A superpipe is a large halfpipe structure used in extreme sports such as snowboarding, freestyle skiing, scooters, freestyle BMX and vert skating. For winter sports, the term superpipe is used to describe a halfpipe built of snow which has walls 22 ft high from the flat bottom on both sides. Other features of a superpipe are that the width of the pipe is greater than the height of the walls, the walls extend to near vertical. In the FIS snowboard world cup rules, the recommended width for 64 ft walls is 22 ft; the term superpipe has evolved over the years as the size of halfpipes has grown. 18 ft halfpipes were known as superpipes, but during the early 2000s, major competition organizers listened to rider feedback and began constructing 22' halfpipes for competitions. These became known as superpipes, the 18' halfpipes they replaced are now known as standard halfpipes; the 22' wall size has proved popular with athletes. The length of a superpipe ranges from 400 ft to 600 ft, depending on available terrain and construction funding.
All halfpipes require extensive grooming by specialized equipment. In contrast, a natural snow halfpipe can be cleaned by a normal snow groomer; because of the high expense of constructing and maintaining them, there are not that many halfpipes in the world, few true superpipes. During the 2013–2014 northern-hemisphere winter, only fourteen 22' superpipes existed globally. While 22' superpipes are standard for all major competitions, many ski resorts have halfpipes ranging in size from 12 ft to 18 ft. 18' is the most popular size globally for halfpipes
A skatepark, or skate park, is a purpose-built recreational environment made for skateboarding, BMX, scooter and aggressive inline skating. A skatepark may contain half-pipes, quarter pipes, spine transfers, funboxes, vert ramps, banked ramps, full pipes, bowls, snake runs and any number of other objects; the first skatepark in the world, Surf City, opened for business at 2169 E. Speedway in Tucson, Arizona on September 3, 1965. Patti McGee, Women’s National Champion, attended the grand opening; the park was operated by Arizona Surf City Enterprises, Inc.. A skatepark for skateboarders and skaters made of plywood ramps on a half-acre lot in Kelso, Washington, USA opened in April 1966, it was lighted for night use. California's first skatepark, the Carlsbad Skatepark opened on March 3, 1976; the World Skateboard Championships were held here on April 10, 1977. It operated until 1979, when it was buried intact beneath a layer of dirt for more than two decades, before being destroyed in 2005; the current Carlsbad Skatepark is in a different location.
The East Coast's first skatepark, Ocean Bowl Skate Park, in Ocean City, Maryland, USA, opened the first week of June, 1976. It is the oldest operating municipal skate park in the United States. Due to time and the current needs of skaters, the old bowl and ramp were torn down in the Fall of 1997 and the new park opened in July 1998. In 1999 the City of Hermosa Beach, California opened a small skatepark at the site of the first skateboard competition; the competition held at the Pier Avenue Junior Hugh School was organized by Dewey Weber across the street from his surf and skateboard shop. Makaha Skateboards was a sponsor of the competition. In 1987 an all wooden indoor skate park opened in Bristol, CT called CT Bike, still in business today over 20 years later. CT Bike is; the indoor skate park today is still operated by the same family who built the park despite a fire that threatened the park in 1988. In more extreme climates, parks were built indoors of wood or metal. By the end of the 1970s, the skateboarding fad had waned, the original parks of the era began to close.
A downturn in the general skateboard market in the 1980s and high liability insurance premiums contributed to the demise of the original skateparks. Some second-generation parks such as Upland, California's Pipeline survived into the 1980s. However, few of the private parks of the 1970s remain, with the notable exception of Kona Skatepark in Jacksonville, United States. However, many public parks of that era can still be found throughout Western Europe and New Zealand; the modern skatepark designs of the Pacific Northwest can be traced back to Burnside Skatepark, a DIY "barge build" beneath the Burnside Bridge in Portland, Oregon. Skateboarders used an area populated by the city's "undesirable elements" to create a skatepark, building one section at a time; the process is called "design/build", is a characteristic of many skateparks today. The design/build process ensures that adjacent skatepark features are harmonious and rideable, allowing skateboarders to create endless "lines" to ride among the many features.
Skate parks, related obstacles/ramps and locations designed for extreme sport utilization have made their way into the media over time, such as with the aforementioned Burnside Skatepark being included in the movie Free Willy. Public skateparks have had a resurgence in the US, made possible by legislation such as California's 1998 law stating that skateboarding is an inherently "Hazardous Recreational Activity", therefore municipalities and their employees may not be held liable for claims of negligence resulting in skateboarders' injuries. Street skating has blurred the line between skateparks and street spots; some cities are starting to put in skate spots/plazas with features that would not have been classically designed for skateboarding, but can be skated by street skaters legally. In some instances spots that were not designed for skateboarding have been made legal so that cities did not need to build a new park for skaters; the Skate Plazas allow for legal street skateboarding. There is a movement of making art and sculpture skate-able.
