Track Structure Question

Does anyone know the reason that some roller coasters have track that is built in a triangle but some track that is built as a square in other parts of the track plan? If that doesn't make sense then look at a roller coaster where the rails are connected to a third tube of the same diameter to for a triangle. There are also coasters that have 4 tubes. What I'm interested to know is the engineering reason why a coaster would have some track of one configuration and some of another configuration even though the support structure looks the same at the different parts of the track. The Thunder Dolphin has track like this and it even changes configuration during a diving turn.

I'm looking for some real information and not speculation about the stiffness or strength of the different configurations.

Dave

You are most likely referring to Intamin Box and Triangle track. Different parts of the ride will need different amounts of structural support. If you look at Millennium Force's lift hill, for example, it has box track of the downward slope, and triangle track on the 122* 165' overbank. There are countless amounts of track styles, each varying in a different way. Look for CB's glossary on the subject, and maybe search for a topic like this.

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Well, I used to be able to see TTD from my house, then I moved.
Life's not fair.

Thanks for the info. I've seen only a few coasters that use the two different configurations on the same coaster which is why it is interesting.

Can't do much of a search on the subject since I don't know what uncommon words would get used to describe the benefits of these different structures.

Dave

Another example is Batwing, which has a single-pipe spine for most of the track length but a double-pipe spine in the loop.

Umm most of Batwing's track has a double spine,not single Two face also has a similar engineering for the spine as well.

Isn't there a track spottiing 101 feature on the site somewhere? Rectorsquid can find a whole host of info on just about every different track configuration just by reading the article.

The Track Spotting 101 article is under the Features button on the top of the page (under the logo). Its the only article there.

It's a matter of cost efficiency. There are 3 types of Intamin track...4 rail "Box" track, 3 rail "triangle" track and 2 rail "flat" track. Obviously, Box is stronger than Triangle which is stronger than Flat...stronger means it can span further between supports. Box track is more expensive than triangle track and so on.

The other part of this equation are the supports. The higher you go, the more expensive the supports get. Intamin's logic is that the higher you go, the less supports you use to save money, which means they use box tracks to span between columns. On areas very low to the ground, they can use many supports and the cheaper flat track. It's quite revolutionary...saving money all around because they're using the appropriate strength combination of track and supports for each section. Because Superman Ride of Steel isn't exceptionally tall it uses triangle and flat track. Notice the low helix turnaround is all flat track whereas the higher parts are triangle. Millennium Force is no exception to this rule. On Xcellerator and TTD, the forces are high enough to warrant an all box track design, save for the brake run. There is no safety concern at all...it's like building design....why use a 2x12 when a 2x6 will do?

-Seth

I just think it boils down to how much pressure is on the track. If not much is on, you don't need box track, so why waste that extra steel when you don't need it? I don't think the support thing is what they're going for though.

It's both the force exerted on the track and economics that determine what is used. First they evaluate the economics of the design, then they evaluate the stresses on the track to determine the overall configuration. Some rides have enough forces to warrant all box track (Wicked Twister...any Impulse for that matter) or all triangle track (Volcano) Or a healthy mix of all three (MF...the pull out and the overbanks use 4-rail track because of the force exerted).

The othe manufactures do this to some extent. While B&M's supports are more aesthetic than structurally efficient, their track spine depth changes based on the spacing of supports and forces exerted. The pull out on Nitro or Silver Star illustrates just how deep the box spine gets. Arrow woould thicken the spine on it's track in certain spots. It wasn't outwardly noticeable, but the walls of that center spine could get quite thick.

-seth

BATWING FAN SFA said:
Umm most of Batwing's track has a double spine,not single

Only part of the first drop and the looping has a double backbone.

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Roarrrr...

Actually, the taller the supports, the more expensive they are...so you'd want fewer supports then. When the track is closer to the ground, having more supports with flat track becomes cheaper than fewer with box track.

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"SOME people have NO class!" - Mom from the Whizzer queue

When standing in line for MF you can see all three of Intamin's track styles. Coming through the tunnel and over the bunny hill is the triangle track which switches to the box track for the overbanked turn which then switches to the flat track for the brake run.

Speaking of different track on the same coaster. My favorite has to be Phantom's Revenge with both Arrow and Morgan track. There's only the slightest difference but it is easily distinguishable where they switch from one to the other near the top of the drop heading into the ravine.