A monorail is a railway in which the track consists of a single rail or beam. Colloquially, the term "monorail" is often used to describe any form of elevated rail or people mover . More accurately, the term refers to the style of track . Monorail systems are most frequently implemented in large cities, airports, and theme parks.
105-474: SUTRA , abbreviation for Scomi Urban Transit Rail Application , is a monorail electrical multiple unit (EMU) type train system designed by Malaysian rail company Scomi Rail . The design is currently the main product offering of Scomi Rail, which has won several contracts with the design, with the first customer being the Mumbai Monorail project. In 2019 Scomi Rail was placed in receivership and it
210-423: A railroad double-crossover . Vehicle specifications are generally not open to the public, as is standard for rolling stock built for public services. An alternative to using a wye or other form of switch, is to use a turntable , where a car sits upon a section of track that can be reoriented to several different tracks. For example, this can be used to switch a car from being in a storage location, to being on
315-563: A GaAs p-n junction light emitter and an electrically isolated semiconductor photodetector. On August 8, 1962, Biard and Pittman filed a patent titled "Semiconductor Radiant Diode" based on their findings, which described a zinc-diffused p–n junction LED with a spaced cathode contact to allow for efficient emission of infrared light under forward bias . After establishing the priority of their work based on engineering notebooks predating submissions from G.E. Labs, RCA Research Labs, IBM Research Labs, Bell Labs , and Lincoln Lab at MIT ,
420-671: A current source of a battery or a pulse generator and with a comparison to a variant, pure, crystal in 1953. Rubin Braunstein of the Radio Corporation of America reported on infrared emission from gallium arsenide (GaAs) and other semiconductor alloys in 1955. Braunstein observed infrared emission generated by simple diode structures using gallium antimonide (GaSb), GaAs, indium phosphide (InP), and silicon-germanium (SiGe) alloys at room temperature and at 77 kelvins . In 1957, Braunstein further demonstrated that
525-562: A faulty monorail from a confidence trickster at a wildly inflated price. The Monorail Society, an organization with 14,000 members worldwide, has blamed the episode for sullying the reputation of monorails, to which Simpsons creator Matt Groening responded "That's a by-product of our viciousness...Monorails are great, so it makes me sad, but at the same time if something's going to happen in The Simpsons , it's going to go wrong, right?" The 2005 feature film Batman Begins features
630-554: A glass window or lens to let the light out. Modern indicator LEDs are packed in transparent molded plastic cases, tubular or rectangular in shape, and often tinted to match the device color. Infrared devices may be dyed, to block visible light. More complex packages have been adapted for efficient heat dissipation in high-power LEDs . Surface-mounted LEDs further reduce the package size. LEDs intended for use with fiber optics cables may be provided with an optical connector. The first blue -violet LED, using magnesium-doped gallium nitride
735-653: A load-bearing single rail and an external wheel for balance. A highspeed monorail using the Lartigue system was proposed in 1901 between Liverpool and Manchester. In 1910, the Brennan gyroscopic monorail was considered for use to a coal mine in Alaska. In June 1920, the French Patent Office published FR 503782, by Henri Coanda, on a 'Transporteur Aérien' -Air Carrier. One of the first monorails planned in
840-568: A longer lifetime, improved physical robustness, smaller sizes, and faster switching. In exchange for these generally favorable attributes, disadvantages of LEDs include electrical limitations to low voltage and generally to DC (not AC) power, the inability to provide steady illumination from a pulsing DC or an AC electrical supply source, and a lesser maximum operating temperature and storage temperature. LEDs are transducers of electricity into light. They operate in reverse of photodiodes , which convert light into electricity. Electroluminescence as
945-485: A loudspeaker. Intercepting the beam stopped the music. We had a great deal of fun playing with this setup." In September 1961, while working at Texas Instruments in Dallas , Texas , James R. Biard and Gary Pittman discovered near-infrared (900 nm) light emission from a tunnel diode they had constructed on a GaAs substrate. By October 1961, they had demonstrated efficient light emission and signal coupling between
1050-557: A manually operated monorail of limited but sufficient capacity for the transport of small timber and firewood in the Northern Surabaya forest district. In later years, this idea was further developed by L. A. van de Ven, who was a forester in the Grobogan forest district around 1908–1910. Monorails were built by plantation operators and wood processing companies throughout the mountains of Central Java. In 1919/1920, however,
1155-557: A method for producing high-brightness blue LEDs using a new two-step process in 1991. In 2015, a US court ruled that three Taiwanese companies had infringed Moustakas's prior patent, and ordered them to pay licensing fees of not less than US$ 13 million. Two years later, in 1993, high-brightness blue LEDs were demonstrated by Shuji Nakamura of Nichia Corporation using a gallium nitride (GaN) growth process. These LEDs had efficiencies of 10%. In parallel, Isamu Akasaki and Hiroshi Amano of Nagoya University were working on developing
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#17327878118651260-829: A monorail, constructed by Bruce Wayne's father through Gotham City, that is part of the climax of the film. The monorail is also included in the spin-off video game . Blaine the Mono is a train featured in Stephen King 's The Dark Tower series of books and first appears in The Dark Tower III: The Waste Lands . Monorails have also appeared in a number of other video games including Transport Tycoon (since 1999), Japanese Rail Sim 3D: Monorail Trip to Okinawa by Sonic Powered , SimCity 4: Rush Hour , Cities in Motion 2 , Cities: Skylines in
