Alpine skiing

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Alpine ski slope in the Zillertal valley, Austria

Alpine skiing, or downhill skiing, is the sport of sliding down snow-covered hills on skis with fixed-heel bindings. It is characterized by the requirement for mechanical assistance getting to the top of the hill, since the equipment does not allow efficient walking or hiking, unlike cross-country skis which use free-heel bindings. It is typically practiced at ski resort which provides services such as ski lifts, artificial snow making and grooming, first aid, and restaurants. Back-country skiers uses alpine skiing equipment to ski off the marked pistes, with the transport by helicopter or snowcat.

There are four competitive alpine skiing disciplines: slalom has short tight turns, whereas giant slalom races are set with more widely-spaced turns. super giant slalom and downhill have few turns; the courses have gates spaced widely apart and skiers often reach 100 km/h.

Alpine skiing began as a club sport in 1861 at Kiandra in Australia and a number of similar clubs in North America and the Austrian and Swiss Alps.

Technique[edit]

A skier following the fall line will reach the maximum possible speed for that slope. A skier with skis pointed perpendicular to the fall line, across the hill instead of down it. The speed of descent down any given hill can be controlled.You can change the angle of motion in relation to the fall line, skiing across the hill rather than down it.

However, ski runs are generally of finite width and a skier using this technique to slow down it will eventually move sideways to the edge of the run. At this point the skier must turn around to continue the descent in another direction. In theory, a run down the hill would consist of straight sections across the hill. They have to be sharp turns to the complementary angle, as if the skier is being reflected from the edges of the run.

Downhill skiing technique focuses on the use of turns to smoothly turn the skis from one direction to another. Additionally, the skier can use the same techniques to turn the ski away from the direction of movement. Generating skidding forces between the skis and snow which further control the speed of the descent. Good technique results in a flowing motion from one descent angle to another one. Adjusting the angle as needed to match changes in the steepness of the run. This looks more like a single series of S's than turns followed by straight sections.

Stemming[edit]

Main article: Stem (skiing)

The oldest and still common form of alpine ski turn is the stem, turning the front of the skis sideways from the body so they form an angle to the direction of travel. In doing so, the ski pushes snow forward and to the side, and the snow pushes the skier back and to the opposite side. The force backwards directly counteracts gravity, and slows the skier. The force to the sides, if unbalanced, will cause the skier to turn.

Carving[edit]

Main article: Carve turn

Carving is based on the shape of the ski itself; when the ski is rotated onto its edge, the pattern cut into its side causes it to bend into an arc. The contact between the arc of the ski edges and the snow naturally causes the ski to want to move along that arc.

Equipment[edit]

Skis[edit]

Main article: Ski § Alpine

Modern alpine skis are shaped to enable carve turning, and have evolved significantly since the 1980s.

Bindings[edit]

Main article: Ski_binding § Alpine

During the 1930s, the Kandahar binding was introduced, which could be locked down at the heel for the downhill portions. The Kandahar remained in widespread use until the 1960s. As more skiers took up the sport, especially in the 1950s, broken legs became common. Dr. Richard Spademan saw 150 spiral fractures pass through his emergency department near Squaw Valley in three days, an event that led to the development of the Spademan binding. By the early 1950s, several safety bindings were on the market that allowed the ski to come off when the ski twisted to the side. This helped reduce the incidence of spiral fractures.

Boots[edit]

Main article: Ski boot § Alpine

Originally boots were cut low, just over the ankle, and soft laterally, both of which limited the amount of sideways rotating force that could be applied. Around 1966, two new ski boots made of plastic came to market. Compared to leather designs, the Rosemount and Lange boots dramatically increased the amount of lateral stiffness, and in turn, the amount of edging control over the ski. Additionally, the plastic did not change shape over time or when it got wet. This allowed the bindings to be much more closely matched to the fit of the boot, and offer dramatically improved performance.

Competitions[edit]

Ski racer competing in a Giant Slalom race
Alpine ski slopes in San Carlos de Bariloche (Argentina)

Various Alpine skiing competitions have developed in the history of skiing. Broadly speaking, competitive skiing is broken up into two disciplines: racing and freestyle.

