View source for Vertical loop

{{Short description|Roller coaster inversion}}
{{Redirect|Loop-the-Loop}}

[[File:Shockwave coaster sfot.jpg|thumb|right|Vertical loop on the [[Shockwave (Six Flags Over Texas)|Shockwave]] coaster at [[Six Flags Over Texas]]]]
[[File:Flipflaprailway.jpg|thumb|right|An early looping roller coaster, the [[Flip Flap Railway]] at [[Coney Island]]]]
[[File:Ci loop.jpg|thumb|right|Edwin Prescott's Loop-the-Loop]]
[[File:Mickey Mouse Silhouette On California Screamin'.jpg|thumb|right|Loop in Disney California Adventure's [[Incredicoaster]] (formerly California Screamin')]]

The generic [[roller coaster]] '''vertical loop,''' also known as a loop-the-loop or a loop-de-loop, where a section of track causes the riders to complete a 360 degree turn, is the most basic of [[roller coaster inversion]]s. At the top of the loop, riders are completely inverted.

== History ==
The vertical loop is not a recent roller coaster innovation. Its origins can be traced back to the 1850s when ''[[centrifugal railway]]s'' were built in [[France]] and [[Great Britain]].<ref name="scream machine">{{Cite book | last = Cartmell | first = Robert | title = The Incredible Scream Machine: A History of the Roller Coaster | publisher = Popular Press | year = 1987 | pages = 156 | url = https://books.google.com/books?id=Qtyoe7tlkVcC&pg=PP1 | isbn = 0-87972-342-4}}</ref><ref name="Timbs">{{Cite book | last = Timbs | first = John | title = The Year-book of facts in science and art | publisher = Simpkin, Marshall, and Co. | year = 1843 | location = London | url = https://archive.org/details/yearbookfactsin24timbgoog | page = [https://archive.org/details/yearbookfactsin24timbgoog/page/n23 15] | quote = centrifugal railway. }}</ref> The rides relied on [[centripetal force]]s to hold the car in the loop. One early looping coaster was shut down after an accident.<ref>[https://web.archive.org/web/20080822061644/http://www.ultimaterollercoaster.com/coasters/history/start/history_early.shtml Roller Coaster History - Early History]</ref>
Later attempts to build a looping roller coaster were carried out during the late 19th century with the ''[[Flip Flap Railway]]'' at [[Sea Lion Park]], designed by Roller coaster engineer Lina Beecher.<ref>"American Pioneers of Amusement, Part 2." ''Off the Leash.'' Published 10 July 2016. Accessed 5 May 2024. https://offtheleash.net/2016/07/10/american-pioneers-of-amusement-part-2/.</ref> The ride was designed with a completely circular loop (rather than the teardrop shape used by many modern looping roller coasters), and caused neck injuries due to the intense G-forces pulled with the tight radius of the loop.<ref name="Physics for Scientists and Engineers">{{cite book |last1=Tipler |first1=Paul A. |last2=Mosca |first2=Gene |title=Physics for Scientists and Engineers |url= https://books.google.com/books?id=AttDBYgLeZkC |access-date=August 9, 2013 |edition=6th |volume=Standard |year=2008 |publisher=W. H. Freeman and Company |location=New York |isbn= 978-1429201247 }}</ref><ref name="Mental_Floss">{{cite book |last1=Pearson |first1=Will |last2=Hattikudur |first2=Mangesh |last3=Koerth-Baker |first3=Maggie |title=Mental_Floss Presents Instant Knowledge |url= https://books.google.com/books?id=qJ2ENnuK5ZEC |access-date=August 9, 2013  |year=2005 |publisher=HarperCollins |location=New York |isbn= 0061747661 }}</ref>

