A chair lift is an aerial transportation system primarily associated with winter ski resorts where it is used to carry skiers up a mountain. Chairs or bench-style seats are suspended from a motorized looped cabling system strung between terminal posts. Fixed grip chair lifts move slowly enough that passengers can disembark while the chairs are in motion, once they reach their destinations. To get on a chair lift skiers stand in the path of a chair, then sit down as it reaches them. Between entrance and exits points chairs might travel over points where the mountainside falls away to some distance.
Chair lifts in ski resorts are commonly referred to as skilifts and are further defined by how many people each chair can take. A “double” chair can take two, a “triple” three, a “quad” four, and a “six pack” lifts six persons. While the aforementioned fixed-grip chair lift moves slowly to allow loading and unloading while remaining in motion, a detachable-grip chair lift releases the pulley cable for loading and unloading. This allows chairs to move slower for this operation, but faster for the actual trip up the slope. Therefore, a detachable-grip chair lift is known as a “high-speed lift.”
A terminal post is fixed at each end of a chair lift’s path, each terminal supporting a bullwheel that redirects the lift up or down the mountain. One of the two bullwheels is the drive bullwheel, the other, the return bullwheel. The drive bullwheel is where the motorized mechanism is located. Between these two terminals there are usually a series of intermediate towers where pulley assemblies (sheaves) support and guide the cabling.
A chair lift is sometimes referred to as ropeway, although the “rope” of a chair lift is made from many wires wound around each other in specific patterns and orientations. This gives the cabling its strength. Ropeways must also be lubricated to allow the cabling to remain flexible and reduce friction that could cause fraying, particularly as the cable bends and flexes to pass over intermediate tower points and around bullwheels.
The braking system on a chair lift is located at the drive terminal, with an emergency brake that acts directly on the bullwheel. With the drive mechanism stopped and the bullwheel locked into place, the chair lift cannot accidentally “slip” or reverse itself. Some chair lifts also have braking systems built into the pulley assemblies located on the towers. Bullwheel positioning is also adjustable to maintain proper cable tension.
In addition to ski areas chair lifts are sometimes used in amusement parks. More often, however, these are enclosed lifts or elevated trams.