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82-403: Leitner Ropeways manufactures various types of ropeways, such as fixed-grip and detachable chairlifts ; monocable , bicable , and tricable gondola lifts ; telemix ; surface lifts ; aerial tramways ; funiculars ; and inclined elevators. In 1888, Gabriel Leitner established the business, specializing in farm machinery, ropeways for material transportation, waterwheels and sawmills. In 1925,

164-606: A 6.4 mm ( 1 ⁄ 4  in) diameter. Static wire ropes are used to support structures such as suspension bridges or as guy wires to support towers. An aerial tramway relies on wire rope to support and move cargo overhead. Modern wire rope was invented by the German mining engineer Wilhelm Albert in the years between 1831 and 1834 for use in mining in the Harz Mountains in Clausthal , Lower Saxony , Germany . It

246-435: A strand . Several strands are wound around a textile core, their twist oriented in the same or opposite direction as the individual wires; this is referred to as Lang lay and regular lay respectively. Rope is constructed in a linear fashion, and must be spliced together before carriers are affixed. Splicing involves unwinding long sections of either end of the rope, and then winding each strand from opposing ends around

328-402: A Flemish eye and splice; to 100% for potted ends and swagings. When the wire rope is terminated with a loop, there is a risk that it will bend too tightly, especially when the loop is connected to a device that concentrates the load on a relatively small area. A thimble can be installed inside the loop to preserve the natural shape of the loop, and protect the cable from pinching and abrading on

410-509: A centre. The direction of the outer strands is opposite to that of the underlying strand layers. Ropes with three strand layers can be nearly non-rotating. Ropes with two strand layers are mostly only low-rotating. Depending on where they are used, wire ropes have to fulfill different requirements. The main uses are: Technical regulations apply to the design of rope drives for cranes, elevators, rope ways and mining installations. Factors that are considered in design include: The calculation of

492-433: A distance of a few miles or kilometers. Steel wires for wire ropes are normally made of non-alloy carbon steel with a carbon content of 0.4 to 0.95%. The very high strength of the rope wires enables wire ropes to support large tensile forces and to run over sheaves with relatively small diameters. In the so-called cross lay strands, the wires of the different layers cross each other. In the mostly used parallel lay strands,

574-407: A force is the rate at which it does work , and is given by the product of the driving force and the cable velocity) . In most localities, the prime mover is required to have a backup drive; this is usually provided by a Diesel engine that can operate during power outages. The purpose of the backup is to permit clearing the rope to ensure the safety of passengers; it usually is much less powerful and

656-604: A number of innovations in the design, materials and manufacture of wire rope. Ever with an ear to technology developments in mining and railroading, Josiah White and Erskine Hazard , principal owners of the Lehigh Coal & Navigation Company (LC&N Co.) — as they had with the first blast furnaces in the Lehigh Valley — built a Wire Rope factory in Jim Thorpe, Pennsylvania , in 1848, which provided lift cables for

738-404: A passenger missing a ski, or otherwise unable to efficiently unload, such as patients being transported in a rescue toboggan . These uses are the chief purpose for a visible identification number on each carrier. Aerial ropeways always have several backup systems in the event of failure of the prime mover. An additional electric motor, diesel or gasoline engine—even a hand crank—allows movement of

820-478: A series of chairs . They are the primary on-hill transport at most ski areas (in such cases referred to as 'ski lifts'), but are also found at amusement parks and various tourist attractions. Depending on carrier size and loading efficiency, a passenger ropeway can move up to 4,000 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

902-404: 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" or "express" lift, which results in an "express quad" or "high-speed six pack". The capacity of a lift is constrained by

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984-406: A wire rope tends to fray readily, and cannot be easily connected to plant and equipment. There are different ways of securing the ends of wire ropes to prevent fraying. The common and useful type of end fitting for a wire rope is to turn the end back to form a loop. The loose end is then fixed back on the wire rope. Termination efficiencies vary from about 70% for a Flemish eye alone; to nearly 90% for

1066-400: Is activated all power is cut to the motor and the emergency brake or bull-wheel brake is activated. In the case of a rollback, some lifts utilize a ratchet like system to prevent the bull-wheel from spinning backwards while newer installations utilize sensors which activate one or more bull-wheel brakes. All braking systems are fail-safe in that a loss of power or hydraulic pressure will activate