This provides for more legal skate spots that are blended in with landscape. They can even be picturesque destinations for both skaters and non-skaters; the world's largest skatepark is located in Shanghai. Unlike organized sports, like basketball or football, skateboarding has no set arena or rules and skateparks have no standard design template; each skatepark is designed to provide unique challenges to its users. There are, three main categories of skatepark design: bowl, street plaza and flow parks. Bowl parks are designed to improve upon the pool skating experience. Skaters in bowl parks can move around the park without taking their feet off the board to push; the curved walls of bowls allow skaters to ride around and across the bowl in addition to the back and forth skating you might see on a traditional half pipe. Bowls and bowl parks come in an endless variety of shapes and sizes but most bowls are between 3' and 12’ deep. Street plaza parks are the favorite of the vast majority of skaters and they are designed to emulate and improve upon the street skating experience.
Obstacles in a street plaza are styled to look like natural street terrain such as stairs, railings and benches. Skaters will push off with their feet to gain momentum in a street plaza; the first public outdoor skate plaza is the Vancouver Skate Plaza, built in 2004 by New Line Skateparks. Flow parks (or Park style
A half-pipe is a structure used in gravity extreme sports such as snowboarding, skiing, freestyle BMX, skating and scooter riding. The structure resembles a cross-section of a swimming pool two concave ramps, topped by copings and decks, facing each other across a flat transition known as a tranny. Half-pipes were half sections of a large diameter pipe. Since the 1980s, half-pipes contain an extended flat bottom between the quarter-pipes. Flat ground provides time to regain balance after landing and more time to prepare for the next trick. Half-pipe applications include leisure recreation, skills development, competitive training and professional competition, as an adjunct to other types of skills training. A skilled athlete can perform in a half-pipe for an extended period of time by pumping to attain extreme speeds with little effort. Large half-pipes make possible many of the aerial tricks in skating and skateboarding. For winter sports such as freestyle skiing and snowboarding, a half-pipe can be dug out of the ground or snow combined with snow buildup.
The plane of the transition is oriented downhill at a slight grade to allow riders to use gravity to develop speed and facilitate drainage of melt. In the absence of snow, dug out half-pipes can be used by dirtboarders and mountain bikers. Performance in a half-pipe has been increasing over recent years; the current limit performed by a top-level athlete for a rotational trick in a half-pipe is 1440 degrees. In top level competitions, rotation is limited to emphasize style and flow. In the early 1970s, swimming pools were used by skateboarders in a manner similar to surfing ocean waves. In 1975, some teenagers from Encinitas and other northern San Diego County communities began using 7.3-metre-diameter water pipes in the central Arizona desert associated with the Central Arizona Project, a federal public works project to divert water from the Colorado River to the city of Phoenix. Tom Stewart, one of these young California skateboarders, looked for a more convenient location to have a similar skateboarding experience.
Stewart consulted with his brother Mike, an architect, on how to build a ramp that resembled the Arizona pipes. With his brother's plans in hand, Tom built a wood frame half-pipe in the front yard of his house in Encinitas. In a few days, the press had contacted him directly. Tom went on to create Rampage, Inc. and began selling blueprints for his half-pipe design. About five months Skateboarder magazine featured both Tom Stewart and Rampage. Little did Tom know that his design would go on to inspire countless others to follow in his foot steps; the character of a half-pipe depends on the relationship between four attributes: most the transition radius and the height, less so, the degree of flat bottom and width. Extra width grinds; the flat bottom, while valued for recovery time, serves no purpose if it is longer than it needs to be. Thus, it is the ratio between height and transition radius that determines the personality of a given ramp, because the ratio determines the angle of the lip. On half-pipes which are less than vertical, the height between 50% and 75% of the radius, profoundly affects the ride up to and from the lip, the speed at which tricks must be executed.
