A side-friction roller coaster is an early wooden roller coaster design invented by Edward Joy Morris. The design introduced side-friction wheels to help prevent trains from derailing on turns. In addition to weight-bearing road wheels, which were traditionally located on the direct underside of each train, side-friction wheels were added to the sides, and rolled perpendicular along the inner edge of the track.
The first side-friction roller coasters appeared in the late 1800s and were mild in comparison to modern roller coasters. They declined in popularity into the 1920s and 1930s as newer roller coasters began incorporating a third set of wheels, upstop wheels, which further improved safety and allowed for more thrilling track layouts than what roller coasters with only road and side-friction wheels could offer.
History

Inspired by the Mauch Chunk Switchback Railway, inventor and businessman LaMarcus Adna Thompson12 developed his own patent for a ride called Switchback Railway.3 The first such installation opened as the Gravity Pleasure Switchback Railway at Coney Island in 1884 as the first roller coaster in the United States. Scenic railway roller coasters inspired by this one became popular across the country in the years that followed.
In 1894, Edward Joy Morris took the concept one step further with the invention of side-friction wheels that were installed vertically on the sides of each rider car. Patented as Figure Eight Toboggan Slide, the side-friction wheels made contact with the side rails, making derailment less likely and allowing for sharper turns.4
Side-friction roller coasters could achieve greater speeds than scenic railways, especially around curves, which led to thrill-inducing lateral g-forces. The security of the updated design enabled roller coasters to operate without a brakeman, which were previously required to ride along and slow the train at various points along the track layout. Instead, ride operators working in the loading station only needed to rely on a hand-operated friction brake to stop the train when it returned.
Morris formed the Morris Chute Company, which manufactured carousels and roller coasters. More than 250 side-friction roller coasters (also known as figure eight roller coasters and toboggans) were installed across the United States, but only one is left standing today. Leap-The-Dips opened in 1902 at Lakemont Park in Altoona, Pennsylvania,56 and is the last remaining side-friction roller coaster in the world, though it has not operated since 2023.7
In 1903, Morris sold the company, which reemerged in 1904 as the Philadelphia Toboggan Company. The invention of upstop wheels and what they allowed new roller coasters to do resulted in the demise of the side-friction roller coaster style.8 Introduced in 1920 by John A. Miller, the newer design added a third set of wheels running beneath the track, further preventing derailment and paving the way for even faster speeds, steeper drops, and newer elements in track design, such as the airtime hill.89
References
References
- Frato, John (July 5, 2022). "Opening Day: First Roller Coaster in the USA June 16, 1884". Western Reserve Historical Society. Archived from the original on May 10, 2023. Retrieved May 10, 2023.
- "The Story of LaMarcus Adna Thompson and his Roller Coaster Business". PeoPlaid. May 29, 2021. Archived from the original on May 10, 2023. Retrieved May 10, 2023.
- Potter, Derek (November 10, 2013). "Theme Park History: L.A. Thompson, the father of the themed roller coaster". Theme Park Insider. Archived from the original on May 10, 2023. Retrieved May 10, 2023.
- "Leap-The-Dips Roller Coaster Historical Marker". ExplorePAhistory.com. Archived from the original on May 10, 2023. Retrieved May 10, 2023.
- Marden, Duane. "Leap-The-Dips (Lakemont Park)". Roller Coaster DataBase. Retrieved May 10, 2023.
- Todd W. Fornwalt (2010). "Leap-the-Dips: A Thrill From the Past". Penn State University. Archived from the original on May 28, 2015. Retrieved May 14, 2015.
- Fornwalt, Todd W. (2010). "Leap-the-Dips: A Thrill From the Past". The Pennsylvania State University. Archived from the original on May 10, 2023. Retrieved May 10, 2023.
- "A Century of Screams: The History of the Roller Coaster". PBS. Archived from the original on May 10, 2023. Retrieved May 10, 2023.
- "Coaster Landmark - Jack Rabbit". American Coaster Enthusiasts. August 15, 2015. Archived from the original on May 10, 2023. Retrieved May 10, 2023.