1365-523: A phenomenon was discovered in 1907 by the English experimenter Henry Joseph Round of Marconi Labs , using a crystal of silicon carbide and a cat's-whisker detector . Russian inventor Oleg Losev reported the creation of the first LED in 1927. His research was distributed in Soviet, German and British scientific journals, but no practical use was made of the discovery for several decades, partly due to
1470-574: A phosphor-silicon mixture on the LED using techniques such as jet dispensing, and allowing the solvents to evaporate, the LEDs are often tested, and placed on tapes for SMT placement equipment for use in LED light bulb production. Some "remote phosphor" LED light bulbs use a single plastic cover with YAG phosphor for one or several blue LEDs, instead of using phosphor coatings on single-chip white LEDs. Ce:YAG phosphors and epoxy in LEDs can degrade with use, and
1575-508: A red light-emitting diode. GaAsP was the basis for the first wave of commercial LEDs emitting visible light. It was mass produced by the Monsanto and Hewlett-Packard companies and used widely for displays in calculators and wrist watches. M. George Craford , a former graduate student of Holonyak, invented the first yellow LED and improved the brightness of red and red-orange LEDs by a factor of ten in 1972. In 1976, T. P. Pearsall designed
1680-450: A standing area when not utilised. Similar to the previous generation Scomi monorails, there are center seats which also function as bogie covers. The vehicle management system (VMS) provides supervised control, monitoring and diagnostic systems for train operators. Train status information is graphically displayed to the operator via the HMI panel. The user-friendly interface display allows
1785-457: A wooden platform (in the full-scale project the trestle would have been concrete). A model train, built to 1/5 scale to test the vehicle concept, was capable of reaching speeds of up to 70 km/h. The full-scale project was expected to reach speeds of up to 300 km/h. In the latter half of the 20th century, monorails had settled on using larger beam- or girder-based track, with vehicles supported by one set of wheels and guided by another. In
1890-781: Is also capable of towing another SUTRA during emergency connections and is also designed to absorb impact energy in case of accidents. The interior of the SUTRA is customisable, and was designed with the consideration of passenger safety and comfort. It was designed with a minimalist concept with the aim of increased interior space and maximised flow of passengers and minimised obstruction in and around doorways. Hand rails and stanchions are available to assist safe boarding, seating, standing and alighting assistance, including for persons with disabilities. Other safety features include an emergency door release knob and emergency passenger intercom as well as emergency ventilation windows. The flooring of
1995-463: Is also more energy-efficient due to an improved direct-drive propulsion system and lower vehicle weight. The SUTRA also has a smaller turning radius of 50m and can also handle gradients on a slope of up to six degrees. The SUTRA also features couplings for up to eight cars that have a capacity of 1,050 passengers. The SUTRA is a highly customisable design, and is designed to accommodate two to eight cars per set, with capacity ranging from 6,400 pphpd in
2100-438: Is because Chongqing is criss-crossed by numerous hills, mountains and rivers, therefore tunneling is not feasible except in some cases (for example, lines 1 and 6 ) due to the extreme depth involved. Today it is the largest and busiest monorail system in the world. In July 2009, two Walt Disney World monorails collided , killing one of the drivers and injuring seven passengers. The National Transportation Safety Board found
2205-550: Is difficult but desirable since it takes advantage of existing semiconductor manufacturing infrastructure. It allows for the wafer-level packaging of LED dies resulting in extremely small LED packages. GaN is often deposited using metalorganic vapour-phase epitaxy (MOCVD), and it also uses lift-off . Even though white light can be created using individual red, green and blue LEDs, this results in poor color rendering , since only three narrow bands of wavelengths of light are being emitted. The attainment of high efficiency blue LEDs
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#17327878118652310-492: Is difficult on silicon , while others, like the University of Cambridge, choose a multi-layer structure, in order to reduce (crystal) lattice mismatch and different thermal expansion ratios, to avoid cracking of the LED chip at high temperatures (e.g. during manufacturing), reduce heat generation and increase luminous efficiency. Sapphire substrate patterning can be carried out with nanoimprint lithography . GaN-on-Si
2415-794: Is more apparent with higher concentrations of Ce:YAG in phosphor-silicone mixtures, because the Ce:YAG decomposes with use. The output of LEDs can shift to yellow over time due to degradation of the silicone. There are several variants of Ce:YAG, and manufacturers in many cases do not reveal the exact composition of their Ce:YAG offerings. Several other phosphors are available for phosphor-converted LEDs to produce several colors such as red, which uses nitrosilicate phosphors, and many other kinds of phosphor materials exist for LEDs such as phosphors based on oxides, oxynitrides, oxyhalides, halides, nitrides, sulfides, quantum dots, and inorganic-organic hybrid semiconductors. A single LED can have several phosphors at
2520-546: Is no longer selling its monorail system. In late 2006, Scomi Rail decided to develop its own next generation monorail after gaining experience from the manufacture of the KL Monorail system. Within twelve months after commencing engineering design, on 26 November 2007, the SUTRA was unveiled by the then Malaysian deputy prime minister Datuk Seri Najib Tun Razak , who described the launch as "a significant milestone". The total investment expenditure spent by Scomi Rail for
2625-599: Is perceived as white light, with improved color rendering compared to wavelengths from the blue LED/YAG phosphor combination. The first white LEDs were expensive and inefficient. The light output then increased exponentially . The latest research and development has been propagated by Japanese manufacturers such as Panasonic and Nichia , and by Korean and Chinese manufacturers such as Samsung , Solstice, Kingsun, Hoyol and others. This trend in increased output has been called Haitz's law after Roland Haitz. Light output and efficiency of blue and near-ultraviolet LEDs rose and
