches,” he adds.
Several elements factor into a slider’s quest for speed. A luge athlete trains to deliver a quick, powerful, explosive start. Careful attention also is given to racing gear, which includes a helmet designed to reduce wind resistance, a new textile, skin-tight suit and booties constructed to hold a slider’s feet in a straight position. The material the sled’s steels [or runners] are made from and how they are shaped and finished is equally important.
Following the 2010 games, an aging fleet of sleds and the need to jumpstart innovation prompted USA Luge to form a closer technical partnership with Norton. The association tapped the company for solutions that included development of a high performance steel and the right choice of abrasive products for improving the performance and maintenance of the sled’s pod and its steels. Norton, a brand of Saint-Gobain, Worcester, Mass., is a leading producer of abrasives solutions for the metalworking, industrial manufacturing and maintenance, auto repair, construction and home improvement markets.
Cooking up a new recipe
“We first got involved with USA Luge in 1980 when we began to supply free products for sled preparation,” says Brad Johnson, vice-president of Saint-Gobain Abrasives North America. “The relationship evolved. We became the primary sponsor for USA Luge in 2009 and saw an opportunity to put our technology and experience with steel to work for the association.”
The team had been sourcing steel from Europe but the raw material lacked consistency. Engineers at the Norton/Saint-Gobain R&D Center, Northboro, Mass., took on the challenge to develop a solution. “After gaining an understanding of sled preparation and requirements for shape and surface finish, changing ice conditions and the likes and dislikes of each athlete, we talked with coaches and trainers about steel composition, coatings and profiles relative to vibration and control of the sled,” says Douglas Wakefield, R&D engineer with Saint-Gobain. “The luge coaches also provided us with many sets of steels so we could evaluate and analyze their composition.” The resulting recipe optimizes performance on the ice track and allows the team to race in the 2014 games for the first time on steel produced in the U.S. According to Duncan Kennedy, manager for technical programs for USA Luge, the four years of preparation for the 2014 games have demonstrated the stability and consistency of Norton’s steel and the superiority of its abrasive products.
Kennedy has been sliding since he was 11 years old and tinkering with sleds since he was 14. He bends and shapes the sled’s steels from Hadfield steel, which he uses for its high impact strength and resistance to abrasion once it is work-hardened, and A36 mild steel. Kennedy designs and makes the dies for the steels and performs the prototype work on a bender he invented. “I couldn’t find a bender capable of doing what I needed it to do,” he says, “so I took a few different ideas and morphed them into a machine that is ugly but does a great job bending.” Beginning with 4-ft. lengths, Kennedy runs the A36 through the bender to make the first two bends in what will be the steel’s bow. He makes similar bends in the lengths of Hadfield before drilling bolt holes and joining the pieces together as a laminate. In addition to bending the proper bow in the steels, Kennedy must grind the right radii along the length of the steels, a process that can take up to 20 hours from initial grind to final polish.
“The steel’s edge is not like an ice skating blade where you are just looking for sharpness,” says Sheer. “It’s a constantly changing profile that depends on the skill and weight of the athlete and his or her psychological mindset. That’s why these complex profiles are customized to each athlete for each event.”
Kennedy uses data gleaned from experience, a bit of spy work, some tribal knowledge and a lot of exploration and testing with the athlete to perform the precise metalwork required to fabricate a new set of steels. “This is the fun of it,” he says. “You begin to come up with some pretty interesting things.” In addition to the shaping process, the steels’ radii must also be ground parallel to each other—jobs for which Kennedy relies upon a wide range of Norton products. His primary tool is the Norton Blaze sanding belt and the different grits and belt sizes it offers. Sharp ceramic grains produce an aggressive, yet cooler, cut than other products on the market. The combination allows Kennedy to perform an initial rough grinding process to remove bulk faster and more efficiently. “The quality of the Norton belts makes my job easier,” says Kennedy. “I’m in control of how much material I take off and how quickly. These belts move through metal like it’s butter.”
Finer grits help refine the steel’s custom profile. Norton’s BlackIce waterproof sanding paper provides the final finish. The sandpaper offers a desirable cut rate and is able to produce the uniform finish required in a competitive luge heat. “I’m addicted to the Norton Blaze products and use them for each step required to get a pair of steels race ready,” Kennedy says. “I also use the Blaze belt sander to finish shaping the bow once I make the third and final bend. Sometimes you can have the smallest discrepancy or unevenness in the surface that the bender won’t pick up. Running the bow on the Blaze belt takes care of that.”
Fighting friction
Hadfield forms the bottom portion of the laminate and gives the steels their superior gliding surface. It’s also the only thing connecting the sled with the ice. The athlete’s legs are in direct contact with the runners. The shape of the steels determines the characteristics of how the sled will steer. “Much of the precise shaping work we’re able to do with Norton’s products allows us to balance drivability with speed,” says Kennedy. “We try to see how far we can minimize friction without losing the element of control. It’s a trade-off, though. We want to find an edge the athlete is comfortable with but that is not chipping away at the ice too much.”
The ability of Norton products to run cool is an advantage both on and off the race track. “Norton’s steel recipe is so specific we have to be very careful we’re not changing its composition with excessive heat,” Kennedy explains. “We also have to make sure we don’t warp the steels.”
On the track, rules dictate the steels must remain at a pre-specified temperature or the slider is considered to have an unfair advantage over the rest of the field. “One of the challenges our coaches face is that an athlete may have 30 minutes or less between races,” says Sheer. “A bit of dirt or the smallest grain of sand on the track can actually gouge the steels enough to hinder the sled’s performance and its speed. This is where the Norton products work really fast and cool to eliminate that scratch or gouge without generating too much heat.” Kennedy also uses the BlackIce sanding paper to make slight adjustments to the steels’ radii between races based on athlete feedback.
“We’ve always been a behind-the-scenes product line,” says Johnson. “The ability to partner with USA Luge and use our expertise to help the Olympic athletes by adding value to their hard work and dedication is very satisfying and motivating for us as a company and for our engineers.”
USA Luge has already medaled this season, a tally that includes silver medals in the men’s singles and two World Cup silver medals in the new Team Relay which premieres in Sochi. Kennedy says the wins speak for themselves when it comes to measuring the effectiveness of the Norton products. Norton/Saint-Gobain will remain the USA Luge primary sponsor through 2018. “Having a partner that provides financial support is important,” says Sheer, “but having a technical partner like Norton is a game-changer.” FFJ
