Minimum Operating Temperature

So, I was at Silver Dollar City this past weekend and after a freakishly early and strong cold front moved through, most of their coasters were not operating in the morning due to temps right around freezing. It did warm up later and just barely hit 41 in the afternoon, so for a brief window all of their major rides were running at one point or another, but what struck me was the variation in "minimum safe operating temperatures" they had posted out front for the guests. They ranged from right at 32F for Outlaw Run up to 41F for Time Traveler.

I'm sure these are set by the manufacturer, but does anyone here know what drives these? I couldn't help but wonder all day about the specific piece of the ride that could potentially start to have issues below a certain degree, and why does it vary so much? What is it about an RMC that allows it to function fine at freezing but a brand new Mack stops at 41?

I thought perhaps the brakes... but if I'm not mistaken Time Traveler uses magnetic brakes which, in my very uneducated-about-mechanical-engineering brain, I would think that would allow it to function in more weather types and a wider range of temps than other tech?

Perhaps TT has a different type of grease which becomes thicker at lower temps, meaning TT may struggle to complete its circuit at lower temps?

Anyone have some inside info?
Thanks a million!

My uneducated assumption is that the polyurethane wheels need to heat up to a certain temperature to ensure the train completes the circuit, but I don't really know.

Lubricants (both kind and type) in the train assemblies play a large role in safe operating temperatures.

They talk a little bit about wheels and temperatures in this video from Dollywood:

and really, nothing rides right with cold lubricant

Don't know if they still do,but at one time Cp used propane torches to heat to the

wheels for the Cedar Creek Mine Ride.

You could see them on the benches in the maintainence shed when you left the station.

I would have to think that air and hydraulic cylinders, that in many cases move braking assemblies, don't work so well in the cold. Lots of rubber seals in them that may stiffen up.

Yeah, plus if there's any moisture in the system you risk it freezing and the pneumatics potentially failing.

Zamperla sets limits for some of their rides in the low to mid 40s. I'd guess that the *real* limit is freezing, but you need to have some buffer there.

I have worked at lots of plants that use pneumatic systems in below freezing applications. Just have to make sure that dry air, typically with a dew point of -40F, is used.

Also consider if a ride runs a lot in the cold. Take rides at CP for example. They are use to extreme temps and run in cold weather compared to rides down south. The coldest temps I've ridden in was at CP when it dropped to 12 degrees with a 2 degree windchill and was riding Magnum until midnight. I remember the ride-ops were expecting it to go down due to the lines freezing but it kept going. Those rides were so brutal! Scott Short will back me up on this. We questioned our sanity staying there until close! :)

Also if the ride has run at all that day or not. I know years ago I asked the question to Dollywood. If the ride has been running for extended amount of time, it can continue to run in lower temps. But once it shuts down, the temps need to be higher before starting back up.

CoffinBoy said:

The coldest temps I've ridden in was at CP when it dropped to 12 degrees with a 2 degree windchill and was riding Magnum until midnight.

Not only would the ride likely not be operating, the record low in Sandusky, Ohio for anytime in the month of October is 24º F in October of 1981.

#fakenews

https://www.plantmaps.com/ohio-record-high-and-low-temperature-map.php

CoffinBoy said:

Scott Short will back me up on this.

I was a doubter until I read this.

Totally unrelated question: who's Scott Short?

An ironically named enthusiast who lives in the Cleveland area, and an OG member of CB and the podcast.

Cool. Now I know.

Conversation hasn’t changed much in the last decade.

https://coasterbuzz.com/Forums/Topic/coldest-temps-coasters-can-run-in

Shades said:

I have worked at lots of plants that use pneumatic systems in below freezing applications. Just have to make sure that dry air, typically with a dew point of -40F, is used.

Ski resort snow making systems (both air and water are pumped) operate in extremely cold sub zero temperatures. It's certainly possible to run pneumatics in the cold.

If those pneumatics were engineered for that purpose, absolutely. Amusement rides generally are not engineered for operation in freezing temps.

It should also go without saying that multi-million dollar amusement rides are just slightly more mechanically complex than devices that shoot water into the air.

A few years ago I got in a Request For A Proposal to design a pump station for Mc Murdo Station in Antarctica.

The station had to be able to operate down to -40F.

Believe it or not, the design temperatures weren't the biggest issues.

The contract would have required one of the design engineers (me) to supervise construction.

My wife didn't like the idea of me spending 8 months + in Antarctica.

BrettV said:

CoffinBoy said:

The coldest temps I've ridden in was at CP when it dropped to 12 degrees with a 2 degree windchill and was riding Magnum until midnight.

Not only would the ride likely not be operating, the record low in Sandusky, Ohio for anytime in the month of October is 24º F in October of 1981.

#fakenews

https://www.plantmaps.com/ohio-record-high-and-low-temperature-map.php

He must’ve meant 12° CELSIUS... That’s like 54° in ‘Murican temperatures. Oh and that windchill would’ve been 36°.