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62-678: The Hells Gate Airtram is an aerial tramway that crosses Fraser Canyon immediately above Hells Gate in British Columbia , Canada . It starts at a parking lot off the Trans-Canada Highway and descends to its lower terminal on the opposite side of the canyon where there is an observation deck, a restaurant, a gift shop and other tourist attractions. It was built in 1970 by the Swiss manufacturer Habegger Engineering Works and opened on 21 July 1971. Before its construction,

124-399: A ferromagnetic core. Electric current passing through the wire causes the magnetic field to exert a force ( Lorentz force ) on it, turning the rotor. Windings are coiled wires, wrapped around a laminated, soft, iron, ferromagnetic core so as to form magnetic poles when energized with current. Electric machines come in salient- and nonsalient-pole configurations. In a salient-pole motor

186-441: A haulage rope ), and one or two passenger or cargo cabins. The fixed cables provide support for the cabins while the haulage rope, by means of a grip, is solidly connected to the truck (the wheel set that rolls on the track cables). An electric motor drives the haulage rope which provides propulsion . Aerial tramways are constructed as reversible systems ; vehicles shuttling back and forth between two end terminals and propelled by

248-430: A magnetic field that passes through the rotor armature, exerting force on the rotor windings. The stator core is made up of many thin metal sheets that are insulated from each other, called laminations. These laminations are made of electrical steel , which has a specified magnetic permeability, hysteresis, and saturation. Laminations reduce losses that would result from induced circulating eddy currents that would flow if

310-404: A 100- horsepower induction motor currently has the same mounting dimensions as a 7.5-horsepower motor in 1897. In 2022, electric motor sales were estimated to be 800 million units, increasing by 10% annually. Electric motors consume ≈50% of the world's electricity. Since the 1980s, the market share of DC motors has declined in favor of AC motors. An electric motor has two mechanical parts:

372-431: A 20-hp squirrel cage and a 100-hp wound rotor with a starting rheostat. These were the first three-phase asynchronous motors suitable for practical operation. Since 1889, similar developments of three-phase machinery were started Wenström. At the 1891 Frankfurt International Electrotechnical Exhibition, the first long distance three-phase system was successfully presented. It was rated 15 kV and extended over 175 km from

434-461: A cable loop which stops and reverses direction when the cabins arrive at the end stations. Aerial tramways differ from gondola lifts in that gondola lifts are considered continuous systems (cabins attached onto a circulating haul rope that moves continuously). Two-car tramways use a jig-back system: a large electric motor is located at the bottom of the tramway so that it effectively pulls one cabin down, using that cabin's weight to help pull

496-470: A commutator-type direct-current electric motor was built by American inventors Thomas Davenport and Emily Davenport , which he patented in 1837. The motors ran at up to 600 revolutions per minute, and powered machine tools and a printing press. Due to the high cost of primary battery power , the motors were commercially unsuccessful and bankrupted the Davenports. Several inventors followed Sturgeon in

558-463: A comparatively small air gap. The St. Louis motor, long used in classrooms to illustrate motor principles, is inefficient for the same reason, as well as appearing nothing like a modern motor. Electric motors revolutionized industry. Industrial processes were no longer limited by power transmission using line shafts, belts, compressed air or hydraulic pressure. Instead, every machine could be equipped with its own power source, providing easy control at

620-502: A continuously circulating cable whereas aerial trams simply shuttle back and forth on cables. In Japan, the two are considered as the same category of vehicle and called ropeway , while the term cable car refers to both grounded cable cars and funiculars . An aerial railway where the vehicles are suspended from a fixed track (as opposed to a cable) is known as a suspension railway . An aerial tramway consists of one or two fixed cables (called track cables ), one loop of cable (called

682-422: A generator and the other as motor. The drum rotor was introduced by Friedrich von Hefner-Alteneck of Siemens & Halske to replace Pacinotti's ring armature in 1872, thus improving the machine efficiency. The laminated rotor was introduced by Siemens & Halske the following year, achieving reduced iron losses and increased induced voltages. In 1880, Jonas Wenström provided the rotor with slots for housing