1148-410: Is also used to transmit force in mechanisms, such as a Bowden cable or the control surfaces of an airplane connected to levers and pedals in the cockpit. Only aircraft cables have WSC (wire strand core). Also, aircraft cables are available in smaller diameters than wire rope. For example, aircraft cables are available in 1.2 mm ( 3 ⁄ 64  in) diameter while most wire ropes begin at

1230-428: Is composed of as few as two solid, metal wires twisted into a helix that forms a composite rope , in a pattern known as laid rope . Larger diameter wire rope consists of multiple strands of such laid rope in a pattern known as cable laid . Manufactured using an industrial machine known as a strander, the wires are fed through a series of barrels and spun into their final composite orientation. In stricter senses,

1312-399: Is connected to the cable with a steel cable grip that is either clamped onto or woven into the cable. Clamping systems use either a bolt system or coiled spring or magnets to provide clamping force. For maintenance or servicing, the carriers may be removed from or relocated along the rope by loosening the grip. Also called a retention bar or safety bar , these may help hold passengers in

1394-465: Is largely limited to smaller chairlift installations, otherwise the AC motor would need to be significantly oversized relative to the equivalent horsepower DC motor. The driveshaft turns at high RPM , but with lower torque . The gearbox transforms high RPM/low torque rotation into a low RPM/high torque drive at the bullwheel. More power is able to pull heavier loads or sustain a higher rope speed (the power of

1476-634: Is located at the site in Telfs , Austria . Leitner France SAS is located at the site in Montmélian , France . Leitech s.r.o. is located at the Stará Ľubovňa site in Poprad , Slovakia . Chairlift An elevated passenger ropeway , or chairlift , is a type of aerial lift , which consists of a continuously circulating steel wire rope loop strung between two end terminals and usually over intermediate towers, carrying

1558-457: Is not used for normal operation. The secondary drive connects with the drive shaft before the gear box, usually with a chain coupling. Some chairlifts are also equipped with an auxiliary drive, to be used to continue regular operation in the event of a problem with the prime mover. Some lifts even have a hydrostatic coupling so the driveshaft of a snowcat can drive the chairlift. Carriers are designed to seat 1, 2, 3, 4, 6, or 8 passengers. Each

1640-451: Is on the ends of the drag ropes on a dragline . The end loop of the wire rope enters a tapered opening in the socket, wrapped around a separate component called the wedge. The arrangement is knocked in place, and load gradually eased onto the rope. As the load increases on the wire rope, the wedge become more secure, gripping the rope tighter. Poured sockets are used to make a high strength, permanent termination; they are created by inserting

1722-451: Is then fitted to the bolt over the ropes (the saddle includes two holes to fit to the U-bolt). The nuts secure the arrangement in place. Two or more clips are usually used to terminate a wire rope depending on the diameter. As many as eight may be needed for a 2 in (50.8 mm) diameter rope. The mnemonic "never saddle a dead horse" means that when installing clips, the saddle portion of

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1804-428: Is used specifically on wire rope, it is called a "Molly Hogan", and, by some, a "Dutch" eye instead of a "Flemish" eye. Swaging is a method of wire rope termination that refers to the installation technique. The purpose of swaging wire rope fittings is to connect two wire rope ends together, or to otherwise terminate one end of wire rope to something else. A mechanical or hydraulic swager is used to compress and deform

1886-437: Is useful for children—who do not fit comfortably into adult sized chairs—as well as apprehensive passengers, and for those who are disinclined or unable to sit still. In addition, restraining bars with footrests reduce muscle fatigue from supporting the weight of a snowboard or skis, especially during long lift rides. The restraining bar is also useful in very strong wind and when the chair is coated by ice. Some ski areas mandate

1968-566: Is usually constructed of transparent acrylic glass or fiberglass. In most designs, passenger legs are unprotected; however in rain or strong wind this is considerably more comfortable than no canopy. Among more notable bubble lifts are the Ramcharger 8 at Big Sky Resort , North America's first high speed eight pack; and the longest bubble lift in the world is the American Flyer high speed six pack at Copper Mountain . To maintain safe operation,

