News New Gondola Transportation - Disney Skyliner -

[GoofGoof]

Well thats not 100% the case, but the insurance risk would be to a point where it would be minimized before they'd sign off. The system is safe, it will be safe, and the craziness that people come up with is absolutely mind boggling. But then I'm reminded that people thought that if a train went over 50 mph, women's uteruses would fly out of their bodies, or that your entire body would melt.

Forget about even the insurance guys. Disney operations is incredibly focused on reducing costs and controlling maintenance expense. If there was even a remote chance that this rope would wear significantly faster than a standard rope they would have switched it out.

 

[flynnibus]

On the towers they don't really 'spin' at all, the cable just moves through them. They do move, but they're just rotating because of the cable. In the stations they are slower because they have to downgear the cabins so they are moving slower in the station so you can board.

Here’s something for you to google... your tires on your car operate as static friction as well... when both coasting and accelerating (up or down). Just like a sheave does and a brake or boost wheel.

When your tires loose traction... you switch to the kinetic coefficients of friction and you have far less friction, and hence far less control and hence “slip and slide”. You still have friction, just far far far less. Hence how the wheels will eventually will “catch” again and you go back to static friction.

Edit:
And a system being held together with friction still can generate a lot of heat... hence why tires are speed rated.

 

[MisterPenguin]

Those materials heat up in the sun more than ambient temperature because metal is a better conductor of the energy than air. The difference is not due to the structure — it’s basic chemistry. The point of the example was to simply illustrate that ambient temperature as a threshold is irrelevant because air doesn’t hold heat like metal does. The direct exposure to the sun is far more powerful than simple ambient air temp.

Metal gets hot in the sun because it will conduct faster than it transfers to the adjacent air. And ambient temp is more relative to the discussion if you want to talk about how efficient the ambient cooling can get. But it’s still going to be hotter than ambient air temp.... so back to my point. Ambient air don’t mean #&&$#* here

Wow.

At this point if you're discounting shape, trapped heat, IR radiation, and ambient conduction then, IMO, you have nothing useful to add.

I know that a metal cable holding a telephone pole upright is going to be way, way cooler than the metal of a car roof in the same sun. Because that's what happens in the real world.

 

[Nubs70]

Here’s something for you to google... your tires on your car operate as static friction as well... when both coasting and accelerating (up or down). Just like a sheave does and a brake or boost wheel.

When your tires loose traction... you switch to the kinetic coefficients of friction and you have far less friction, and hence far less control and hence “slip and slide”. You still have friction, just far far far less. Hence how the wheels will eventually will “catch” again and you go back to static friction.

And static friction still can generate a lot of heat... hence why tires are speed rated.

There is also a third breed of friction. That being rolling friction.

 

[flynnibus]

Wow.

At this point if you're discounting shape, trapped heat, IR radiation, and ambient conduction then, IMO, you have nothing useful to add.

I know that a metal cable holding a telephone pole upright is going to be way, way cooler than the metal of a car roof in the same sun. Because that's what happens in the real world.

You just moved the goal posts. The comparison was the metal to the air - not different metal shapes. I didn’t those topics because they are immaterial to debunking the initial claim - that ambient air temp is a meaningful temperature threshold in a system that is being blasted by thermal radiation.

Thermal conduction is a separate process that would work to offset the absorption of the thermal radiation. But no one is debating the cooling efficiency of the cable design... someone was trying to use air temperature as a threshold to the max temp of a metal being exposed to an external energy source.

 

[larryz]

You just moved the goal posts. The comparison was the metal to the air - not different metal shapes. I didn’t those topics because they are immaterial to debunking the initial claim - that ambient air temp is a meaningful temperature threshold in a system that is being blasted by thermal radiation.

Thermal conduction is a separate process that would work to offset the absorption of the thermal radiation. But no one is debating the cooling efficiency of the cable design... someone was trying to use air temperature as a threshold to the max temp of a metal being exposed to an external energy source.

Since you bring it up... anyone know how much the cable will stretch when it's hot and loaded versus when it's unloaded and cool?

 

[MisterPenguin]

You just moved the goal posts. The comparison was the metal to the air - not different metal shapes. I didn’t those topics because they are immaterial to debunking the initial claim - that ambient air temp is a meaningful temperature threshold in a system that is being blasted by thermal radiation.

