35 replies to this topic

[liftmech]

crazyskier91, on May 27 2004, 08:35 AM, said:

I haven't looked at any of the tower guards or whatever they are called recently but I made a couple of sketchs and still don't understand how effective they would be in high crosswinds.  The guards would catch the hanger arm but by the time that happened the angle of the arm and cabin would already be hitting the tower.  What am I missing in my thoughts?

The guidage should be placed so that the carrier does not hit tower or sheaves before it strikes the halo. If you have an undesirable chair/tower interface. then the guidage is probably misadjusted. I've had to adjust Riblet halos before due to slippage over the years.
If you're referring to a Poma when you say the chair will hit the tower first, you're right. That's not guidage at all (highlighted in the photo) but a 'Pomapass'- their version of a maintenance catwalk.

Attached File(s)

•  T_10_F_copy_2.JPG (119.23K)
  Number of downloads: 70

[crazyskier91]

That is what I was thinking of. So I wasen't wrong with my thoughts. Thanks for the pic John.

[floridaskier]

Doesn;t Poma have normal maintainance catwalks on their new lifts now?

[liftmech]

Only if you pay for it... Kind of a bad shot, but the in highlighted area is the new Pomapass- standard unless you specifically order catwalks. It's better than the old in that you can tie your fall protection lanyard to it and feel that it will hold you if you slip. The old ones weren't that sturdy.

Attached File(s)

•  T_11_E_copy.JPG (500.95K)
  Number of downloads: 52

[floridaskier]

Did the old ones have any place to hook the lanyard to? Doesn't look like it in the pictures

[spunkyskier01]

i have and have seen people hit the halos, its prtty scary, big jolt. i was at west mountain in new york and the kids love to swing the old center pole double into the guide. and some time its sends a shock wave down the line causing other chairs to bash into the guides(including mine). it jolts u around, thats for shure.

[liftmech]

Yes it does. The older Riblets, especially the centre-pole variety, wouldn't stop swinging (if you did't load exactly in the centre of the ramp) until you got about halfway up the line. The haul rope on most lifts is stretched so tight that rotating it in just one place will affect several hundred feet on both sides- that's the main reason why you're not supposed to swing the carriers while riding.

[edmontonguy]

The tension the lift creates as the chair passes over also manages to magnify the swinging dramatically.

[floridaskier]

On some Yans, the chairs lean in a lot as they go around the bullwheel, and then they swing in perfect time for about 3 towers after. It's kinda fun to watch

[edmontonguy]

That seems to be a common characteristic of Fg Lifts especially doubles. Is that because of the bullwheel flange or some other factor?

[liftmech]

On Yans it is a design factor. The upper shoulder of the bulwheel liner is much larger than the lower, and as the grip contacts it the chair rolls inward. Supposedly you use that to control chair swing, but as Tyler mentions it doesn't always work. The theory is that the chair has a tendency to swing outward because of centrifugal force, and by swinging it inward on purpose the two cancel. I've found that it only works at about 105% of full speed :P Other factors in chair swing are misajusted guide sheaves, which cause the rope to roll down or up into the liner, which then imparts a twist to the rope causing the chairs to swing. The higher the tension on a given lift, the more pronounced bullwheel issues become as well. Of course, ona low-tension lift, you then have line bounce to worry about, which is magnified in the wind (i.e. older Riblets).
The older Pomapasses had no place to hook your fall pro into, thus you walk out to the end of an 8-rocker and your lanyard is stretched tight because you have to hook it to the lifting frame.

[poloxskier]

The falcon at Breck is a really windy lift, since most of the line is exposed to the wind and the gusts frequently top 70mph. The only place I have been on the chair when it hit a guide was at the top where it is really high above the ground a gust blew us into the guide for the third to last tower. Needless to say the chair was shut down right afterwards.

There is also an anoying little ecentricity to chair 6 at breck. The Halo on the first tower is adjusted such that almost all of the chairs hit it when loaded.

[SkiBachelor]

I wonder why the falcon lift doesn't have a chair parking rail at the bottom of the wind can be that strong?

[poloxskier]

There are very few resorts in Colorado that park their chairs or cabins. Actualy off hand I cant think of any that park their chairs.

[Kicking Horse]

I can't think of any lift that parks the chairs @ night during the winter. Unless it's a Detachable Surface lift....

[poloxskier]

KZ, on May 25 2004, 11:47 PM, said:

Any lift will close. At boreal they stop the hsq at 50 M/H winds, so the gondola would probably be something like 40 or so since it probably isnt too aerodynamic.
<{POST_SNAPBACK}>

Breckenridge did or may still have an automatic switch that lowers the speed of the Falcon to 500fpm in high winds(60mph i think). They can either disable it in the motor house or keep running at that speed. The switch did at one point completely shut off the lift. We used to sit on the lift for about 10 min not moving and then hear a snowmobile in the distance and know that the circuit had been tripped.