Cold Weather Cable Lift Operation?

[Hyde]

So I was at Cedar Point this weekend, which was very cold, very wet, or very both. To the park’s credit, they worked to keep coasters online, despite literal concern of trains stopping on pre-lifts due to cold wheels (Gemini operators were encouraging guests to cheer trains to make it to the lift hill), or Steel Vengeance have trains overshoot a cold, wet brake run, leaving one set of tires to do all the lifting which, only barely, would drag trains back into the station (essentially taking ~45 seconds to move the train from brake run to station). For other coasters (Valravn, Gatekeeper, TTD), there was immense testing to get wheel assemblies warmed up to take on riders. Even then, such as for TTD, the immense weight of the train and coldness of the wheels made it difficult for the traction tires to catch in the brake run, causing rubber to squeal and will the train along.

So it was on Sunday, Millennium was operating in 40F/7C weather, but with a very weird operation cycle - the cable lift was moving very slowly. MF’s typical cable lift cycle begins slow for the first half, and then shifts to a faster gear for the second. MF this day was only staying in the first gear, very slowly creating the lift hill. So the operation was like this:

Instead of like this:

Anyone know if manufacturers/parks have cold weather operation of lift hills? Any concern of damage to the cable lift system in the cold?

 

[HeartlineCoaster]

ExpGeForce spited me once, with the claim 'too cold for the cable'.
So it's a thing. I can confirm that much.

 

[Snoo]

I've never seen it in cold weather mode but hell that is very interesting.

I will say it's no surprise. My car JUST did the same thing to me last night as it wouldn't let me go faster then 82mph due to the cold. Don't ask why I was driving almost 20mph over the speed limit but the normal limiter is 112mph. Cold is huge and slowing it down makes sense.

 

[Antinos]

The only thing I can think of is that the cold temperatures cause the material to be slightly more brittle. I wouldn't imagine that it'd cause THAT much of a change in material behavior to cause an issue, but I'd rather not dig up my notes from six years ago and try and figure out the math behind it.

Many things are simply designed to work in certain temperature ranges and, as @Snoo stated, engines are a great example. Essentially, there's a thin temperature band where the engine will optimally combust - if temperatures rise or fall too much, the engine won't output as much power or torque and fuel economy will suffer. Engine auto-stop is a good example of this: the whole point is to temporarily shut off the engine to improve fuel economy, but if the engine remains off for too long, the internal temperature will drop too low and worse emissions will come out of the tailpipe.

The point being...roller coasters are supposed to be ridden in the summer time.

 

[DelPiero]

Nerdy Mcnerdossi stuff

 

[Hixee]

^Whelp.

As ever, I can't actually answer this, but I can add to Marc's point. It's probably not an issue of "the ride can't work", but more a case of "let's not knacker it".

I suspect the lift hill staying at it's slow speed isn't so much about the additional force required to accelerate the train, but more to do with limiting the speed of the cables over the various drums and rollers. If the cable runs slowly over these tight radii it's subjected to less rapid stress changes than if it ran faster.

An engineer at Intamin has probably done a calculation to say:
>10°C: Cable is malleable enough to be run at any speed.
>0°C: Cable won't stand up to the rapid stresses, but will be okay run at low speed.
<0°C: Nah mate.

An analogy for @DelPiero - if in normal operation the cable has the feel of al dente spaghetti, when it gets cold it starts to take on the attitude of raw spaghetti. Perfectly capable of supporting a load, but won't like being rapidly wrapped round a drum.

Does TTD run on days like this? That'd bring this whole post down in flames, of course.

 

[DelPiero]

^Whelp.

As ever, I can't actually answer this, but I can add to Marc's point. It's probably not an issue of "the ride can't work", but more a case of "let's not knacker it".

I suspect the lift hill staying at it's slow speed isn't so much about the additional force required to accelerate the train, but more to do with limiting the speed of the cables over the various drums and rollers. If the cable runs slowly over these tight radii it's subjected to less rapid stress changes than if it ran faster.

An engineer at Intamin has probably done a calculation to say:
>10°C: Cable is malleable enough to be run at any speed.
>0°C: Cable won't stand up to the rapid stresses, but will be okay run at low speed.
<0°C: Nah mate.

An analogy for @DelPiero - if in normal operation the cable has the feel of al dente spaghetti, when it gets cold it starts to take on the attitude of raw spaghetti. Perfectly capable of supporting a load, but won't like being rapidly wrapped round a drum.

Does TTD run on days like this? That'd bring this whole post down in flames, of course.

I get it dude. It's just a really nerdy conversation

 

[Hyde]

Does TTD run on days like this? That'd bring this whole post down in flames, of course.

That's the irony, TTD was running perfectly fine throughout the entire day. Granted, it took them quite a few launches to get the trains over the top hat, and the slightest gust of wind would probably shut the whole operation down.

As mentioned by others, I suspect it to be a tolerance issue of components (wheel bearings, cable lift system, etc.), and not wanting to cause too much stress with colder weather. It was definitely noticeable on oldest rides opening first (which have relatively few "tight" tolerance components), while newer rides did not open until later in the day. Many rides were running 2 train operation as well, which I imagine is in part to keep the wheel assemblies warm and not let sit in the brake run. Good reason to still keep old Arrows around - they can run in a wider variety of weather!

 

[Hixee]

Well then, I'm ****ed if I know.

The other thing to bear in mind, is that it could be coincidental. Maybe they were running it at low speed for some other maintenance reason, and that just happened to be a cold(er) day.

Unless we can find a ride-op or engineer, I doubt we'd know for sure.

 

[Hyde]

Agreed - it was truly the strangest phenomena. I have never seen this kind of operation in the 18 years I've known the ride.

 

[b&mfanboy123]

Wasn't there something about how the Lift cable needed to be replaced and all?

 

[Snoo]

Wasn't there something about how the Lift cable needed to be replaced and all?

Not recently. The cable has been replaced, both through fatigue as well as snaps, throughout it's history. But if the cable is in urgent need of repair, they wouldn't run the ride.

 

[b&mfanboy123]

Not recently. The cable has been replaced, both through fatigue as well as snaps, throughout it's history. But if the cable is in urgent need of repair, they wouldn't run the ride.

Thanks!