- Overlap and Confusion
- The Information Center for Ropeway Studies and the ROPEWAY Database
"Ropeways" is a general term, all inclusive, used for the various transport systems qualifying as a ropeway. For example: "The ropeways at XYZ Ski Area are excellent; they have a large double-reversible aerial tramway with 80 passenger carriers, a six passenger gondola, a new detachable quad chair lift, two remaining fixed-grip double chair lifts, a T-bar surface lift, and a wire rope tow."
A ropeway is a system for transporting materials and/or passengers in carriers suspended from or controlled by ropes. A system would qualify when a rope propels or controls carrier motion in transit on rail or other fixed support (funicular).
An individual ropeway is immediately described to identify it from others included under the general term. The first division is always to identify what the system as intended to transport: passengers or materials. Materials ropeways or tramways are seldom further classified other than monocable or bicable systems. In a monocable system, one rope serves to both support and control the carriers in transit. In a bicable system, separate ropes serve the two functions: a static support rope or "track cable" and a moving "haul rope." Passenger ropeways are more extensively classified depending upon operational characteristics and carriers. The following are most common and each will be briefly described: aerial tramway, gondola, funicular, detachable chair, fixed grip chair, surface lift, tows, and unique types.
An aerial tramway uses large carriers or cabins and travels high above ground. The carrier(s) -- one or single reversible, two or double reversible travel between terminals, stop, reverse direction and travel back on the same, usually stationary and counter weighted, track rope. Carriers are said to reciprocate between terminals. These systems are commonly referred to as "reversibles". Some of the large cabin reversible systems are seen extensively in Europe and in the United States at, among others: Estes Park and Royal Gorge, Colorado; Albuquerque, New Mexico; and Palm Springs, California.
Gondolas are small carriers set at regularly-spaced close intervals. The systems are continuously circulating with carriers passing around terminal bull-wheels. Carriers detach from hauling rope in terminals, are decelerated and carried through the unloading and reloading areas at very slow speed, then accelerated for reattaching to the haulage rope for high speed travel "on the line" between terminals. These systems are popular in ski areas and amusement parks. Gondolas can be seen and used at Vail, Steamboat and other areas in Colorado and quite extensively in ski areas around the United States and Europe.
The funicular is controversial among ropeways. It qualifies in that a wire rope controls the carriers even though a funicular may travel at ground level or on structurally supported steel tracks. The installation at Royal Gorge, Colorado, is classic. It was built by Otis Elevator in 1929 and is considered by many as an inclined elevator; but is qualified as a ropeway and falls under the jurisdiction of the Colorado Passenger Tramway Safety Board.
Detachable Chair Lift
Detachable chair lifts are virtually the same as gondolas, but the carrier is a multi-passenger open chair (usually 4 or more) with restraining bar and footrest. Extremely high capacity is common for skiers using special arrangements to facilitate loading at a comfortably slow carrier speed and traveling at a high line speed.
Fixed-grip Chair Lift
Fixed-grip chair lifts were "standards of the industry" from the early 1940s to the mid 1980s. Multi-passenger carriers circulated between and around terminals at a constant speed. The drawback was, the carrier speed comfortable for loading and unloading was slow "on the line" between terminals. Systems were popularly designated by carrier capacity; e.g. single-chair, double-chair, triple, quad, etc.
Surface lifts are largely used in ski areas to move skiers along the snow surface by means of an overhead haulage rope with attached towing devices. Further designation was by carrier type; e.g., disc, J-bar, T-bar, etc. Loading and unloading is accomplished between terminals with empty carriers circulating around the terminal bull-wheels at constant line speed.
Unique and/or special type passenger ropeways are occasionally introduced. The "Funitel", introduced in Europe ten years ago and now in the United States, is a classic example.
In addition to the classifications as discussed above, ropeways are described and compared by: operational characteristics, capacity, length and vertical rise, line speed, and loading speed. Each are briefly discussed here.
Operational characteristics indicate whether the system operation is: continuous circulating, intermittent circulating (stop to load), or reversible. In continuous circulating, carriers move around the terminals and maintain their order on the return line; most commonly, a fixed grip chairlift with carrier speed constant on the line and through the terminals. An intermittent system slows or stops periodically but carriers eventually go around a terminal and return on a parallel line. For a reversible, the carriers stop at each terminal, reverse direction of travel and return on the same line.
Capacity of a ropeway is stated in passengers per hour. Capacity is a function of carrier capacity, carrier spacing, and the speed of the line at the loading point. A double chair ski lift with carriers at 60 foot spacing and traveling at 550 feet per minute has a capacity of 1100 passengers per hour.
