Those of us who enjoy going out to the slopes regularly every winter, will have spent a lot of time going up on the many lifts at the hill. Whether you take the T-bar or the chair, the odds are pretty good that you have spent a few minutes looking up as the poles go by and thinking about what exactly it is that is moving you along. You might have even noticed the wire rope and sheaf systems as you go alongside; depending on the speed and length of the lift, you probably have had more time to notice these features than you would have liked.
Ski lifts are actually fairly simple machines in nature, although in order to successfully run one the hills cannot afford to take any short cuts. The continuous wire ropes that the chairs hook on to are pulled through sets of sheaves at regular intervals, the whole process driven by a big motor usually located at the base of the lift.
Obviously, the sheaves that the wire rope runs through are the critical elements when it comes to the proper functioning of the lift, both in terms of safety and expedient delivery. An individual sheaf must be hardy and wear well, or the whole system may be compromised.
Generally, top of the line sheaves used to run the high end, high performance, high speed lifts are manufactured of cold formed steel and include self lubricating bushings. This type of bushing assists in keeping the maintenance of the sheaf up without too much manual attention.
It stands to reason that the functioning, moving parts of the lift, the sheaves and rope, are the most likely items to need replacing on these units, and it is important for the operators of the ski hill to find a good balance between quality and cost. The harsh conditions that this equipment is subjected to up on the hill also take their toll, so ski resort developers are very particular when it comes to finding the right wire ropes and sheaves for their mountains.