On a

roller coaster A roller coaster, or rollercoaster, is a type of amusement ride that employs a form of elevated railroad track designed with tight turns, steep slopes, and sometimes inversions. Passengers ride along the track in open cars, and the rides are o ...

train, the underfriction, up-lift, or up-stop wheels are a device to keep the train from jumping off the track under intense movement. The design was patented in 1919 by

John A. Miller John A. Miller (born August John Mueller; 1872 – June 24, 1941) was an American roller coaster designer and builder, inventor, and businessman. Miller patented over 100 key roller coaster components, and is widely considered the "father of th ...

References

Roller coaster technology {{tech-stub