2730-477: Is speeding towards a stricken bridge. The James Bond film franchise features monorails in three movies, all belonging to the villain. In You Only Live Twice (1967) there is a working ground level monorail inside the SPECTRE volcano base. During Live and Let Die (1973), a prop monorail is shown in the villain's lair on the fictional Caribbean island of San Monique. In the 1977 The Spy Who Loved Me there
2835-481: Is the straddle-beam, in which the train straddles a steel or reinforced concrete beam 2 to 3 feet (0.6 to 0.9 m) wide. A rubber - tired carriage contacts the beam on the top and both sides for traction and to stabilize the vehicle. The style was popularized by the German company ALWEG . There is also a historical type of suspension monorail developed by German inventors Nicolaus Otto and Eugen Langen in
2940-465: Is to place a moving apparatus on top of a sturdy platform capable of bearing the weight of vehicles, beams and its own mechanism. Multiple-segmented beams move into place on rollers to smoothly align one beam with another to send the train in its desired direction, with the design originally developed by ALWEG capable of completing a switch in 12 seconds. Some of these beam turnouts are quite elaborate, capable of switching between several beams or simulating
3045-451: Is to use individual LEDs that emit three primary colors —red, green and blue—and then mix all the colors to form white light. The other is to use a phosphor material to convert monochromatic light from a blue or UV LED to broad-spectrum white light, similar to a fluorescent lamp . The yellow phosphor is cerium -doped YAG crystals suspended in the package or coated on the LED. This YAG phosphor causes white LEDs to appear yellow when off, and
3150-567: Is under construction in Wuhu and several "Cloudrail" systems developed by BYD under construction a number of cities such as Guang'an , Liuzhou , Bengbu and Guilin . Monorails have seen continuing use in niche shuttle markets and amusement parks. Modern mass transit monorail systems use developments of the ALWEG beam and tyre approach, with only two suspended types in large use. Monorail configurations have also been adopted by maglev trains . Since
3255-709: Is using the BYD SkyRail design. Other significant monorail systems are under construction such as two lines for the Cairo Monorail , two lines for the MRT (Bangkok) and the SkyRail Bahia in Brazil . Modern monorails depend on a large solid beam as the vehicles' running surface. There are a number of competing designs divided into two broad classes, straddle-beam and suspended monorails. The most common type
Scomi SUTRA - Misplaced Pages Continue
3360-555: Is working monorail on the villain's supertanker (submarine dock). In 1987, Lego released a monorail among the Futuron Space line. Despite being the most expensive Lego set of its time (due to being massive and including electrical elements), it was very popular, with Lego releasing a Town themed monorail in 1990 and another Space monorail in 1994 among the Unitron line, as well as additional track. The monorail system
3465-597: The 1964–1965 World's Fair . This high-cost perception was challenged most notably in 1963 when the ALWEG consortium proposed to finance the construction of a major system in Los Angeles County, California , in return for the right of operation. This was turned down by the Los Angeles County Board of Supervisors under pressure from Standard Oil of California and General Motors (which were strong advocates for automobile dependency ), and
3570-454: The Bradford and Foster Brook Railway was built in 1877 and ran for one year from January 1878 until January 1879. Around 1879 a "one-rail" system was proposed independently by Haddon and by Stringfellow, which used an inverted "V" rail (and thus shaped like "Λ" in cross-section). It was intended for military use, but was also seen to have civilian use as a "cheap railway." Similarly, one of
3675-537: The Centennial Monorail demonstrated in 1876, in 1877 the Bradford and Foster Brook Railway began construction of a 5 mi (8.0 km) line connecting Bradford and Foster Township, McKean County in Pennsylvania . The line operated from 1878 until 1879 delivering machinery and oil supplies. The first twin-boiler locomotive wore out quickly. It was replaced by a single boiler locomotive which
3780-518: The Changsha Maglev Express ). However, it is argued that the larger width of the guideway for the maglevs makes it not legitimate to be called monorails. Some early monorails (notably the suspended monorail at Wuppertal , Germany) have a design that makes it difficult to switch from one line to another. Some other monorails avoid switching as much as possible by operating in a continuous loop or between two fixed stations, as in
3885-720: The Docklands Light Railway , Vancouver SkyTrain , the AirTrain JFK and cable propelled systems like the Cable Liner people mover which run on two rails. Monorail vehicles often appear similar to light rail vehicles, and can be staffed or unstaffed. They can be individual rigid vehicles, articulated single units, or multiple units coupled into trains. Like other advanced rapid transit systems, monorails can be driven by linear induction motors ; like conventional railways, vehicle bodies can be connected to
3990-553: The Interstate Highway System . Monorails in particular may have suffered from the reluctance of public transit authorities to invest in the perceived high cost of un-proven technology when faced with cheaper mature alternatives. There were also many competing monorail technologies, splitting their case further. One notable example of a public monorail is the AMF Monorail that was used as transportation around
4095-609: The Lartigue Monorail , used steam locomotives. Magnetic levitation train (maglev) systems such as the German Transrapid were built as straddle-type monorails. The Shanghai Maglev Train runs in commercial operation at 430 km/h (270 mph), and there are also slower maglev monorails intended for urban transport in Japan ( Linimo ), Korea ( Incheon Airport Maglev ) and China ( Beijing Subway Line S1 and
4200-802: The Lausanne Metro has grades of up to 12% and the Montreal Metro up to 6.5%, while VAL systems can handle 7% grades. Manufacturers of monorail rolling stock with operating systems include Hitachi Monorail , BYD , Bombardier Transportation (now Alstom ), Scomi , PBTS (a joint venture of CRRC Nanjing Puzhen & Bombardier), Intamin and EMTC. Other developers include CRRC Qingdao Sifang , China Railway Science and Industry Group , Zhongtang Air Rail Technology, Woojin and SkyWay Group . François Truffaut 's 1966 film adaptation of Ray Bradbury 's 1953 novel Fahrenheit 451 contains suspended monorail exterior scenes filmed at
