Stalls?

Who knows what was causing Top Thrill Dragster to be stalled last year. I know that the fixed the cable problem but what was the problem with it after that. From what I can remember back in august I believe it was the little green square nodes in the station.

What are those green nodes for anyway. Here is what they look like

http://img15.photobucket.com/albums/v45/mxpxtreme13/16230726.jpg
*** This post was edited by Adam Grignon 3/20/2004 11:53:23 PM ***

If I am not mistaken, those are proximity sensors. They tell the computer where the trains are at all times.

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2003 Season Visits: 42 Dragster: 27 Rollbacks:0

I figured that. I've been telling people that that's what they were when I really did not know in the first place.:)

Those are proximity sensors indeed. notice how most of them are in one position and a few are in another. The more common position is for train position, they are used to position the trains and occupie the block. The blocks stay occupied even after all of the sensors are off. The other set resets the block in a redundant manner. After the train is completely out of a block, the train has a single point at the back of the last car to turn on the block reset proximity sensors in a sequenced manner. Any one sensor occupies the block, only a set sequence clears the block.

As for what makes the train stall... Sometimes the train gets close to the point where the train's weight is balanced on either side of the tower. I guess there is a very small window where the fricton from the 72 wheels is great enough to completely stop the train. I knew it was a very small possiblity, but didn't think it would actually happen... but it did it for the second time in the middle of the season.

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Eddy the retard is awesome.

I think he meant stall, as in... broken. But thanks for the Patrick-like description of how proxes work. :)

Adam, there were multiple reason why dragster wasn't working last summer. I can tell you that as soon as one problem was fixed, another would pop up.

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Brent Haley
Gemini Crew '02
Dragster Crew '03, ATL '04

Here's a shorten summed up version of what happened to Dragster in 2003:

Late May: One of the tires on the back of the trains fell off while in operation and the cable that launches the ride snapped (closed for a few days)

Early June: Hydraulic Fluid was contaminated and an extra row of seats were added(closed until July 4)

July: Many rollbacks and heat issues on launch track (closed for a week)

Late July to Oct: No major problems, the ride had it's good days and it's bad.

I no there was more that happened in July but not sure what else happened.

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Opening Day - May 8, 2004 :) It's coming

Keep Arms Down, Head Back, and Hold On!!

I wonder how much it costs for a brand new catch car to be fabricated and shipped to CP pretty much overnight...

At least the accumulators and nitrogen tanks have a very high burst pressure, probably 15,000 - 20,000 PSI or more, if one of those went, it would take the hydraulic building with it.

It would be interesting if one of the pressure line hose burst, oil all over the place.
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Eddy the retard is awesome.

Speaking of those hydraulic tanks and the hydraulic fluid, who knows if the same hydraulic fluid is used over and over or if it's replaced by new fluid after each launch. I contacted Cedar Point via e-mail (duh) and asked them but I have yet to get an answer. Dose anybody out there know.
*** This post was edited by Adam Grignon 3/22/2004 7:44:20 PM ***

The same fluid is used for every launch. ------------------
TTD '03 Crew
69 Launches - 65 Complete Circuits
Which of the 4 TL's will be listed in the SOP manual?

I agree P.U.E.! At my work, one of the things we test are fuel rails . This machine impulses roughly 600 cycles a minute, at 379 bar. we use a inline Kidney loop filter.

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Millie:20
TTD: 1
CP&LE RR: 150
*** This post was edited by imadj 3/22/2004 10:34:44 PM ***

Imadj, wow, with that fuel rail tester, you could have your own dragster if you had a large enough flow volume. That tester operates at about 1kpsi above the maximum pressure that Dragster's safety system will allow trains to be launched with. Just out of professional curiosity, please tell me the testing is done at 379bar just to meet the safety factor for the fuel rails, because, frankly, I'm a little frightened of a vehicle that actually has fuel provided to it at about 5500psi.
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TTD '03 Crew
69 Launches - 65 Complete Circuits
Which of the 4 TL's will be listed in the SOP manual?

Probably stress testing. The only accumulators I've worked with had a working pressure of 1000 PSI and a burst pressure of at least 10,000 PSI.

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Eddy the retard is awesome.

SteelMonsters you are close. Its a longevity test per the SAE/ACES testing guidelines. these rails are connected by S.T.C. connectors(snap to clip) wich was designed by Aeroquip wich is now owned by Eaton Corp. I work in the test lab. we test all kinds of hydralic lines,valves. P.U.E. not alot of volume on the fuel rail testing. Just enough to circulate through the system. There'sa check valve to stop the flow when the intensifier is gonna hit. we do have two giant machines to impulse test -32 lines, up to six samples at about 4.5 feet in length.Those require lots of volume.

Its kinda cool we just had a student here working on a project to try and predict hose failure by capacitence. He was from purdue also.

*** This post was edited by imadj 3/23/2004 7:43:14 PM ***
*** This post was edited by imadj 3/23/2004 7:44:04 PM ***

Guys (purdue,imadj,steelmonster), I have a related question since you are all talking over my head about engineering and pressure testing.

What is the limit for a hydrolic system like Dragster. Can the existing technology be increased or modified to reach speeds of 150 MPH or 200 MPH.

Tom

Yes, hydraulics are capable of a 200 MPH launch, It would require several changes. Larger drum, different gear ratio between the hydraulic motors and drum, more power output of the motors combined.

Problems. Cost, Top Thrill Dragster uses 4 hydaulic pumps, 4 very large accumulators, and 32 hydrualic motors. This equipment isn't cheap. The cost of the launch would 2x-4x to produce a 200 MPH launch. Another problem is what are you going to do with that much speed. Elements become rediculously large and expensive at very high speeds. Notice how TTD hits brakes after it's only element.

TTD's motor 120 MPH

Xcelerator's 82 MPH

Twice as many motors for a launch thats 50% faster. Which makes sense, consitering that when you double the speed, you quadruple the energy.

Basiclly, very expensive, the ride is very limited, but it's do-able.

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Eddy the retard is awesome.

Hah, you can tell what department I work for.

When I saw this thread, I thought it was going to be about a solution to the guest complaints about the wait time and the need to relieve themselves. ;)

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"Hmm. . .we don't have anything like that. . .but I can give you this comment card."

Steel, thanks for the info, I was just curious if TTD was at the upper limits of its technology. I did not know when you double the speed, you quadruple the energy, and completely understand the other issues. If those speeds were ever attained, I am not sure you would need to do much in terms of height, the speed itself may provide some great thrills close to the ground, eventhough it would require significant space.

Tom

TTD also had the calbe snap on Memorial day....

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I own you!

The cable failure had nothing to do with the height or speed of the ride.

I am positive that Intamin lost money on TTD after picking up the repairs for the ride. I also think their crazy enough to bid on a taller and faster roller coaster with the technology.

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Eddy the retard is awesome.