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744-437: A model electric vehicle that same year. A major turning point came in 1864, when Antonio Pacinotti first described the ring armature (although initially conceived in a DC generator, i.e. a dynamo). This featured symmetrically grouped coils closed upon themselves and connected to the bars of a commutator, the brushes of which delivered practically non-fluctuating current. The first commercially successful DC motors followed

806-1037: A power grid, inverters or electrical generators. Electric motors may be classified by considerations such as power source type, construction, application and type of motion output. They can be brushed or brushless , single-phase , two-phase , or three-phase , axial or radial flux , and may be air-cooled or liquid-cooled. Standardized motors provide power for industrial use. The largest are used for ship propulsion, pipeline compression and pumped-storage applications, with output exceeding 100 megawatts . Applications include industrial fans, blowers and pumps, machine tools, household appliances, power tools, vehicles, and disk drives. Small motors may be found in electric watches. In certain applications, such as in regenerative braking with traction motors , electric motors can be used in reverse as generators to recover energy that might otherwise be lost as heat and friction. Electric motors produce linear or rotary force ( torque ) intended to propel some external mechanism. This makes them

868-425: A rotating bar winding rotor. Steadfast in his promotion of three-phase development, Mikhail Dolivo-Dobrovolsky invented the three-phase induction motor in 1889, of both types cage-rotor and wound rotor with a starting rheostat, and the three-limb transformer in 1890. After an agreement between AEG and Maschinenfabrik Oerlikon , Doliwo-Dobrowolski and Charles Eugene Lancelot Brown developed larger models, namely

930-398: A solid core were used. Mains powered AC motors typically immobilize the wires within the windings by impregnating them with varnish in a vacuum. This prevents the wires in the winding from vibrating against each other which would abrade the wire insulation and cause premature failures. Resin-packed motors, used in deep well submersible pumps, washing machines, and air conditioners, encapsulate

992-584: A type of actuator . They are generally designed for continuous rotation, or for linear movement over a significant distance compared to its size. Solenoids also convert electrical power to mechanical motion, but over only a limited distance. Before modern electromagnetic motors, experimental motors that worked by electrostatic force were investigated. The first electric motors were simple electrostatic devices described in experiments by Scottish monk Andrew Gordon and American experimenter Benjamin Franklin in

1054-493: A world record, which Jacobi improved four years later in September 1838. His second motor was powerful enough to drive a boat with 14 people across a wide river. It was also in 1839/40 that other developers managed to build motors with similar and then higher performance. In 1827–1828, Jedlik built a device using similar principles to those used in his electromagnetic self-rotors that was capable of useful work. He built

1116-592: A wound rotor forming a self-starting induction motor , and the third a true synchronous motor with separately excited DC supply to rotor winding. One of the patents Tesla filed in 1887, however, also described a shorted-winding-rotor induction motor. George Westinghouse , who had already acquired rights from Ferraris (US$ 1,000), promptly bought Tesla's patents (US$ 60,000 plus US$ 2.50 per sold hp, paid until 1897), employed Tesla to develop his motors, and assigned C.F. Scott to help Tesla; however, Tesla left for other pursuits in 1889. The constant speed AC induction motor

1178-399: Is a type of aerial lift which uses one or two stationary ropes for support while a third moving rope provides propulsion. With this form of lift, the grip of an aerial tramway cabin is fixed onto the propulsion rope and cannot be decoupled from it during operations. In comparison to gondola lifts , aerial tramways generally provide lower line capacities and longer wait times. Cable car

1240-516: Is the usual term in British English, where tramway generally refers to a railed street tramway . In American English, cable car may additionally refer to a cable-pulled street tramway with detachable vehicles (e.g., San Francisco's cable cars ). As such, careful phrasing is necessary to prevent confusion. It is also sometimes called a ropeway or even incorrectly referred to as a gondola lift . A gondola lift has cabins suspended from