Length and vertical rise
Length of a ski lift is considered the slope length between terminals. Vertical rise is the change in elevation between terminals. Downhill skiers love knowing how much "vertical" they will ski each time they run between ski terminals. The skiing industry was largely responsible for introducing a new term to ropeway terminology: vtfh (vertical transport feet per hour). This is a measure of lift capacity in passengers per hour multiplied times the vertical rise in feet and divided by 1000.
An older model double chair lift having a capacity of 1200 passengers per hour and a vertical rise of 800 feet would have a vtfh of 1200 x 800 / 1,000 = 960. Vtfh influences the horsepower requirement of the drive and therefore, the cost of the lift. It determines the common classification of large or small. Today a vtfh of 1000 or less would be small; 2000 to 3000 are large and now commonplace.
Line speed and loading speed
Line speed and loading speed Carrier speed is measured on the line between terminals. If working with a detachable gondola or chair, the speed at the load or discharge point is loading speed. Speed "on the line" determines time in transit and speed " at loading and discharge points" facilitates loading and unloading, increasing comfort and safety. Line speed for fixed grip quad-chairs serving skiers is 450 feet per minute ( 5 miles per hour); the same carrier as a detachable system can run 1,150 feet/minute (13 miles per hour). Carrier speed of loading (or unloading) of a fixed grip system is the same as line speed; for the detachable it could be 150 feet per minute.
Standards governing passenger ropeways include The American National Standard for Passenger Ropeways, Aerial Tramways, Aerial Lifts, Surface Lifts, Tows and Conveyers -- Safety Requirements ANSI B77.1-1999. Additionally in this state, Colorado Passenger Tramway Safety Board Rules and Regulations must be followed.
Every ropeway has some basic components. Carriers, terminals, towers, ropes, and evacuation and rescue systems will be briefly discussed.
Carriers are an essential and distinguishing component of every ropeway. On materials ropeways they are generally buckets. On passenger ropeways they may be large cabins, usually described by capacity (e g.; two 80 passenger cabins on a double reversible system). They are almost always totally enclosed. There is usually standing room only at full capacity; otherwise, seating is optional.
- Gondolas are usually totally enclosed for year-round use or (less often) partially enclosed as in amusement parks. The term is most often preceded by capacity, for example, 6 passenger gondola.
- Chairs are described by capacity such as single, double, triple, quad, 6 passenger, 8 passenger etc. Chairs may have a foot rest and restraining bar (do not call restraining bar a safety bar).
- Surface lift towing units are designated: disc type when a single circular disc is inserted between the legs, J-bar (single) or T-bar (for 2 or more) when between and behind passengers.
- The carrier for a funicular is large and, generally, seating is provided. It can also be called a car. It is most often enclosed. Wheels below the carrier support it on fixed steel rails; carrier motion is controlled by wire rope.
Virtually all ropeways have two terminals. If a vertical change takes place, the terminals are upper and lower terminals. For ski lifts, the two terminals are referred to as loading and unloading (or discharge) terminals. Always, there is a drive terminal and a return (idler) terminal. Either may be a tension terminal where counter- weights or a tensioning device is located. A loading/unloading structure between terminals is now seldom used. On material ropeways an intermediate structure could be used to change the otherwise straight alignment of the ropeway. This called an angle station.
Intermediate structures support carrying and haulage ropes between terminals. These are most often called towers although occasionally they can be a large pressure frame. Seldom is a pylon used. Towers carry line sheaves (not called wheels and pronounced shiv not sheev) for moving ropes and/or "saddles" for stationary track ropes.
The rope is the heart of the ropeway. The rope (almost always a wire rope) is formed by inter-twining individual wire to form a strand and then the strands to form a rope. There are many variations of the processes used in manufacturing rope and in choosing the rope for the application. This is a major concern for rope manufacturers and ropeway designers. Of more impact to those of us in the Library would be to determine if there are both a haulage rope and track rope (bicable) or that one rope support both functions (monocable). Ropes are generally described by their outside diameter in inches; other aspects of their construction are not as important. Common usage would be a 1 1/8 inch haul rope and a 1 7/8 inch track rope for a bicable system or a 1 3/8 inch rope for a monocable system. Ropes are made endless by using a "long splice" or they are terminated by attaching an end to a carrier, anchor, or counterweight by use of end connections such as sockets.
Evacuation and Rescue System
Aerial ropeways have provision for an auxiliary drive in the event of electric power failure, usually gasoline or diesel driven. Large reversibles have a rescue system which send an independently powered, small carrier out to remove passengers from a stranded carrier. Most aerial systems have provision for evacuation of stranded carriers using harness and rope to lower individual passengers to the ground below.
