Skytran (stylized as skyTran) is a personal rapid transit system concept. It was first proposed by the inventor Douglas Malewicki in 1990 and is under development by Unimodal Inc. A prototype of the skyTran vehicle and a section of track have been constructed. The early magnetic levitation system, Inductrack, which SkyTran has replaced with a similar proprietary design, has been tested by General Atomics with a full-scale model.[1] In 2010, Unimodal signed an agreement with NASA to test and develop skyTran.[2] skyTran has proposed additional projects in France, Germany, India, Indonesia, Malaysia, the United Kingdom, and the United States.[3][4][5][6]
To minimize maintenance and make switching on and off the tracks efficient at high speeds, early versions of the system were proposed using the Inductrack passive magnetic levitation system instead of wheels. Passive maglev requires no external power to levitate vehicles. Rather, the magnetic repulsion is produced by the movement of the vehicle over shorted wire coils in the track.[1] The cars would be driven by a linear motor in the track or vehicle. Therefore, the system would have no electromechanical moving parts, making it entirely a "solid-state".[7]
In this first version, the passive maglev coils are enclosed and supported by a light shell called a guideway that also captures the vehicles mechanically to prevent derailment. Malewicki proposes a 3D grid design that avoids accident-prone intersections by grade separation, with guideways and their exit and entry ramps crossing above or below each other. Tracks will be supported 20 or 30 feet (6 or 9m) above the ground by standard metal utility poles. They could also be attached to the sides of buildings.
After identifying problems with Inductrack and the cost associated with it, skyTran described an improved design during a Horizon BBC interview with skyTran at NASA Ames in Mountain View, CA.
New details about the levitation and motor were described in a keynote speech in June 2016, showing levitation stators being plain aluminum plates and motor stators as aluminum tubes. The guideway is also significantly enlarged and wider than the vehicle, so the switching can be vertical, going through the guideway. The guideway shape is shown at 16:26 above the referenced video. This new concept can be seen in a short simulation film[dead link]. Instead of the purely passive induct rack system, the new mechanism modifies lift by mechanically angling the magnetic pads and needs a servo-controlled actuation. The lift control also does the switching by moving vertically through the rails.
Malewicki conceived the basic idea of skyTran in 1990, filing a US patent application that year that was granted as US Patent #5108052 in 1992.[8] He published several technical papers on skyTran in the following years. In 1991, he presented a paper entitled "People Pods – Miniature Magnetic Levitation Vehicles for Personal Non-Stop Transportation" to the Society of Automotive Engineers (SAE) Future Transportation Conference in Portland, Oregon.[9] The paper is a thorough description of the concept at that point, although some important features of the current skyTran design are only discussed as options, including magnetic levitation rather than wheels and hanging below the guideway instead of riding above it.
