How Luge Works

In Olympic luge, the slider (usually not called a "luger") lies down on a fiberglass sled, with no braking system, and heads feet-first down an icy track.

There are actually two types of luge: natural track and artificial track.

Olympic luge is kunstbahn, and it's not for the meek. Two weeks before the start of the 1964 Innsbruck Games, a slider from the British luge team died on the luge track during a practice run. Crashing at 90 miles per hour (145 kilometers per hour) on an icy track can be very ugly, and luge athletes often face serious injuries if they come off the sled. In 2010, Georgian Nodar Kumaritashvili died while training for the Vancouver Olympics when he lost control of his sled. He flew off the track and into a metal pole. The types of artificial luge tracks used in the Olympics are tremendous structures that embody a lot of technology. There are fewer than two dozen artificial luge tracks in the world.

An Olympic track is artificially refrigerated. The course is usually a reinforced concrete track with evaporators buried in the concrete. The evaporators cool the track to 12 degrees Fahrenheit (-11 degrees Celsius). The track is then sprayed with water to create the approximate 2-inch (5-centimeter) surface of ice.

A typical luge course is less than 1 mile (1.6 km) long and drops about 300 to 400 feet (90 to 120 meters) or 30 stories over a one-minute run. The configuration includes straightaways, left and right turns, downhills (and sometimes a short uphill) and at least one S-type curve combination like the "labyrinth," which consists of three or four consecutive turns with no straightaways between them.

The track built in Yanqing for all sliding events — bobsled, luge and skeleton — at the 2022 Winter Olympics in Beijing, is 5,298 feet long (1,615 meters) with a maximum grade of 16 percent. It features 16 curves (turns) including the world's first 360-degree Kreisel turn ("kreisel" is the loose German translation for "circle").

The men's singles course is 0.84 miles (approximately 1,352 meters.) while the women's singles and doubles course is 0.75 miles long (approximately 1,207 meters).

Just staying on the sled is a feat for a highly trained athlete. But sliders don't just have to stay on the sled — they also need to maintain a strictly aerodynamic form, watch where they're going and try to keep the sled in the "sweet spot" that will carry them smoothly between turns, all while facing up to 6 Gs on particularly strenuous courses.

"The craziest part about going down is the G-force you're hitting in some of these tight corners," Canadian slider Reid Watts told the CBC in 2018. "It's a real flow state." Watts first tried luge when he was just 9 years old and will be representing Canada in Beijing in 2022.

For the level of danger sliders face on each run, the amount of protective gear they wear is shockingly sparse. In the next section, we'll examine the equipment of luge.

For all the complexity of navigating a luge course, the equipment involved is limited. Every piece of equipment in luge is designed for utmost aerodynamics, minimal friction and top speed. Required equipment includes:

A luge sled is the most important piece of equipment; it's a high-tech machine. It's made primarily of fiberglass and steel, and it's custom-built for each athlete based on his or her height, weight and proportions. Luge teams contract companies to design and build their sleds based on custom specifications. The single sled weighs between 46 and 55 pounds (21 and 25 kilograms), while a double sled weighs between 55 and 66 pounds (25 and 30 kilograms). The seat runs from the slider's shoulders to his or her knees, and there is no head support.

The sled consists of:

A slider's racing gear consists of:

During a race, something like a snag in a racing bootie can affect the slider's aerodynamics enough to mean the difference between a win and a loss. Sliders typically race in brand-new gear to reduce the chance of an unnoticed imperfection.

In the next section, we'll put this all together and see what happens during a luge run.

The Olympic luge competition has four divisions: men's singles, women's singles, gender-neutral doubles and team relay. Since a higher weight is advantageous in luge, doubles teams are typically all male. Most international races besides the Olympics have single sliders doing two runs each. Times for both runs are added together, and the slider with the fastest cumulative time wins.

In the Olympics, singles luge competition consists of four runs instead of two (doubles still perform only two runs), all of which count toward the final time.

Since every luge track is different, there are no blanket World or Olympic record in luge. There are only track records.

At the start of the luge course, the slider grabs two handles — one on each side of the track — and uses these to rock back and forth to build momentum for the start. Then the slider propels themself down the course with their hands, using their spiked gloves to paddle through the first 10 feet (3 meters) or so of the track to help them gain speed before lying down on the sled.

Approaching the start of the downhill, the slider lies face up and feet first on their back and remains is this position for the remainder of the run. Sliders only lift their head enough to have an idea where they are on the track. They use their body weight to navigate the twists, turns and straightaways while remaining relaxed, something not easy achieve. Their body must be stiff enough to maximize acceleration — any wobbling or looseness increases friction between the sled and the track — and yet relaxed enough to absorb the intense forces acting on them throughout the run.

Since steering also increases friction, the slider steers as little as possible, only pressing on the bows when necessary. Most of the time, control is a matter of being one with the sled and letting gravity do its thing.

Sliders must cross the finish line with their sleds; finishing without it or even pushing it across the finish line means automatic disqualification.