2050-627: The Ashley Planes project, then the back track planes of the Summit Hill & Mauch Chunk Railroad , improving its attractiveness as a premier tourism destination, and vastly improving the throughput of the coal capacity since return of cars dropped from nearly four hours to less than 20 minutes. The following decades featured a burgeoning increase in deep shaft mining in both Europe and North America as surface mineral deposits were exhausted and miners had to chase layers along inclined layers. The era

2132-633: The J-bar , the two most common skier transports at the time—apart from mountain climbing . His basic design is still used for chairlifts today. The patent for the original ski lift was issued to Mr. Curran along with Gordon H. Bannerman and Glen H. Trout (Chief Engineer of the Union Pacific RR) in March 1939. The patent was titled "Aerial Ski Tramway,' U.S. patent 2,152,235 . W. Averell Harriman , Sun Valley's creator and former governor of New York State , financed

2214-442: The 17th century for crossing chasms in mountainous regions. Men would traverse a woven fiber line hand over hand. Evolutionary refinement added a harness or basket to also transport cargo. The first recorded mechanical ropeway was by Venetian Fausto Veranzio who designed a bicable passenger ropeway in 1616. The industry generally considers Dutchman Adam Wybe to have built the first operational system in 1644. The technology, which

2296-432: The 1990s are infrequently fixed-grip. Existing fixed-grip lifts are being replaced with detachable chairlifts at most major ski areas. However the relative simplicity of the fixed-grip design results in lower installation, maintenance and, often, operation costs. For these reasons, they are likely to remain at low volume and community hills, and for short distances, such as beginner terrain. Wire rope Wire rope

2378-534: The assembly is placed on the load-bearing or "live" side, not on the non-load-bearing or "dead" side of the cable. This is to protect the live or stress-bearing end of the rope against crushing and abuse. The flat bearing seat and extended prongs of the body are designed to protect the rope and are always placed against the live end. The US Navy and most regulatory bodies do not recommend the use of such clips as permanent terminations unless periodically checked and re-tightened. An eye splice may be used to terminate

2460-410: The bar must be swung up, out of the way. The physics of a passenger sitting properly in a chairlift do not require use of a restraining bar. If the chairlift stops suddenly (as from use of the system emergency brake), the carrier's arm connecting to the grip pivots smoothly forward—driven by the chair's inertia—and maintains friction (and seating angle) between the seat and passenger. The restraining bar

2542-463: The boarding area. This ensures the correct, safe and quick boarding of all passengers. For fixed grip lifts, a walkway can be designed so that it moves at a slightly slower speed than the chairs: passengers stand on the moving walkway while their chair approaches, hence easing the boarding process since the relative speed of the chairlift will be slower. Aerial passenger ropeways were known in Asia well before

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2624-446: The brake. Older chairlifts, for example 1960s-era Riblet Tramway Company lifts, have a hydraulic release emergency brake with pressure maintained by a hydraulic solenoid. If the emergency brake/stop button is depressed by any control panel, the lift cannot be restarted until the hydraulic brake is hand-pumped to proper operating pressure. Some installations use brittle bars to detect several hazardous situations. Brittle bars alongside

2706-402: The bullwheel. This prevents the potentially disastrous situation of runaway reverse operation. The rope must be tensioned to compensate for sag caused by wind load and passenger weight, variations in rope length due to temperature and to maintain friction between the rope and the drive bullwheel. Tension is provided either by a counterweight system or by hydraulic or pneumatic rams, which adjust

2788-403: The chair in the same way as a safety bar in an amusement park ride. If equipped, each chair has a retractable bar, sometimes with attached foot rests. In most configurations, a passenger may reach up and behind their head, grab the bar or a handle, and pull the restraint forward and down. Once the bar has swung sufficiently, gravity assists positioning the bar to its down limit. Before disembarking,

2870-443: The chairlift's control system monitors sensors and controls system parameters. Expected variances are compensated for; out-of-limit and dangerous conditions cause system shutdown. In the unusual instance of system shutdown, inspection by technicians, repair or evacuation might be needed. Both fixed and detachable lifts have sensors to monitor rope speed and hold it within established limits for each defined system operating speed. Also,