Ropeways may well overlap and there may be confusion with closely related transport systems using wire rope, notably: cableways, elevators, and people-movers.
Cableway is a misnomer in discussing ropeways. A cableway is a system for hauling materials on a hook or is a carrier supported and controlled by wire rope(s), but it has the unique ability to raise or lower the load in transit. Most often a cableway is used for construction as on a dam, bridge, pipeline, or similar projects. It can also be used for dredging, moving materials, stock piling, etc. Cableways have their own national standard: Safety Standards for Cableways, Cranes, Derricks, Hoists, Hooks, Jacks and Slings (ASME/ANS/B30.19).
An elevator is a mechanical device with a moving platform or cage for conveying persons or goods from one level to another as in a building. The carrier most often raises and lowers vertically and operates in a guided shaft. Confusion may arise between an inclined elevator and the funicular which qualifies as a ropeway.
Avoid using the term "cable" when discussing ropeways although term like monocable, bicable, track cable, and track cable brake will prevail. Cable, when used, most often relates to electricity and implies a bound or sheathed group of mutually insulated conductors.
A passenger ropeway otherwise qualifying and used for transporting large numbers of foot passengers, particularly in an urban environment, is classified a "people mover." The large cabin, reversible ropeway operating from Manhattan to Governor's Island in New York is an example.
The first indication of transport using rope comes from the rugged Asiatic countries of China, Japan, and India. Men used fiber rope to cross the chasms, initially transferring themselves, hand over hand, with the body suspended by a crude harness. The next application was to pull oneself in a basket that also had a few belongings of the traveler. Although Fausto Veranzio of Venice illustrated a bicable passenger ropeway in 1616, the ropeway industry generally credits Wybe Adam, a Dutchman, with erecting the first successful operational system in 1644. Early ropeway technology and development were lead by the Europeans, particularly Germany and the alpine countries, Austria and Switzerland; later Italy and France. Most rapid development followed introduction of wire rope and later, the electric drive. Many innovations were introduced by extensive use of military tramways in the ferocious mountain warfare between Italy and Austria in World War I.
Ropeway technology and use of wire rope has a long history in North America dating back to the last century when wire rope was used for transportation applications, such as canal transport or the famous San Francisco cable cars. Materials ropeways or tramways, once used extensively in mining operations, find limited use in the United States today. During the past forty to fifty years, however, the major growth of ropeway systems has been generated within the ski/recreational industry and most recently for people movers, an urban transportation application.
The above very brief account regarding ropeway classification, operational characteristics is intended for general use. For the ropeway design engineer, manufacturer, owner/operator and others, more specific and technically oriented material is more appropriate. Access to that information is available from the Information Center for Ropeway Studies at the Colorado School of Mines, among others, and the ROPEWAY Database.
In 1991, the Information Center for Ropeway Studies was established at the Arthur Lakes Library on the Colorado School of Mines campus in Golden, Colorado. The Information Center provides access to a comprehensive collection on information relative to the history, theory, design, and operation of ropeway systems including recreational and materials ropeways. The Center currently houses over 300 books, seven journal and newsletter titles, a manufacturers' catalog file, a slide and lantern slide collection, and other media.
From its beginning, the Ropeway Center has been guided by an Advisory Board to ensure its applicability and serviceability to those interested in this subject. Because of their desire to have ropeway information available on a national and international level, an early decision to build a publicly accessible, comprehensive database was made. This database, ROPEWAY, contains citations not only for information held in the Center but also information pertaining to the theory, design, history, and operation of ropeway systems found elsewhere.
The ROPEWAY Database is a bibliographic database of journal articles, symposia, books, reports, handbooks, manufacturers' catalogs, and any other information pertaining to the history, theory, design, and operation of ropeway systems. Each record had the following information: author, title, source, meeting, publisher, publication year, key words, abstracts, location of the item, call number in the Arthur Lakes Library, and the language of the document.
In 2005, individuals from O.I.T.A.F.-N.A.C.S. (the International Organization for Transportation by Rope - North American Continental Section) pledged personal monetary gifts or corporate funds to endow the Ropeway Center. In 2006, O.I.T.A.F. contributed funds toward the endowment so that adequate support for the Center would continue in perpetuity.
The Associated Wire Rope Fabricators (AWRF), in 2007, gifted a significant collection of manufacturers' catalogs pertaining to wire rope fittings, slings, and related components to the Ropeway Center, along with memorabilia from various companies. Individuals and companies from this organization endowed a special fund for the preservation and conservation of these materials.
For more information, contact the Ropeway Center at 303-273-3690 or email us.