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G-force from launch acceleration graph

Bench.addict

Bench.addict

TS Member
So after a late night conversation on Skype, I decided to dress in the following attire and make a spreadsheet/graph of the G-force (including constant 1G) experienced on certain launch coasters around the world using their data from RCDB.

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Moi crunching numbers after midnight

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Table of raw data and calculated results

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Final graph of results with acceleration in metres per second per second on the left y-axis and G-Force on the right y-axis.

As can be seen, Dodonpa is the outright winner of the group, with Ring Racer surprisingly still coming second and poor old Kanonen coming last, beaten even by Incredible Hulk, which uses rubber tyres for its launch.

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And, as an added bonus, I worked out the theoretical distance used for the launch of each coaster in metres. Unsurprisingly, the three major Intamin launchers are the longest, though Formula Rossa is surprisingly long at approx. 133m. Feel free to comment any roller coaster below (as long as you can find the starting and finishing speeds of the launch and time taken to launch) and I'll add it to the list/graphs
 
The stats don't lie.... Stealth is better than Rita! :p

Cheers for doing all this number crunching matey. My curiosity is satisfied. All hail the engineering geek! :D
 
DiogoJ42 said:
The stats don't lie.... Stealth is better than Rita! :p
Click to expand...

By the reckoning, Stealth is also better than Kingda Ka; it's not! ;)
 
Wonder why Liseberg paid for a coaster with such a pitiful launch capability. Especially when other coasters that use the same system have launches three times as fast.
 
I think you need to be careful with these numbers, as it assumes the times quoted by parks/RCDB are entirely accurate. This seems a little unlikely - especially as Thorpe somehow shaved 0.4s off Stealth's launch after it's first season. A lot of these figures are probably rounded to the nearest second or half second, which isn't precise enough for this calculation.

Looking at the launch track length data demonstrates the problem. The figures suggest that Kanonen, Rita and Stealth all have very similar track lengths. A quick look at these rides will demonstrate that this is not the case! Kanonen's launch track is very short, as you would expect for a much slower ride.

It's an interesting exercise, but I don't think it really gives an accurate measure of launch intensity.
 
Is it possible to take measurements of the launch track from Google Earth? If so, a) would it be accurate enough, and b) would that help the calculations?
 
I don't know how accurate Google Earth's ruler tool is, but using the length of the launch track would probably be better than using times as it would be easier to get an accurate measurement.

You'd have to be careful though - Intamin coasters cannot use the full length of the launch track as they need some distance to stop the catch car. I don't think aerial photos would show this clearly enough to measure.
 
I understand that all values after 1.d.p should not be trusted (had I been more awake, I would've formatted the cells) and all values on RCDB should be taken with a pinch of salt (though where do they get their values from?), but it does still give a general, theoretical comparison between the rides.

I could write an entire Discussion & Evaluation on the results if you wanted, but nobody would really read it :p
 
I am on my mobile but would something like Thunderlooper be measurable?

My posts have that many mistakes in them?! Damn this Tapatalk milarky :)
 
It's just dawned on me that Baco goes downhill after the launch. So either the launch speed or the top speed listed on RCDB must be wrong, as the train would surely gain some speed after leaving the launch track?
 
Indeed Intamin launch tracks only use about 2 thirds of the launch to.... launch. You then have as John said need distance to stop the catch car.

And different launches pack the majority of the acceleration in different phases of the launch, so intamin cable launches pack a lot of the acceleration into the early part of the launch when any LIM style launch can vary the points of acceleration (though the bulk tends to be near the end of the launch as LIMS take a bit of time to get things moving).

As Rob said i have never heard anyone say Stealths launch is better than Kingda Ka so the numbers are not an accurate predictor of how good the launch feels.
 
Most advertising for Backache seem to hint towards 83.9mph in 3.5 seconds as the launch speed, but whether or not the dip is taken into account is unsure. You could debate the resistance from the track slows the train more than it accelerates downwards (which might be likely knowing that track)
 
I'd have thought with those trains wind resistance would be a bigger factor. But still, going downhill would still make them go faster.
Unless, since the launch is inclined upwards, after it peaks at 83.9, is disengages the catch car, starts to slow, then hits the dip and picks up speed again, and happens to hit exactly 83.9mph again... I refuse to believe Intamin's calculations are that good. :p
 
There's a break at the end of the launch, is there not. So it would launch, reach its top speed of 83.9 mph, then slow to say 65 mph, before dropping to around 75-80 mph. Also the launch is has a slight gradient upwards, but I'm not sure if that would have much of an effect.
 
Most launches are on an incline are they not? Easier to evac in the case of a failed launch
 
Furius Baco has quite a steep launch compared to most rocket coasters. I don't know what the exact incline of it is but if it was as much as 10 degrees, it would effectively add 1.7m/s^2 to the acceleration felt by the rider.

Also, why does every acceleration in the table have a constant of 1G added to it? Gravity isn't acting in the same direction as the launch unless you're taking into account the component due to the incline as above.
 
These are only meant to be generalistic, theoretical views of what the launches do if they work at constant acceleration (which admittedly nothing ever does, but it's nice for mathematics), and a bit of late-night Skype fun. You're quite right, gravity works at a near perpendicular angle to the launch track and, if the angle was given, the resultant G-force of the rider could be calculated using simple trig. However, while creating the spreadsheet at 00:30am, I took the British 'mend-and-make-do' decision just to add +1 to each value rather than guess an angular value for each launch track.
 
I don't mean to be on your case about it as it's genuinely interesting to see which are the world's fastest accelerating coasters but whatever the gravitational component down the launch track is, it's always going to be closer to 0 than 9.81 so why not just ignore gravity completely? It's given some of your calculations more than 100% error.
 
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