Ramps near or below 0.91 m of height sometimes fall below 50% of the height of their radius. Technical skaters spin maneuvers. Smaller transitions that maintain the steepness of their larger counterparts are found in pools made for skating and in custom mini ramps; the difficulty of technical tricks is increased with the steepness, but the feeling of dropping in from the coping is preserved. Common mistake in the construction of ramps is constant radius in transitions: Most of the ramps are built with a quarter circle of constant radius for easy construction, but the best ramps are not constant radius but a parabola with little final vert; the parabola allows for easy big air with return still on the curve and not on the flat. A cycloid profile will theoretically give the fastest half-pipe, it is called a brachistochrone curve. Such a curve in its pure form is π times as wide as it is high. Frame and support for skateboard, BMX, inline skating half-pipes consist of a 2x6x8 lumber framework sheathed in plywood finished with sheets of masonite or Skatelite.
A metal frame finished in wood or metal is sometimes used. Most commercial and contest ramps are surfaced by attaching sheets of some form of masonite to a frame. Many private ramps are surfaced in the same manner but may use plywood instead of masonite as surface material; some ramps are constructed by spot-welding sheet metal to the frame, resulting in a fastener-free surface. Recent developments in technology have produced various versions of improved masonite substances such as Skatelite, RampArmor, HARD-Nox; these ramp surfaces are far more expensive than traditional materials. Channels and roll-ins are the basic ways to customize a ramp. Sometimes a section of the platform is cut away to form a roll-in and a channel to allow skaters to commence a ride without dropping in and perform tricks over the gap. Extensions are permanent or temporary additions to the height of one section of the ramp that can make riding more challenging. Creating a spine ramp is another variation of the half-pipe.
A spine ramp is two quarter pipes adjoined at the vertical ed
A funbox is a standard element of a skatepark. It consists of a box shape with a flat top and a ramp on two or more sides. A funbox may include other elements that allow for more complicated skateboarding tricks. Like other skatepark features, funboxes are used by inline-skaters and BMX-riders. Table-top - The main characteristic of a funbox is the standard table-top; the table-top can vary in surface area. Ramps - To allow access to the table-top, a funbox will be surrounded by ramps or stairs to allow tricks or transitions on, off or over the table-top. Other elements - A funbox may include a number of other elements including ledges, spines, angled ramps, wall sections to allow "wallrides" and improvised street furniture pieces. A funbox with ramps on opposite sides may allow for the conduct of aerial tricks; as such, funboxes are placed in line with the "outlet" of a larger ramp to allow for a build-up of speed. A funbox with ramps or transitions on all sides of the table will be placed in the middle of a park.
Funboxes are constructed of concrete or wood. Some variations include steel frames and both concrete and wood constructions will include steel copings or rails; some funboxes will be constructed in sections to allow for further customization. The construction must resist dynamic structural load resulting from aerial tricks or jumps onto the funbox
Levi is a fell located in Finnish Lapland, the largest ski resort in Finland. The resort is located in Kittilä municipality and is served by Kittilä Airport and Kolari railway station. At a latitude of 67.8° north, it is located 170 km north of the Arctic Circle. The peak of the Levi fell. There are 27 ski lifts in Levi. Ascending the fell are 2 gondolas, 1 chairlift, 14 T-bar lifts, 5 stick lifts, 4 rope tows, 1 magic carpet for children. Levi is one of two locations of gondola lifts in Finland, has been chosen the best domestic skiing resort in Finland four times. Levi is an early stop on the FIS Alpine Ski World Cup circuit; the climate is somewhat too cold to host them in January–February. The slopes in Levi are suitable for beginners or intermediates, but there are three black slopes for experts; the highest vertical drop is 325 m and the longest slope is 2.1 km in length. The longest ski lift is about 1,636 metres long. Levi has one superpipe, one halfpipe, two streets, two snow parks, 10 free children's slopes and seven slope restaurants.
The skiing and snowboarding season in Levi is long lasting from October to mid-May. The ski school provides instruction in downhill skiing, telemark skiing and cross-country skiing. Cross-country skiers have illuminated ski tracks and snow. There are 886 km of snowmobiling tracks in Levi; the resort's location, north of the Arctic Circle guarantees generous snow cover and sub-zero temperatures throughout winter. It allows for excellent chances of seeing the Northern Lights. Although popular in winter, Levi is quiet in the summertime yet still a good base location for exploring the surrounding areas. At 8 km from the centre of Levi is Luvattumaa, Levi Ice Hotel & Ice Gallery and at 45 km from Levi is the Snow Village Lainio. Official website Levi Finland - Information on the area and resort Snow Village.fi - Lainio Snow Village Levi Finland - Airlines and Destinations visits Levi Finland
Ultra-high-molecular-weight polyethylene is a subset of the thermoplastic polyethylene. Known as high-modulus polyethylene, it has long chains, with a molecular mass between 3.5 and 7.5 million amu. The longer chain serves to transfer load more to the polymer backbone by strengthening intermolecular interactions; this results in a tough material, with the highest impact strength of any thermoplastic presently made. UHMWPE is odorless and nontoxic, it embodies all the characteristics of high-density polyethylene with the added traits of being resistant to concentrated acids and alkalis, as well as numerous organic solvents. It is resistant to corrosive chemicals except oxidizing acids, its coefficient of friction is lower than that of nylon and acetal and is comparable to that of polytetrafluoroethylene, but UHMWPE has better abrasion resistance than PTFE. Polymerization of UHMWPE was commercialized in the 1950s by Ruhrchemie AG, which has changed names over the years. Today UHMWPE powder materials, which may be directly molded into a product's final shape, are produced by Ticona, Braskem, DSM, Teijin and Mitsui.
