Sky Rides, Ski Lifts, Gondolas, Aerial Trams

[Schrecken]

ALT2870 - since you apparently know quite a bit about cable lifts, how exactly does the part of the gondola that grabs onto the cable work? I am referring to the kind that are permanently affixed to the cable. Someone mentioned worrying about wind, but I find the attachment point to the cable (and not the cable itself) on the gondola to be the most precarious and "sketchy" looking part..... Now whenever I am at a park that has a skyride or lift of any kind I will always ride it, but sometimes I find myself unconsciously gritting my teeth whenever the gondola passes a tower. This is because the attachment point seems to be barely hanging on - not unlike an acrobat in a circus hanging onto a tight rope with only a few fingers.

Obviously it isn't as precarious and tenuous as it looks (clearly in the one video the ski lift seat was tossed around quite a bit by high winds and did not come off...) but it does look as though there is precious little there to keep the gondola or chair attached to the cable.

[KingRCT3]

Since ALT2870 isn't responding yet, I thought I could give you some visuals in the meantime:

 

 

 

So here is a fixed chairlift grip. They have the same basic shape as detachable grips.

The actual grip is only the grey thing, as the two black blades are only here to help passing under depression towers. They lift the sheaves.

The grip doesn't go all around the cable for allowing the sheaves to pass under it when it's a lift tower. But it's tightly squeezed.

To open the grip, there's a screw on the far right. It allow the piece in turquoise on the drawing to slide to the left.

[ALT2870]

Sorry, this thread got lost somewhere near the bottom.

 

But yes, grips are extremely durable. There are two types of grips, a detachable grip and a fixed grip which is what I deal with. As King noted, the grip has multiple parts with the actual grip being what holds onto the haul rope. The grip can be pressured by several different means. (Though older chairs, especially Riblet chairs are actually woven into the haul rope.) The actual force extorted is over what the maximum carrier is rated to. Not only as a fail safe but as the grade gets steeper, the more weight it actually needs to hold to prevent slipping. (Hope I explained that well enough.) Our grip leave about 1-2 inches of space on the bottom or exposed haul rope, I'll take a picture for ya.

 

The black things that extend on either side of the grip are called needles or duck bills. They as mentioned are mainly for a comfortable ride for depression towers. (Technically they aren't needed, but it would be an extremely rough ride.) What actually connects the grip to the carrier is called a hanger.

 

With a fixed grip system, obviously the grip stays in the same spot. This over time can stretch a haul rope only in one location is a big problem. Therefore every month the cabins are moved 21 inches further down the line. This allows the haul rope to stretch more evenly. Unfortunately I do not have video of this as it is usually done early morning but I did get to see it last year when they did it after we were closed. There is a dedicated pump that hooks up to the tension system and is clamped onto the grip. The tension is applied and opens up the grip just enough to move the cabin. The tram is started and the cabin stays in place. It's a little jerky but it gets the job done.

 

The grip goes through a non-destructive test once a year. Basically the grip is "x-rayed" and they look for any cracks, fractures, etc. As far as I know the actually recorded incidents of a carrier falling off the haul rope is less then 20? (If that, I couldn't find a record.) Same thing with a grip slippage.

 

Let me know if that clears it up.

 

Also, I'm putting together a video showing the APU test that I did on Monday.