4305-541: The Mass transit expansion pack of 2017, Planet Zoo and a rideable elevated monorail system in the 2020 video game Cyberpunk 2077 . From 1950 to 1980, the monorail concept may have suffered, as with all public transport systems, from competition with the automobile . At the time, the post–World War II optimism in America was riding high and people were buying automobiles in large numbers due to suburbanization and
Scomi SUTRA - Misplaced Pages Continue
4410-934: The Nobel Prize in Physics in 2014 for "the invention of efficient blue light-emitting diodes, which has enabled bright and energy-saving white light sources." In 1995, Alberto Barbieri at the Cardiff University Laboratory (GB) investigated the efficiency and reliability of high-brightness LEDs and demonstrated a "transparent contact" LED using indium tin oxide (ITO) on (AlGaInP/GaAs). In 2001 and 2002, processes for growing gallium nitride (GaN) LEDs on silicon were successfully demonstrated. In January 2012, Osram demonstrated high-power InGaN LEDs grown on silicon substrates commercially, and GaN-on-silicon LEDs are in production at Plessey Semiconductors . As of 2017, some manufacturers are using SiC as
4515-484: The Seattle Center Monorail . Current monorails are capable of more efficient switching than in the past. With suspended monorails, switching may be accomplished by moving flanges inside the beamway to shift trains to one line or another. Straddle-beam monorails require that the beam moves for switching, which was an almost prohibitively ponderous procedure. Now the most common way of achieving this
4620-695: The Transrapid and Linimo . Maglevs differ from other monorails in that they do not physically contact the beam while moving. The first monorail prototype was made in Russia in 1820 by Ivan Elmanov . Attempts at creating monorail alternatives to conventional railways have been made since the early part of the 19th century. The Centennial Monorail was featured at the Centennial Exposition in Philadelphia in 1876. Based on its design
4725-553: The U.S. patent office issued the two inventors the patent for the GaAs infrared light-emitting diode (U.S. Patent US3293513 ), the first practical LED. Immediately after filing the patent, Texas Instruments (TI) began a project to manufacture infrared diodes. In October 1962, TI announced the first commercial LED product (the SNX-100), which employed a pure GaAs crystal to emit an 890 nm light output. In October 1963, TI announced
4830-561: The elevated train systems of New York, Chicago, and elsewhere, a monorail beamway casts a narrow shadow. Conversely, monorails can be more expensive than light-rail systems that do not include tunnels. In addition, monorails must either remain above ground or use larger tunnels than conventional rail systems, and they require complex track-switching equipment. Under the Monorail Society's beam-width criterion, some, but not all, maglev systems are considered monorails, such as
4935-457: The human eye as a pure ( saturated ) color. Also unlike most lasers, its radiation is not spatially coherent , so it cannot approach the very high intensity characteristic of lasers . By selection of different semiconductor materials , single-color LEDs can be made that emit light in a narrow band of wavelengths from near-infrared through the visible spectrum and into the ultraviolet range. The required operating voltages of LEDs increase as
5040-519: The 1880s. It was built in the twin cities of Barmen and Elberfeld in Wuppertal, Germany, opened in 1901, and is still in operation. The Chiba Urban Monorail is the world's largest suspended network. Almost all modern monorails are powered by electric motors fed by dual third rails , contact wires or electrified channels attached to or enclosed in their guidance beams, but diesel-powered monorail systems also exist. Historically some systems, such as
5145-579: The 1950s, a 40% scale prototype of a system designed for speed of 200 mph (320 km/h) on straight stretches and 90 mph (140 km/h) on curves was built in Germany. There were designs with vehicles supported, suspended or cantilevered from the beams. In the 1950s the ALWEG straddle design emerged, followed by an updated suspended type, the SAFEGE system. Versions of ALWEG's technology are used by
5250-536: The 1980s, most monorail mass transit systems are in Japan , with a few exceptions. Tokyo Monorail , is one of the world's busiest, averages 127,000 passengers per day and has served over 1.5 billion passengers since 1964. China recently started development of monorails in the late 2000s, already home to the world's largest and busiest monorail system and has a number of mass transit monorails under construction in several of cities. A Bombardier Innovia Monorail -based system
5355-515: The 2000s, with the rise of traffic congestion and urbanization, there has been a resurgence of interest in the technology for public transport with a number of cities, such as Malta and Istanbul , today investigating monorails as a possible mass transit solution. In 2004, Chongqing Rail Transit in China adopted a unique ALWEG-based design with rolling stock that is much wider than most monorails, with capacity comparable to heavy rail . This
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#17327878118655460-451: The 3-subpixel model for digital displays. The technology uses a gallium nitride semiconductor that emits light of different frequencies modulated by voltage changes. A prototype display achieved a resolution of 6,800 PPI or 3k x 1.5k pixels. In a light-emitting diode, the recombination of electrons and electron holes in a semiconductor produces light (be it infrared, visible or UV), a process called " electroluminescence ". The wavelength of
5565-577: The 750 V DC power line. The motor of the SUTRA is fitted with a variable-voltage-variable-frequency (VVVF) drive which is fine-tuned for smooth acceleration / deceleration. The VVVF has high torque and duty cycle capabilities, rated at a power of 200 kW . The brake system consists of electro-pneumatic systems and regenerative brakes , providing multiple uses including high integrity emergency brakes , service brakes, security brakes and parking brakes. The SUTRA has an automatic coupling system that can connect up to eight cars together. The coupling system