The paper describes how Malewicki had built and driven a freeway-legal 154-MPG car in 1981, but realised it could never be safe on a street surrounded by far larger and heavier vehicles. Elevated tracks would allow a very light vehicle to be safe. They are also basic to the system's inexpensiveness, because there is no need to acquire a huge right of way and tear down buildings. It presents an aerodynamic analysis (Malewicki is an aerospace engineer) supporting claims of very high energy efficiency (the paper claims 407mpg‑US or 489mpg‑imp or 0.578L/100km for skyTran's current two-passenger tandem design, though the Unimodal site claims only, "over 200mpg‑US or 240mpg‑imp or 1.2L/100km").[10][11] It also described how a very light vehicle that can squeeze both surfaces of a track simultaneously could reliably achieve a 6-G deceleration, allowing it to brake safely to a stop from 100 miles per hour (161km/h) in just 55 feet (16.76m).[12]
The 2008, energy shortages stimulated renewed interest in green vehicle proposals such as skyTran. The "Maglev skyTran" topic quoted a number of skyTran and personal rapid transit ideas, such as passengers exiting and boarding at off-line elevated "portal" stops while high-speed traffic continues to speed by on its main line.[13]
In September 2009, the US NASA (National Aeronautics and Space Administration) signed a Space Act joint development agreement with Unimodal. Unimodal has tested prototype vehicles on short guideway sections at NASA's Ames Research Center, in Mountain View, California. NASA control and vehicle dynamics simulation software was made available to Unimodal, which hired NASA subcontractors to program them using US DOT grant funding.[14]
In June 2014, Unimodal and Israel Aerospace Industries (IAI) contracted to build a 400-500 meter elevated loop test track on IAI's campus in central Israel. If the pilot project is successful, IAI will build a commercial skyTran network in the city of Tel Aviv, Herzliya and Netanya.[15][16] In April 2015, the Herzliya city council approved a budget for the skyTran project.[17]
In June 2016, skyTran signed a memorandum of understanding in the United Arab Emirates for the study and implementation of a personal rapid transit system in Yas Island.[18]
In 2018, it was announced that Indian conglomerate Reliance Industries had acquired a 12.7% stake in SkyTran through its subsidiary Reliance Strategic Business Ventures Limited. As part of the deal, Reliance would supply communication equipment and a prototype would be built in India.[19]
In April 2019, SkyTran signed a memorandum of understanding with Eilat to build an elevated rail system serving Ramon Airport.[20]
In June 2019 a memorandum of understanding was signed between skyTran and the Roads and Transport Authority (RTA) of Dubai in the United Arab Emirates to develop a Sky Pod suspended transit system.[21]
In February 2021, Reliance Industries increased its shareholding in skyTran to 54.46% with an additional investment of $26.76 million making Reliance Industries Limited the majority stakeholder in SkyTran.
In September 2023, skyTran was shuttered and filed for bankruptcy due to no additional funding from Reliance Industries; even though a full-scale in-door prototype was within 6 to 9 months.[22][23][24][25]
A monorail is a railway in which the track consists of a single rail or a 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.
A linear motor is an electric motor that has had its stator and rotor "unrolled", thus, instead of producing a torque (rotation), it produces a linear force along its length. However, linear motors are not necessarily straight. Characteristically, a linear motor's active section has ends, whereas more conventional motors are arranged as a continuous loop.
Personal rapid transit (PRT), also referred to as podcars or guided/railed taxis, is a public transport mode featuring small low-capacity automated vehicles operating on a network of specially built guideways. PRT is a type of automated guideway transit (AGT), a class of system which also includes larger vehicles all the way to small subway systems. In terms of routing, it tends towards personal public transport systems.
A people mover or automated people mover (APM) is a type of small scale automated guideway transit system. The term is generally used only to describe systems serving relatively small areas such as airports, downtown districts or theme parks.
Transrapid is a German-developed high-speed monorail train using magnetic levitation. Planning for the Transrapid system started in 1969 with a test facility for the system in Emsland, Germany completed in 1987. In 1991, technical readiness for application was approved by the Deutsche Bundesbahn in cooperation with renowned universities.
Electrodynamic suspension (EDS) is a form of magnetic levitation in which there are conductors which are exposed to time-varying magnetic fields. This induces eddy currents in the conductors that creates a repulsive magnetic field which holds the two objects apart.
Inductrack is a passive, fail-safe electrodynamic magnetic levitation system, using only unpowered loops of wire in the track and permanent magnets on the vehicle to achieve magnetic levitation. The track can be in one of two configurations, a "ladder track" and a "laminated track". The ladder track is made of unpowered Litz wire cables, and the laminated track is made out of stacked copper or aluminium sheets.
Maglev is a system of rail transport whose rolling stock is levitated by electromagnets rather than rolled on wheels, eliminating rolling resistance.
