Coaster Track Joints

Does anyone know what they use to inhibit corrosion at the joints where track sections meet? It would seem to me a gasket of some sort would be in order.

Steel coasters? The old Arrow rides, there are no joints...sections are welded together. Everything else...paint, mostly.

--Dave Althoff, Jr.

I never knew that about Arrows, I bet that makes it a pain when one is relocated.

I think they leave, where the sections meet (track+track and track+support), primed but not painted. I'd say the primer acts pretty well against corrosion.

MF Track Piece

Looks like Adam is right (at least with regards to Intamin). Which makes sense. There aren't coaster wheels rolling over that area, and they are close enough together that it's not really exposed to the elements. The primer should be enough to prevent corrosion for the life of any coaster.

Liebe - a lot of them were also hand built on site, not pre-fab track sections. Just raw steel brought in, hand bent and welded into place.

liebevision said:
I never knew that about Arrows, I bet that makes it a pain when one is relocated.

That is one of the reasons you rarely see one relocated. It's usually not worth it.

While we are on the topic of joints.....why do some look like this and others don't??

http://www.sanduskyregister.com/media-gallery/detail/3418596/157921

That is a result of grinding. They grind down the areas where 2 joining rails aren't perfectly aligned. So the result is a smooth transition which, I believe, helps protect the wheels from being damaged. They will eventually paint over the grinded areas so you never know it was done.

Thanks Adam. I assumed it was a clearance/alignment issue, but I wasn't sure how much altering could be done onsite.

JuggaLotus said:

Liebe - a lot of them were also hand built on site, not pre-fab track sections. Just raw steel brought in, hand bent and welded into place.

No, even the Arrows were built from manufactured track sections. What is different is how they were put together. Arrow's track (prior to Steel Phantom) was all fit together on site and then the track and spine were welded. With later projects, they added flanges to the track spine so that the track sections could be bolted together and the rails welded.

Vekoma came up with a bolt-together method, where there is a plug at each end of each rail section. The plug is a half-round and has two holes in it. The half-rounds fit together to form a full circle, and two capscrews are threaded into place to hold the rail together. Obviously the heads go on the side where the wheels aren't, so if the guide wheels are on the outside, as on Woodstock, the screw heads will be on the inside; if the guide wheels are on the inside as on an SLC, the screw heads are on the outside.

--Dave Althoff, Jr.

^

Honest question. Why are Vekomas so much rougher than an Intamin or B&M? Is that a maintenance, ride design, or track style problem?

I always felt it had to do with the slop in the wheel bogies

Partly it is the fabrication. Compare Tennessee Tornado to GASM-II, for instance...the trains are virtually identical mechanically, but the ride quality is vastly different. Arrow and Vekoma tended to use circular curves at least in part because it made it a lot easier to translate from AutoCAD to rolled steel pipe. I actually think Arrow made smoother rides before they started using computers.

Another important issue, though, as Jason suggests, is guide tolerance. Arrow and Vekoma (their chassis are virtually identical) use fixed guide wheels on a rectangular axle set. The advantage to the design is that it steers from both ends and on both sides, but the disadvantage is that it requires a certain amount of slop to function. Watch Corkscrew closely from underneath and notice that the train will sometimes go through the final brake run with *none* of the guide wheels touching. This means that when the train approaches a curve, it won't begin to steer until the leading guide wheel on the outboard side strikes the rail. That is going to make a bit of a bump when it happens. By comparison, B&M and Intamin put a spring assembly on the guide wheels to hold them tight against the rail, so you get a much more gradual correction when the inboard leading wheel hits the curve. That, and the steering geometry is a bit different, allowing for less required play in the axle.

--Dave Althoff, Jr.