12 replies to this topic

[skiingintherain]

Hey, I'm new here, and I have some questions about ski lifts, and since, from what I have seen, you guys have some great knowledge on the technicalities of ski lifts. So here are a few questions regarding ski lift's safety, though this all only apply to detatchable chairlifts, that desperately need answering, lol:

1. What are some of the most common incidents that result in destroying/failing an auxiliary/gearbox/diesel engine/motor? I need as many answers as possible for at least 2 of those.

2. What exactly is a guide rail, and where is it located?

3. Diference between the conveyer and bullwheel?

4. How do hydraulics work when you use them for tensioning the haul ropes?

5. What would happen if the wires connected to the counterweight were suddenly cut off from the weight, and where is the counterweight located?

6. Where does the other end of the wires connected to the counterweight lead to?

7. What would happen to the chairlift and haul rope if the counterweight was disconnected?

8. Does every detatchable chairlift have down/compression assemblies? If so, where are they located, and what is their purpose exactly?

9. How many people attend each terminal during a ride?

10. How tough are haul ropes?

This post has been edited by skiingintherain: 29 June 2010 - 08:43 PM

[SuperRat]

1. What are some of the most common incidents that result in destroying/failing an auxiliary/gearbox/diesel engine/motor? I need as many answers as possible for at least 2 of those.

Poor lubrication or lubrication failure can destroy both gearboxes and diesel engines

2. What exactly is a guide rail, and where is it located?

The guide rail is used to stabilize a detachable grip as the jaws are opened & closed and as the grip moves around the terminal. The horizontal roller at the end of the hanger axle rides in the guide rail. Where the rail enters and exits the terminal it is flaired and is sometimes called the trumpet rail

3. Diference between the conveyer and bullwheel?

The conveyor turns the grip & chair 180 degrees around the terminal. The bullwheel deflects the haul rope 180 degrees and if it is the drive wheel, provides the traction to move the rope

4. How do hydraulics work when you use them for tensioning the haul ropes?

Hydraulic rams pull on the bullwheel carriage to keep tension on the rope. Rams use oil in a cylinder to push or pull on a piston by pumping the oil from on side of the piston to the other.

5. What would happen if the wires connected to the counterweight were suddenly cut off from the weight, and where is the counterweight located?

With no tension on the rope the weight of the rope and the chairs (and people if the chairs are loaded) would succumb to gravity's pull and fall to the ground. This violent act would also derope the towers and cause other damage. The counter weight is located at either the top or bottom of the lift.

6. Where does the other end of the wires connected to the counterweight lead to?

The counterweight rope is connected to the bullwheel carriage, the rolling frame the tension bullwheel is mounted to

7. What would happen to the chairlift and haul rope if the counterweight was disconnected?

If it was done in a controlled manner the rope would droop between towers and possibly touch the ground (see attached picture)

 DSCF0005.JPG (487.08K)
Number of downloads: 70

8. Does every detatchable chairlift have down/compression assemblies? If so, where are they located, and what is their purpose exactly?

Most chair lift's have a depression assembly at tower one where the angle of the rope changes. I'm not sure if I'll explain this clearly but where the terrain under the lift changes angle and makes a depression the lift's haul rope will also have be depressed to maintain proper loading on the nearby support assemblies. Because some tower's loads can change from positive to near negative between a unloaded and loaded condition (chairs) some towers have compression assemblies meaning they have both sheaves below and above the haul rope.

9. How many people attend each terminal during a ride?

This answer will vary a lot from area to area. At my area, not including the attendants managing the corral of skiers, we like to have one person in the load area and one inside on "buttons" watching the loading and up the line. The top of the lift is manned by one person.

