What is the life expectancy of a rollercoaster?

With all this talk of repainting some of the major coasters at CP and after seeing all of that rust on the track, and then the tear down of BBW,(and that ride not bein that old)I would like to know what is the life expectancy of a roller coaster?
I mean if you look at MF and Raptor and TTD there is rust all over the track, ok it could be surface rust, but if you let that rust go too far it makes the metal thin and weak and if you blast or grind the rust away you make the metal thin as well.
And as we all know they just don't make things like they use to, things don't really last like they use to. Ok look at CS it was built in the 70's, back then they use to build things with longevity (look at the cars and houses) now they just build with cheaper,lighter materials, and with all of the use as well,you really have to sit down and really think are these rides getting close to there time or how much longer do they have before there declared unsafe?
And some of those rides don't need just a paint job,They need to be overhauled!!!
So what dose some of the people of this community think?

Coasters have long lives, both steel and wood. It depends though on how well the park keeps up on maintenance and checks. Sometimes if it's too cost effective to keep the ride running they'll tear the ride down....or move it.

CP does extensive tests every year on the steel coasters to find if there's any stress fractures or weak spots in the steel that may cause problems. Not to mention the routine daily/weekly checks they do during operation. So rest assured if there's any problems, they take care of them. Be it grinding, or complete replacement of track. Wood coasters are another story altogether in that it's easier/cheaper to replace wood than steel.

Yes a lot of the rust you see is surface rust and will happen no matter what you do. Heck, some coasters even have traces of rust even before their grand opening. Like you said though, it's not the rust you see that should worry you but the internal deterioration that you can't see. That's what those tests help find. I'm no metallurgist however so this can probably be explained better by someone else here. :)

Male roller coasters around... 74 years, and the females are about 62.

Might as well add that coasters in Canada live longer since they have universal healthcare. ;)

Very cold weather up there though, so I don't know. ;)

It also depends on the coasters performance. At least that's what I'm guessing. For example, Son Of Beast I will be very surprised if Kings Island keeps that coaster going with all the lawsuits, ratings and overall roughness it has had since it opened.

My question though is, every year when they do their check on the steel coasters, do they ever have to remove a piece of track because of rust?

Given that oxidation/rusting is a relatively slow process, I'd imagine they'd notice any problematic rust before fixing it required replacing any of the track, in most cases.

I'm no expert, but I seem to recall my dad (who is a metallurgist) explaining to me that thin surface rust can actually be quite good because it provides a protective coating to the metal underneath. Of course, when he explained it we were talking about highway light posts in Indiana, which had all been intentionally rusted before installation. Clearly the functions of a lamp pole are a little different than the stresses on a coaster track. I should ask him about it again sometime.

Ralph Wiggum said:
I'm no expert, but I seem to recall my dad (who is a metallurgist) explaining to me that thin surface rust can actually be quite good because it provides a protective coating to the metal underneath. Of course, when he explained it we were talking about highway light posts in Indiana, which had all been intentionally rusted before installation. Clearly the functions of a lamp pole are a little different than the stresses on a coaster track. I should ask him about it again sometime.

As an engineer I can tell you that there are certain types of steel that are designed to rust and that the rust acts as protective coating.

We use it for bridges and highway guide rails.

The only "problem" with these type of steels,at least the ones we use,are that they can't be painted.In fact the U.S. Steel building in Pitt.was made from this type of steel and got the nick name "The Rusty Nail".

I can also tell you that it is almost impossible to stop surface rust on most steel structures.

rpbobcat said:

I can also tell you that it is almost impossible to stop surface rust on most steel structures.

I don't agree. There are essentially two problematic components to existing rust - the iron oxide and embedded oxygen.

Acids like Phosphoric or Hydrochloric dissolve iron oxide quite rapidly, and dissolve the non-rusted iron much more slowly, making them (Phosphoric especially) well-suited for rust removal. However, the acid process brings hydrogen into the equation, which weakens the steel (hydrogen embrittlement).

The embedded oxygen is more tricky, which is why a process like electrolytic rust removal is much better, since it removes not only the iron oxide, but also that embedded oxygen, preventing further local rusting. And being that the process is electrolytic, its very effective. The problem is that the process isn't well-suited to coasters.

I know when they tore down the Double Loop, looking at the pictures, it was looking sad! There was alot of rust! It was 30 years old! I wonder what the Corkscrew looks like?

Well CS looks like it is in great shape compared to the other new ones but, we also have to take into consideration the weather as well.
I mean the ID looks good too but, I'm thinking it just could be those 2 just got a fresh coat of paint but the raptor use to have silver rails on it and then they re-did them (that will always be a mystery, cause it looked cooler that way) But that rust is all over those rides and there really starting to look very decrepit.
To me it just looks like they don't care about the appearance of there rides and keeping them looking nice and well taken care of, I know that they take great pride in there coasters but you look at it and some people think "Is it really safe?, with all of that rust on it" Not everyone thinks like this community dose!