A Science Teacher Rigged a Roller Coaster with Sensors ~Big Thunder Mountain Edition~
I’m Ken Kuwako, your Science Trainer. Every day is an experiment.
I took a sensor with me on two roller coasters at Tokyo Disneyland—Big Thunder Mountain and Splash Mountain. And I discovered all sorts of things that you’ll never find in a guidebook.
In my previous post, I analyzed the data I collected on Splash Mountain. This time, I’m taking a closer look at the data from Big Thunder Mountain. If you’d like to see the results from Splash Mountain, or learn more about why I decided to do this experiment in the first place, check out this article.
Many of you probably already know what Big Thunder Mountain looks like. This video was filmed by someone else, but if you’ve never ridden it before, take a look!
What the Data Reveals About the Ride’s “True Nature”
So, I actually got on Big Thunder Mountain with a sensor in hand—even though I’m not a fan of roller coasters. To be perfectly honest, it was terrifying. I really don’t want to ride it again. (Unfortunately, I had to ride it twice just to collect the data.)
The thing about thrill rides is that they aren’t scary simply because they’re fast. What makes them frightening is the way the acceleration acting on your body changes from moment to moment, creating unexpected jolts and movements. Our sense of balance is extremely sensitive to these sudden changes. You can find the acceleration and altitude data here.
The data showed that Big Thunder Mountain has a maximum vertical drop of about 9.9 m (9.6 m on the first run, and 9.9 m and 9.0 m on the second). The highest point is about 9.5 m above the loading area.
The ride itself lasts about three minutes, which is shorter than Splash Mountain. What I found particularly interesting is that the ride makes three separate “energy top-ups”, converting potential energy into kinetic energy as it goes.
In other words, the coaster isn’t designed to climb one huge hill and then make one enormous drop. Instead, it repeatedly climbs and descends a series of smaller hills. That’s because the coaster’s motor isn’t running continuously. The energy initially supplied by the chain lift is effectively reused as the coaster races through the course.
The Maximum Speed You Won’t Find in the Official Specs
Using the law of conservation of mechanical energy (※), I calculated the maximum speed. The result was 13.9 m/s, which works out to about 47.5 km/h.
This is probably not a figure you’ll find in the official specifications, but it’s still pretty fast! It may come as a surprise that a speed approaching the legal speed limit for cars on city streets is reached on such a relatively compact track.
The data also shows some remarkably intense acceleration and deceleration. This is probably caused by the many small rises and dips along the track.
All of this means that your body is being shaken around quite vigorously, and that seems to be one of the major differences between Big Thunder Mountain and Splash Mountain.
Splash Mountain creates its thrills with one big drop, while Big Thunder Mountain seems to create its thrills through a continuous series of smaller jolts and rapid changes. The data gives us a fascinating glimpse into how differently the two rides are designed, despite both being thrill rides.
It’s quite interesting to see that the underlying design philosophy can be so different.
I’m also making the original data from both Splash Mountain and Big Thunder Mountain available here. If you’d like to analyze the data yourself, feel free to give it a try.
Data exported to a spreadsheet
Original altitude and acceleration data for Splash Mountain
Original altitude and acceleration data for Big Thunder Mountain
Analyzed data
Analyzed altitude and acceleration data for Big Thunder Mountain
Analyzed altitude and acceleration data for Splash Mountain
※ For details on how to calculate speed from the height of a drop, see this article.
Use these data to calculate the speeds of Mount Fuji and Splash Mountain.
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