62 replies to this topic

[floridaskier]

It looks like just a regular tire.
I always thought it was something that was added on later , it looks so out of place.
When was the lift in the picture that John posted built? (Mayflower was in 85 I think)

[KZ]

Nob Hill at Sierra has one. The grips hit it on every chair, so maybe it prevents the rope from hopping out on a quick stop or something with a lot of bounce to it.

[liftmech]

I think Zack's on to something. I guess old B-1 had two or three of those as well, and they really are wheelbarrow tyres, I found out. They were part of the original design of the lift. That particular lift is a '79.

[Allan]

Why wouldn't they just use sheaves!!

[edmontonguy]

Cheaper then sheaves and less maintnence as it does much less than what sheaves would require


an interesting arrangement i saw on a doppelmayr t-bar had a combo sheave like this:

O____O
__OO___
with the top sheaves overhanging the bottom ones
is This a common type?

This post has been edited by edmontonguy: 28 April 2004 - 08:08 PM

[Allan]

A tire would be the same if not more maintenance - if it's an air-filled it would be more. It would be cheaper though. Is the first one in the picture below the one you're talking about? If so, yes it's quite common - we have four of these on our 6 tower T-Bar. There's one on the T-Bar picture I posted at the beginning of this thread, it's on the other side of the tower.

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•  Assemblies.jpg (321.86K)
  Number of downloads: 21

[Allan]

Hmm I actually had a picture... this one?

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•  T_Bar___Combo_Tower_Downhill__1.JPG (232.39K)
  Number of downloads: 19

[ODDfreakPERSON]

what brand is that???

[SkiBachelor]

It's a Doppelmayr.

[edmontonguy]

Yep those ones are they for a relatively neutral load?

[Allan]

You're right on with the neutral load - we have on on the uphill side of tower two which isn't so neutral - and it derails all the time from kids pulling sideways on the springboxes. Well except for last winter!

[edmontonguy]

How much to Compression assemblies help with horizontal forces? and is that why theu are more common on t-bars?

[Allan]

With compression assemblies the rope is kinda locked into the sheaves - you can adjust the bottom (support) sheaves to lift the rope a bit in the middle of the assembly, while the depression sheaves would cause a bit of pressure, hopefully holding the rope in place.
With T-Bars a lot of funny forces can come into play - like when someone lets go of a T over a tower could cause a bit of upward force, and if someone slingshots under a tower it would cause downward force. Bad kids also come into play bouncing the rope every which way.

[liftmech]

Combo assemblies are generally hard to derope, although it's not impossible- we had a ski instructor do that this winter on Storm King when he tried to ski on the wrong side of the tower. When removing the rope from a true combo, one has to remove the pressure that the opposing sheaves generate on the rope. On Pomas, for instance, you can stick a piece of all-thread through some slots in the spring assembly and tighten down some nuts; this compresses the spring and lifts the opposing sheaves up.

[Bill]

When you de-rail a "T" does it close the lift for the day or can you respond to the call and get it running again that day?

[edmontonguy]

I have been on a t-bar which had one of the sensors on the line alignment go. It wasn't a full derail but it took about 10 minutes to get the lift up and running again. Is it possible to receive injuries from a t-bar carrier cable that snaps? i have seen many broken ones which are often just left on the line.

[Allan]

Derail: I depends how serious it is, if the rope is out of the sheaves and 15ft above the tower - yes it will be closed. We have to bring a cat in to stand on and attach things to, and that just tears up the tow path. Not to mention the time it takes to get the rope back into the sheaves & inspect for damage. If it's just on the edge of the sideplate (not a full derail) we can get it running again fairly easily. If a towing cable snaps - yes injures can result, especially if it's on a steep section. If it's icy the people can fall and slide down into the next people, or even a tower. The broken ones circulating on the lift don't post much of a problem.

[floridaskier]

Towing cables snapping- how often does that happen?

[Allan]

It's not too common, we had none snap this year - but it does happen, and has happened to me!

[edmontonguy]

This is not a Compression assembly but i though it was very interesting. The single breakover tower has 16 sheaves!

(sorry to the two guys in the pic)

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•  Ski_20Lifts.jpg (996.35K)
  Number of downloads: 29