Wheel assembly water misters?

[Hyde]

^ I did not say that brakes do not produce heat. Of course they get hot, even by just sitting in the sun. What I said is that it has no real effect on their braking ability.

California Screamin' has misters on its launch, not brakes. If brake overheating was a concern, we would see misters on numerous roller coasters' brake runs; especially those with magnetic brakes.

Ridged wheels would be indeed lighter than other a similar sized wheel with more mass, but the weight difference is negligible. The true advantage is in increased structural integrity and more surface area which leads to faster cooling.

 

[LiveForTheLaunch]

I never noticed them on Millennium Force, but as people have said, they use them on I-305. When it first opened they had that whole problem with the wheel that actually melted during the ride, so then they installed them to stop the melting and such.

 

[Hyde]

^ Millennium's misters are a new addition this year - I first spotted them in the middle of July, which prompted me to start this topic.

 

[LiveForTheLaunch]

I wonder why, after twelve years, they finally decided to install them. It hasn't been a problem in the past so I don't get why it's a problem now.

 

[Hyde]

It could just very well be testing a new theory.

We saw the misters crop up with I305. If it helps increase wheel life on I305, then you can also try the misters on MF to see if it might help improve its wheel life as well.

 

[Luxornv]

^ If magnetic brakes don't as you say produce heat, why on earth do California Screamin' have water misters on the main launch run, they offer no contact either but still get hot??
60-80% of the energy on an LSM launch moves the train the rest is transformed to heat > electromagnets get really hot.

On magnetic brakes works by inducing eddy currents in the fins, but these currents have nowhere to go so they are transformed into heat, all of it. The only coaster that recovers any form of energy from it's brakes is Freishütz. The rest of the magnetic brakes all transforms all it's energy into heat, contact or not, where else does the energy go it can't vanish into thin air. The faster and heavier the train is the more kinetic energy the brakes have to deal with.
And yes heat do offer changed properties on magnetic brakes. The hotter the brakes are the more the brakes "fade", and once you get to a certain point then you might end up with trains overshooting and causing havoc on the block system forcing the ride to emergency stop. Why else have the people from Intamin talked about that when I was chatting with them at Atmosfear press day and Mack maintenance guys checking the temperatures on the brakes on Blue Fire during it's first year of operation.

Ridges on the wheels are for lightness without sacrificing the rigidity that a solid wheel offer. And the lighter the train the less kinetic energy you have to deal with on the ride.

LIMs/LSMs get hot because they have electric current traveling through them during the launch. The current induces a magnetic field which is what propels the train. The magnetic brakes on the other hand are permanent magnets that have no current running through them. The heat generated by the reaction from the train is negligible and any heat gathered by sitting in the sun is just as insignificant.

As for the cooling on TTD's launch cable, I think it's only on the end of the launch where it begins to go below the track and into the hydraulic building.

As for the cooling of the wheels on coasters, I don't see it creating a noticeable difference. I can see why a tremendous amount of heat would build up in the wheels. The outside is a relatively soft polyurethane coating. The interaction with the track not only causes an immense amount of heat, but the flexing of the material causes even more. I think it would be better to let them go at a steady state temperature as opposed to cycling them. Any cracks that propagate in the material will grow more quickly when the wheels are cooled as the material itself will contract.