The next attempt at building a looping roller coaster was in 1901 when Edwin Prescott built the ''[[Loop the Loop (Coney Island)|Loop the Loop]]'' at [[Coney Island]]. This ride used the modern teardrop-shaped loop and a steel structure, however more people wanted to watch the attraction, rather than ride. In 1904, Beecher further redesigned the vertical loop to have an even more elliptical design with [[Olentangy Park]]'s [http://olentangypark.com/wiki/index.php/Loop-the-Loop Loop-the-Loop]. Vertical loops weren't attempted again until the design of [[The New Revolution (roller coaster)|Great American Revolution]] at [[Six Flags Magic Mountain]], which opened in 1976. Its success depended largely on its [[Euler spiral|clothoid]]-based (rather than circular) loop. The loop became a phenomenon, and many parks hastened to build roller coasters featuring them.{{Citation needed|date=August 2013}}

In 2000, a modern looping [[wooden roller coaster]] was built, the [[Son of Beast]] at [[Kings Island]]. Although the ride itself was made of wood, the loop was supported with steel structure. Due to maintenance issues however, the loop was removed at the end of the 2006 season. The loop was not the cause of the ride's issues, but was removed as a precautionary measure. Due to an unrelated issue in 2009, Son of Beast was closed until 2012, when Kings Island announced that it would be removed.<ref name="DDN tear down">{{cite news|last=McClelland|first=Justin|title=Kings Island to tear down Son of Beast|url=http://www.daytondailynews.com/news/news/kings-island-removing-roller-coaster/nP5bH/|access-date=July 27, 2012|newspaper=[[Dayton Daily News]]|date=July 27, 2012}}</ref><ref name="Demolition">{{cite web |url=http://www.visitkingsisland.com/article/media-center/Son-of-Beast-roller-coaster-to-be-removed-to-make-room-for-future-park-expansion |title=Son of Beast roller coaster to be removed to make room for future park expansion |publisher=Kings Island |date=July 27, 2012 |access-date=July 27, 2012 |archive-url=https://web.archive.org/web/20120729224326/http://www.visitkingsisland.com/article/media-center/Son-of-Beast-roller-coaster-to-be-removed-to-make-room-for-future-park-expansion |archive-date=July 29, 2012 |url-status=dead |df=mdy-all }}</ref>

On June 22, 2013, [[Six Flags Magic Mountain]] introduced [[Full Throttle (roller coaster)|Full Throttle]], a steel launch coaster with a {{convert|160|ft|m|adj=on}} loop, the tallest in the world at the time of its opening.<ref>{{cite news|last=MacDonald|first=Brady|title=Six Flags Magic Mountain spills plans for record-setting coaster|url=https://www.latimes.com/travel/la-xpm-2012-mar-07-la-trb-six-flags-magic-mountain-full-throttle-03201207-story.html|access-date=18 April 2018|newspaper=[[Los Angeles Times]]|date=7 March 2012}}</ref> {{As of|2016|}}, the largest vertical loop is located on Flash, a roller coaster produced by [[Mack Rides]] at Lewa Adventure in Shaanxi, China<!-- 42.52 m (139 ft 6 in) -->.<ref>{{Cite web|url=https://www.guinnessworldrecords.com/world-records/111031-largest-roller-coaster-loop/|title=Largest rollercoaster loop|website=Guinness World Records|language=en-GB|access-date=2020-04-24}}</ref><ref name=":0">{{Cite RCDB|coaster_name=Flash|location=Lewa Adventure|access-date=2020-04-22|num=6764}}</ref> The record is shared by a [[hypercoaster]] in Turkey's Land of Legends theme park (named 'Hyper Coaster'), built in 2018, which is identical to Flash at Lewa Adventure.<ref name=":0" /><ref>{{Cite RCDB|coaster_name=Hyper Coaster|location=Land of Legends Theme Park|access-date=2020-04-22|num=14440}}</ref>

=== Loops on non-roller coasters ===
In 2002, the Swiss company Klarer Freizeitanlagen AG began working on a safe design for a looping water slide.<ref>{{Cite web|url=http://www.eap-magazin.de/index.php?id=127&L=1|archiveurl=https://web.archive.org/web/20070928033013/http://www.eap-magazin.de/index.php?id=127&L=1|url-status=dead|title=EAP-Magazin.de: Special Feature2|archivedate=September 28, 2007}}</ref> Since then, multiple installations of the slide, named the [[AquaLoop]] and constructed by companies including Polin, Klarer, Aquarena and [[WhiteWater West]], have appeared in many parks. This ride does not feature a vertical loop, instead using an [[Roller coaster elements#Inclined loop|inclined loop]] (a vertical loop tilted at an angle), which puts less force on the rider. AquaLoop slides feature a safety hatch, which can be opened by a rider in case they do not reach the highest point of the loop.