Processed UHMWPE is available commercially either as fibers or in consolidated form, such as sheets or rods. Because of its resistance to wear and impact, UHMWPE continues to find increasing industrial applications, including the automotive and bottling sectors. Since the 1960s, UHMWPE has been the material of choice for total joint arthroplasty in orthopedic and spine implants. UHMWPE fibers, commercialized in the late 1970s by the Dutch chemical company DSM, are used in ballistic protection, defense applications, in medical devices. UHMWPE is a type of polyolefin, it is made up of long chains of polyethylene, which all align in the same direction. It derives its strength from the length of each individual molecule. Van der Waals bonds between the molecules are weak for each atom of overlap between the molecules, but because the molecules are long, large overlaps can exist, adding up to the ability to carry larger shear forces from molecule to molecule; each chain is bonded to the others with so many van der Waals bonds that the whole of the inter-molecular strength is high.
In this way, large tensile loads are not limited as much by the comparative weakness of each van der Waals bond. When formed into fibers, the polymer chains can attain a parallel orientation greater than 95% and a level of crystallinity from 39% to 75%. In contrast, Kevlar derives its strength from strong bonding between short molecules; the weak bonding between olefin molecules allows local thermal excitations to disrupt the crystalline order of a given chain piece-by-piece, giving it much poorer heat resistance than other high-strength fibers. Its melting point is around 130 to 136 °C, according to DSM, it is not advisable to use UHMWPE fibres at temperatures exceeding 80 to 100 °C for long periods of time, it becomes brittle at temperatures below −150 °C. The simple structure of the molecule gives rise to surface and chemical properties that are rare in high-performance polymers. For example, the polar groups in most polymers bond to water; because olefins have no such groups, UHMWPE does not absorb water nor wet which makes bonding it to other polymers difficult.
For the same reasons, skin does not interact with it making the UHMWPE fiber surface feel slippery. In a similar manner, aromatic polymers are susceptible to aromatic solvents due to aromatic stacking interactions, an effect aliphatic polymers like UHMWPE are immune to. Since UHMWPE does not contain chemical groups that are susceptible to attack from aggressive agents, it is resistant to water, most chemicals, UV radiation, micro-organisms. Under tensile load, UHMWPE will deform continually as long as the stress is present—an effect called creep; when UHMWPE is annealed, the material is heated to 135 °C to 138 °C in an oven or a liquid bath of silicone oil or glycerine. The material is cooled down at a rate of 5 °C/h to 65 °C or less; the material is wrapped in an insulating blanket for 24 hours to bring to room temperature. Ultra-high-molecular-weight polyethylene is synthesized from its monomer ethylene, bonded together to form the base polyethylene product; these molecules are several orders of magnitude longer than those of familiar high-density polyethylene due to a synthesis process based on metallocene catalysts, resulting in UHMWPE molecules having 100,000 to 250,000 monomer units per molecule each compared to HDPE's 700 to 1,800 monomers.
