Editing Half-pipe (section)

==Overview==
The structure resembles a cross-section of a swimming pool, essentially two concave ramps (or quarter-pipes), topped by copings and decks, facing each other across a flat transition, also known as a ''tranny''.<ref name="google">{{cite book|title=Sports Rules Book-3rd Edition, The|author1=Human Kinetics (Organization)|author2=Hanlon, T.W.|date=2009|publisher=Human Kinetics|isbn=9781450408103|url=https://books.google.com/books?id=HJ0BeoJnbCUC|page=206|access-date=December 22, 2014|url-status=live|archive-url=https://web.archive.org/web/20180106035625/https://books.google.com/books?id=HJ0BeoJnbCUC|archive-date=January 6, 2018}}</ref> Originally half-pipes were half sections of a large diameter pipe. Since the 1980s, half-pipes contain an extended ''flat bottom'' between the quarter-pipes. The original style half-pipes are no longer built. Flat ground provides time to regain balance after landing and more time to prepare for the next trick.
[[Image:Half-Pipe Vert Ramp.svg|360px|thumbnail|right|Half-pipe diagram]]
Half-pipe applications include leisure recreation, skills development, competitive training, amateur and professional competition, demonstrations, and 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 [[pump (skateboarding)|pumping]] to attain extreme speeds with relatively little effort. Large (high [[amplitude]]) half-pipes make possible many of the aerial tricks in BMX, [[Inline skating|skating]] and [[skateboarding trick#Aerial|skateboarding]].

For winter sports such as [[freestyle skiing]] and [[snowboarding]], a half-pipe can be dug out of the ground or snow perhaps 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 dirt-boarders, motorcyclists, and [[mountain biking|mountain bikers]].

Performance in a half-pipe has been rapidly increasing over recent years. The current limit performed by a top-level athlete for a rotational trick in a half-pipe is 1440 degrees (four full 360 degree rotations). In top level competitions, rotation is generally limited to emphasize style and flow.