Thermal conduction is a separate process that would work to offset the absorption of the thermal radiation. But no one is debating the cooling efficiency of the cable design... someone was trying to use air temperature as a threshold to the max temp of a metal being exposed to an external energy source.

OK.

But, let's say a car in winter is getting hit by an hour's worth of sun. And another car in summer is getting hit by an hour's worth of sun, but later in the afternoon so that the angle of incidence is the same. You're saying the roof of the car in sub-freezing weather isn't going to be significantly cooler than the roof of the car in ninety degree heat?

 

[danlb_2000]

Does anyone know the average air speed velocity of a laden swallow?

 

[flynnibus]

There is also a third breed of friction. That being rolling friction.

Which is kind of a misnomer...it’s more like “energy loss”.

The energy loss of the rolling system elements are likely a far greater component of the heat generation in the system than any discussion of rope friction... and it’s going to be more in the drive train and contacts than at the cable itself. The cable is rather rigid when it comes to deformity.

If anyone fears the cable getting really hot... just remember the cable is touching drive wheels all the time in the stations. They couldn’t let the cable slip all the time, nor get super heated or risk hyper accelerated wear or failure of those rubber drive wheels. If they are not solid... they are even more temperature sensitive.

TLr - all of this cable temperature due to friction is a non issue

 

[larryz]

Does anyone know the average air speed velocity of a laden swallow?

African or European?

 

[danlb_2000]

African or European?

I don't know!

 

[Nubs70]

Since you bring it up... anyone know how much the cable will stretch when it's hot and loaded versus when it's unloaded and cool?

Yes, thermal expansion of materials is a standard calculation. Any slack resulting in thermal contraction is counter acted by the tension created by the bullwheel counter weight. Problems will occur when cable temperature reaches the glass transition temperature of cable material.

 

[Monty]

Since you bring it up... anyone know how much the cable will stretch when it's hot and loaded versus when it's unloaded and cool?

There will likely be at least one, possibly multiple, hydraulic tensioners at the ends of routes, which will be able to adjust the tension on the cables to optimum based on the slight variations in cable length. I don't believe steel cables will stretch or contract significantly, but it would certainly be accounted for in the design.

 

[flynnibus]

OK.

But, let's say a car in winter is getting hit by an hour's worth of sun. And another car in summer is getting hit by an hour's worth of sun, but later in the afternoon so that the angle of incidence is the same. You're saying the roof of the car in sub-freezing weather isn't going to be significantly cooler than the roof of the car in ninety degree heat?

I reiterate what I said... “that ambient air temp is a meaningful temperature threshold”

So to use your example environment... the ice on your car can melt even if the air temperature is at freezing because the surface can be hotter than ambient air temperature.

All the other stuff you are trying to interject are completely different measures that are immaterial to the opening statement.

 

[flynnibus]

Since you bring it up... anyone know how much the cable will stretch when it's hot and loaded versus when it's unloaded and cool?

It’s a common design criteria for cable design. I don’t know what they have for a rule of thumb.. but I believe the stranded nature helps in this regard and the stations have some sort of tension adjustment on the wheel. I think that was one of the things liftblog highlighted in the review of that new install was the amount of travel they had in the adjustment.

 

[flynnibus]

The nylon in the cable maybe a design consideration to help reduce wear in the cable due to the cable literally rubbing against itself and fretting. Since the cable does through so much dynamic movement verse a traditional static stranded cable

 

[Ripken10]

Does anyone know the average air speed velocity of a laden swallow?

Wait, I'm confused. Are you talking European or African. I mean, that's a big deal you know.

 

[GoofGoof]

Does anyone know the average air speed velocity of a laden swallow?

I can only help with an unladen swallow:

 

[GoofGoof]

Wait, I'm confused. Are you talking European or African. I mean, that's a big deal you know.

It’s amazing how many of life’s most challenging questions were answered in one epic movie....or that 40+ years later there’s still so many people that can quote it line for line

 

[King Panda 77]

It’s amazing how many of life’s most challenging questions were answered in one epic movie....or that 40+ years later there’s still so many people that can quote it line for line

I find your lack of faith disturbing.