UHMWPE is processed variously by compression moulding, ram extrusion, gel spinning, sintering. Several European companies began compression molding UHMW in the early 1960s. Gel-spinning arrived much and was intended for different applications. In gel spinning a heated gel of UHMWPE is extruded through a spinneret; the extrudate is drawn through the air and cooled in a water bath. The end-result is a fiber with a high degree of molecular orientation, therefore exceptional tensile strength. Gel spinning depends on isolating individual chain molecules in the solvent so that intermolecular entanglements are minimal. Entanglements make chain orientation more difficult, lower the strength of the final product. Dy
Snowboarding is a recreational activity and Winter Olympic and Paralympic sport that involves descending a snow-covered slope while standing on a snowboard attached to a rider's feet. The development of snowboarding was inspired by skateboarding, sledding and skiing, it was developed in the United States in the 1960s, became a Winter Olympic Sport at Nagano in 1998 and first featured in the Winter Paralympics at Sochi in 2014. Its popularity in the United States has been in a decline since. Modern snowboarding began in 1965 when Sherman Poppen, an engineer in Muskegon, invented a toy for his daughters by fastening two skis together and attaching a rope to one end so he would have some control as they stood on the board and glided downhill. Dubbed the "snurfer" by his wife Nancy, the toy proved so popular among his daughters' friends that Poppen licensed the idea to a manufacturer, Brunswick Corporation, that sold about a million snurfers over the next decade. And, in 1966 alone over half a million snurfers were sold.
In February 1968, Poppen organized the first snurfing competition at a Michigan ski resort that attracted enthusiasts from all over the country. One of those early pioneers was a devotee of skateboarding; as an eighth grader in Haddonfield, New Jersey, in the 1960s, Sims crafted a snowboard in his school shop class by gluing carpet to the top of a piece of wood and attaching aluminum sheeting to the bottom. He produced commercial snowboards in the mid-70s. Articles about his invention in such mainstream magazines as Newsweek helped publicize the young sport; the pioneers were not all from the United States. During this same period, in 1977, Jake Burton Carpenter, a Vermont native who had enjoyed snurfing since the age of 14, impressed the crowd at a Michigan snurfing competition with bindings he had designed to secure his feet to the board; that same year, he founded Burton Snowboards in Vermont. The "snowboards" were made of wooden planks that had water ski foot traps. Few people picked up snowboarding because the price of the board was considered too high at $38, but Burton would become the biggest snowboarding company in the business.
In the early 1980s, Aleksey Ostatnigrosh and Alexei Melnikov, two Snurfers from the Soviet Union, patented design changes to the Snurfer to allow jumping by attaching a bungee cord, a single footed binding to the Snurfer tail, a two-foot binding design for improved control. The first competitions to offer prize money were the National Snurfing Championship, held at Muskegon State Park in Muskegon Michigan. In 1979, Jake Burton Carpenter, came from Vermont to compete with a snowboard of his own design. There were protests about Jake entering with a non-snurfer board. Paul Graves, others, advocated that Jake be allowed to race. A "modified" "Open" division was won by Jake as the sole entrant; that race was considered the first competition for snowboards and is the start of what has now become competitive snowboarding. Ken Kampenga, John Asmussen and Jim Trim placed 1st, 2nd and 3rd in the Standard competition with best 2 combined times of 24.71, 25.02 and 25.41 and Jake Carpenter won prize money as the sole entrant in the "open" division with a time of 26.35.
In 1980 the event moved to Pando Winter Sports Park near Grand Rapids, Michigan because of a lack of snow that year at the original venue. As snowboarding became more popular in the 1970s and 1980s, pioneers such as Dimitrije Milovich, Jake Burton Carpenter, Tom Sims, Mike Olson came up with new designs for boards and mechanisms that developed into the snowboards and other related equipment that we know today. In April 1981 the "King of the Mountain" Snowboard competition was held at Ski Cooper ski area in Colorado. Tom Sims along with an assortment of other snowboarders of the time were present. One entrant showed up on a homemade snowboard with a formica bottom that turned out to not slide so well on the snow. In 1982, the first USA National Snowboard race was held near Vermont, at Suicide Six; the race, organized by Graves, was won by Burton's first team rider Doug Bouton. In 1983, the first World Championship halfpipe competition was held at California. Tom Sims, founder of Sims Snowboards, organized the event with the help of Mike Chantry, a snowboard instructor at Soda Springs.
In 1985, the first World Cup was held in Zürs, further cementing snowboarding's recognition as an official international competitive sport. In 1990, the International Snowboard Federation was founded to provide universal contest regulations. In addition, the United States of America Snowboard Association provides instructing guidelines and runs snowboard competitions in the U. S. today, high-profile snowboarding events like the Winter X Games, Air & Style, US Open, Olympic Games and other events are broadcast worldwide. Many alpine resorts have terrain parks. At the 1998 Winter Olympic Games in Nagano, Snowboarding became an official Olympic event. France's Karine Ruby was the first to win an Olympic gold medal for Woman's Snowboarding at the 1998 Olympics, while Canadian Ross Rebagliati was the first to win an Olympic gold medal for Men's Snowboarding. Ski areas adopted the sport at a much slower pace than the winter s