Timing

Olympic luge is timed to 1/1000 of a second; it is timed using photoelectric sensors at the start and finish. The setup has a light transmitter/receiver pair at each end of the run. The transmitter is on one side of the track, and the receiver is on the other. At the start, the slider triggers the timer when he crosses the line because he blocks the light beam. At the finish line, he stops the timer the same way.

At the 1998 Nagano Games, the time difference between the women's gold and the women's silver was 2/1000 of a second, the smallest margin in luge history. This minuscule difference between first and second place drew a great deal of controversy, and engineers were called in to calculate the system's margin of error.

Since the 1998 Games, luge timing systems have been calibrated before each race using a GPS satellite with an atomic clock that's accurate to the 10-10 seconds. The calibration process is basically about synchronizing the timers on the luge course with the atomic clock on the satellite. With a modified GPS receiver built into the timing system, the satellite can trigger the start timer and then trigger the stop timer after a certain interval. If the time noted by the satellite and the time noted by the ground system matches to at least the second thousandth of a second, the timing system is ready for a race.

Completing a luge run is an exhilarating and physically demanding task. Let's take a look at the physics involved in making it from the start to the finish.

The physics concepts involved in a luge run are fairly basic:

At the start of the course, the slider/sled unit is at rest. The slider's goal is to begin the run with the utmost speed, so they need to propel the sled onto the course with as much force as possible to overcome its inertia (its desire to remain at rest).

If the slider weighs 198 pounds (89 kilograms), and the sled weighs 50.6 pounds (23 kilograms), that's a combined mass of about 247 pounds (112 kilograms). By rocking back and forth at the top of the track, the slider needs to generate enough momentum to propel 247 pounds through the first 10 feet (3 meters) of the course in about two seconds to achieve a good start.

As the slope begins, the slider lies down on the sled and lets gravity take over. In luge, heavier weight means faster speed. The heavier the weight of the athlete, the greater the force of gravity pulling them down the track. One of the forces standing in the way of gravity is friction. To reduce the amount of friction between the sled and the track, the steels on the sled are polished with things like sandpaper and diamond paste.

Another force acting against the pull of gravity throughout the run is aerodynamic drag, which consists of air friction and form drag. In luge, when air runs over the top of the slider, it interacts with the materials of the helmet and racing suit. This results in air friction. To reduce air friction, racing suits are slippery and skin-tight, and the visor on a luge helmet is rounded and extends all the way under the slider's chin so there are no air pockets. The interaction between the air and the frontal shape of the slider/sled combination results in form drag.

In addition to using the most aerodynamic shapes for the sleds, the slider tries to further minimize form drag by maintaining an aerodynamic body position. The less area they present, the better. Even lifting their head an inch to see the track increases drag and can add several thousandths of a second to their run time.

In doubles luge, the taller athlete lies in front, between their partner's legs, to achieve a smoother profile. Many sliders spend hours training in wind tunnels to find the ideal body position to minimize drag.

Probably the most physically battering points on a luge run are the turns, and especially the turn combinations, when G-forces increase. Acceleration and deceleration throughout a luge course put an average force of up to 3 Gs on a slider's body. Forces can reach up to 5 Gs in banked turns, when centripetal force adds another dimension to the forces acting on the slider.

Centripetal force pulls the slider outward in the turn. To maintain speed, the slider must perfectly balance the centrifugal force with the force of gravity pulling them downward through the course. This means finding the "sweet spot" and staying there. If the forces are balanced, the sled will smoothly move through each turn and back into the straightaways. If they are unbalanced, the slider will have to steer too much, slowing down the run.

With so much at stake in so little time, luge athletes train all year to shave a few thousandths of a second off their time. In the next section, we'll find out what's involved in luge training.

Because luge is one of the few Olympic sports timed to 1/1000 of a second, the start is the most important part of the race. It's the time when the slider is most in control, so his or her training can have the greatest effect on the outcome.

Luge athletes build tremendous upper body strength for the start, when they'll propel themselves, their sled and any extra weights onto the course. Hand strength is also required for the start, when the slider paddles as quickly as possible for the first several feet of the course.

During the offseason, luge athletes train to build upper body muscles through swimming, weight training and calisthenics. When tracks are open, they practice runs as often as possible, sometimes focusing only starts, developing strength, agility and technique.

While the athletes are doing practice runs and starts, coaches are analyzing them all using footage from digital cameras, specialized software and prior reports from athletes about what they're feeling on the course. Luge coaches have a deep understanding of sleds and luge physics, and they use all of this information to make tiny adjustments to the sleds to maximize speed and control for each slider.

Luge training also involves sessions in wind tunnels, during which athletes figure out the form that achieves minimum aerodynamic drag. Monitors above the slider's head and at their feet display a number that represents the amount of drag they're experiencing. These sessions allow them to make minute adjustments to their position to lower drag.

Training for luge is about strength and precision, but a slider has to have a certain temperament, too. In luge, adrenaline junkies win.

"The run might only be 50 seconds long, not more than a minute, and you're absolutely knackered after the run because you're focusing mentally and physically," British luger Rosen told the IOC. "You're putting your body through so much and you're doing all this while taking the bumps and steering precisely through all these curves going down. But the more you do it, the more you get used to it, you're constantly navigating the sled."