2952-419: The chairlift, it is preferable to strike the safety gate—that is, it should not be avoided—and stop the lift than be an unexpected downhill passenger. Many lifts are limited in their download capacity; others can transport passengers at 100 percent capacity in either direction. The boarding area of a detachable chairlift can be fitted with a moving walkway which takes the passengers from the entrance gate to

3034-449: The company grew from a workshop employing 10 employees to a factory to produce agricultural machinery. In 1947, the company build its first chairlift in Corvara, Italy. In 1970, agricultural machinery production ceased and was replaced by snow groomer engineering. In 1980 a production plant was built. In 1983, the company developed a detachable grip for chairlifts and gondola lifts . In 1985,

3116-491: The company's first tricable gondola lift . Originally founded in 1861, Agudio was later acquired by Leitner Ropeways. In 2015, Agudio was integrated into Leitner Ropeways, however, the brand was retained. The company has five sites. The Sterzing site located in Sterzing/Vipiteno, Italy, serves as the headquarters of Leitner AG / SpA. The Sterzing-Unterackern site is also located in Sterzing/Vipiteno, Italy. Leitner GmbH

3198-480: The construction Filler, Seale or Warrington. In principle, spiral ropes are round strands as they have an assembly of layers of wires laid helically over a centre with at least one layer of wires being laid in the opposite direction to that of the outer layer. Spiral ropes can be dimensioned in such a way that they are non-rotating which means that under tension the rope torque is nearly zero. The open spiral rope consists only of round wires. The half-locked coil rope and

3280-400: The core (fibre core or steel core). The lay direction of the strands in the rope can be right (symbol Z) or left (symbol S) and the lay direction of the wires can be right (symbol z) or left (symbol s). This kind of rope is called ordinary lay rope if the lay direction of the wires in the outer strands is in the opposite direction to the lay of the outer strands themselves. If both the wires in

3362-401: The core. Sections of rope must be removed, as the strands overlap during the splicing process. Every lift involves at least two terminals and may also have intermediate supporting towers. A bullwheel in each terminal redirects the rope, while sheaves (pulley assemblies) on the towers support the rope well above the ground. The number of towers is engineered based on the length and strength of

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3444-644: The detached carriers through the terminals. Aerial lifts have a variety of mechanisms to ensure safe operation over a lifetime often measured in decades. In June 1990, Winter Park Resort performed planned destructive safety testing on Eskimo , a 1963 Riblet Tramway Company two-chair, center-pole fixed grip lift, as it was slated for removal and replacement with a high-speed quad Poma lift. The destructive testing attempted to mimic potential real-life operating scenarios, including tests for braking, rollback, oily rope, tree on line, fire, and tower pull. The data gleaned from this destructive safety testing helped improve

3526-746: The first detachable gondola lifts were made in Brunico and Valtournenche , Italy. The first 4-seater chair was made in Obereggen , Italy. In 1999, the company acquired the ropeway division of Waagner Biro . In 2003, a company-wide reorganization resulted in the Leitner Group being formed. In the same year, the Leitwind wind turbine was released. In 2008 the MiniMetro was first built in Perugia, Italy. In 2009, Leitner produced

3608-469: The fitting, creating a permanent connection. Threaded studs, ferrules, sockets, and sleeves are examples of different swaged terminations. Swaging ropes with fibre cores is not recommended. A wedge socket termination is useful when the fitting needs to be replaced frequently. For example, if the end of a wire rope is in a high-wear region, the rope may be periodically trimmed, requiring the termination hardware to be removed and reapplied. An example of this

3690-406: The full-locked coil rope always have a centre made of round wires. The locked coil ropes have one or more outer layers of profile wires. They have the advantage that their construction prevents the penetration of dirt and water to a greater extent and it also protects them from loss of lubricant. In addition, they have one further very important advantage as the ends of a broken outer wire cannot leave

3772-404: The height of some towers to improve clearance over a road. Passenger loading and unloading is supervised by lift operators. Their primary purpose is to ensure passenger safety by checking that passengers are suitably outfitted for the elements and not wearing or transporting items which could entangle chairs, towers, trees, etc. If a misload or missed unload occurs—or is imminent—they slow or stop

