Question on Magnetic Brakes ... New Idea?

Yes this is probably far-fetched but it occured to me in the shower this morning, and since I do my best thinking in the shower, thought maybe I was on to something =)

First question is for Rideman or whoever else might be able to explain this - how do the Intamin magnetic brakes work? From what I've seen, it looks like an on-board system of some sort that generates the magnetic field which is then attracted to the copper brake fins. Is this correct or is it the other way around?

Second point: if the system is on-board, would it not be possible (albeit unlikely) to have a "reverse-LIM" on the second part of the ride? Those fins could actually keep the train's speed up and maybe even add a little that might have been lost for a second tower? Unlikely? Definitely, but something to add fuel to the fire =) The support structure I do not see as being a problem as the supports for Impulses on the launch track aren't all that massive, so LIM launches don't seem to generate that much force on support beams, and this might also be helped along by the large power conduit work being seen diverting power from the Wicked Twister area over to Dragster. If this thing is hydraulic launched, would that really require *that* much additional power supply? Perhaps it's for this kind of system?

Now, working for a company that does work with the Maglev, I've seen a lot of magnetically propelled systems, and none have ever had an on-board "launch mechanism" (that I can think of right now), but maybe Intamin has created something to this effect ... or maybe those fins are able to carry the travelling field necessary for acceleration/mainting speed?

Any thoughts?

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1. Kumba 2. Millie 3. Mantis 4. Lightning Racer 5. Wicked Twister (front seat)
"The key to a happy life is moderation" -- Jon Stewart

The braking system is just the reverse of Millennium Force. The fins are on the track and magnets on the train, instead of the reverse.

Why would you want to have an on-board system? There would be no advantage to do so.

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Jeff
Webmaster/GTTP
"There's nowhere to run, nowhere to hide, when it's all in your mind. You gotta let go." - Ghetto, Supreme Beings of Leisure

It's been a while since I've taken EM, but I've been wondering about something. I suspect that the force applied by the braking system is proportional to the speed of the train. Something about changing flux by running a magnet through a coil; go faster, generate larger flux, apply larger force, etc. The reason I suspect this is that if the magnets apply constant force, and are strong enough to burn off the momentum of a many-ton train doing 80, how is the gentle slope enough to get the train through them? If I recall Xcelerator correctly, there are no kicker wheels in the brake track; they are later. The reason I suspect this is wrong is that there is, in fact, no coil. Anyone know the details?

PS: don't tell any of my engineering students that I've forgotten my physics. :)

I also had a though about the brakes as I was walking past the site yesterday. Maybe those brakes won't be as powerfull as the MF brakes, becuase there is a ton of them.

As the fins move through a chagning magnetic field, or vice versa, an electric current is generated in the fins. The generation of the electric current slows the train, and the energy is converted to heat.

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"Millennium Force, the Future is riding on it."
Now, Cedar Point is "Bulding for the future."
Coincidence?
*** This post was edited by 0g 10/28/2002 10:27:59 AM ***

But Jeff, what you are saying is what I'm referring to as an "on-board" system, that the mechanics of the brakes themselves are actually on the train. What it seems to me is using an analogy to friction brakes, the air-powered part that moves as the train goes over it is actually on the train, and the "skids" are mounted to the track. This is what I'm referring to as an "on-board" system. By the way it seems to be described, it would be possible to create a reverse field that would propel as opposed to slow the trains. That is what I was originally getting at.

And Brian Nobel, its nice to know that even engineering profs forget their Physics 3 ;)

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1. Kumba 2. Millie 3. Mantis 4. Lightning Racer 5. Wicked Twister (front seat)
"The key to a happy life is moderation" -- Jon Stewart

I'm no worse than the typical undergraduate. After the final exam, who needs to remember anything? ;)

(kidding, kidding)

Hey guys. how old are you guys anyways? I'm in high school and I can figure out this problem with no difficulty. The magnets are on the trains because not only do the trains have to brake, but they launch as well using LIMS. Since magnets are needed to launch, they just simply inverted the brakes from MF design. Wow that was tough.

Fight the power.

http://listen.to/one-too-many

Before you get sarcastic orangechicken don't you think you should look into what your saying. This is a hydrolically launched coaster, not LIM launched. The magnets are only to brake, and will be much like the MF design.

The braking system here is basically the same as Intamin uses on their drop towers. Permanent magnets on the train provide magnetic flux; the copper fins on the track interact with that flux...when the magnetic field passes around the conductor, an electrical current is generated in the conductor (fin). The conductor is basically a short circuit, which means it will sink a theoretically infinite current, which will rob the passing magnet of kinetic energy. The practical upshot of all this is that you get a braking force which is proportional to the speed of the magnet...in exactly the same way that on Millennium Force or Wicked Twister with their fixed magnets and moving fins, you get a braking force proportional to the speed of the fin.

In order to generate a current in a conductor, you need to have a MOVING magnetic field. If you wanted to turn this system into an induction motor (which you could do...) you would need to provide an alternating current to the train to drive an electromagnet to supply a moving magnetic field to get the train going. It's not so far-fetched; this is how linear motors are used in transit systems (the motor is mounted on the vehicle rather than on the track). But that requires power and control equipment on the vehicle. For a roller coaster, you're going to see permanent magnets on the vehicle and no power connection to the train at all. Coaster designers like to keep things simple. Well, apart from Vekoma, anyway... :)

PittDesigner, you've worked with PSAC or whatever they call themselves now? THOSE guys are the real LIM experts...

--Dave Althoff, Jr

OrangeChicken505...

Uh, no...there are no LIM's on this ride! It's launch by hydraulics. There are many advantages to hydraulics vs. LIM's such as faster acceleration, less power needed to launch, and the launching mechanisms don't heat up like LIM's.

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Launch: Tophat: Twistage: Brakes...

...Denial is an ugly thing.
*** This post was edited by CP_bound 10/28/2002 1:50:30 PM ***

Dave - I'm not sure about PSAC ... might just be the old name for my company, I've worked for Maglev, Inc. for the last two years and have read through a lot of papers by Transrapid Intl., the German firm that has the only commercial-ready maglev system. That's where most of my "magnetic knowledge" comes from.
And I think what you were talking about with the moving field is what I was talking about too. Although this isn't simple (maybe Vekoma could sub-contract it ;) ) they could "wire" the brake fins on the current flat strech and create a traveling field pretty easily the way I see it. Oh well, I was just grasping for another way to get more than L-TH-T-B on this thing ;)

So Brian, you're saying its a bad thing that I already did forget all my Physics 3?? ;)
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1. Kumba 2. Millie 3. Mantis 4. Lightning Racer 5. Wicked Twister (front seat)
"The key to a happy life is moderation" -- Jon Stewart

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