1302-649: The San Juan Mountains of the US state of Colorado . Another famous use of aerial tramways was at the Kennecott Copper mine in Wrangell-St. Elias National Park , Alaska . Other firms entered the mining tramway business—Otto, Leschen, Breco Ropeways Ltd., Ceretti and Tanfani, and Riblet for instance. A major British contributor was Bullivant who became a constituent of British Ropes in 1924. In

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1364-483: The South Side Elevated Railroad , where it became popularly known as the " L ". Sprague's motor and related inventions led to an explosion of interest and use in electric motors for industry. The development of electric motors of acceptable efficiency was delayed for several decades by failure to recognize the extreme importance of an air gap between the rotor and stator. Efficient designs have

1426-439: The armature . Two or more electrical contacts called brushes made of a soft conductive material like carbon press against the commutator. The brushes make sliding contact with successive commutator segments as the rotator turns, supplying current to the rotor. The windings on the rotor are connected to the commutator segments. The commutator reverses the current direction in the rotor windings with each half turn (180°), so

1488-416: The 1740s. The theoretical principle behind them, Coulomb's law , was discovered but not published, by Henry Cavendish in 1771. This law was discovered independently by Charles-Augustin de Coulomb in 1785, who published it so that it is now known by his name. Due to the difficulty of generating the high voltages they required, electrostatic motors were never used for practical purposes. The invention of

1550-582: The Lauffen waterfall on the Neckar river. The Lauffen power station included a 240 kW 86 V 40 Hz alternator and a step-up transformer while at the exhibition a step-down transformer fed a 100-hp three-phase induction motor that powered an artificial waterfall, representing the transfer of the original power source. The three-phase induction is now used for the vast majority of commercial applications. Mikhail Dolivo-Dobrovolsky claimed that Tesla's motor

1612-484: The beginning of the 20th century, the rise of the middle class and the leisure industry allowed for investment in sight-seeing machines. Prior to 1893, a combined goods and passenger carrying cableway was installed at Gibraltar . Initially, its passengers were military personnel. An 1893 industry publication said of a two-mile system in Hong Kong that it "is the only wire tramway which has been erected exclusively for

1674-637: The cable car business: Bleichert , Heckel, Pohlig, PHB (Pohlig-Heckel-Bleichert), Garaventa and Waagner-Biró. Now there are three groups dominating the world market: Doppelmayr Garaventa Group , Leitner Group, and Poma , the last two being owned by one person. Some aerial tramways have their own propulsion , such as the Lasso Mule or the Josef Mountain Aerial Tramway near Merano , Italy . While typically used for ski resorts, aerial tramways have been ported over for usage in

1736-512: The cable run. The first design of an aerial lift was by Croatian polymath Fausto Veranzio and the first operational aerial tram was built in 1644 by Adam Wybe in Gdańsk , Poland. It was moved by horses and used to move soil over the river to build defences. It is called the first known cable lift in European history and precedes the invention of steel cables. It is not known how long this lift

1798-549: The carriage of individuals" (albeit workmen). After the pioneer cable car suitable for public transport on Mount Ulia in 1907 ( San Sebastián , Spain ) by Leonardo Torres Quevedo and the Wetterhorn Elevator ( Grindelwald , Switzerland) in 1908, others to the top of high peaks in the Alps of Austria, Germany and Switzerland resulted. They were much less expensive to build than the earlier rack railway . One of

1860-523: The development of DC motors, but all encountered the same battery cost issues. As no electricity distribution system was available at the time, no practical commercial market emerged for these motors. After many other more or less successful attempts with relatively weak rotating and reciprocating apparatus Prussian/Russian Moritz von Jacobi created the first real rotating electric motor in May 1834. It developed remarkable mechanical output power. His motor set