== Physics/mechanics ==
[[File:Walygator Comet looping.jpg|thumb|Most vertical loops are not circular.]]

Most roller coaster loops are not circular in shape. A commonly used shape is the [[clothoid]] loop, which resembles an inverted tear drop and allows for less intense G-forces throughout the element for the rider.<ref>{{cite web|url=http://fy.chalmers.se/LISEBERG/eng/loop_pe.html|archive-url=https://web.archive.org/web/20070827183113/http://fy.chalmers.se/LISEBERG/eng/loop_pe.html|archive-date=2007-08-27|title=Roller Coaster Loop Shapes|access-date=2008-08-13}}</ref> The use of this shape was pioneered in 1976 on [[The New Revolution (roller coaster)|The New Revolution]] at [[Six Flags Magic Mountain]], by [[Werner Stengel]] of leading coaster engineering firm Ing.-Büro Stengel GmbH.

On the way up, from the bottom to the top of the loop, gravity is in opposition to the direction of the cars and will slow the train. The train is slowest at the top of the loop. Once beyond the top, gravity helps to pull the cars down around the bend. If the loop's curvature is constant, the rider is subjected to the greatest force at the bottom. If the curvature of the track changes suddenly, as from level to a circular loop, the greatest force is imposed almost instantly {{xref|(see: [[Jerk (physics)|Jerk]])}}. Gradual changes in curvature, as in the clothoid, reduce the force maximum (permitting more speed) and allow the rider time to cope safely with the changing force.<ref name="Physics for Scientists and Engineers"/>

This "gentling" runs somewhat contrary to the coaster's ''raison d'être''. [[Anton Schwarzkopf|Schwarzkopf]]-designed roller coasters often feature near-circular loops (in case of [[Zonga|Thriller]] even without any reduction of curvature between two almost perfectly circular loops) resulting in intense rides—a trademark for the designer.{{Citation needed|date=August 2013}}

It is rare for a roller coaster to stall in a vertical loop, although this has happened before. The Psyké Underground coaster (then known as Sirocco) at [[Walibi Belgium]] once stranded riders upside-down for several hours. The design of the trains and the rider restraint system (in this case, a simple lap bar) prevented any injuries from occurring, and the riders were removed with the use of a [[cherry picker]].{{Citation needed|date=August 2013}} A similar incident occurred on [[Demon (roller coaster)|Demon]] at [[Six Flags Great America]].<ref name=DemonIncident>{{cite news|title=Roller coaster stuck in loop at Six Flags|url=https://news.google.com/newspapers?id=JDpFAAAAIBAJ&dq=demon%20great-america&pg=6613%2C4120790|access-date=27 August 2017|newspaper=The Telegraph Herald|date=19 April 1998|agency=Associated Press}}</ref>

== References ==
{{Reflist}}

== External links ==
* [http://iwant2study.org/ospsg/index.php/interactive-resources/physics/02-newtonian-mechanics/05-circle/282-coaster96wee vertical loop simulator]
* [http://www.rcstengel.com/ Ing.-Buero Stengel GmbH]
* [http://physics.gu.se/LISEBERG/eng/loop_pe.html Loop Shapes in Roller Coasters] {{Webarchive|url=https://web.archive.org/web/20100418065633/http://physics.gu.se/LISEBERG/eng/loop_pe.html |date=2010-04-18 }}

{{Roller coaster}}

{{DEFAULTSORT:Vertical Loop}}
[[Category:Roller coaster elements]]