Chairlifts

An elevated passenger ropeway, or chairlift, is a type of aerial lift, which consists of a continuously circulating steel cable loop strung between two end terminals and usually over intermediate towers, carrying a series of chairs. They are the primary onhill transport at most ski areas (in such cases referred to as 'skilifts'), but are also found at amusement parks, various tourist attractions, and increasingly in urban transport.

Depending on carrier size and loading efficiency, a passenger ropeway can move up to 4000 people per hour, and the fastest lifts achieve operating speeds of up to 12 m/s (39.4 ft/s) or 43.2 km/h (26.8 mph). The two-person double chair, which for many years was the workhorse of the ski industry, can move roughly 1200 people per hour at rope speeds of up to 2.5 m/s (8.2 ft/s). The four person detachable chairlift ("high-speed quad") can transport 2400 people per hour with an average rope speed of 5 m/s (16.4 ft/s). Some bi and tri cable elevated ropeways and reversible tramways achieve much greater operating speeds.

A chairlift consists of numerous components to provide safe efficient transport.

Especially at ski areas, chairlifts are referred to with a ski industry vernacular. A one-person lift is a "single", a two-person lift is a "double", a three-person lift a “triple”, four-person lifts are “quads”, and a six-person lift is a "six pack". If the lift is a detachable chairlift, it is typically referred to as a “high-speed” lift, which results in a “high-speed quad” or “high-speed six pack”.

The capacity of a lift is constrained by the motive power (), the rope speed, the carrier spacing, the vertical displacement, and the number of carriers on the rope (a function of the rope length). Human passengers can load only so quickly until loading efficiency decreases; usually an interval of at least five seconds is needed.

The rope is the defining characteristic of an elevated passenger ropeway. The rope stretches and contracts as the tension exerted upon it increases and decreases, and it bends and flexes as it passes over sheaves and around the bullwheels. The fibre core contains a lubricant which protects the rope from corrosion and also allows for smooth flexing operation. The rope must be regularly lubricated to ensure safe operation and long life.

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