A geeky present for Theme Park Review

[MG]

Hey everyone,

Every year my school operates a Physics trip to Thorpe Park for the Lower Sixth (that's people aged 16-17 for Non-UK). This is because Thorpe Park is about 10 minutes away from our school and they collect data that's helpful to their course.

We collect data using Pasco Accelerometers in a vest format as shown below:

This is from my original review when I visited last year with my school http://www.themeparkreview.com/forum/viewtopic.php?f=2&t=49856&hilit=+thorpe+park

Last year I couldn't get hold of the results from the accelerometers but this year I HAVE THEM FOR YOU!!!

The graphs below are of a few of the rides. Time is on the X axis and acceleration is on the Y axis. Acceleration is shown in ms^2. To convert this to "g" simply divide by 9.8 (or 10 if you want a quick glance!). Positive g is anything above 9.8, negative g is anything below 9.8. You can see that Saw has some pretty intense negative g.

If anyone wants the original results readout just PM me and I'll email it to you. It's in an Excel document.

Rush

RIDE TYPE: S&S Screamin' Swing

Zodiac

RIDE TYPE: Huss Enterprise

Vortex

RIDE TYPE: KMG Afterburner

Nemesis Inferno

RIDE TYPE: B&M Inverted Coaster

Stealth

RIDE TYPE: Intamin Rocket Coaster

Slammer

RIDE TYPE: S&S Flyswat

Saw The Ride

RIDE TYPE: Gerstlauer Eurofighter

[iplf]

This is very interesting! Thanks a lot. I guess my girlfriend is going to be proud that she rode Stealth frontseat!

[dragon2000]

Wow - I love it. You've got some great data there.

I really like how you can see the rides characteristics from the graphs:

 

Rush - the buildup to full swing, then the abrupt braking at the end of the ride.

Zodiac - it's got some lovely symmetry to the graph!

Vortex - similar to Rush in that it slowly builds up to full swing, before the brakes kick in towards the end. The amount of positive G surprises me too.

Inferno - interesting to see the pre-lifthill section.

Stealth - the clear pull up on the tophat, going over the top, then the pull down of the tophat.

Slammer - similar to Vortex in the lovely symmetry! Can even see the 'bump' at the end of the ride where the arm bounces on the tires at ground level...

SAW - can see just how manic a ride it is - and high Gs, both positive and negative!

 

Great

[cobra_roll06]

I don't know if I am just misinterpreting these graphs but your units seem to be way off and clash with the objective of the experiment. Could you explain the graphs in more detail please? I'm probably missing something!

[andyuk200523]

They look pretty interesting, however is the data for Saw incorrect? Or am I missing something, I am not seeing the Pre-Lift data?

[MG]

Thanks guys

^^ I assume you're talking about the time axis. They don't all start at zero because sometimes the meters were started before the ride began. The data before then was simply deleted. So some start at zero, some don't. It doesn't make any difference to the data collected.

As for the acceleration axis, this has been calculated in ms^2. That's meters per second squared. This is the standard unit for acceleration. 1g=9.8ms^2

The meters read out the results in a 3D sense with the acceleration in the X Y and Z directions. I then calculated the resultant of these to achieve the graphs.

I hope that's cleared it up a bit

^I see what you mean and I have been thinking about that. It might be the person who was using the accelerometer forgot to start it in the station and only started it as they were waiting at the bottom of the lift.

[rcoasters]

Really interesting graphs. It's amazing to see how on some rides you can go from negative to positive g's so fast. If only every school could do this in physics classes !

[Six Flags Enthuseast]

Very interesting. I'm actually into accelerometer tellemetry/force graphing on rides like that, so it pleases me somebody's able to give me some graphs.

[Pingu1651]

^^ We did rollercoasters in math class, although it wasn't physics related. My friend and I were the only ones that knew what "airtime" was.

 

This is pretty cool! I knew how to find acceleration, but not g's. The graphs make total sense. You can even see the top-hat on Stealth's graph. I'd love to do something like this.

[triggernel]

Do the flatrides listed have pretty standard G's, in comparison to similar rides at other parks?

[MG]

^Zodiac is probably the most 'normal'

Generally these are pretty intense rides.

I'd expect Vortex to compare well to a Huss Frisbee. You can see that Vortex here pulls a cool 4.4g.

Rush is pretty much the same as Skyhawk at Cedar Point

Slammer is pretty intense, but not in a G force sense, just a being upside down sense.

[triggernel]

My local park being VF where we have an Enterprise and a Screamin' Swing, I was just wondering if I could compare the g's between VF's and Thorpe's.

[MG]

Screamin' Swing should be nearly identical. Enterprises vary in size slightly I think, which would affect the G-force. I don't know which model Zodiac is.