1922-478: The developments by Zénobe Gramme who, in 1871, reinvented Pacinotti's design and adopted some solutions by Werner Siemens . A benefit to DC machines came from the discovery of the reversibility of the electric machine, which was announced by Siemens in 1867 and observed by Pacinotti in 1869. Gramme accidentally demonstrated it on the occasion of the 1873 Vienna World's Fair , when he connected two such DC devices up to 2 km from each other, using one of them as

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1984-460: The electric energy produced in the US. In 1824, French physicist François Arago formulated the existence of rotating magnetic fields , termed Arago's rotations , which, by manually turning switches on and off, Walter Baily demonstrated in 1879 as in effect the first primitive induction motor . In the 1880s many inventors were trying to develop workable AC motors because AC's advantages in long-distance high-voltage transmission were offset by

2046-576: The electric grid, provided for electric distribution to trolleys via overhead wires and the trolley pole, and provided control systems for electric operations. This allowed Sprague to use electric motors to invent the first electric trolley system in 1887–88 in Richmond, Virginia , the electric elevator and control system in 1892, and the electric subway with independently powered centrally-controlled cars. The latter were first installed in 1892 in Chicago by

2108-474: The electrochemical battery by Alessandro Volta in 1799 made possible the production of persistent electric currents. Hans Christian Ørsted discovered in 1820 that an electric current creates a magnetic field, which can exert a force on a magnet. It only took a few weeks for André-Marie Ampère to develop the first formulation of the electromagnetic interaction and present the Ampère's force law , that described

2170-472: The first device to contain the three main components of practical DC motors: the stator , rotor and commutator. The device employed no permanent magnets, as the magnetic fields of both the stationary and revolving components were produced solely by the currents flowing through their windings. The first commutator DC electric motor capable of turning machinery was invented by English scientist William Sturgeon in 1832. Following Sturgeon's work,

2232-662: The first trams was at Chamonix , while others in Switzerland, and Garmisch soon followed. From this, it was a natural transposition to build ski lifts and chairlifts. The first cable car in North America was at Cannon Mountain in Franconia, New Hampshire in 1938. Many aerial tramways were built by Von Roll Ltd. of Switzerland, which has since been acquired by Austrian lift manufacturer Doppelmayr . Other German, Swiss, and Austrian firms played an important role in

2294-586: The inability to operate motors on AC. The first alternating-current commutatorless induction motor was invented by Galileo Ferraris in 1885. Ferraris was able to improve his first design by producing more advanced setups in 1886. In 1888, the Royal Academy of Science of Turin published Ferraris's research detailing the foundations of motor operation, while concluding at that time that "the apparatus based on that principle could not be of any commercial importance as motor." Possible industrial development

2356-644: The load are exerted beyond the outermost bearing, the load is said to be overhung. The rotor is supported by bearings , which allow the rotor to turn on its axis by transferring the force of axial and radial loads from the shaft to the motor housing. A DC motor is usually supplied through a split ring commutator as described above. AC motors' commutation can be achieved using either a slip ring commutator or external commutation. It can be fixed-speed or variable-speed control type, and can be synchronous or asynchronous. Universal motors can run on either AC or DC. DC motors can be operated at variable speeds by adjusting

2418-470: The lower terminal where the blocks have a leeway of 7.9m to move up and down. The haul rope and its counter rope are tensioned by a counterweight of 3.5 tons, also in the lower terminal. The max output of the motor is 140 HP (104 kW). The total carrying capacity of the aerial tramway is 530 passengers per hour (one way). Aerial tramway An aerial tramway , aerial tram , sky tram , aerial cablecar , aerial cableway , telepherique , or seilbahn

2480-546: The magnet, showing that the current gave rise to a close circular magnetic field around the wire. Faraday published the results of his discovery in the Quarterly Journal of Science , and sent copies of his paper along with pocket-sized models of his device to colleagues around the world so they could also witness the phenomenon of electromagnetic rotations. This motor is often demonstrated in physics experiments, substituting brine for (toxic) mercury. Barlow's wheel