5670-609: The French SAFEGE test track in Châteauneuf-sur-Loire near Orléans , France (since dismantled). The Thunderbirds February 1966 episode " Brink of Disaster " is about the financing and building of a high speed driverless cross-country monorail project. Two of the Thunderbirds-crew find themselves trapped on board the a monorail train, and with no possibility of escape, when it is discovered it
5775-452: The Monorail Society defines a monorail as a "single rail serving as a track for passenger or freight vehicles. In most cases, rail is elevated, but monorails can also run at grade , below grade, or in subway tunnels. Vehicles either are suspended from or straddle a narrow guide way. Monorail vehicles are wider than the guideway that supports them." Monorails are often elevated, sometimes leading to confusion with other elevated systems such as
5880-402: The SUTRA is slip-resistant and made of fire-retardant material. Each car has a 40 kW roof mounted air conditioning unit. Passenger information systems include LED texts and television screens in addition to audio announcements. The cabs are equipped with specially designed mass transit seats and two adjacent flippable seats as well as a disabled wheelchair area, which also functions as
5985-568: The SUTRA monorail was about RM35mil including for research, development and factory expansion. The SUTRA complies with 50 international standards comprising safety, quality assurance, vehicle certification, reliability, availability and maintainability. Compared to the previous design used in the KL Monorail , the SUTRA has improved features such as a composite body and interior panel, new bogie system and structure, mass transit components drive train , improved propulsion and control system, and regenerative and pneumatic brake system. The SUTRA
6090-619: The United States was in New York City in the early 1930s, scrubbed for an elevated train system. The first half of the 20th century saw many further proposed designs that either never left the drawing board or remained short-lived prototypes. One of the most interesting projects created on the layout was the ball-bearing train by Nikolai Grigorievich Yarmolchuk. This train moved on spherical wheels with electric motors embedded in them, which were located in semi-circular chutes under
6195-500: The beam via bogies , allowing curves to be negotiated. Monorails are sometimes used in urban areas alongside conventional parallel railed metro systems. Mumbai Monorail serves alongside Mumbai Metro , while monorail lines are integrated with conventional rail rapid transit lines in Bangkok's MRT network. Unlike some trams and light rail systems, modern monorails are always separated from other traffic and pedestrians due to
6300-800: The blending of the colors. Since LEDs have slightly different emission patterns, the color balance may change depending on the angle of view, even if the RGB sources are in a single package, so RGB diodes are seldom used to produce white lighting. Nonetheless, this method has many applications because of the flexibility of mixing different colors, and in principle, this mechanism also has higher quantum efficiency in producing white light. There are several types of multicolor white LEDs: di- , tri- , and tetrachromatic white LEDs. Several key factors that play among these different methods include color stability, color rendering capability, and luminous efficacy. Often, higher efficiency means lower color rendering, presenting
6405-489: The cause of the accident to be human error by both the driver and controller, contributed to by a lack of standard operating procedures. São Paulo , Brazil, is building two high-capacity monorail lines as part of its public transportation network. Line 15 was partially opened in 2014, will be 27 km (17 mi) long when completed in 2022 and has a capacity of 40,000 pphpd using Bombardier Innovia Monorail trains. Line 17 will be 17.7 km (11.0 mi) long and
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#17327878118656510-1088: The cladding and quantum well layers for ultraviolet LEDs, but these devices have not yet reached the level of efficiency and technological maturity of InGaN/GaN blue/green devices. If unalloyed GaN is used in this case to form the active quantum well layers, the device emits near-ultraviolet light with a peak wavelength centred around 365 nm. Green LEDs manufactured from the InGaN/GaN system are far more efficient and brighter than green LEDs produced with non-nitride material systems, but practical devices still exhibit efficiency too low for high-brightness applications. With AlGaN and AlGaInN , even shorter wavelengths are achievable. Near-UV emitters at wavelengths around 360–395 nm are already cheap and often encountered, for example, as black light lamp replacements for inspection of anti- counterfeiting UV watermarks in documents and bank notes, and for UV curing . Substantially more expensive, shorter-wavelength diodes are commercially available for wavelengths down to 240 nm. As
6615-417: The cost of reliable devices fell. This led to relatively high-power white-light LEDs for illumination, which are replacing incandescent and fluorescent lighting. Experimental white LEDs were demonstrated in 2014 to produce 303 lumens per watt of electricity (lm/W); some can last up to 100,000 hours. Commercially available LEDs have an efficiency of up to 223 lm/W as of 2018. A previous record of 135 lm/W
6720-1075: The earliest LEDs emitted low-intensity infrared (IR) light. Infrared LEDs are used in remote-control circuits, such as those used with a wide variety of consumer electronics. The first visible-light LEDs were of low intensity and limited to red. Early LEDs were often used as indicator lamps, replacing small incandescent bulbs , and in seven-segment displays . Later developments produced LEDs available in visible , ultraviolet (UV), and infrared wavelengths with high, low, or intermediate light output, for instance, white LEDs suitable for room and outdoor lighting. LEDs have also given rise to new types of displays and sensors, while their high switching rates are useful in advanced communications technology with applications as diverse as aviation lighting , fairy lights , strip lights , automotive headlamps , advertising, general lighting , traffic signals , camera flashes, lighted wallpaper , horticultural grow lights , and medical devices. LEDs have many advantages over incandescent light sources, including lower power consumption,