[lond]

If you want to see some more measurements: www.themeparkreview.com/forum/viewtopic.php?p=503921#p503921.

 

I have measurements from over 100 coaster so far from Europa, Japan, South Korea and USA.

 

// Marcus

[Blythy]

you say the sensors collect it in all three axes? then that is more interesting, otherwise you've only got the size of the force acting, no matter what direction it is going.

 

if you've calculated the resultant vector, (root(x^2 + Y^2 + Z^2)), you will not be able to show negative vs positive just because of the maths involved, so your ascertation that below 9.81 m/s^2, is negative gs is wrong.

 

If you get your raw data for the Z axis (presuming positive is up) then you can see where you're getting negative g - i.e. where it goes below zero.

[MG]

I'm not sure I'm afraid, I've only learnt to deal with 2D forces so far at school. I used the formula the teachers had used on Stealth and applied it to the others.

I'll go back and look at the data. Thanks for bringing it up.

[Blythy]

3d forces are exactly the same as 2d, you just add on the extra component before you do the root. e.g. a force of 3i + 4j - 5k has a magnitude of about 7. (i j and k being unit vectors in the x y and z directions respectively, similar to 2D)

 

Because you're doing a square root, you will have no information about the actual direction of the force (it's because you are squaring vectors, which results in a scalar), therefore you can't say whether it's positive or negative (it's like temperature, when you use a proper scale of temperature (i.e. kelvin), you can't have negative temperature)

 

now, as for accelerations themselves, 0g means weightlessness. Hence zero-g rolls. Take a look at your nemesis traces, you can spot the zero g roll as it's the lowest part of the trace, but you still have an acceleration (I'm fairly sure that there's some rotational acceleration in there that's screwing up the actual zero g part, although getting a pure zero g read is nearly impossible, especially with a roll)

 

Airtime comes from negative g, this is when the coaster car is falling away from you faster than you fall towards earth. (unless you're slow and upside down, then you're in hangtime )

 

What you need is the z trace - this is the one which will have the resting noise hovering about 9.81 m/s, and will vary by far the most. If a standard right hand convention is used, the X will be the forward and backwards direction (or longitudinal - forwards positive, backwards negative), and the y will be the left right direction, with left acceleration positive (to remember, write x on your thumb, y on your index finger and z on your middle finger, and make it so that they're all at right angles to each other [easier than it sounds - do the usual gun shape with your thumb and index finger, and sitck the middle out to the side], and the directions they point are the positive directions.

 

as for how they feel on the body, eyeballs are the best I find , generally your eyeballs feel like they want to keep going in the opposite direction to the acceleration that you're undertaking (because they're mostly liquid). So for positive vertical acceleration, that's eyeballs down. negative vertical - eyeballs up (vertical acceleration is the most important because it controls the amount of blood that goes to your head). For laterals, positive is eyeballs right, negative eyeballs left. And for longitudinal, positive is eyeballs back, and negative is eyeballs forward (generally this is felt most when braking heavily, and you're looking round for your eyeballs at the end)

 

(if you're having trouble telling the traces apart, look at the one for stealth, it should be fairly obvious because of stealth's layout as well as the launch )

[MG]

Wow, what a silly error on my part. Of course, since I have merely calculated the magnitude of the force. I simply assumed since there appeared to be negative g on the graph that it must be correct. I'll go and have a look at their results again.

I understand how positive and negative g work, it was the way that the graph was plotted was the problem. The graphs still show the overall magnitude of the forces which is still quite interesting to see.

[Loefet]

It's interesting to see your logs of Rush, since the one we (me and lond) have on Uppswinget (same kind of ride) at Liseberg shows somewhat that Uppswinget is a bit more intense, more air on the top (negative g's) and higher g's at the bottom...

 

Your log of Rush:

 

Our Log on Uppswinget:

Blue = Vertical forces, Red = Acceleration force, Green = Lateral force.

 

EDIT:

I red through your and Blythy's posts and I understand why your plot is so different compared to ours, can you post of the plot of the raw data of your logs instead of the magnitude, since the raw data makes much more sense and shows the real world way better than the Magnitude ever will...

[Evan1127]

Airtime comes from negative g, this is when the coaster car is falling away from you faster than you fall towards earth.

 

Well, ejector air, yes. Floater air is between 0 and 1 G.

[CorkscrewFoley]

Maybe I read this wrong, but I believe vortex is a KMG Afterburner, not a HUSS Frisbee.

 

I love the graphs, it's like quantom physics to me, I don't fully understand it, but the curiosity is definitely there.

[MG]

I said that on the first page. I compared it to a Huss Frisbee for similar forces for another person trying to compare rides.