3854-453: The inner wires much better from corrosion than synthetic fibers do. Fiber cores are the most flexible and elastic, but have the downside of getting crushed easily. The second type, wire strand core, is made up of one additional strand of wire, and is typically used for suspension. The third type is independent wire rope core (IWRC), which is the most durable in all types of environments. Most types of stranded ropes only have one strand layer over

3936-451: The inside of the loop. The use of thimbles in loops is industry best practice . The thimble prevents the load from coming into direct contact with the wires. A wire rope clip, sometimes called a clamp, is used to fix the loose end of the loop back to the wire rope. It usually consists of a U-bolt , a forged saddle, and two nuts. The two layers of wire rope are placed in the U-bolt. The saddle

4018-443: The inspection of the wire ropes. Lifting installations for passenger transportation require that a combination of several methods should be used to prevent a car from plunging downwards. Elevators must have redundant bearing ropes and a safety gear. Ropeways and mine hoistings must be permanently supervised by a responsible manager and the rope must be inspected by a magnetic method capable of detecting inner wire breaks. The end of

4100-495: The lay length of all the wire layers is equal and the wires of any two superimposed layers are parallel, resulting in linear contact. The wire of the outer layer is supported by two wires of the inner layer. These wires are neighbors along the whole length of the strand. Parallel lay strands are made in one operation. The endurance of wire ropes with this kind of strand is always much greater than of those (seldom used) with cross lay strands. Parallel lay strands with two wire layers have

4182-406: The lift to prevent carriers from colliding with or dragging any person. Also, if the exit area becomes congested, they will slow or stop the chair until safe conditions are established. The lift operators at the terminals of a chairlift communicate with each other to verify that all terminals are safe and ready when restarting the system. Communication is also used to warn of an arriving carrier with

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4264-438: The loose end of a wire rope when forming a loop. The strands of the end of a wire rope are unwound a certain distance, then bent around so that the end of the unwrapped length forms an eye. The unwrapped strands are then plaited back into the wire rope, forming the loop, or an eye, called an eye splice. A Flemish eye, or Dutch Splice, involves unwrapping three strands (the strands need to be next to each other, not alternates) of

4346-420: The minimum and maximum rope tension, and speed feedback redundancy are monitored. Many—if not most—installations have numerous safety sensors which detect rare but potentially hazardous situations, such as the rope coming out of an individual sheave. Detachable chairlift control systems measure carrier grip tension during each detach and attach cycle, verify proper carrier spacing and verify correct movement of

4428-411: The most common, though AC motors and AC drives are becoming economically competitive for certain smaller chairlift installations. DC drives are less expensive than AC variable-frequency drives and were used almost exclusively until the 21st century when costs of AC variable-frequency drive technology dropped. DC motors produce more starting torque than AC motors, so applications of AC motors on chairlifts

4510-417: The motive power ( prime mover ), 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

4592-497: The outer strands and the outer strands themselves have the same lay direction, the rope is called a lang lay rope (from Dutch langslag contrary to kruisslag , formerly Albert's lay or langs lay). Regular lay means the individual wires were wrapped around the centers in one direction and the strands were wrapped around the core in the opposite direction. Multi-strand ropes are all more or less resistant to rotation and have at least two layers of strands laid helically around

4674-414: The position of the bullwheel carriage to maintain design tension. For most chairlifts, the tension is measured in tons . Either Diesel engines or electric motors can function as prime movers. The power can range from under 7.5 kW (10 hp ) for the smallest of lifts, to more than 750 kW (1000 hp) for a long, swift, detachable eight-seat up a steep slope. DC electric motors and DC drives are

4756-686: The project. Mont Tremblant , Quebec opens in February 1938 with the first Canadian chairlift, built by Joseph Ryan. The ski lift had 4,200 feet of cable and took 250 skiers per hour. The first chairlift in Europe was built in 1938 in Czechoslovakia (present-day Czech Republic ), from Ráztoka, at 620 m (2,034 ft), to Pustevny, at 1,020 m (3,346 ft), in the Moravian-Silesian Beskids mountain range. New chairlifts built since