2542-434: The only way to the observation deck was to hike down the canyon to the pedestrian suspension bridge that bridges the canyon. The aerial tramway contains two cabins that can carry 25 people each, plus the cabin attendant. Each cabin travels up and down along its own track rope at a maximum speed of 5 m/s (18 km/h, 984 ft/min) over an inclined length of 341 m (1118 ft). The horizontal distance between

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2604-444: The other cabin up. A similar system of cables is used in a funicular railway. The two passenger or cargo cabins, which carry from 4 to over 150 people, are situated at opposite ends of the loops of cable. Thus, while one is coming up, the other is going down the mountain, and they pass each other midway on the cable span . Some aerial trams have only one cabin , which lends itself better for systems with small elevation changes along

2666-485: The point of use, and improving power transmission efficiency. Electric motors applied in agriculture eliminated human and animal muscle power from such tasks as handling grain or pumping water. Household uses (like in washing machines, dishwashers, fans, air conditioners and refrigerators (replacing ice boxes ) of electric motors reduced heavy labor in the home and made higher standards of convenience, comfort and safety possible. Today, electric motors consume more than half of

2728-485: The production of mechanical force by the interaction of an electric current and a magnetic field. Michael Faraday gave the first demonstration of the effect with a rotary motion on 3 September 1821 in the basement of the Royal Institution . A free-hanging wire was dipped into a pool of mercury, on which a permanent magnet (PM) was placed. When a current was passed through the wire, the wire rotated around

2790-428: The rotor and stator ferromagnetic cores have projections called poles that face each other. Wire is wound around each pole below the pole face, which become north or south poles when current flows through the wire. In a nonsalient-pole (distributed field or round-rotor) motor, the ferromagnetic core is a smooth cylinder, with the windings distributed evenly in slots around the circumference. Supplying alternating current in

2852-465: The rotor and the stator. The product between these two fields gives rise to a force and thus a torque on the motor shaft. One or both of these fields changes as the rotor turns. This is done by switching the poles on and off at the right time, or varying the strength of the pole. Motors can be designed to operate on DC current, on AC current, or some types can work on either. AC motors can be either asynchronous or synchronous. Synchronous motors require

2914-402: The rotor, which moves, and the stator, which does not. Electrically, the motor consists of two parts, the field magnets and the armature, one of which is attached to the rotor and the other to the stator. Together they form a magnetic circuit . The magnets create a magnetic field that passes through the armature. These can be electromagnets or permanent magnets . The field magnet is usually on

2976-454: The stator and the armature on the rotor, but these may be reversed. The rotor is the moving part that delivers the mechanical power. The rotor typically holds conductors that carry currents, on which the magnetic field of the stator exerts force to turn the shaft. The stator surrounds the rotor, and usually holds field magnets, which are either electromagnets (wire windings around a ferromagnetic iron core) or permanent magnets . These create

3038-435: The stator in plastic resin to prevent corrosion and/or reduce conducted noise. An air gap between the stator and rotor allows it to turn. The width of the gap has a significant effect on the motor's electrical characteristics. It is generally made as small as possible, as a large gap weakens performance. Conversely, gaps that are too small may create friction in addition to noise. The armature consists of wire windings on

3100-562: The summit of the Stanserhorn in Switzerland carries 60 persons, with the upper floor accommodating 30 people in the open air. Despite the introduction of various safety measures (back-up power generators, evacuation plans, etc.) there have been several serious incidents on aerial tramways, some of which were fatal. Electric motor Electric motors can be powered by direct current (DC) sources, such as from batteries or rectifiers , or by alternating current (AC) sources, such as

3162-458: The terminals is 303 m (994 ft) and their difference in altitude is 157 m (515 ft). The mean inclination between the terminals is 51%. The track ropes have a diameter of 40mm, the haul rope connecting the two cabins via the drive bull wheel in the upper terminal has a diameter of 19mm and its counter rope 15mm. The track ropes are anchored in the upper terminal and are tensioned by two concrete blocks of 42 tons each suspended inside