Racing involves making fast turns around gates in an attempt to attain the fastest overall time down one or two runs of a race course by having the tightest line possible. Elite competitive skiers participate in the annual World Cup series, as well as the quadrennial Olympic Games and the biennial World Championships. Slalom (SL), giant slalom (GS), super giant slalom (super-G), and downhill (DH) are the four racing disciplines. Slalom is the most technical discipline and has the shortest turns with distances ranging from 6 to 15 metres apart. It has speeds that can reach 35 km/h. Downhill is the fastest, where speeds can exceed 140 km/h, showing the clear distinction between the two disciplines. The Giant slalom event is also considered a technical event with medium sized turns and the Super-giant slalom considered a speed event, as similar speeds are reached as in the downhill discipline though jumps are provided. There is also a "Combined" event that includes one downhill race and one slalom race. In 2004, the FIS (Fédération Internationale de Ski) introduced a new event to the World Cup calendar called the super combined, or super combi, consisting of one shortened downhill run and just one slalom run, both raced during one day. That year, the FIS also introduced an Alpine team racing event at the World Championships in Bormio, Italy.

Ski racing is controlled by a set of rules which are enforced by FIS. These rules include such things as regulation ski sizes, sidecuts, boot heights, binding risers and other regulations such as limitations to chemical substances found in winning racers as well as many other things which all ensure one particular skier has no advantage over another. In 2008, these regulations were changed in order to make it harder for racers to complete a race course. Some changes included increasing the minimum ski length and also the sidecut which makes the ski turn less tightly, as it was found by physiotherapists that the shorter skis combined with the constant knee jerking movements were considered unnecessarily harmful to racers' knees due to the turning radius of the skis (especially the slalom skis). The minimum ski length became in slalom for women 155 cm and men 165 cm. Other size minimums were put in place in the other three events.

Freestyle skiing incorporates events such as moguls, aerials, and sometimes "new-school" events such as halfpipe, big air, slopestyle, and skiercross. Together with extreme skiing, new-school freestyle skiing is also sometimes known as freeskiing. Until relatively recently, freestyle competitions also included an event called ballet, later renamed "acro-ski".

In addition to racing and freestyle, other types of Alpine skiing competitions exist. One discipline administered by the FIS but not usually considered part of racing is speed skiing, in which competitors strive to achieve the highest total speed in a straight line, with no gates or turns. More traditional events include gelandesprung jumping (ski jumping for distance on Alpine equipment), and "powder 8" contests; among the more recent introductions are "big mountain" or "extreme skiing" contests, in which athletes start at the top of a mountain and ski a route down that involves wide, fast turns as well as cliff drops. The competitors are judged on the technical difficulty of their routes and any tricks they perform on the way down the hill.

Organization of Alpine ski competition[edit]

Ski competition rules and scheduling are managed internationally by the International Ski Federation (FIS) based in Switzerland. Each participating nation worldwide is represented by a national association that manages the sport in that respective nation.

Recreational Ski Racers at a NASTAR race
Man skiing slope overlooking Lake Tahoe

Most organized skiing competitions are dependent on a team of Race Officials and course workers who plan, organize and run the events. Alpine ski races are usually organized by a Race Organizing Committee (ROC), led by a Race Chair. Race Officials include the Chief of Race, chief of course, starters, timers, gate judges, referees, a jury and others who organize the event and ensure it is run safely and according to governing body rules. Under the leadership of a Chief of Course, course workers erect safety systems (usually nets), prepare and maintain the surface of the race course, erect and maintain other equipment such as a start tent, a finish area and the gates through which competitors must pass, and remove any fresh snow that may fall during the event. A FIS World Cup downhill, for example, requires a team of several hundred course workers that may spend over two weeks preparing a course prior to a week of racing, during which the course workers will continue to maintain the course. Race Officials and course workers are usually volunteers, but may include paid staff and, in some European countries, members of the military. Most regular venues of major Alpine ski races have a local ROC which remains in place from year to year. An example of an organization of volunteer course workers are the Whistler Weasel Workers.

Ski trail ratings[edit]

Main article: Piste § Ratings

In most ski resorts, the runs are graded according to comparative difficulty so that skiers can select appropriate routes. The grading schemes around the world are related, although with significant regional variations.

