Skyride cable being replaced.

Walt:

How did you get those photos? Those are pretty f'n cool.

Also and this is almost off topic, but... I did not see any anti rollback devices on Demon Drop. Would they be similar to an elevator where it would use a set of breaks?

Look at Walt's picture #2. Located right above the word "Walt" on the copyright, there is an antirollback. Another about 5 feet above it on the same side and also some on the other side (has 2 green nylon pieces at it's bottom).

Demon Drop uses a set of one way pressure cams that pinch the secondary fins (not the brake fin) located on the back of the cars.

The fins can pass through the anti-rollbacks going up, however if the car was to reverse direction the cams, which are about half circle shaped with teeth, lock onto the fin and press it against the other plate of the anti-rollback device.

I don't have a picture of them but the cam looks very similar to the anti-rollbacks on a Vekoma SLC train (which I know Dave has posted a picture of before).

*** Edited 11/26/2005 8:12:31 PM UTC by Red Garter Rob***

Signal 37 Demon Drop reverse drive. :)

ForgottenEE, how could I forget Cedar Downs? Particularly given that I THINK the main drive on that one is a looped (read "spliced") wire rope, just like the one on Sky Ride only smaller. Although it is possible on a ride like that, where the rope is used to drive the ride, that the rope could be spliced with cable clamps, as on a Whip. I think the ropes that tie the horses together are segments as on the other rides mentioned. Incidentally, Cedar Point's Tilt-A-Whirl is an electric model, not a rope drive.

Hmm...I also failed to mention the wire ropes used for control purposes on Scramber (to operate the brake) and on Skyride (to activate the switches). But in fairness, I was trying to enumerate hoisting and hauling ropes. :)

Walt, thanks for the photos. Photo 1 shows the catcher I was talking about, and photos 2 and 3 clearly show the roller chain in the main elevator.

Red Garter Rob, you mentioned the anti-rollbacks on the SLC...the photos you mentioned are HERE on my web site. Actually, I think you're particularly familiar with the ride pictured on that page, although its color is a little different now... :)

--Dave Althoff, Jr.

Ohh yeah.. VERY familiar with that one.. ;)

http://www.cedarpoint.com/public/inside_park/webcam/camera2.cfm

If you check out the webcam right now there's a crane on the midway. I'm assuming this has to do with the cable replacement. :-)

If you click here, you can see live video of the event.

*** Edited 11/29/2005 6:07:47 PM UTC by Walt***

Thanks Walt, I forgot about that cam.

The Sky Ride cable is 1 & 1/8" (29mm) in dia. it is approx. 3400 feet in length after splicing (then its endless) the splice is apporx. 140 feet in length. The whole process takes a lot of time. A crane is used to lift the cable skyward at the lowest tower - thus lifting the counterweight, which is then blocked up to the desired height. The cable on the lake side of the towers is lowered to the ground. Care must be taken to tie off the sheave systems on the towers so they remain stable. The old cable is the cut and the new cable is "butt" sliced into the new cable. The old cable is pulled through and around - thus pulling the new cable on. The old cable is then scraped. After this is done the 2 new ends are pulled together and spliced together. Then lifted back in place. The whole job takes about 2 weeks. There are 6 tucks at each end of the splice. this splice is inspected annually as is the whole cable. What wears the cable out is the detatchable grips from the cars and the constant flexing as it goes around the large sheaves on the tension end and the drive end. (PS) (same thing with Cedar Downs only smaller cable) There have been approx. 8 or 9 cables installed on the Sky Ride since it was new.

I'm sorry - the new cable is "butt" spliced into the end of the OLD cable

Walt said:
Dave - here are 3 pictures that may help. 1 2 3

Walt, you never seem to disapoint. I want pics of CP's offseason (you have it). I want pics of WWL demo (you have it). I want pics of Skyhawk construction (you have it). And so on. You seem to have a picture of everything, and when you don't, you come out no where and add it.

Thank you!

Jim, do you know why they removed the sheave system on both sides of the lower tower? The Cleveland Cam showed that in the 2:29pm archive picture. Are they rebuilding the sheave systems?

Yes - The sheave assemblies are lowered to the ground via crane all in 1 piece. They are moved to a shop - dismantled and overhauled completely. New rubber liners, bearings checked and the entire unit inspected and all bushing changed if needed. Repainted and re-installed. Thats why the cable change will take so long.

So it's not just a cable change, but a full overhaul including bits that are rather difficult to work on with the rope in place. Got it. :)

--Dave Althoff, Jr.

It is possible that a sky ride/tram cable will last many, many, many years.... Cables are inspected yearly(at lest in a part-time/seasonal situation), the inspection will tell you how many broken strands there are in the cable, if any. Talking about the chair lifts with "fixed position chairs" (do not detach from cable to load and unload)... the chairs grips or clips(where the chair attaches to the cable) are removed and the position where the clip was attached to the cable is marked... the clips are then inspected with non-destructive testing and when reinstalled they are installed on a new position on the cable(not the marked positions). Once the chairs are removed the cable is coated with oil for off season protection.

Talking about the splices on the cable... there are only a few people qualified to do such a splice.

I would not recommend operating a cable type ride with a broken "strand" - a strand is a group of wires twisted together - thence a group of strands make up a wire rope or cable (along with a core wire or rope center). Code allows for so many broken "wires" in so many feet (depends on size of cable and application) Same with the splice - the length of the splice depends on the size of the rope (dia) and the application. The rope is usually replaced due to corrosion - or reduction in dia. (especially at the splice) - or so many broken wires in so many feet.

Jim Hancock said:
I would not recommend operating a cable type ride with a broken "strand" - a strand is a group of wires twisted together - thence a group of strands make up a wire rope or cable (along with a core wire or rope center). Code allows for so many broken "wires" in so many feet (depends on size of cable and application) Same with the splice - the length of the splice depends on the size of the rope (dia) and the application. The rope is usually replaced due to corrosion - or reduction in dia. (especially at the splice) - or so many broken wires in so many feet.

Sorry... yes, you are right. Typing a little faster than I was thinking. Thanks for the correction.

To be pedantic about it, the standards discuss the number of allowable broken wires per rope-lay.

For the vast majority of the people in this group who haven't the slightest idea what a rope lay is, it's (more or less) the length of rope in which a strand (and hence a wire) will rotate around the full circumference of the rope. That can be quite a distance; I have a piece of 22-gauge stranded electrical wire, and the rope-lay is about three inches. If you scale that up to the size of the Sky Ride haul rope (which you probably shouldn't, as the rope construction is very different from electrical wire....) that suggests a rope lay of about nine feet.

--Dave Althoff, Jr.

It's something like a foot or two.

The standard that I know of is 3 wires per strand per lay or 6 wires total for all strands per lay. I still don't know what the type of cable it is in terms of wires per strand and number of strands. I'm guessing that there are well over 100 wires in the rope. If there were 6 broken wires per lay for every lay then the cable would pull apart some wires and develop a flat spot or reduced diameter over time. A very good warning sign that the cable needs to be replaced

How are ropeways with detachable cabins handled if a wire frys? I know other applications utilize good ol' duct tape around the cable. I've seen it done on Millennium Force. Not to prevent seperation, but simply to hold the strands in place so they don't catch anything. It takes many weeks from the first known seperation on MF's cable before it's in a state of danger. Ropeways don't appear to be able to use duct tape effectively.

I was told that if a fray was detected that the ride would automatically e-stop, and they'd have to use a cherry picker to get everyone down.

Don't know how accurate that information is, it's what I was told.