What is the first inversion feature commonly found in roller coasters?

The first inversion feature commonly found in roller coasters is the loop. Loops are circular elements that allow riders to experience a complete rotation upside down as the train moves through the structure. This design was one of the earliest ways to introduce inversion into roller coasters, providing a thrilling experience that became iconic in the amusement park industry.

The loop serves as a fundamental inversion because it utilizes a simple circular shape, making it easier to engineer and safer for riders compared to the more complex inversion designs that would follow, such as corkscrews and dive loops. Its introduction marked a significant evolution in roller coaster design, as it allowed for increased excitement and unique sensations of weightlessness that enthusiasts sought.

Other inversion types, while popular and exciting, emerged later in the development of roller coasters. The corkscrew, for instance, adds a twisting motion to the ride, whereas dive loops involve an initial drop followed by an inversion. Vertical loops also provide an inversion but are often designed differently than the traditional loop shape.