Sunday, October 22, 2006 11:44 PM
I apologize if this has been discussed before or sounds foolish, but this has interested me for a long time.
PKI's Drop Zone, and other rides like it, are said to utilize "permanent magnetic braking" systems. My question is this: Are these electromagnets? Do they require surges of electricity to stop the vehicle, such as a propulsion system on a ride such as FoF?
If they do, does the ride "store" the amount of energy needed to stop the vehicle in case of a power failure?
Sunday, October 22, 2006 11:49 PM
They're just plain old magnets... no electricity required, and thus, no braking backup required.
Red Garter Rob
Monday, October 23, 2006 6:14 AM
I wouldn't say "plain onld magnets" .. they are very strong rare earth magnets. Not cheap to make or purchase for a ride.
*** Edited 10/23/2006 10:15:10 AM UTC by Red Garter Rob***
Monday, October 23, 2006 9:35 AM
What's cool about them is that the faster the magnets and fins interact, the harder the braking force. A couple of years ago at the IAAPA trade show, a vendor had a little "skate" with a fin on it and the magnets on the "track." It as neat how you could move it pretty freely at low speed, but if you tried to jam it through, it resisted hard.
Monday, October 23, 2006 2:32 PM
The other thing that is cool about that is that because the braking force is proportional to the relative velocity of magnet and fin, if you use a magnetic brake as a trim brake and you make it long enough, the train will always come out of the brake at the same speed. Many other braking systems are dependent on the vehicle mass or caliper air pressure, or stuff like that.
You can see this in action on The Beast. If the train is lightly loaded, then when the train hits the mid-course trim brake it will very quickly slow down (brick-wall style) to the exit speed and maintain that same speed until it comes out of the brakes. A heavier train will slow down more gradually (because it has more energy and is therefore harder to slow) but will come out of the brakes at the same speed as the lightweight train.
In contrast, with friction brakes, a lightly loaded train will lose too much speed to the brakes, while a heavily loaded train might not lose enough at a given pressure setting. The action of the magnetic brakes ends up being more consistent.
--Dave Althoff, Jr.