The M-Bahn or Magnetbahn was an elevated Maglev train line operating in Berlin, Germany, experimentally from 1984 and in passenger operation from 1989 to 1991. The line was 1.6 kilometres (1 mi) in length, and featured three stations, two of which were newly constructed. Presumed to be the future of rail transit in Berlin, the line was built to fill a gap in the West Berlin public transport network created by the construction of the Berlin Wall. It was rendered redundant by the reunification of Berlin and was closed to enable reconstruction of the U2 line.
The Urban Transportation Development Corporation Ltd. (UTDC) was a Crown corporation owned by the Government of Ontario, Canada. It was established in the 1970s as a way to enter what was then expected to be a burgeoning market in advanced light rail mass transit systems. It developed significant expertise in linear propulsion, steerable trucks and driverless system controls which were integrated into a transit system known as the Intermediate Capacity Transit System (ICTS). It was designed to provide service at rider levels between a traditional subway on the upper end and buses and streetcars on the lower, filling a niche aimed at suburbs that were otherwise expensive to service.
Electromagnetic suspension (EMS) is the magnetic levitation of an object achieved by constantly altering the strength of a magnetic field produced by electromagnets using a feedback loop. In most cases the levitation effect is mostly due to permanent magnets as they have no power dissipation, with electromagnets only used to stabilise the effect.
The SCMaglev is a magnetic levitation (maglev) railway system developed by Central Japan Railway Company and the Railway Technical Research Institute.
A vactrain is a proposed design for very-high-speed rail transportation. It is a maglev line using partly evacuated tubes or tunnels. Reduced air resistance could permit vactrains to travel at very high (hypersonic) speeds with relatively little power—up to 6,400–8,000 km/h (4,000–5,000 mph). This is 5–6 times the speed of sound in Earth's atmosphere at sea level.
Ultra is a personal rapid transit podcar system developed by the British engineering company Ultra Global PRT.
ROMAG was a personal rapid transit (PRT) system produced by the American company Rohr, Inc. It featured a linear induction motor that was arranged to provide both traction and suspension in a magnetic levitation system.
Krauss-Maffei's Transurban was a 12-passenger automated guideway transit (AGT) mass transit system based on a maglev guideway. Development started in 1970 as one of the many AGT and PRT projects that followed in the wake of the HUD reports of 1968. Its selection as the basis of the GO-Urban system in Toronto in 1973 made it well known in the industry; it would have been the basis of the first large-area AGT mass transit network in the world. Technical problems cropped up during the construction of the test track, and the sudden removal of funding by the West German government led to the project's cancellation in late 1974. The Ontario government completed development and installation of a non-maglev version, today known as the Bombardier Advanced Rapid Transit.
Magnetic levitation (maglev) or magnetic suspension is a method by which an object is suspended with no support other than magnetic fields. Magnetic force is used to counteract the effects of the gravitational force and any other forces.
TransPod Inc. is a Canadian company designing ultra-high-speed transportation technology and vehicles.
The Old Dominion University (ODU) maglev was a failed public transit maglev system for the campus, developed in 2001. It was developed in partnership with the company American Maglev Technology (AMT) from Georgia and with funding coming from Dominion Virginia Power, Lockheed Martin, and the state. The track spanned 1 kilometer from Powhatan Avenue to 46th Street in Norfolk, Virginia. ODU claimed it would have been the first of its kind in America. The guideway served as an important landmark for students. The system has been completely torn down, with the only part remaining being a section of the concrete guideway that spans overtop Hampton Boulevard.
↑ Burke, Wallace R. (September 1, 1992). "Monorail vehicle". US Patent and Trademark Office. Retrieved June 21, 2015.
↑ Malewicki, Douglas J.; Baker, Frank J. (June 1991). "People Pods - Miniature Magnetic Levitation Vehicles for Personal Non-Stop Transportation". Irvine California, USA: AeroVisions, Inc., and Monitoring Automation Systems.{{cite journal}}: Cite journal requires |journal= (help)
↑ "People Pods". Table 2 "Performance Comparisons of Possible People Pod Concepts," page 5.{{cite journal}}: Cite journal requires |journal= (help)
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