4838-588: The rope and prevent it from falling if it should come out of the track. They are designed to allow passage of chair grips while the lift is stopping and for evacuation. It is extremely rare for the rope to leave the sheaves. In May 2006, a cable escaped the sheaves on the Arthurs Seat, Victoria chairlift in Australia causing four chairs to crash into one another. No one was injured, though 13 passengers were stranded for four hours. The operator blamed mandated changes in

4920-448: The rope drive limits depends on: The wire ropes are stressed by fluctuating forces, by wear, by corrosion and in seldom cases by extreme forces. The rope life is finite and the safety is only ensured by inspection for the detection of wire breaks on a reference rope length, of cross-section loss, as well as other failures so that the wire rope can be replaced before a dangerous situation occurs. Installations should be designed to facilitate

5002-430: The rope if it has the proper dimensions. Stranded ropes are an assembly of several strands laid helically in one or more layers around a core. This core can be one of three types. The first is a fiber core, made up of synthetic material or natural fibers like sisal. Synthetic fibers are stronger and more uniform but cannot absorb much lubricant. Natural fibers can absorb up to 15% of their weight in lubricant and so protect

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5084-403: The rope to eventually unload passengers. In the event of a failure which prevents rope movement, ski patrol may conduct emergency evacuation using a simple rope harness looped over the aerial ropeway to lower passengers to the ground one by one. A steel line strung alongside a mountain is likely to attract lightning strikes. To protect against that and electrostatic buildup, all components of

5166-410: The rope, worst case environmental conditions, and the type of terrain traversed. The bullwheel with the prime mover is called the drive bullwheel ; the other is the return bullwheel . Chairlifts are usually electrically powered, often with Diesel or gasoline engine backup, and sometimes a hand crank tertiary backup. Drive terminals can be located either at the top or the bottom of an installation; though

5248-421: The safety and construction of both existing as well as the next generation of chairlifts. As mentioned above, there are multiple redundant braking systems. When a Normal Stop is activated from the control panel, the lift will be slowed and stopped using regenerative braking through the electric motor and the service brake located on the highspeed shaft between the gearbox and electric motor. When an Emergency Stop

5330-447: The sheaves detect the rope coming out of the track. They may also be placed to detect counterweight or hydraulic ram movement beyond safe parameters (sometimes called a brittle fork in this usage) and to detect detached carriers leaving the terminal's track. If a brittle bar breaks, it interrupts a circuit which causes the system controller to immediately stop the system. These are small hooks sometimes installed next to sheaves to catch

5412-455: The strands such as a broken wire, pitting caused by corrosion or wear, variations in cross sectional area, and tightening or loosening of wire lay or strand lay. If passengers fail to unload, their legs will contact a lightweight bar, line, or pass through a light beam which stops the lift. The lift operator will then help them disembark, reset the safety gate, and initiate the lift restart procedure. While possibly annoying to other passengers on

5494-460: The summer of 1936. Prior to working for Union Pacific, Curran worked for Paxton and Vierling Steel, also in Omaha, which engineered banana conveyor systems to load cargo ships in the tropics. (PVS manufactured these chairs in their Omaha, NE facility.) Curran re-engineered the banana hooks with chairs and created a machine with greater capacity than the up-ski toboggan ( cable car ) and better comfort than

5576-417: The system are electrically bonded together and connected to one or many grounding systems connecting the lift system to earth ground. In areas subject to frequent electrical strikes, a protective aerial line is fixed above the aerial ropeway. A red sheave may indicate it is a grounding sheave. In most jurisdictions, chairlifts must be load inspected and tested periodically. The typical test consists of loading

5658-418: 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. Various techniques are used for constructing the rope. Dozens of wires are wound into

5740-436: The term wire rope refers to a diameter larger than 9.5 mm ( 3 ⁄ 8  in), with smaller gauges designated cable or cords. Initially wrought iron wires were used, but today steel is the main material used for wire ropes. Historically, wire rope evolved from wrought iron chains, which had a record of mechanical failure. While flaws in chain links or solid steel bars can lead to catastrophic failure , flaws in

5822-415: The top-drive configuration is more efficient, practicalities of electric service might dictate bottom-drive. The drive terminal is also the location of a lift's primary braking system. The service brake is located on the drive shaft beside the main drive, before the gearbox. The emergency brake acts directly on the bullwheel. While not technically a brake, an anti-rollback device (usually a cam) also acts on