6825-543: The emitted wavelengths become shorter (higher energy, red to blue), because of their increasing semiconductor band gap. Blue LEDs have an active region consisting of one or more InGaN quantum wells sandwiched between thicker layers of GaN, called cladding layers. By varying the relative In/Ga fraction in the InGaN quantum wells, the light emission can in theory be varied from violet to amber. Aluminium gallium nitride (AlGaN) of varying Al/Ga fraction can be used to manufacture
6930-496: The field of luminescence with research on radium . Hungarian Zoltán Bay together with György Szigeti patenting a lighting device in Hungary in 1939 based on silicon carbide, with an option on boron carbide, that emitted white, yellowish white, or greenish white depending on impurities present. Kurt Lehovec , Carl Accardo, and Edward Jamgochian explained these first LEDs in 1951 using an apparatus employing SiC crystals with
7035-612: The first commercial hemispherical LED, the SNX-110. In the 1960s, several laboratories focused on LEDs that would emit visible light. A particularly important device was demonstrated by Nick Holonyak on October 9, 1962, while he was working for General Electric in Syracuse, New York . The device used the semiconducting alloy gallium phosphide arsenide (GaAsP). It was the first semiconductor laser to emit visible light, albeit at low temperatures. At room temperature it still functioned as
7140-521: The first commercially available blue LED, based on the indirect bandgap semiconductor, silicon carbide (SiC). SiC LEDs had very low efficiency, no more than about 0.03%, but did emit in the blue portion of the visible light spectrum. In the late 1980s, key breakthroughs in GaN epitaxial growth and p-type doping ushered in the modern era of GaN-based optoelectronic devices. Building upon this foundation, Theodore Moustakas at Boston University patented
7245-721: The first high-brightness, high-efficiency LEDs for optical fiber telecommunications by inventing new semiconductor materials specifically adapted to optical fiber transmission wavelengths. Until 1968, visible and infrared LEDs were extremely costly, on the order of US$ 200 per unit, and so had little practical use. The first commercial visible-wavelength LEDs used GaAsP semiconductors and were commonly used as replacements for incandescent and neon indicator lamps , and in seven-segment displays , first in expensive equipment such as laboratory and electronics test equipment, then later in such appliances as calculators, TVs, radios, telephones, as well as watches. The Hewlett-Packard company (HP)
7350-584: The first monorail locomotive was a 0-3-0 steam locomotive on this line. A high-speed monorail using the Lartigue system was proposed in 1901 between Liverpool and Manchester. The Boynton Bicycle Railroad was a steam-powered monorail in Brooklyn on Long Island , New York . It ran on a single load-bearing rail at ground level, but with a wooden overhead stabilising rail engaged by a pair of horizontally opposed wheels. The railway operated for only two years beginning in 1890. The Hotchkiss Bicycle Railroad
7455-483: The first systems put into practical use was that of French engineer Charles Lartigue, who built a line between Ballybunion and Listowel in Ireland, opened in 1888 and lasting 36 years, being closed in 1924 (due to damage from Ireland's Civil War). It used a load-bearing single rail and two lower, external rails for balance, the three carried on triangular supports. It was cheap to construct but tricky to operate. Possibly
7560-470: The four-car KL Monorail to 36,000 in the 5/6-car Line 17 (São Paulo Metro) and Manaus Monorail . The monocoque (load-bearing single-shell frame) body structure of the SUTRA is constructed with aluminium extrusion materials. The lightweight structure combined with the aluminium apron structure provides enhanced strength and durability of up to 30 years. The SUTRA's propulsion is provided by an electric motor with gear reducers which draws power from
7665-574: The geometry of the rail. They are both guided and supported via interaction with the same single beam, in contrast to other guided systems like rubber-tyred metros , such as the Sapporo Municipal Subway ; or guided buses or trams, such as Translohr . Monorails can also use pantographs . As with other grade-separated transit systems, monorails avoid red lights, intersection turns, and traffic jams. Surface-level trains, buses, automobiles, and pedestrians can collide each one with
7770-502: The hand-operated monorails gradually disappeared and were replaced by narrow-gauge railways with steam locomotives as forest utilization changed. In the 1920s the Port of Hamburg used a petrol powered, suspended monorail to transport luggage and freight from ocean-going vessels to a passenger depot. LED A light-emitting diode ( LED ) is a semiconductor device that emits light when current flows through it. Electrons in
7875-407: The important GaN deposition on sapphire substrates and the demonstration of p-type doping of GaN. This new development revolutionized LED lighting, making high-power blue light sources practical, leading to the development of technologies like Blu-ray . Nakamura was awarded the 2006 Millennium Technology Prize for his invention. Nakamura, Hiroshi Amano , and Isamu Akasaki were awarded
7980-534: The later proposed subway system faced criticism by famed author Ray Bradbury as it had yet to reach the scale of the proposed monorail. Several monorails initially conceived as transport systems survive on revenues generated from tourism , benefiting from the unique views offered from the largely elevated installations. Monorails have been used for number of applications other than passenger transportation. Small suspended monorail are also widely used in factories either as part of moveable assembly lines. Inspired by
8085-497: The legacy systems in use today. However, monorails gained little foothold compared to conventional transport systems. In March 1972, Alejandro Goicoechea-Omar had patent DE1755198 published, on a 'Vertebrate Train', build as experimental track in Las Palmas de Gran Canaria, Spain. Niche private enterprise uses for monorails emerged, with the emergence of air travel and shopping malls , with shuttle-type systems being built. From