10. How tough are haul ropes?

Very tough. I found this pdf on wire rope manufacturer Fatzer"s website: Haul Rope Breaking Strength

This post has been edited by SuperRat: 30 June 2010 - 05:29 AM

[SuperRat]

SuperRat, on 30 June 2010 - 05:08 AM, said:

2. What exactly is a guide rail, and where is it located?

The guide rail is used to stabilize a detachable grip as the jaws are opened & closed and as the grip moves around the terminal. The horizontal roller at the end of the hanger axle rides in the guide rail. Where the rail enters and exits the terminal it is flaired and is sometimes called the trumpet rail

The underlined above should be: The vertical roller. Its called the horizontal guide roller because it and the rail hold the grip in a horizontal plane but the roller itself is vertical. I've attached a photo of a Doppelmayr DT grip. Most detachable grips have a similar "guide roller".

 med_gallery_837_1_170720 (2).jpg (61.85K)
Number of downloads: 76

I've also attached a picture of a terminal without its enclosure. The trumpet section is seen on the right side in green. Its then continues horizontally, now orange, under the bank of conveyor tires. After a missing section of rail it continues, in orange, contouring around the back of the terminal. It continues on the far side until it ends in another green trumpet.

 dscf0034 (2).jpg (156.62K)
Number of downloads: 88

[Lift Dinosaur]

What Law Firm do you work for?

Dino

[Lift Kid]

Here is another photo of the guide roller SuperRat is referring to, but on a Poma TB-41 grip:

 tb41.jpg (392.54K)
Number of downloads: 34

The roller indicated by the arrow rides on the "trumpet" and guide rails to keep the grip stabilized while it's in the terminal.

[mthornton]

SuperRat, on 30 June 2010 - 05:08 AM, said:

1. What are some of the most common incidents that result in destroying/failing an auxiliary/gearbox/diesel engine/motor? I need as many answers as possible for at least 2 of those.

Poor lubrication or lubrication failure can destroy both gearboxes and diesel engines

I'll add a few more

> DC electric motors require periodic internal cleaning. The presence of moisture + a dirty atmosphere can accelerate accumulation of conductive contamination
> DC electric motors contain commutator/brush system which must receive periodic attention. A damaged commutator or worn brushes, left unattended, can quickly ruin a motor.
> Electrical events (external), can cause electrical stress in an electric motor which exceeds the insulation strength.
> All rotating machinery can be damaged by vibrations resulting from component imbalance, misalignment, thrust or shock. Lack of corrective action will result in premature failure. Vibration can also have electrical origin, such as improper operation of the SCR drive.
> Loss of effective cooling can result in overheating of equipment outside it's normal operating range.
> Time operating & routine wear necessitate periodic rebuilding of both electric motors and gearbox. If scheduled rebuilding is not performed, risk of component failure increases.

[SkiLiftsRock]

What would happen to a lift if the resorts power suddenly went out? Would the brakes apply?

[SuperRat]

Lift Dinosaur, on 30 June 2010 - 05:36 PM, said:

What Law Firm do you work for?

Dino

http://www.paynefears.com/

Not really though. I'm practicing without a license.

This post has been edited by SuperRat: 01 July 2010 - 12:55 PM

[Emax]

SuperRat, on 01 July 2010 - 12:54 PM, said:

http://www.paynefears.com/

Not really though. I'm practicing without a license.

Whew! It seemed like Dewey Getem & Howe.

[rniemi]

Did we miss some incident where a counterweighted detachable with no compression assemblies had a simultaneous counterweight and gearbox/motor/aux failure? Other than that, the questions were sorta written like homework questions, except I can't conceive of a class that would ask those specific questions!

-Ryan

[svlifttech68]

SkiLiftsRock, on 01 July 2010 - 09:51 AM, said:

What would happen to a lift if the resorts power suddenly went out? Would the brakes apply?

This does happen from time to time. Yes, as soon as the power goes out the breaks will dump and the lift will stop. At that point the power for the lift will have to be switched to AUX mode and the breaks (and possibly the tensioning system) pumped up manually. You can then run the lift as normal.

[SkiLiftsRock]

svlifttech68, on 02 July 2010 - 08:26 PM, said:

This does happen from time to time. Yes, as soon as the power goes out the breaks will dump and the lift will stop. At that point the power for the lift will have to be switched to AUX mode and the breaks (and possibly the tensioning system) pumped up manually. You can then run the lift as normal.

Thanks :) I wasn't sure is there would be a roll back or not.

[skiingintherain]

Thank you all for your answers, this has definetely helped me with my research =). Thanks again!