5904-515: The uphill chairs with bags of water (secured in boxes) weighing more than the worst case passenger loading scenario. The system's ability to start, stop, and forestall reverse operation are carefully evaluated against the system's design parameters. Load testing a new lift is shown in a short video. Frequent visual inspection of the rope is required in most jurisdictions, as well as periodic non-destructive testing. Electromagnetic induction testing detects and quantifies hidden adverse conditions within

5986-604: The use of safety bars on dangerous or windy lifts, with forfeiture of the lift ticket as a penalty. Vermont and Massachusetts state law also require the use of safety bars, as well as most Ontario and Quebec in Canada. Restraining bars (often with foot rests) on chairlifts are more common in Europe and also naturally used by passengers of all ages. Some chairlifts have restraining bars that open and close automatically. Some lifts also have individual canopies which can be lowered to protect against inclement weather. The canopy, or bubble,

6068-417: The wire and keeping them off to one side. The remaining strands are bent around, until the end of the wire meets the "V" where the unwrapping finished, to form the eye. The strands kept to one side are now re-wrapped by wrapping from the end of the wire back to the "V" of the eye. These strands are effectively rewrapped along the wire in the opposite direction to their original lay. When this type of rope splice

6150-477: The wires making up a steel cable are less critical as the other wires easily take up the load. While friction between the individual wires and strands causes wear over the life of the rope, it also helps to compensate for minor failures in the short run. Wire ropes were developed starting with mining hoist applications in the 1830s. Wire ropes are used dynamically for lifting and hoisting in cranes and elevators , and for transmission of mechanical power . Wire rope

6232-613: The world: from Alaska to Argentina, Australia and Spitsbergen. The Bleichert company also built hundreds of aerial tramways for both the Imperial German Army and the Wehrmacht. In the latter part of the 19th century, wire rope systems were used as a means of transmitting mechanical power including for the new cable cars . Wire rope systems cost one-tenth as much and had lower friction losses than line shafts . Because of these advantages, wire rope systems were used to transmit power for

6314-750: Was early in railroad development and steam engines lacked sufficient tractive effort to climb steep slopes, so inclined plane railways were common. This pushed development of cable hoists rapidly in the United States as surface deposits in the Anthracite Coal Region north and south dove deeper every year, and even the rich deposits in the Panther Creek Valley required LC&N Co. to drive their first shafts into lower slopes beginning Lansford and its Schuylkill County twin-town Coaldale . The German engineering firm of Adolf Bleichert & Co.

6396-464: Was founded in 1874 and began to build bicable aerial tramways for mining in the Ruhr Valley . With important patents, and dozens of working systems in Europe, Bleichert dominated the global industry, later licensing its designs and manufacturing techniques to Trenton Iron Works, New Jersey, USA which built systems across America. Adolf Bleichert & Co. went on to build hundreds of aerial tramways around

6478-618: Was further developed by the people living in the Alpine regions of Europe, progressed rapidly and expanded due to the advent of wire rope and electric drive. World War I motivated extensive use of military tramways for warfare between Italy and Austria. The world's first three ski chairlifts were created for the ski resort in Sun Valley, Idaho in 1936 and 1937, then owned by the Union Pacific Railroad . The first chairlift, since removed,

6560-517: Was installed on Proctor Mountain, two miles (3 km) east of the more famous Bald Mountain , the primary ski mountain of Sun Valley resort since 1939. One of the chairlifts still remains on Ruud Mountain, named for Thomas Ruud a famous Norwegian ski racer. The chairlift has been preserved with its ski jump and original single chairs as it was during WWII. The chairlift was developed by James Curran of Union Pacific's engineering department in Omaha during

6642-466: Was quickly accepted because it proved superior strength from ropes made of hemp or of metal chains , such as had been used before. Wilhelm Albert's first ropes consisted of three strands consisting of four wires each. In 1840, Scotsman Robert Stirling Newall improved the process further. In America wire rope was manufactured by John A. Roebling , starting in 1841 and forming the basis for his success in suspension bridge building. Roebling introduced

6724-543: Was the workhorse of the ski industry, can move roughly 1,200 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 2,400 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 American ski areas, chairlifts are referred to with

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