A pipeline roller coaster is a type of roller coaster where the trains ride between the tracks as opposed to a traditional roller coaster where they ride above them. The concept was first developed by Japanese ride company TOGO as the Ultratwister model. They built six installations of the design, four of which are still in existence. Arrow Dynamics created an alternate version of the concept, but it never made it past the prototype stage in development. Intamin developed a version known as the Spiral Coaster model, building only one installation, which is no longer in operation.
TOGO's Ultratwister model features an 85-degree lift hill followed by three heartline roll inversions. Between the second and third rolls is a switch track that tilts trains to an approximately 45 degree angle, sending them through the remainder of the course backwards. The Ultratwister at Rusutsu Resort is the only S-II model built by TOGO, featuring a dive loop instead of a switch track.[3]
Arrow Dynamics attempted to develop a pipeline roller coaster, building a prototype at Arrow's facility in Utah. In 1990, John Wardley worked with Alton Towers to attempt to build one at the park. This was later scrapped in favor of Nemesis after Wardley rode the prototype and disliked the experience it offered.[4][5]
In the 1996, Intamin built Sky Plaza Comet, a Spiral Coaster at Sky Plaza in South Korea.[6] In 2000, the coaster was relocated to Al-Sha'ab Leisure Park in Kuwait (now known as Winter Wonderland Kuwait), before permanently closing in 2005. The ride remained standing but not operating until its removal in 2017.[7]
