White fins on Mack and Gerstlauer launch coaster break runs?

[CrashCoaster]

I don't understand what the white fins are for on Mack launch coaster and Gerstlauer launch coaster break runs. The silver ones, sure, they're just magnetic brakes. Are the white ones LSMs, or are they brakes that can be disabled? What do you think?

 

[GuyWithAStick]

Brakes?

 

[CrashCoaster]

Brakes?

Well why have white ones and silver ones?

 

[Hixee]

Do you have a picture as an example? I've had a very quick look through the offerings on RCDB for Mack and Gerstlauer launch coasters and I'm not sure I can spot what you're referring to.

 

[CrashCoaster]

Do you have a picture as an example? I've had a very quick look through the offerings on RCDB for Mack and Gerstlauer launch coasters and I'm not sure I can spot what you're referring to.

Watch a POV on Helix, and you will see the white fins on the track (which look like LSM's)...

 

[CrashCoaster]

 

[Dar]

Maybe they're just coated brakes? I don't think they're controllable because there's no control boxes on the catwalks like there are on the launches, so they might just be a different composition that comes coated from the manufacturer.

 

[Hixee]

^I think there are control boxes - you can see them on the right fastened to the catwalk railings just after the second set of fins in question.

This almost certainly points to ATI's first assumption being correct. The "non-covered" brake fins are just standard "dumb" magnetic brakes. The covered fins contain the coils/fins for the LSMs. I suspect that they're used to control the speed of the train (I would assume slowing down only) a little bit more accurately than the normal magnetic brakes, and possibly even stop the train if required.

 

[CrashCoaster]

^and possibly even stop the train if required.

That's what the RCT3 brakes are for at the end of the brake run. Mag brakes can't physically stop a train.

I have also noticed that blue fire has them on its brake run, and it's entire mid-course have white fins... Besides the RCT3 brakes...

 

[Hixee]

That's what the RCT3 brakes are for at the end of the brake run...

I have also noticed that blue fire has them on its brake run, and it's entire mid-course have white fins... Besides the RCT3 brakes...

You mean friction brakes?

The mid-course brakes probably use LSMs as they can do all three jobs of trimming speed, stopping and starting the train.

I'm taking an educated guess now, but I think the friction brakes at the end of the brake run (both the MCBR and the final brakes) serve as more of a "last resort" brake. Friction brakes [usually] default to closed, so a power failure in the park would cause the fins to close and keep the block safe. The LSM fins are perfectly capable of stopping the train - provided they have power. The engineers will have made sure that they accounted for the scenario that the ride loses power while a train in on course. (Note: the "uncovered" fins do not rely on power, they're completely static, so they'd still slow the train down, as would unpowered LSM fins). Plus, even though the LSMs can actually stop the train, they'd need to keep running to hold a train there, so the friction brake probably helps there too.

Also, presumably if the train was to pass through the majority of the magnetic fins before they activated to stop the train (a last minute E-stop, for example), then their "active length" is no longer enough to stop the train. The friction brake is there to grab the fins in case they need to stop the train by the last car. Although we're getting into more and more speculation now.

 

[CrashCoaster]

- I'm well aware they're friction brakes, but you can't say that they don't look like the ones in RCT3.

On the LSM launches, the track type changes to more of a Vekoma or B&M kind of track with a spine, but on the MCBR and the FBR they stay with the old intamin-style track.

I doubt that a single pair of friction brakes would have the power to stop the train, bearing in mind the momentum going into it on the MCBR. The breaks would have to be very powerful. I'm currently reading the Coasters 101 book by Nick Weisenberger, and I have learned that the default position for friction brakes is closed because they are spring loaded, and that they use compressed air hydraulics to open them. (Most of you probably already knew that, but I highly recommend the book)...

 

[Hixee]

- I'm well aware they're friction brakes, but you can't say that they don't look like the ones in RCT3.

Oh absolutely, but don't forget which one came first.

On the LSM launches, the track type changes to more of a Vekoma or B&M kind of track with a spine, but on the MCBR and the FBR they stay with the old intamin-style track.

I wouldn't know the reason for this, but it's probably something to do with having to fit all of the launch hardware "into" the track. I suspect the additional stuff needed in the MCBR and final brakes isn't as bulky, as it wouldn't have to deal with the same currents? Or something, I'm not a Mack engineer unfortunately.

I doubt that a single pair of friction brakes would have the power to stop the train, bearing in mind the momentum going into it on the MCBR.

Don't underestimate the power of one of those friction brakes, they can excerpt a lot of force on the train. Also don't forget that the train would always be going reasonably slowly when it hits those friction brakes, due to all of the magnetic brakes proceeding it. The reason why is goes through the MCBR at such a speed is because the LSMs essentially push the train through. Remember, if the power is removed from an LSM fin, it acts just like a normal magnetic brake - the magnetic fins on the train will interact with the static fin and slow the train down. (As another aside: as the LSMs have the coils attached to the fins, you can use this to recover energy from the brake run - although it's never been awfully clear to me how many coasters utilise this).

 

[Hyde]

On the painting of fins for certain LSM fins, I'd agree that it is a protective coating; does anyone know if there could even be different metals used in those LSM hardware (like copper, etc.) that could rust or not be weatherized?

I'm taking an educated guess now, but I think the friction brakes at the end of the brake run (both the MCBR and the final brakes) serve as more of a "last resort" brake.

I've always understood it to be a rider comfort measure for doing a combination of "dumb" magnetic brakes and friction brakes. Magnetic brakes carry a higher capital cost, but provide a far smoother braking sensation. And since they have no moving parts and are quite literally large magnetics that are not electrified (that is, they do their work without any external power source), they prove to be more fail-safe than friction brakes which could fail due to component failure, environment (lots of rain), etc. By putting the magnetic brakes first, they do the brunt of braking work, with friction brakes and friction wheels (e.g. tires) taking over for lower speeds.

It's also important to bear in mind; magnetic brakes can not bring the train to a complete stop - only physical contact with the train can do that by way of a tire or friction brake. So friction brakes serve the primary purpose of blocking, and allowing the train to come to a quick, complete stop. Friction brakes also let you do easy blocking on an incline, which can be a space saving measure for brake runs and also allow for quicker dispatch of the train once it's released from the brakes (that is, gravity pulling it down!). Valravn's brake run is a good example of a mixture of magnetic and friction brakes, which give way to friction brakes and drive wheels once the brake run flattens out (drive wheels also serve the purpose of transfer track in this case).

 

[Dar]

^I think there are control boxes - you can see them on the right fastened to the catwalk railings just after the second set of fins in question.

This almost certainly points to ATI's first assumption being correct. The "non-covered" brake fins are just standard "dumb" magnetic brakes. The covered fins contain the coils/fins for the LSMs. I suspect that they're used to control the speed of the train (I would assume slowing down only) a little bit more accurately than the normal magnetic brakes, and possibly even stop the train if required.

Ah, I thought those control boxes were for the friction brakes at the end of the brake run! It seems silly to have them so far down the track from the actual fins?

 

[Hixee]

Ah, I thought those control boxes were for the friction brakes at the end of the brake run! It seems silly to have them so far down the track from the actual fins?

I suspect it's a combined controls/distribution enclosure for all of the sensors and brakes on that brake run. As it's not having to carry the large currents like the launch sections are, they probably need fewer enclosures and one/two will do. The same can be seen on blue fire's MCBR, which only has a couple of boxes at one end.

They've probably put it down that end to minimise the distance the larger cables are having to run from the main panels in the station.