I love Big Thunder Mountain Railroad with the intensity of a thousand suns. I think it is a perfect attraction. On my last trip to Walt Disney World, I rode Big Thunder Mountain Railroad and then used a FastPass for Seven Dwarfs Mine Train. I was surprised by how smooth Seven Dwarfs was compared to Big Thunder Mountain and that got me thinking.
Here at TouringPlans, we like numbers and we use them for good. Actually, we love numbers. We love data and we do beautiful things with them. We collect data on a lot of different things. We track schools in session and weather to estimate crowd levels. We track posted and actual wait times to help you minimize your wait in line and visit more attracions. And now we have a new source of data that will tell use how bumpy rides are.
A quick view of any theme park message board will reveal hundreds of posts about which rides are too bumpy for some guests. For example, some guests report that they cannot ride the Matterhorn at Disneyland because it is too bumpy, or they compare how smooth Seven Drawfs Mine Train is relative to Space Mountain.
Since we love data and theme parks, we thought we would collect some data on how bumpy some of these rides are.
It turned out that “bumpy” isn’t a term that physicists use. But guess what, there is a term that describes how much you get jerked around.
Jerk is an admittedly loaded term. It could refer to that person that tries to slip under the ropes from the standby to the FastPass line at Big Thunder Mountain. That person is a jerk, but we are talking about the jerk you feel when riding an attraction. You know that saying “getting jerked around? That kind of jerk.
What is jerk?
Roughly speaking, jerk is how much you get whipped around on a ride. The term jerk isn’t a word we just innovented, it is an actual term used in physics. Don’t believe us? Check out this scientific paper written by @Eager:2016fw.
Let’s talk about motion for a bit, shall we? We experience a wide variety of motion every day, even if we don’t realize it. When we are on a plane or in a car, we are moving but we don’t feel it. But we do feel it when the plane is taking off or we accelerate from a stoplight. We feel a change in motion. If you are slowing down for a stoplight and have to swerve to avoid a cat that just darted in front of you, that is jerk. It is a change in the change of motion.
- You don’t feel constant motion
- You do feel a change in motion
- A change in the change of motion is called jerk
We have a handy dandy device called an accelerometer that measures motion for use. Our accelerometer is small enough to fit in our sock when we take it on attractions.
Now that we are all familiar with jerk, let’s look at how much jerk we experience on a ride.
We are going to create a visual depiction of the data we recorded. The horizontal axis is the time in seconds. Big Thunder Mountain Railroad is about 3 minutes long or 180 seconds. The vertical axis is the amount of jerk experienced on the ride. If the line is between 0 and 1, there is not much jerk. If the line is goes beyond 2, then there is a good amount of jerk. Let’s look at this for Big Thunder Mountain Railroad.
I think this is beautiful, and not just because I made it.
Let’s break this plot down into parts.
From 0-20 seconds there is a little bit of jerk, but nothing bad. This is where the ride vehicle is leaving the station but before the first lift hill.
From 20 to 45 seconds the ride vehicle is on the first lift hill. Not a lot of jerk here.
From 45 to 65 seconds the vehicle is going through the first set of twists and turns and we experience a fair amount of jerk. This makes sense!
From 65 to 100 seconds the ride vehicle is one the second lift hill and the jerk is low.
From 100 to 125 seconds the ride vehicle is going through the second set of twists and turns and we experience some significant jerk.
From 125 to 150 seconds the ride vehicle is on the third and final lift hill.
From 150 to 180 seconds we go through the third and final set of twists and turns and then slow down before returning to the station.
Great, you can record data and make beautiful plots with it. How does that help me?
With our new power we can finally answer that age-old question, is it smoother to ride in the front of the ride vehicle or in the back?
The pictures that I showed you above were all from row 1 of the front car of Big Thunder Mountain Railroad. How does it compare to the back row of the back car (row 15)?
I’m glad you asked. Take a look. The front row is the top picture, the back row is the picture on the bottom.
It appears the amount of jerk in the rear car is lower than the front car. Huh? What? The rear car gives a smoother ride than the front car. See how much narrower the width of the lines is?
TouringPlans, answering the hard questions you never knew you wanted to ask.
In the future, we will be going to all the parks with our accelerometer to put numbers to how much jerk we experience on these rides. We hope you will be able to use these data to plan which attractions you feel comfortable on. Stay tuned.
Comments? Thoughts? Let us know what you think about these types of experiments.