8190-417: The light depends on the energy band gap of the semiconductors used. Since these materials have a high index of refraction, design features of the devices such as special optical coatings and die shape are required to efficiently emit light. Unlike a laser , the light emitted from an LED is neither spectrally coherent nor even highly monochromatic . Its spectrum is sufficiently narrow that it appears to
8295-420: The light produced is engineered to suit the human eye. Because of metamerism , it is possible to have quite different spectra that appear white. The appearance of objects illuminated by that light may vary as the spectrum varies. This is the issue of color rendition, quite separate from color temperature. An orange or cyan object could appear with the wrong color and much darker as the LED or phosphor does not emit
8400-409: The main line. The now-closed Sydney Monorail had a traverser at the depot, which allowed a train on the main line to be exchanged with another from the depot. There were about six lines in the depot, including one for maintenance. Rubber-tired monorails are typically designed to cope with a 6% grade . Rubber-tired light rail or metro lines can cope with similar or greater grades – for example,
8505-596: The monorail car. A surviving suspended version is the oldest still in service system: the Wuppertal monorail in Germany. Also in the early 1900s, Gyro monorails with cars gyroscopically balanced on top of a single rail were tested, but never developed beyond the prototype stage. The Ewing System , used in the Patiala State Monorail Trainways in Punjab, India , relies on a hybrid model with
8610-583: The monorail. a contract was signed in 2012 but the project never began construction Monorail The term possibly originated in 1897 from German engineer Eugen Langen , who called an elevated railway system with wagons suspended the Eugen Langen One-railed Suspension Tramway (Einschieniges Hängebahnsystem Eugen Langen). Monorails have found applications in airport transfers and medium capacity metros. To differentiate monorails from other transport modes,
8715-492: The operator to quickly respond and understand all train system status. The train system status and abnormal conditions are categorised and displayed in real time and prioritised in order of critical system hierarchy. As an option, critical data can be logged for further analysis. The train is equipped with automatic train protection (ATP) system to prevent collisions. The ATP system can be optionally upgraded to an automatic train operation (ATO) system to automate operations of
8820-488: The other, while vehicles on dedicated, grade-separated rights-of-way such as monorails can collide only with other vehicles on the same system, with much fewer opportunities for collision. As with other elevated transit systems, monorail passengers receive sunlight and views. Monorails can be quieter than diesel buses and trains. They obtain electricity from the track structure, whereas other modes of transit may use either third rail or overhead power lines and poles. Compared to
8925-448: The phosphors, the Ce:YAG phosphor converts blue light to green and red (yellow) light, and the PFS phosphor converts blue light to red light. The color, emission spectrum or color temperature of white phosphor converted and other phosphor converted LEDs can be controlled by changing the concentration of several phosphors that form a phosphor blend used in an LED package. The 'whiteness' of
9030-599: The photosensitivity of microorganisms approximately matches the absorption spectrum of DNA , with a peak at about 260 nm, UV LED emitting at 250–270 nm are expected in prospective disinfection and sterilization devices. Recent research has shown that commercially available UVA LEDs (365 nm) are already effective disinfection and sterilization devices. UV-C wavelengths were obtained in laboratories using aluminium nitride (210 nm), boron nitride (215 nm) and diamond (235 nm). There are two primary ways of producing white light-emitting diodes. One
9135-421: The rudimentary devices could be used for non-radio communication across a short distance. As noted by Kroemer Braunstein "…had set up a simple optical communications link: Music emerging from a record player was used via suitable electronics to modulate the forward current of a GaAs diode. The emitted light was detected by a PbS diode some distance away. This signal was fed into an audio amplifier and played back by
9240-480: The same time. Some LEDs use phosphors made of glass-ceramic or composite phosphor/glass materials. Alternatively, the LED chips themselves can be coated with a thin coating of phosphor-containing material, called a conformal coating. The temperature of the phosphor during operation and how it is applied limits the size of an LED die. Wafer-level packaged white LEDs allow for extremely small LEDs. In 2024, QPixel introduced as polychromatic LED that could replace
9345-442: The semiconductor recombine with electron holes , releasing energy in the form of photons . The color of the light (corresponding to the energy of the photons) is determined by the energy required for electrons to cross the band gap of the semiconductor. White light is obtained by using multiple semiconductors or a layer of light-emitting phosphor on the semiconductor device. Appearing as practical electronic components in 1962,
9450-408: The space between the crystals allow some blue light to pass through in LEDs with partial phosphor conversion. Alternatively, white LEDs may use other phosphors like manganese(IV)-doped potassium fluorosilicate (PFS) or other engineered phosphors. PFS assists in red light generation, and is used in conjunction with conventional Ce:YAG phosphor. In LEDs with PFS phosphor, some blue light passes through
9555-547: The subsequent device Pankove and Miller built, the first actual gallium nitride light-emitting diode, emitted green light. In 1974 the U.S. Patent Office awarded Maruska, Rhines, and Stanford professor David Stevenson a patent for their work in 1972 (U.S. Patent US3819974 A ). Today, magnesium-doping of gallium nitride remains the basis for all commercial blue LEDs and laser diodes . In the early 1970s, these devices were too dim for practical use, and research into gallium nitride devices slowed. In August 1989, Cree introduced