Snow and weather[edit]

This terrain park begins with three jumps, each with a variety of entries.

Skiers and snowboarders can encounter a wide range of snow and weather conditions, in part due to the location of specific resorts and global weather patterns at the time. Natural snow ranges in consistency from light and powdery to dense and heavy, depending upon atmospheric conditions. Snow is often measured by moisture content. Some areas of the United States' Rocky Mountains, for example, can receive considerable amounts of snow with moisture content as low as three to five percent; in the Northeastern United States and the Alps, moisture content is more typically 15 percent or more. Snow made by mechanical snowmaking often has moisture content of 35 percent or more.

Temperatures play a critical role in snow moisture content, but other atmospheric conditions are also relevant. Air currents and other factors determine snow crystal shape; obviously, the farther apart given snow crystals are, the more air is contained in the newly settled snow, resulting in lower net moisture content in a given volume of snow. Snow produced mechanically typically has high relative moisture content and low amounts of loft because the crystal structure resembles small, dense pellets. Even the fluffiest snow has mass, and snow typically settles under its own weight after time. This is one reason why untouched snow measuring 20 cm on the day it falls might be measured at 15 cm the day following. Snow is also subject to sublimation—a process by which water can go directly from a frozen state to a gaseous state without first melting. It is this same process that ultimately makes ice cubes shrink in a freezer. There are other factors that impact snow beyond its moisture content and crystal shape, however. Snow is impacted by wind, sunlight, skier traffic, ambient air temperature, relative humidity and grooming equipment; all of these factors combine to change snow crystal shape and density over time.

Some of the common conditions include:

Powder
Light, fluffy snow, found during and immediately after snowfall. Skiing and snowboarding in deep powder snow is a favorite among skilled, experienced skiers and snowboarders; sometimes known as "powderhounds" hunting for the next big dump. Because Western snow generally has a lower moisture content, western powder is lighter and easier to ski than heavier eastern powder. Utah and Colorado snow is especially known for being extremely light and dry as well as a lot of snow found in New Zealand.
Packed Powder
Packed powder is compressed powder that is formed after the snow is groomed. Whereas hard pack (see below) is extremely dense and hard to ski on, packed powder is slightly less dense and able to support skis without sinking. This makes it very easy and fun to ski on.
Chowder
Chopped up powder. Powder that has fallen in the prior few days and remains light and fluffy but has been skied or tracked up.
Crud
Once powder snow settles and becomes tracked up by skiers and snowboarders it firms or freezes into texture that is challenging and usually undesirable. Crud may contain "chicken heads", balls of frozen snow.
Groomed or corduroy
Snow that has been tilled by a grooming machine. This snow condition is favored by beginners and the majority of recreational skiers, in that it tends to be relatively forgiving, easy to turn upon, and requires less skill to negotiate than powder snow. The name comes from the look of the snow after it as groomed, as it looks like corduroy fabric.
Granular snow
Snow with large crystals, i.e., small pellets. Depending on sun and temperature conditions, it may be wet granular snow—meaning that there is a considerable amount of unfrozen water in it, or loose granular snow, which has no unfrozen water. Wet granular snow will form a snowball; loose granular snow will not. Wet granular conditions are often found in the springtime. Loose granular conditions are generally produced when wet granular snow has re-frozen and then been broken up by snowgrooming apparatus.
Corn snow
The result of repeated daily thaws and nightly re-freezing of the surface. Because of the thaw-refreeze cycle, snow crystal shapes change over time, producing crystal shapes somewhat akin to wet granular, but larger. True corn snow is a delight to ski or ride once it softens in the afternoons.
Ice Cookies/Snow Snakes
Similar to corn snow but much larger. Snow has melted, re-frozen, and been "skiied out", creating hard snowballs of ice- sometimes as big as tennis balls. Skiing in these conditions can be tricky and sometimes dangerous.
Slush
When the sun heats the snow and causes it to become very wet and very heavy. Skiing in these conditions can be difficult.
Ice/Hard-Pack
Skiers and snowboarders typically regard any snow condition that is very hard as "ice". In fact, true ice conditions are comparatively rare. Much of what is perceived to be ice is actually a frozen granular condition—wet granular snow that has refrozen to form a very dense surface. Telling the difference is comparatively easy; if one can get a ski pole to stand up in it, the surface is likely to be more of a frozen granular surface than an icy one—and while it is certainly not as enjoyable as many other snow conditions, skilled skiers and snowboarders can successfully negotiate it. In fact, ice is a preferred condition among racers, in that the surface tends to be quite fast and race course conditions tend to remain more consistent during the race, with fewer ruts developing on the course. Another form of icy condition can be found at higher elevation resorts in the Rocky Mountains and in Europe; direct sunlight can melt the top layers of snow crystals and subsequent freezing produces a very shiny, slick surface. Snowmaking machinery used at some ski resorts typically generates hard-pack conditions.
Crust
A crust condition exists when soft snow is covered by a harder upper layer upon the surface. This crust can be created by freezing rain (precipitation formed in warmer upper levels of the atmosphere, falling into a temperature inversion at which surface temperatures are below freezing, and freezing on contact with the ground), by direct sunlight, and by wind loading which packs down the upper layers of the snowpack but leaves lower layers more or less unaffected. Crusts are extremely challenging conditions.
Dust on crust
A trace of new snow on top of crust. Undesirable.
Spring conditions
A catch-all term ski areas use to describe conditions when numerous different surface types can be found on the mountain — usually in the later part of the season, although the term is sometimes used during an extended midwinter thaw. The term also generally reflects the presence of bare spots and/or areas of thin cover. With spring conditions, the snow is usually firm in early morning (even reaching frozen granular status if left ungroomed), breaking a softer corn or wet granular surface mid-day, and is often very soft and mushy in afternoon (many skiers refer to this type of snow condition as "mashed potatoes", due to its heaviness). In some instances when the snow is untracked, sun baked, slightly dirty, with the consistency of a snow cone, it is called "tecate powder". The speed with which conditions change on a given spring day is directly related to the exposure of the slope relative to the sun. In the northern hemisphere, east- and south-facing slopes tend to soften first; west-facing slopes generally soften by mid-day. North-facing slopes may hold on to their overnight snow conditions throughout the day.
Windblown
A type of snow that forms when powder isn't skied on for a long period of time. It is essentially powder past its expiration date. The consistency is that of a thick and "sticky" powder, that provides lots of resistance; it often is covered by a crust of hard packed snow. It is prone to happening in large, open areas where there is little shelter from the wind. Its appearance often fools inexperienced skiers to believe it is fresh powder.
Variable
"Variable" simply means that all types of snow can be on the mountain, ranging from hard pack to crud. It is usually a secondary classification.

Salting[edit]

Chemicals can be applied to the snow surface in order to harden the course. The most common chemicals used are sodium chloride, calcium chloride, urea, ammonium nitrate, and potassium nitrate. This "salting" is done mostly when the snow is wet and slushy. When a race course is salted, the salt crystals break up into ions. These ions lower the freezing point of the snow, which hardens the surface. This provides a dense layer of snow with a consistent surface throughout the course, making the race more fair for athletes skiing later in the race.

Two important factors that determine whether salt will work are crystal structure and moisture. Crystals that are too sharp will prevent the deep penetration of the salt into the snow. Crystals that are too round lack flat surfaces that can bond tightly to adjacent crystals. The snow also needs to have a moisture content of around 60%. Salting a race course works best when the weather is sunny and warm. Salting may also work when it is raining, since the rain adds moisture to the snow. In general, salt will not harden the snow if it is cloudy and just above freezing.

Salting is typically only done in slalom and giant slalom events. It is important to salt the apex of the turn especially well, because that is the part of the turn when the skier exerts the most pressure on the snow. Speed events (downhill and super giant slalom) have a larger surface area, making salting expensive; the high speeds of these events also make salting potentially dangerous.

Safety[edit]

In alpine skiing, for every 1000 people skiing in a day, on average between two and four will require medical attention. Knee injuries account for 33 percent of injuries. Most accidents are the result of user error leading to an isolated fall.[1]

See also[edit]

References[edit]

  1. ^ Langran, Mike. "FAQ". ski-injury.com. Retrieved 27 September 2012. 

External links[edit]