Red Reflectors

hey has anyone here noticed that in the stations of mf and gemini there are red reflectors on the track in the station i was wondering what they were for???

They also added some to the helix on Raptor as you're in the queue just getting to the pop machines...

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MF 2000 - 269 laps

MF 2001 - Tell ya when I hit triple digits....

Maybe related to block sensors?

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PO!NT OF VIEW - A Different Look at Roller Coasters
http://www.crosswinds.net/~justmayntz/thrills/

I was thinking that at first myself but there isn't a block for another 600 feet of track or so where they have them on Raptor...

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MF 2000 - 269 laps

MF 2001 - Tell ya when I hit triple digits....

RideMan and I noticed these yesterday. They're location markers that are used in ride testing. Some sort of light emitter is placed over the reflector line. When the train passes over, a mark is placed in the data file. This way when the data is examined they'll know where exactly the train was on the track. From what we found, the reflectors were either placed at logical breaks during the ride (ie blocks), or at easy access high-G moments (ie the low spots on MF).

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Scott W. Short, Rail Junkie
scott@midwestcoastercentral.com
http://www.midwestcoastercentr

Some public television station produced a videotape documenting the construction of the Knoebel's Twister. I believe that videotape includes a segment where the accelerometer testing procedure is described and the use of reflectors on the course is explained. I'll try to remember to check tonight and verify that I'm thinking of the right show. Anyway, I'm reasonably certain that's what the reflectors are for on the Cedar Point coasters. I'm guessing they've all undergone some testing recently, probably being done by a different engineer than they've used in the past.

--Dave Althoff, Jr.

Last night on extreme rides they were talking about some type of censors using lights for S:UE. They said they could know within a cm where the train was at all times.
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Crady Crady!! CRADY CRADY!!

That's not reflectors.. they are using a fiber optic sensor that detects the difference between the black painted part of the track and the areas cut open. The computer then counts how many of the "clicks" it sees and can compute where they have the train.

The same technology is used in copier machines actually to control motors for feed wheels and motor rotation speed. It's actually old technology and most stepping motors have such an encoder to help count steps.

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MF 2000 - 269 laps

MF 2001 - Tell ya when I hit triple digits....

Are those physically on track or are they mounted to the sides of the track? I know they use reflectors in the station on the Gemini for ride control. Are these the same type of reflectors or are they completely different?

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Get with it or die in the process.....

I've noticed them on Shivering Timbers this year. They are in strange locations, though, like just on the downside of a hill.

I always assumed they were used for laser distancing, myself.

The reflectors in question are red, and are positioned on selected track ties to the left of the track centerline. They are on the upper surface of the track tie, pointing straight up. They look like bicycle reflectors.

--Dave Althoff, Jr.

You're right Dave. The reflectors are from a ride testing firm from Arizona I believe (completely going blank on the company's name at the moment). It seems Cedar Fair has switched to having their testing done by these guys which I see as a good thing (very thorough and knowledgeable company). Before opening, they also had tested out Talon and had plans to go through the rest of Dorney too. As far as I understood it, the reflectors are there to mark positions throughout the track. They then mount an optical sensor to the train tied in to their data box to be able to match accelerometer data with location as precise as possible.

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-Brian
I really should be working...

Hi, Brian! Since I don't recall seeing you here before, welcome to CP Place!

I figured it was a change in either the testing vendor or in the hardware they were using. I know the reflectors are new...and I saw them on everything except Woodstock. Well, I didn't see them on Mantis:TCFKAB or Jr. Gemini 'cause I didn't ride those two, but still... :)

A word about accelerometer testing...

It's not just a matter of doing a couple of accelerometer runs when the ride is new, analyzing the data, and saying, "Yup, that looks good." Ideally, the tests should be done on a regular basis and compared with the original baseline tests if for no reason other than that the accelerometer will identify certain problems long before other inspection methods will. Scrambler unit pole top bearing wear comes immediately to mind as something that will show up on a force graph before you can feel it in the tub...!

--Dave Althoff, Jr.

Dave, you're not the only one who was suprised (and happy) to see him on here. Welcome! :) ::grins::

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*-CP Irvine-* I know who's fault it is!
*The FewER, The Proud, The Po!nter Girls*
AIM SN: ACEerCP

Awwww, I feel so special now :).

As for your comments, Dave, I also was very glad to see that it seems that Cedar Fair is at least putting in the time and effort. Hopefully other parks and chains are also following suit.

By the way, the company I know of that uses these reflectors is GMH Engineering from Utah. That was going to drive me nuts if I didn't track it down.

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-Brian
I really should be working...

What Dave described is exactly what is on Timbers. I did verify that they are fiber optic, although their usage may differ. My source thought it may have been part of the computer system to determine where the train is on the track.

At the same time, I can also guarantee you they are plain reflectors on Raptor and other coasters and have zero to do with the control system. Curious...how did you verify that they are fiber optic? In general, that media is not used for control systems and in knowing a bit about CCI's controls, I'm just about sure they don't use that. However, there are photoeyes that consist of a sender paired with one of these reflectors. Perhaps that is what you saw on Timbers?

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-Brian
I really should be working...

I've seen the photoeyes, they are blue boxes mounted on the walkways. There's one on the first turn out of the station, actually. It's pretty obvious if you look for it.

I asked, actually. Maintenance guy mentioned that they were light detectors, but didn't think they were for acceleration testing (and like I said, in strange locations for that) and supposed that they might be for the computer.

Maybe the track guys know.

I can't be sure, but aside from the drop out of the mid-course, that point on the helix might be the fastest point in the second half. I don't know if that matter.

"Pretty obvious if you look for it..." Isn't that like saying not obvious at all? :)

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Jeff
Webmaster/Guide to The Point
Futuristic bow-wow... do the dog catcher!

Hmmm, odd since photo eyes that use reflectors tend to be good over only very short distances such as a few meters maximum and really are pretty bad in outdoor use. I also haven't seen any blue ones yet, unless that is just a case built by the park.

As far as accelerometer testing, the idea is to spread the reflectors evenly throughout the ride (although often that is determined by the areas you can reach with only a ladder....bringing in a man lift can get expensive for such a thing). They aren't meant to mark troubled spots but just act as general markers so the areas of trouble can be a lot more accurately determined than by going off of only a time base.

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-Brian
I really should be working...