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3224-406: The torque applied to the rotor is always in the same direction. Without this reversal, the direction of torque on each rotor winding would reverse with each half turn, stopping the rotor. Commutated motors have been mostly replaced by brushless motors , permanent magnet motors , and induction motors . The motor shaft extends outside of the motor, where it satisfies the load. Because the forces of

3286-715: The urban environment in recent times. The Roosevelt Island Tramway in New York City, the Rakavlit cable car in Haifa, Israel and the Portland Aerial Tram are examples where this technology has been successfully adapted for public transport purposes. The telpherage concept was first publicised in 1883 and several experimental lines were constructed. It was designed to compete not with railways, but with horses and carts. The first commercial telpherage line

3348-663: The voltage applied to the terminals or by using pulse-width modulation (PWM). AC motors operated at a fixed speed are generally powered directly from the grid or through motor soft starters . AC motors operated at variable speeds are powered with various power inverter , variable-frequency drive or electronic commutator technologies. The term electronic commutator is usually associated with self-commutated brushless DC motor and switched reluctance motor applications. Electric motors operate on one of three physical principles: magnetism , electrostatics and piezoelectricity . In magnetic motors, magnetic fields are formed in both

3410-406: The winding, further increasing the efficiency. In 1886, Frank Julian Sprague invented the first practical DC motor, a non-sparking device that maintained relatively constant speed under variable loads. Other Sprague electric inventions about this time greatly improved grid electric distribution (prior work done while employed by Thomas Edison ), allowed power from electric motors to be returned to

3472-431: The windings creates poles in the core that rotate continuously. A shaded-pole motor has a winding around part of the pole that delays the phase of the magnetic field for that pole. A commutator is a rotary electrical switch that supplies current to the rotor. It periodically reverses the flow of current in the rotor windings as the shaft rotates. It consists of a cylinder composed of multiple metal contact segments on

3534-508: Was an early refinement to this Faraday demonstration, although these and similar homopolar motors remained unsuited to practical application until late in the century. In 1827, Hungarian physicist Ányos Jedlik started experimenting with electromagnetic coils . After Jedlik solved the technical problems of continuous rotation with the invention of the commutator , he called his early devices "electromagnetic self-rotors". Although they were used only for teaching, in 1828 Jedlik demonstrated

3596-449: Was envisioned by Nikola Tesla , who invented independently his induction motor in 1887 and obtained a patent in May 1888. In the same year, Tesla presented his paper A New System of Alternate Current Motors and Transformers to the AIEE that described three patented two-phase four-stator-pole motor types: one with a four-pole rotor forming a non-self-starting reluctance motor , another with

3658-458: Was found not to be suitable for street cars, but Westinghouse engineers successfully adapted it to power a mining operation in Telluride, Colorado in 1891. Westinghouse achieved its first practical induction motor in 1892 and developed a line of polyphase 60 hertz induction motors in 1893, but these early Westinghouse motors were two-phase motors with wound rotors. B.G. Lamme later developed

3720-717: Was in Glynde , which is in Sussex, England. It was built to connect a newly opened clay pit to the local railway station and opened in 1885. There are aerial tramways with double deck cabins. The Vanoise Express cable car carries 200 people in each cabin at a height of 380 m (1,247 ft) over the Ponturin gorge in France. The Shinhotaka Ropeway carries 121 people in each cabin at Mount Hotaka in Japan. The CabriO cable car to

3782-438: Was not practical because of two-phase pulsations, which prompted him to persist in his three-phase work. The General Electric Company began developing three-phase induction motors in 1891. By 1896, General Electric and Westinghouse signed a cross-licensing agreement for the bar-winding-rotor design, later called the squirrel-cage rotor . Induction motor improvements flowing from these inventions and innovations were such that

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3844-474: Was used. In any case, it would be another 230 years before Germany would get the second cable lift, this newer version equipped with iron wire cable. Tramways are sometimes used in mountainous regions to carry ore from a mine located high on the mountain to an ore mill located at a lower elevation. Ore tramways were common in the early 20th century at the mines in North and South America. One can still be seen in

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