Aroller coaster inversion is aroller coaster element in which the track turns riders upside-down and then returns them to an upright position. Early forms of inversions were circular in nature and date back to 1848 on theCentrifugal railway in Paris. Thesevertical loops produced massiveg-force that was often dangerous to riders. As a result, the element eventually became non-existent with the last rides to feature the looping inversions being dismantled during theGreat Depression. In 1975, designers fromArrow Development created thecorkscrew, reviving interest in the inversion during the modern age of steel roller coasters. Elements have since evolved from simple corkscrews and vertical loops to more complex inversions such asImmelmann loops andcobra rolls.The Smiler atAlton Towers holds the world record for the number of inversions on a roller coaster with 14.[1][2][3]
The first inversion in roller coaster history was part of theCentrifugal Railway ofParis,France, built in 1848.[1] It consisted of a 13-meter (43-foot) sloping track leading into a nearlycircularvertical loop 4 metres (13 ft) in diameter.[4] During the early 1900s, many rides including vertical loops appeared around the world. These early loops had a major design flaw: the circular structure produced intenseg-forces (hereafter "Gs"). TheFlip Flap Railway, designed byLina Beecher and built in 1895 onConey Island ofBrooklyn,United States, had a 7.6-meter (25-foot) circular loop at the end which though initially popular caused some discomfort in passenger's necks, and the ride soon closed.[5][6]Loop the Loop, another looping coaster, was built later in Coney Island as well. This time the loops were slightly oval-shaped rather than circular, though notclothoid in shape like modern loops.[7] Although the ride was safe, it had a low capacity, loading four people every five minutes (48 people per hour, compared to 1800 riders per hour onCorkscrew, an early modern coaster that opened in 1976), and was poorly received after the discomfort of the Flip Flap Railway.[7] As their novelty wore off and their dangerous reputation spread, compounded with the developingGreat Depression, the early looping coasters disappeared.[1]
The concept of inverting riders was not revisited until the 1970s. In 1968, Karl Bacon ofArrow Dynamics created a prototypesteel roller coaster with acorkscrew, the first of its kind. The prototype proved that a tubular steel track, first pioneered by Arrow to createDisneyland'sMatterhorn Bobsleds in 1959, could execute inversions both safely and reliably.[1] The full model of the prototype, aptly namedCorkscrew, was then installed inKnott's Berry Farm inBuena Park,United States, making history as the world's first modern inverting roller coaster (it was relocated toSilverwood Park ofIdaho in 1990).[4] In 1976, the previously disastrous vertical loop was successfully revived whenAnton Schwarzkopf constructed theGreat American Revolution atSix Flags Magic Mountain ofValencia, United States, which became the world's first complete circuit looping roller coaster. Another roller coaster namedCorkscrew, built inCedar Point ofOhio in the same year, became the first with three inversions.[1]
The next few years brought innovations that are still popular in modern coasters. Theshuttle roller coaster (non-complete circuit) was invented by Schwarzkopf in 1977 and realized atKings Island with theScreamin' Demon coaster. These early incarnations used theweight-drop mechanism (as opposed to the laterflywheel methods) to launch the trains.[1] Built in 1978, theLoch Ness Monster inBusch Gardens Williamsburg became the first coaster with interlocking loops.[8]It is still the only coaster with this feature, as the only other coasters containing interlocking loops are now defunct: Lightnin' Loops, built by Arrow inSix Flags Great Adventure, was sold in 1992,[9] andOrient Express ofWorlds of Fun was demolished in 2003.[10] The first Schwarzkopf shuttle loops with a flywheel launch also first appeared in 1978.[1] Arrow's Revolution,Europe's first looping coaster, was built in 1979 atBlackpool Pleasure Beach ofEngland.[1] In 1980,Carolina Cyclone opened atCarowinds as the first roller coaster with four inversions.[4] TheOrient Express opened atWorlds of Fun ofKansas City, United States, in 1980, with the newly inventedbatwing (not to be confused with a boomerang), a single track element with two inversions.[4]
In 1981,Vekoma invented theBoomerang coaster model, which became the most duplicated roller coaster ever. The first Boomerang was built atReino Aventura (nowSix Flags México) ofMexico City,Mexico in 1982.[11] The Boomerang has had over 50 clones built worldwide fromDoha,Qatar, toTashkent,Uzbekistan.[11] 1982 also brought the first five-inversion coaster, Arrow'sViper atDarien Lake in Darien, New York.[12]
The record for number of inversions was broken quickly in the following years. Arrow'sVortex atKings Island, built in 1987, was the first to have six. The next year,Shockwave atSix Flags Great America broke that record with seven inversions. In 1995,Dragon Khan inSpain'sPort Aventura became the first to have eight. In 2002,Colossus atThorpe Park inChertsey,Surrey, England was the first with ten. In 2013,The Smiler atAlton Towers in Staffordshire, England, broke the record again with 14 inversions.
In 2000, Kings Island builtSon of Beast, the world's firstwooden roller coaster with a vertical loop. Until then, all roller coasters with any inversions were steel. After structural problems caused an incident in July 2006 that injured several riders, Son of Beast's loop was removed in December 2006 to make it possible to use lighter trains.
In 2002,X, now X2, designed by Arrow, opened inSix Flags Magic Mountain. It is marketed as the world's firstfourth-dimension roller coaster, capable of rotating riders upside-down independently of any track elements. This adds difficulty in delineating the number of inversions such rides have. As the riders physically rotate360degrees forward and backwards, proponents insist the number of inversions should not include only track elements. According toGuinness World Records, the roller coaster with the most inversions counted this way isEejanaika (Japanese:ええじゃないか, Ain't it great?), another 4th Dimension roller coaster, inFuji-Q Highland ofFujiyoshida,Japan, which rotates riders 14 times. Counting only track elements, however, Alton Tower's The Smiler has the world record for number of inversions, also rotating riders 14 times.[13]
Two or more wooden roller coasters with inversions opened in each of 2013, 2014, and 2017. As opposed to the vertical loop that Son of Beast had,Outlaw Run andHades 360,Mine Blower andGoliath (atSix Flags Great America) have more complex inversions. Outlaw Run atSilver Dollar City has a doublebarrel roll and a 153° over-banked turn, and Hades 360 has a singlecorkscrew. Other elements which partially invert riders, such as theoverbanked turn which occasionally turn riders beyond 90 degrees, are not typically considered inversions.[14]