9660-480: The substrate for LED production, but sapphire is more common, as it has the most similar properties to that of gallium nitride, reducing the need for patterning the sapphire wafer (patterned wafers are known as epi wafers). Samsung , the University of Cambridge , and Toshiba are performing research into GaN on Si LEDs. Toshiba has stopped research, possibly due to low yields. Some opt for epitaxy , which
9765-569: The team at Fairchild led by optoelectronics pioneer Thomas Brandt to achieve the needed cost reductions. LED producers have continued to use these methods as of about 2009. The early red LEDs were bright enough for use as indicators, as the light output was not enough to illuminate an area. Readouts in calculators were so small that plastic lenses were built over each digit to make them legible. Later, other colors became widely available and appeared in appliances and equipment. Early LEDs were packaged in metal cases similar to those of transistors, with
9870-743: The two largest monorail manufacturers, Hitachi Monorail and Bombardier . In 1956, the first monorail to operate in the US began test operations in Houston, Texas. Disneyland in Anaheim, California , opened the United States' first daily operating monorail system in 1959. Later during this period, additional monorails were installed at Walt Disney World in Florida , Seattle , and in Japan . Monorails were promoted as futuristic technology with exhibition installations and amusement park purchases, as seen by
9975-461: The very inefficient light-producing properties of silicon carbide, the semiconductor Losev used. In 1936, Georges Destriau observed that electroluminescence could be produced when zinc sulphide (ZnS) powder is suspended in an insulator and an alternating electrical field is applied to it. In his publications, Destriau often referred to luminescence as Losev-Light. Destriau worked in the laboratories of Madame Marie Curie , also an early pioneer in
10080-538: The wavelength it reflects. The best color rendition LEDs use a mix of phosphors, resulting in less efficiency and better color rendering. The first white light-emitting diodes (LEDs) were offered for sale in the autumn of 1996. Nichia made some of the first white LEDs which were based on blue LEDs with Ce:YAG phosphor. Ce:YAG is often grown using the Czochralski method . Mixing red, green, and blue sources to produce white light needs electronic circuits to control
10185-482: Was a monorail on which a matching pedal bicycle could be ridden. The first example was built between Smithville and Mount Holly , New Jersey, in 1892. It closed in 1897. Other examples were built in Norfolk from 1895 to 1909, Great Yarmouth , and Blackpool , UK from 1896. Early designs used a double- flanged single metal rail alternative to the double rail of conventional railways, both guiding and supporting
10290-618: Was achieved by Nichia in 2010. Compared to incandescent bulbs, this is a huge increase in electrical efficiency, and even though LEDs are more expensive to purchase, overall lifetime cost is significantly cheaper than that of incandescent bulbs. The LED chip is encapsulated inside a small, plastic, white mold although sometimes an LED package can incorporate a reflector. It can be encapsulated using resin ( polyurethane -based), silicone, or epoxy containing (powdered) Cerium-doped YAG phosphor particles. The viscosity of phosphor-silicon mixtures must be carefully controlled. After application of
10395-544: Was also prominent in the unreleased Seatron Space line and prototype Wild West sets. Its popularity has still endured over thirty years later, where Lego has paid homage in promotional sets and fans have manufactured compatible components. The fourth season of the American animated television show The Simpsons features the episode " Marge vs. the Monorail ", in which the town of Springfield impulsively purchases
10500-415: Was engaged in research and development (R&D) on practical LEDs between 1962 and 1968, by a research team under Howard C. Borden, Gerald P. Pighini at HP Associates and HP Labs . During this time HP collaborated with Monsanto Company on developing the first usable LED products. The first usable LED products were HP's LED display and Monsanto's LED indicator lamp , both launched in 1968. Monsanto
10605-433: Was made at Stanford University in 1972 by Herb Maruska and Wally Rhines , doctoral students in materials science and engineering. At the time Maruska was on leave from RCA Laboratories , where he collaborated with Jacques Pankove on related work. In 1971, the year after Maruska left for Stanford, his RCA colleagues Pankove and Ed Miller demonstrated the first blue electroluminescence from zinc-doped gallium nitride, though
10710-443: Was quickly followed by the development of the first white LED . In this device a Y 3 Al 5 O 12 :Ce (known as " YAG " or Ce:YAG phosphor) cerium -doped phosphor coating produces yellow light through fluorescence . The combination of that yellow with remaining blue light appears white to the eye. Using different phosphors produces green and red light through fluorescence. The resulting mixture of red, green and blue
10815-571: Was the first intelligent LED display, and was a revolution in digital display technology, replacing the Nixie tube and becoming the basis for later LED displays. In the 1970s, commercially successful LED devices at less than five cents each were produced by Fairchild Optoelectronics. These devices employed compound semiconductor chips fabricated with the planar process (developed by Jean Hoerni , ). The combination of planar processing for chip fabrication and innovative packaging methods enabled
10920-484: Was the first organization to mass-produce visible LEDs, using Gallium arsenide phosphide (GaAsP) in 1968 to produce red LEDs suitable for indicators. Monsanto had previously offered to supply HP with GaAsP, but HP decided to grow its own GaAsP. In February 1969, Hewlett-Packard introduced the HP Model 5082-7000 Numeric Indicator, the first LED device to use integrated circuit (integrated LED circuit ) technology. It
11025-463: Was too heavy and crashed through the track on its third trip. The third locomotive again had twin boilers. On a trial run one of the boilers ran dry and exploded, killing six people. The railway was closed soon after. Monorails in Central Java were used to transport timber from the forests of Central Java located in the mountains to the rivers. In 1908 and 1909, the forester H. J. L. Beck built
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