Magnetic Brakes

[BBH]

I remember reading in a thread recently (I believe from rollermonkey) that magnetic brakes can't completely stop a coaster, which I believe as a minor physics junkie. But my question is, how do coasters like, for example, the Impulse Coasters or Gatekeepr, which rely solely on magnetic currents, come to a stop in the station? My personal guess is that they slow the ride down to a point where the friction of the wheels against the track slows the coaster to a complete stop. Is this correct, or is there some alternate form of slow/stop?

 

[Snoo]

Gatekeeper has wheels, so it doesn't rely on magnets to stop the train.

As far as the impulses, can't find any good shots, and my memory is fuzzy.. but they do have drop down brakes for when the ride is not in motion but completely forget how they do what they do and such and things.

 

[furie]

Good question and I have no idea... :lol:

I'll have to look on Rita the next time I go to Alton. Does it have kicker wheels in the station?

 

[mistermister]

I'm pretty sure most coasters with magnetic brakes have tires the transport the train through the station, bring it to a complete stop, and then start it moving again. The magnetic brakes are just the primary braking mechanism while the wheels arent meant to be "brakes", but they will stop the train.

 

[bmac]

The wheels are enough to stop the train when its momentum is broken by the brakes and hold it on a block until the next segment is completely clear (see final brake run, station, etc.).

EDIT: Snoo is correct.

 

[jolash]

Gatekeeper has wheels, so it doesn't rely on magnets to stop the train.

As far as the impulses, can't find any good shots, and my memory is fuzzy.. but they do have drop down brakes for when the ride is not in motion but completely forget how they do what they do and such and things.

The LIMs on an impulse cannot be used to slow down the train, but can be used to drive it in either direction, at any speed. When the train slows down using the drop-down magnetic brakes, the LIMs drive the train in reverse, at a slow speed, to park it in the station.

But yeah rides like Gatekeeper or really any modern B&M uses stationary magnetics at the beginning of the brake run. After that friction brakes and wheels are used.

 

[BBH]

Gatekeeper has wheels, so it doesn't rely on magnets to stop the train.

As far as the impulses, can't find any good shots, and my memory is fuzzy.. but they do have drop down brakes for when the ride is not in motion but completely forget how they do what they do and such and things.

I know the Impulses have the drop-down brakes you were referring to in order to bring it to a stop in the station, but I'm not sure if they're friction or magnetic.

 

[jolash]

Gatekeeper has wheels, so it doesn't rely on magnets to stop the train.

As far as the impulses, can't find any good shots, and my memory is fuzzy.. but they do have drop down brakes for when the ride is not in motion but completely forget how they do what they do and such and things.

I know the Impulses have the drop-down brakes you were referring to in order to bring it to a stop in the station, but I'm not sure if they're friction or magnetic.

Magnetic

 

[bmac]

Volcano's is friction but it's a special case.

 

[Antinos]

I'm fairly certain Jolash hit the nail on the head. Coasters like Gatekeeper, Diamondback, Leviathan, Maverick, and other modern coasters with magnetic brakes tend to have a combo of brake fins (some static, some retractable) and drive wheels. The wheels are used to stop the train in these cases.

Regarding the impulse coasters. I'm almost positive (no pun intended) that they just switch the direction of the current until the train comes to a stop.

 

[Jason Voorhees]

I've never heard of "Gatekeepr"

 

[furie]

Imagine you're in a glass house. Imagine throwing stones. Imagine not actually doing it

 

[Hyde]

I'm fairly certain Jolash hit the nail on the head. Coasters like Gatekeeper, Diamondback, Leviathan, Maverick, and other modern coasters with magnetic brakes tend to have a combo of brake fins (some static, some retractable) and drive wheels. The wheels are used to stop the train in these cases.

Regarding the impulse coasters. I'm almost positive (no pun intended) that they just switch the direction of the current until the train comes to a stop.

Bingo.

A 100% magnetic braking system does not actually exist on any full circuit roller coaster. Instead, "hybrid" would be a better term, using a combination of magnetic brakes for the initial deceleration, and frictional brakes (friction wheels, friction brakes) for the final stop.

For instance, majority of B&M brake runs use a horizontal set of magnetic brakes at the top of the brake run, followed by their traditional friction brake, which stand vertical.

To get a good look at the braking hardware on-board, wing coasters offer a great, open view of the assembly.

For the magnetic brakes, notice the horizontal brake fins on the train.

The friction brakes meanwhile catch onto the center spine of the train, which carries some metal/carbon compound. You can see the signs of friction in the center of the train, riding just over the tracks.

Intamin meanwhile begins with magnetic brake fins, slows trains to a very slow pace, and uses friction tires for the final stop.

For impulse roller coasters, it is in essence throwing the roller coaster into "reverse" to bring the train to a stop. The LIMs are then used to bring the roller coaster brake into the station, and taper off once the train is in position - it is an admittedly slow stopping procedure vs. full circuit coasters.

 

[Antinos]

Very well written post, Matt!

 

[Hyde]

^ Thanks!

It is also worth pointing out that B&M attaches the magnetic portion of the brakes to the track, with metal brake fins on-board the train. Intamin has done the opposite on some of their roller coasters (Maverick, Fahrenheit, TTD) - magnetic brake assembly on the train, and metal brake fins on the track.

The first magnetic brake system was installed on Intamin's Millennium Force in 2000 (Also the first-ever stadium seating train and cable lift). Silver Bullet at Knott's Berry Farm was B&M's first magnetic brake system in 2004.

 

[Antinos]

^I'm sure a lot of that has to do with packaging of the trains.

 

[dj-fireball999]

Good question and I have no idea... :lol:

I'll have to look on Rita the next time I go to Alton. Does it have kicker wheels in the station?

It does indeed. The trains come to a complete stop on the final brake run, from a combination of the retractable brake fins, as well as feeder wheels. They then scoot the train along to the offload platform, relying solely on them to stop the train on both platforms. Th13teen has the same system, no actual brakes stop the ride, just retractable magnets just before the station, which you can sometimes hear banging when they retract. They just slow the train down, but it's the kick wheels that do the rest, hence why they get chewed up so quickly. Same story in the drop zone, too.

 

[BBH]

I know Intamin Giant Drops have a primary magnetic braking system to stop the freefall, then hydraulic arms with rubber stops on top to bring the cars to a halt.